dbf-halloween2015: libs/libpng/pngrtran.c annotate

dbf-halloween2015

annotate libs/libpng/pngrtran.c @ 1:c3f5c32cb210

barfed all the libraries in the source tree to make porting easier

author	John Tsiombikas <nuclear@member.fsf.org>
date	Sun, 01 Nov 2015 00:36:56 +0200
parents
children

rev	line source
nuclear@1	1
nuclear@1	2 /* pngrtran.c - transforms the data in a row for PNG readers
nuclear@1	3 *
nuclear@1	4 * Last changed in libpng 1.2.30 [August 15, 2008]
nuclear@1	5 * For conditions of distribution and use, see copyright notice in png.h
nuclear@1	6 * Copyright (c) 1998-2008 Glenn Randers-Pehrson
nuclear@1	7 * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
nuclear@1	8 * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
nuclear@1	9 *
nuclear@1	10 * This file contains functions optionally called by an application
nuclear@1	11 * in order to tell libpng how to handle data when reading a PNG.
nuclear@1	12 * Transformations that are used in both reading and writing are
nuclear@1	13 * in pngtrans.c.
nuclear@1	14 */
nuclear@1	15
nuclear@1	16 #define PNG_INTERNAL
nuclear@1	17 #include "png.h"
nuclear@1	18 #if defined(PNG_READ_SUPPORTED)
nuclear@1	19
nuclear@1	20 /* Set the action on getting a CRC error for an ancillary or critical chunk. */
nuclear@1	21 void PNGAPI
nuclear@1	22 png_set_crc_action(png_structp png_ptr, int crit_action, int ancil_action)
nuclear@1	23 {
nuclear@1	24 png_debug(1, "in png_set_crc_action\n");
nuclear@1	25 /* Tell libpng how we react to CRC errors in critical chunks */
nuclear@1	26 if (png_ptr == NULL) return;
nuclear@1	27 switch (crit_action)
nuclear@1	28 {
nuclear@1	29 case PNG_CRC_NO_CHANGE: /* leave setting as is */
nuclear@1	30 break;
nuclear@1	31 case PNG_CRC_WARN_USE: /* warn/use data */
nuclear@1	32 png_ptr->flags &= ~PNG_FLAG_CRC_CRITICAL_MASK;
nuclear@1	33 png_ptr->flags \|= PNG_FLAG_CRC_CRITICAL_USE;
nuclear@1	34 break;
nuclear@1	35 case PNG_CRC_QUIET_USE: /* quiet/use data */
nuclear@1	36 png_ptr->flags &= ~PNG_FLAG_CRC_CRITICAL_MASK;
nuclear@1	37 png_ptr->flags \|= PNG_FLAG_CRC_CRITICAL_USE \|
nuclear@1	38 PNG_FLAG_CRC_CRITICAL_IGNORE;
nuclear@1	39 break;
nuclear@1	40 case PNG_CRC_WARN_DISCARD: /* not a valid action for critical data */
nuclear@1	41 png_warning(png_ptr,
nuclear@1	42 "Can't discard critical data on CRC error.");
nuclear@1	43 case PNG_CRC_ERROR_QUIT: /* error/quit */
nuclear@1	44 case PNG_CRC_DEFAULT:
nuclear@1	45 default:
nuclear@1	46 png_ptr->flags &= ~PNG_FLAG_CRC_CRITICAL_MASK;
nuclear@1	47 break;
nuclear@1	48 }
nuclear@1	49
nuclear@1	50 switch (ancil_action)
nuclear@1	51 {
nuclear@1	52 case PNG_CRC_NO_CHANGE: /* leave setting as is */
nuclear@1	53 break;
nuclear@1	54 case PNG_CRC_WARN_USE: /* warn/use data */
nuclear@1	55 png_ptr->flags &= ~PNG_FLAG_CRC_ANCILLARY_MASK;
nuclear@1	56 png_ptr->flags \|= PNG_FLAG_CRC_ANCILLARY_USE;
nuclear@1	57 break;
nuclear@1	58 case PNG_CRC_QUIET_USE: /* quiet/use data */
nuclear@1	59 png_ptr->flags &= ~PNG_FLAG_CRC_ANCILLARY_MASK;
nuclear@1	60 png_ptr->flags \|= PNG_FLAG_CRC_ANCILLARY_USE \|
nuclear@1	61 PNG_FLAG_CRC_ANCILLARY_NOWARN;
nuclear@1	62 break;
nuclear@1	63 case PNG_CRC_ERROR_QUIT: /* error/quit */
nuclear@1	64 png_ptr->flags &= ~PNG_FLAG_CRC_ANCILLARY_MASK;
nuclear@1	65 png_ptr->flags \|= PNG_FLAG_CRC_ANCILLARY_NOWARN;
nuclear@1	66 break;
nuclear@1	67 case PNG_CRC_WARN_DISCARD: /* warn/discard data */
nuclear@1	68 case PNG_CRC_DEFAULT:
nuclear@1	69 default:
nuclear@1	70 png_ptr->flags &= ~PNG_FLAG_CRC_ANCILLARY_MASK;
nuclear@1	71 break;
nuclear@1	72 }
nuclear@1	73 }
nuclear@1	74
nuclear@1	75 #if defined(PNG_READ_BACKGROUND_SUPPORTED) && \
nuclear@1	76 defined(PNG_FLOATING_POINT_SUPPORTED)
nuclear@1	77 /* handle alpha and tRNS via a background color */
nuclear@1	78 void PNGAPI
nuclear@1	79 png_set_background(png_structp png_ptr,
nuclear@1	80 png_color_16p background_color, int background_gamma_code,
nuclear@1	81 int need_expand, double background_gamma)
nuclear@1	82 {
nuclear@1	83 png_debug(1, "in png_set_background\n");
nuclear@1	84 if (png_ptr == NULL) return;
nuclear@1	85 if (background_gamma_code == PNG_BACKGROUND_GAMMA_UNKNOWN)
nuclear@1	86 {
nuclear@1	87 png_warning(png_ptr, "Application must supply a known background gamma");
nuclear@1	88 return;
nuclear@1	89 }
nuclear@1	90
nuclear@1	91 png_ptr->transformations \|= PNG_BACKGROUND;
nuclear@1	92 png_memcpy(&(png_ptr->background), background_color,
nuclear@1	93 png_sizeof(png_color_16));
nuclear@1	94 png_ptr->background_gamma = (float)background_gamma;
nuclear@1	95 png_ptr->background_gamma_type = (png_byte)(background_gamma_code);
nuclear@1	96 png_ptr->transformations \|= (need_expand ? PNG_BACKGROUND_EXPAND : 0);
nuclear@1	97 }
nuclear@1	98 #endif
nuclear@1	99
nuclear@1	100 #if defined(PNG_READ_16_TO_8_SUPPORTED)
nuclear@1	101 /* strip 16 bit depth files to 8 bit depth */
nuclear@1	102 void PNGAPI
nuclear@1	103 png_set_strip_16(png_structp png_ptr)
nuclear@1	104 {
nuclear@1	105 png_debug(1, "in png_set_strip_16\n");
nuclear@1	106 if (png_ptr == NULL) return;
nuclear@1	107 png_ptr->transformations \|= PNG_16_TO_8;
nuclear@1	108 }
nuclear@1	109 #endif
nuclear@1	110
nuclear@1	111 #if defined(PNG_READ_STRIP_ALPHA_SUPPORTED)
nuclear@1	112 void PNGAPI
nuclear@1	113 png_set_strip_alpha(png_structp png_ptr)
nuclear@1	114 {
nuclear@1	115 png_debug(1, "in png_set_strip_alpha\n");
nuclear@1	116 if (png_ptr == NULL) return;
nuclear@1	117 png_ptr->flags \|= PNG_FLAG_STRIP_ALPHA;
nuclear@1	118 }
nuclear@1	119 #endif
nuclear@1	120
nuclear@1	121 #if defined(PNG_READ_DITHER_SUPPORTED)
nuclear@1	122 /* Dither file to 8 bit. Supply a palette, the current number
nuclear@1	123 * of elements in the palette, the maximum number of elements
nuclear@1	124 * allowed, and a histogram if possible. If the current number
nuclear@1	125 * of colors is greater then the maximum number, the palette will be
nuclear@1	126 * modified to fit in the maximum number. "full_dither" indicates
nuclear@1	127 * whether we need a dithering cube set up for RGB images, or if we
nuclear@1	128 * simply are reducing the number of colors in a paletted image.
nuclear@1	129 */
nuclear@1	130
nuclear@1	131 typedef struct png_dsort_struct
nuclear@1	132 {
nuclear@1	133 struct png_dsort_struct FAR * next;
nuclear@1	134 png_byte left;
nuclear@1	135 png_byte right;
nuclear@1	136 } png_dsort;
nuclear@1	137 typedef png_dsort FAR * png_dsortp;
nuclear@1	138 typedef png_dsort FAR * FAR * png_dsortpp;
nuclear@1	139
nuclear@1	140 void PNGAPI
nuclear@1	141 png_set_dither(png_structp png_ptr, png_colorp palette,
nuclear@1	142 int num_palette, int maximum_colors, png_uint_16p histogram,
nuclear@1	143 int full_dither)
nuclear@1	144 {
nuclear@1	145 png_debug(1, "in png_set_dither\n");
nuclear@1	146 if (png_ptr == NULL) return;
nuclear@1	147 png_ptr->transformations \|= PNG_DITHER;
nuclear@1	148
nuclear@1	149 if (!full_dither)
nuclear@1	150 {
nuclear@1	151 int i;
nuclear@1	152
nuclear@1	153 png_ptr->dither_index = (png_bytep)png_malloc(png_ptr,
nuclear@1	154 (png_uint_32)(num_palette * png_sizeof(png_byte)));
nuclear@1	155 for (i = 0; i < num_palette; i++)
nuclear@1	156 png_ptr->dither_index[i] = (png_byte)i;
nuclear@1	157 }
nuclear@1	158
nuclear@1	159 if (num_palette > maximum_colors)
nuclear@1	160 {
nuclear@1	161 if (histogram != NULL)
nuclear@1	162 {
nuclear@1	163 /* This is easy enough, just throw out the least used colors.
nuclear@1	164 Perhaps not the best solution, but good enough. */
nuclear@1	165
nuclear@1	166 int i;
nuclear@1	167
nuclear@1	168 /* initialize an array to sort colors */
nuclear@1	169 png_ptr->dither_sort = (png_bytep)png_malloc(png_ptr,
nuclear@1	170 (png_uint_32)(num_palette * png_sizeof(png_byte)));
nuclear@1	171
nuclear@1	172 /* initialize the dither_sort array */
nuclear@1	173 for (i = 0; i < num_palette; i++)
nuclear@1	174 png_ptr->dither_sort[i] = (png_byte)i;
nuclear@1	175
nuclear@1	176 /* Find the least used palette entries by starting a
nuclear@1	177 bubble sort, and running it until we have sorted
nuclear@1	178 out enough colors. Note that we don't care about
nuclear@1	179 sorting all the colors, just finding which are
nuclear@1	180 least used. */
nuclear@1	181
nuclear@1	182 for (i = num_palette - 1; i >= maximum_colors; i--)
nuclear@1	183 {
nuclear@1	184 int done; /* to stop early if the list is pre-sorted */
nuclear@1	185 int j;
nuclear@1	186
nuclear@1	187 done = 1;
nuclear@1	188 for (j = 0; j < i; j++)
nuclear@1	189 {
nuclear@1	190 if (histogram[png_ptr->dither_sort[j]]
nuclear@1	191 < histogram[png_ptr->dither_sort[j + 1]])
nuclear@1	192 {
nuclear@1	193 png_byte t;
nuclear@1	194
nuclear@1	195 t = png_ptr->dither_sort[j];
nuclear@1	196 png_ptr->dither_sort[j] = png_ptr->dither_sort[j + 1];
nuclear@1	197 png_ptr->dither_sort[j + 1] = t;
nuclear@1	198 done = 0;
nuclear@1	199 }
nuclear@1	200 }
nuclear@1	201 if (done)
nuclear@1	202 break;
nuclear@1	203 }
nuclear@1	204
nuclear@1	205 /* swap the palette around, and set up a table, if necessary */
nuclear@1	206 if (full_dither)
nuclear@1	207 {
nuclear@1	208 int j = num_palette;
nuclear@1	209
nuclear@1	210 /* put all the useful colors within the max, but don't
nuclear@1	211 move the others */
nuclear@1	212 for (i = 0; i < maximum_colors; i++)
nuclear@1	213 {
nuclear@1	214 if ((int)png_ptr->dither_sort[i] >= maximum_colors)
nuclear@1	215 {
nuclear@1	216 do
nuclear@1	217 j--;
nuclear@1	218 while ((int)png_ptr->dither_sort[j] >= maximum_colors);
nuclear@1	219 palette[i] = palette[j];
nuclear@1	220 }
nuclear@1	221 }
nuclear@1	222 }
nuclear@1	223 else
nuclear@1	224 {
nuclear@1	225 int j = num_palette;
nuclear@1	226
nuclear@1	227 /* move all the used colors inside the max limit, and
nuclear@1	228 develop a translation table */
nuclear@1	229 for (i = 0; i < maximum_colors; i++)
nuclear@1	230 {
nuclear@1	231 /* only move the colors we need to */
nuclear@1	232 if ((int)png_ptr->dither_sort[i] >= maximum_colors)
nuclear@1	233 {
nuclear@1	234 png_color tmp_color;
nuclear@1	235
nuclear@1	236 do
nuclear@1	237 j--;
nuclear@1	238 while ((int)png_ptr->dither_sort[j] >= maximum_colors);
nuclear@1	239
nuclear@1	240 tmp_color = palette[j];
nuclear@1	241 palette[j] = palette[i];
nuclear@1	242 palette[i] = tmp_color;
nuclear@1	243 /* indicate where the color went */
nuclear@1	244 png_ptr->dither_index[j] = (png_byte)i;
nuclear@1	245 png_ptr->dither_index[i] = (png_byte)j;
nuclear@1	246 }
nuclear@1	247 }
nuclear@1	248
nuclear@1	249 /* find closest color for those colors we are not using */
nuclear@1	250 for (i = 0; i < num_palette; i++)
nuclear@1	251 {
nuclear@1	252 if ((int)png_ptr->dither_index[i] >= maximum_colors)
nuclear@1	253 {
nuclear@1	254 int min_d, k, min_k, d_index;
nuclear@1	255
nuclear@1	256 /* find the closest color to one we threw out */
nuclear@1	257 d_index = png_ptr->dither_index[i];
nuclear@1	258 min_d = PNG_COLOR_DIST(palette[d_index], palette[0]);
nuclear@1	259 for (k = 1, min_k = 0; k < maximum_colors; k++)
nuclear@1	260 {
nuclear@1	261 int d;
nuclear@1	262
nuclear@1	263 d = PNG_COLOR_DIST(palette[d_index], palette[k]);
nuclear@1	264
nuclear@1	265 if (d < min_d)
nuclear@1	266 {
nuclear@1	267 min_d = d;
nuclear@1	268 min_k = k;
nuclear@1	269 }
nuclear@1	270 }
nuclear@1	271 /* point to closest color */
nuclear@1	272 png_ptr->dither_index[i] = (png_byte)min_k;
nuclear@1	273 }
nuclear@1	274 }
nuclear@1	275 }
nuclear@1	276 png_free(png_ptr, png_ptr->dither_sort);
nuclear@1	277 png_ptr->dither_sort = NULL;
nuclear@1	278 }
nuclear@1	279 else
nuclear@1	280 {
nuclear@1	281 /* This is much harder to do simply (and quickly). Perhaps
nuclear@1	282 we need to go through a median cut routine, but those
nuclear@1	283 don't always behave themselves with only a few colors
nuclear@1	284 as input. So we will just find the closest two colors,
nuclear@1	285 and throw out one of them (chosen somewhat randomly).
nuclear@1	286 [We don't understand this at all, so if someone wants to
nuclear@1	287 work on improving it, be our guest - AED, GRP]
nuclear@1	288 */
nuclear@1	289 int i;
nuclear@1	290 int max_d;
nuclear@1	291 int num_new_palette;
nuclear@1	292 png_dsortp t;
nuclear@1	293 png_dsortpp hash;
nuclear@1	294
nuclear@1	295 t = NULL;
nuclear@1	296
nuclear@1	297 /* initialize palette index arrays */
nuclear@1	298 png_ptr->index_to_palette = (png_bytep)png_malloc(png_ptr,
nuclear@1	299 (png_uint_32)(num_palette * png_sizeof(png_byte)));
nuclear@1	300 png_ptr->palette_to_index = (png_bytep)png_malloc(png_ptr,
nuclear@1	301 (png_uint_32)(num_palette * png_sizeof(png_byte)));
nuclear@1	302
nuclear@1	303 /* initialize the sort array */
nuclear@1	304 for (i = 0; i < num_palette; i++)
nuclear@1	305 {
nuclear@1	306 png_ptr->index_to_palette[i] = (png_byte)i;
nuclear@1	307 png_ptr->palette_to_index[i] = (png_byte)i;
nuclear@1	308 }
nuclear@1	309
nuclear@1	310 hash = (png_dsortpp)png_malloc(png_ptr, (png_uint_32)(769 *
nuclear@1	311 png_sizeof(png_dsortp)));
nuclear@1	312 for (i = 0; i < 769; i++)
nuclear@1	313 hash[i] = NULL;
nuclear@1	314 /* png_memset(hash, 0, 769 * png_sizeof(png_dsortp)); */
nuclear@1	315
nuclear@1	316 num_new_palette = num_palette;
nuclear@1	317
nuclear@1	318 /* initial wild guess at how far apart the farthest pixel
nuclear@1	319 pair we will be eliminating will be. Larger
nuclear@1	320 numbers mean more areas will be allocated, Smaller
nuclear@1	321 numbers run the risk of not saving enough data, and
nuclear@1	322 having to do this all over again.
nuclear@1	323
nuclear@1	324 I have not done extensive checking on this number.
nuclear@1	325 */
nuclear@1	326 max_d = 96;
nuclear@1	327
nuclear@1	328 while (num_new_palette > maximum_colors)
nuclear@1	329 {
nuclear@1	330 for (i = 0; i < num_new_palette - 1; i++)
nuclear@1	331 {
nuclear@1	332 int j;
nuclear@1	333
nuclear@1	334 for (j = i + 1; j < num_new_palette; j++)
nuclear@1	335 {
nuclear@1	336 int d;
nuclear@1	337
nuclear@1	338 d = PNG_COLOR_DIST(palette[i], palette[j]);
nuclear@1	339
nuclear@1	340 if (d <= max_d)
nuclear@1	341 {
nuclear@1	342
nuclear@1	343 t = (png_dsortp)png_malloc_warn(png_ptr,
nuclear@1	344 (png_uint_32)(png_sizeof(png_dsort)));
nuclear@1	345 if (t == NULL)
nuclear@1	346 break;
nuclear@1	347 t->next = hash[d];
nuclear@1	348 t->left = (png_byte)i;
nuclear@1	349 t->right = (png_byte)j;
nuclear@1	350 hash[d] = t;
nuclear@1	351 }
nuclear@1	352 }
nuclear@1	353 if (t == NULL)
nuclear@1	354 break;
nuclear@1	355 }
nuclear@1	356
nuclear@1	357 if (t != NULL)
nuclear@1	358 for (i = 0; i <= max_d; i++)
nuclear@1	359 {
nuclear@1	360 if (hash[i] != NULL)
nuclear@1	361 {
nuclear@1	362 png_dsortp p;
nuclear@1	363
nuclear@1	364 for (p = hash[i]; p; p = p->next)
nuclear@1	365 {
nuclear@1	366 if ((int)png_ptr->index_to_palette[p->left]
nuclear@1	367 < num_new_palette &&
nuclear@1	368 (int)png_ptr->index_to_palette[p->right]
nuclear@1	369 < num_new_palette)
nuclear@1	370 {
nuclear@1	371 int j, next_j;
nuclear@1	372
nuclear@1	373 if (num_new_palette & 0x01)
nuclear@1	374 {
nuclear@1	375 j = p->left;
nuclear@1	376 next_j = p->right;
nuclear@1	377 }
nuclear@1	378 else
nuclear@1	379 {
nuclear@1	380 j = p->right;
nuclear@1	381 next_j = p->left;
nuclear@1	382 }
nuclear@1	383
nuclear@1	384 num_new_palette--;
nuclear@1	385 palette[png_ptr->index_to_palette[j]]
nuclear@1	386 = palette[num_new_palette];
nuclear@1	387 if (!full_dither)
nuclear@1	388 {
nuclear@1	389 int k;
nuclear@1	390
nuclear@1	391 for (k = 0; k < num_palette; k++)
nuclear@1	392 {
nuclear@1	393 if (png_ptr->dither_index[k] ==
nuclear@1	394 png_ptr->index_to_palette[j])
nuclear@1	395 png_ptr->dither_index[k] =
nuclear@1	396 png_ptr->index_to_palette[next_j];
nuclear@1	397 if ((int)png_ptr->dither_index[k] ==
nuclear@1	398 num_new_palette)
nuclear@1	399 png_ptr->dither_index[k] =
nuclear@1	400 png_ptr->index_to_palette[j];
nuclear@1	401 }
nuclear@1	402 }
nuclear@1	403
nuclear@1	404 png_ptr->index_to_palette[png_ptr->palette_to_index
nuclear@1	405 [num_new_palette]] = png_ptr->index_to_palette[j];
nuclear@1	406 png_ptr->palette_to_index[png_ptr->index_to_palette[j]]
nuclear@1	407 = png_ptr->palette_to_index[num_new_palette];
nuclear@1	408
nuclear@1	409 png_ptr->index_to_palette[j] = (png_byte)num_new_palette;
nuclear@1	410 png_ptr->palette_to_index[num_new_palette] = (png_byte)j;
nuclear@1	411 }
nuclear@1	412 if (num_new_palette <= maximum_colors)
nuclear@1	413 break;
nuclear@1	414 }
nuclear@1	415 if (num_new_palette <= maximum_colors)
nuclear@1	416 break;
nuclear@1	417 }
nuclear@1	418 }
nuclear@1	419
nuclear@1	420 for (i = 0; i < 769; i++)
nuclear@1	421 {
nuclear@1	422 if (hash[i] != NULL)
nuclear@1	423 {
nuclear@1	424 png_dsortp p = hash[i];
nuclear@1	425 while (p)
nuclear@1	426 {
nuclear@1	427 t = p->next;
nuclear@1	428 png_free(png_ptr, p);
nuclear@1	429 p = t;
nuclear@1	430 }
nuclear@1	431 }
nuclear@1	432 hash[i] = 0;
nuclear@1	433 }
nuclear@1	434 max_d += 96;
nuclear@1	435 }
nuclear@1	436 png_free(png_ptr, hash);
nuclear@1	437 png_free(png_ptr, png_ptr->palette_to_index);
nuclear@1	438 png_free(png_ptr, png_ptr->index_to_palette);
nuclear@1	439 png_ptr->palette_to_index = NULL;
nuclear@1	440 png_ptr->index_to_palette = NULL;
nuclear@1	441 }
nuclear@1	442 num_palette = maximum_colors;
nuclear@1	443 }
nuclear@1	444 if (png_ptr->palette == NULL)
nuclear@1	445 {
nuclear@1	446 png_ptr->palette = palette;
nuclear@1	447 }
nuclear@1	448 png_ptr->num_palette = (png_uint_16)num_palette;
nuclear@1	449
nuclear@1	450 if (full_dither)
nuclear@1	451 {
nuclear@1	452 int i;
nuclear@1	453 png_bytep distance;
nuclear@1	454 int total_bits = PNG_DITHER_RED_BITS + PNG_DITHER_GREEN_BITS +
nuclear@1	455 PNG_DITHER_BLUE_BITS;
nuclear@1	456 int num_red = (1 << PNG_DITHER_RED_BITS);
nuclear@1	457 int num_green = (1 << PNG_DITHER_GREEN_BITS);
nuclear@1	458 int num_blue = (1 << PNG_DITHER_BLUE_BITS);
nuclear@1	459 png_size_t num_entries = ((png_size_t)1 << total_bits);
nuclear@1	460
nuclear@1	461 png_ptr->palette_lookup = (png_bytep )png_malloc(png_ptr,
nuclear@1	462 (png_uint_32)(num_entries * png_sizeof(png_byte)));
nuclear@1	463
nuclear@1	464 png_memset(png_ptr->palette_lookup, 0, num_entries *
nuclear@1	465 png_sizeof(png_byte));
nuclear@1	466
nuclear@1	467 distance = (png_bytep)png_malloc(png_ptr, (png_uint_32)(num_entries *
nuclear@1	468 png_sizeof(png_byte)));
nuclear@1	469
nuclear@1	470 png_memset(distance, 0xff, num_entries * png_sizeof(png_byte));
nuclear@1	471
nuclear@1	472 for (i = 0; i < num_palette; i++)
nuclear@1	473 {
nuclear@1	474 int ir, ig, ib;
nuclear@1	475 int r = (palette[i].red >> (8 - PNG_DITHER_RED_BITS));
nuclear@1	476 int g = (palette[i].green >> (8 - PNG_DITHER_GREEN_BITS));
nuclear@1	477 int b = (palette[i].blue >> (8 - PNG_DITHER_BLUE_BITS));
nuclear@1	478
nuclear@1	479 for (ir = 0; ir < num_red; ir++)
nuclear@1	480 {
nuclear@1	481 /* int dr = abs(ir - r); */
nuclear@1	482 int dr = ((ir > r) ? ir - r : r - ir);
nuclear@1	483 int index_r = (ir << (PNG_DITHER_BLUE_BITS + PNG_DITHER_GREEN_BITS));
nuclear@1	484
nuclear@1	485 for (ig = 0; ig < num_green; ig++)
nuclear@1	486 {
nuclear@1	487 /* int dg = abs(ig - g); */
nuclear@1	488 int dg = ((ig > g) ? ig - g : g - ig);
nuclear@1	489 int dt = dr + dg;
nuclear@1	490 int dm = ((dr > dg) ? dr : dg);
nuclear@1	491 int index_g = index_r \| (ig << PNG_DITHER_BLUE_BITS);
nuclear@1	492
nuclear@1	493 for (ib = 0; ib < num_blue; ib++)
nuclear@1	494 {
nuclear@1	495 int d_index = index_g \| ib;
nuclear@1	496 /* int db = abs(ib - b); */
nuclear@1	497 int db = ((ib > b) ? ib - b : b - ib);
nuclear@1	498 int dmax = ((dm > db) ? dm : db);
nuclear@1	499 int d = dmax + dt + db;
nuclear@1	500
nuclear@1	501 if (d < (int)distance[d_index])
nuclear@1	502 {
nuclear@1	503 distance[d_index] = (png_byte)d;
nuclear@1	504 png_ptr->palette_lookup[d_index] = (png_byte)i;
nuclear@1	505 }
nuclear@1	506 }
nuclear@1	507 }
nuclear@1	508 }
nuclear@1	509 }
nuclear@1	510
nuclear@1	511 png_free(png_ptr, distance);
nuclear@1	512 }
nuclear@1	513 }
nuclear@1	514 #endif
nuclear@1	515
nuclear@1	516 #if defined(PNG_READ_GAMMA_SUPPORTED) && defined(PNG_FLOATING_POINT_SUPPORTED)
nuclear@1	517 /* Transform the image from the file_gamma to the screen_gamma. We
nuclear@1	518 * only do transformations on images where the file_gamma and screen_gamma
nuclear@1	519 * are not close reciprocals, otherwise it slows things down slightly, and
nuclear@1	520 * also needlessly introduces small errors.
nuclear@1	521 *
nuclear@1	522 * We will turn off gamma transformation later if no semitransparent entries
nuclear@1	523 * are present in the tRNS array for palette images. We can't do it here
nuclear@1	524 * because we don't necessarily have the tRNS chunk yet.
nuclear@1	525 */
nuclear@1	526 void PNGAPI
nuclear@1	527 png_set_gamma(png_structp png_ptr, double scrn_gamma, double file_gamma)
nuclear@1	528 {
nuclear@1	529 png_debug(1, "in png_set_gamma\n");
nuclear@1	530 if (png_ptr == NULL) return;
nuclear@1	531 if ((fabs(scrn_gamma * file_gamma - 1.0) > PNG_GAMMA_THRESHOLD) \|\|
nuclear@1	532 (png_ptr->color_type & PNG_COLOR_MASK_ALPHA) \|\|
nuclear@1	533 (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE))
nuclear@1	534 png_ptr->transformations \|= PNG_GAMMA;
nuclear@1	535 png_ptr->gamma = (float)file_gamma;
nuclear@1	536 png_ptr->screen_gamma = (float)scrn_gamma;
nuclear@1	537 }
nuclear@1	538 #endif
nuclear@1	539
nuclear@1	540 #if defined(PNG_READ_EXPAND_SUPPORTED)
nuclear@1	541 /* Expand paletted images to RGB, expand grayscale images of
nuclear@1	542 * less than 8-bit depth to 8-bit depth, and expand tRNS chunks
nuclear@1	543 * to alpha channels.
nuclear@1	544 */
nuclear@1	545 void PNGAPI
nuclear@1	546 png_set_expand(png_structp png_ptr)
nuclear@1	547 {
nuclear@1	548 png_debug(1, "in png_set_expand\n");
nuclear@1	549 if (png_ptr == NULL) return;
nuclear@1	550 png_ptr->transformations \|= (PNG_EXPAND \| PNG_EXPAND_tRNS);
nuclear@1	551 png_ptr->flags &= ~PNG_FLAG_ROW_INIT;
nuclear@1	552 }
nuclear@1	553
nuclear@1	554 /* GRR 19990627: the following three functions currently are identical
nuclear@1	555 * to png_set_expand(). However, it is entirely reasonable that someone
nuclear@1	556 * might wish to expand an indexed image to RGB but not expand a single,
nuclear@1	557 * fully transparent palette entry to a full alpha channel--perhaps instead
nuclear@1	558 * convert tRNS to the grayscale/RGB format (16-bit RGB value), or replace
nuclear@1	559 * the transparent color with a particular RGB value, or drop tRNS entirely.
nuclear@1	560 * IOW, a future version of the library may make the transformations flag
nuclear@1	561 * a bit more fine-grained, with separate bits for each of these three
nuclear@1	562 * functions.
nuclear@1	563 *
nuclear@1	564 * More to the point, these functions make it obvious what libpng will be
nuclear@1	565 * doing, whereas "expand" can (and does) mean any number of things.
nuclear@1	566 *
nuclear@1	567 * GRP 20060307: In libpng-1.4.0, png_set_gray_1_2_4_to_8() was modified
nuclear@1	568 * to expand only the sample depth but not to expand the tRNS to alpha.
nuclear@1	569 */
nuclear@1	570
nuclear@1	571 /* Expand paletted images to RGB. */
nuclear@1	572 void PNGAPI
nuclear@1	573 png_set_palette_to_rgb(png_structp png_ptr)
nuclear@1	574 {
nuclear@1	575 png_debug(1, "in png_set_palette_to_rgb\n");
nuclear@1	576 if (png_ptr == NULL) return;
nuclear@1	577 png_ptr->transformations \|= (PNG_EXPAND \| PNG_EXPAND_tRNS);
nuclear@1	578 png_ptr->flags &= ~PNG_FLAG_ROW_INIT;
nuclear@1	579 }
nuclear@1	580
nuclear@1	581 #if !defined(PNG_1_0_X)
nuclear@1	582 /* Expand grayscale images of less than 8-bit depth to 8 bits. */
nuclear@1	583 void PNGAPI
nuclear@1	584 png_set_expand_gray_1_2_4_to_8(png_structp png_ptr)
nuclear@1	585 {
nuclear@1	586 png_debug(1, "in png_set_expand_gray_1_2_4_to_8\n");
nuclear@1	587 if (png_ptr == NULL) return;
nuclear@1	588 png_ptr->transformations \|= PNG_EXPAND;
nuclear@1	589 png_ptr->flags &= ~PNG_FLAG_ROW_INIT;
nuclear@1	590 }
nuclear@1	591 #endif
nuclear@1	592
nuclear@1	593 #if defined(PNG_1_0_X) \|\| defined(PNG_1_2_X)
nuclear@1	594 /* Expand grayscale images of less than 8-bit depth to 8 bits. */
nuclear@1	595 /* Deprecated as of libpng-1.2.9 */
nuclear@1	596 void PNGAPI
nuclear@1	597 png_set_gray_1_2_4_to_8(png_structp png_ptr)
nuclear@1	598 {
nuclear@1	599 png_debug(1, "in png_set_gray_1_2_4_to_8\n");
nuclear@1	600 if (png_ptr == NULL) return;
nuclear@1	601 png_ptr->transformations \|= (PNG_EXPAND \| PNG_EXPAND_tRNS);
nuclear@1	602 }
nuclear@1	603 #endif
nuclear@1	604
nuclear@1	605
nuclear@1	606 /* Expand tRNS chunks to alpha channels. */
nuclear@1	607 void PNGAPI
nuclear@1	608 png_set_tRNS_to_alpha(png_structp png_ptr)
nuclear@1	609 {
nuclear@1	610 png_debug(1, "in png_set_tRNS_to_alpha\n");
nuclear@1	611 png_ptr->transformations \|= (PNG_EXPAND \| PNG_EXPAND_tRNS);
nuclear@1	612 png_ptr->flags &= ~PNG_FLAG_ROW_INIT;
nuclear@1	613 }
nuclear@1	614 #endif /* defined(PNG_READ_EXPAND_SUPPORTED) */
nuclear@1	615
nuclear@1	616 #if defined(PNG_READ_GRAY_TO_RGB_SUPPORTED)
nuclear@1	617 void PNGAPI
nuclear@1	618 png_set_gray_to_rgb(png_structp png_ptr)
nuclear@1	619 {
nuclear@1	620 png_debug(1, "in png_set_gray_to_rgb\n");
nuclear@1	621 png_ptr->transformations \|= PNG_GRAY_TO_RGB;
nuclear@1	622 png_ptr->flags &= ~PNG_FLAG_ROW_INIT;
nuclear@1	623 }
nuclear@1	624 #endif
nuclear@1	625
nuclear@1	626 #if defined(PNG_READ_RGB_TO_GRAY_SUPPORTED)
nuclear@1	627 #if defined(PNG_FLOATING_POINT_SUPPORTED)
nuclear@1	628 /* Convert a RGB image to a grayscale of the same width. This allows us,
nuclear@1	629 * for example, to convert a 24 bpp RGB image into an 8 bpp grayscale image.
nuclear@1	630 */
nuclear@1	631
nuclear@1	632 void PNGAPI
nuclear@1	633 png_set_rgb_to_gray(png_structp png_ptr, int error_action, double red,
nuclear@1	634 double green)
nuclear@1	635 {
nuclear@1	636 int red_fixed = (int)((float)red*100000.0 + 0.5);
nuclear@1	637 int green_fixed = (int)((float)green*100000.0 + 0.5);
nuclear@1	638 if (png_ptr == NULL) return;
nuclear@1	639 png_set_rgb_to_gray_fixed(png_ptr, error_action, red_fixed, green_fixed);
nuclear@1	640 }
nuclear@1	641 #endif
nuclear@1	642
nuclear@1	643 void PNGAPI
nuclear@1	644 png_set_rgb_to_gray_fixed(png_structp png_ptr, int error_action,
nuclear@1	645 png_fixed_point red, png_fixed_point green)
nuclear@1	646 {
nuclear@1	647 png_debug(1, "in png_set_rgb_to_gray\n");
nuclear@1	648 if (png_ptr == NULL) return;
nuclear@1	649 switch(error_action)
nuclear@1	650 {
nuclear@1	651 case 1: png_ptr->transformations \|= PNG_RGB_TO_GRAY;
nuclear@1	652 break;
nuclear@1	653 case 2: png_ptr->transformations \|= PNG_RGB_TO_GRAY_WARN;
nuclear@1	654 break;
nuclear@1	655 case 3: png_ptr->transformations \|= PNG_RGB_TO_GRAY_ERR;
nuclear@1	656 }
nuclear@1	657 if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
nuclear@1	658 #if defined(PNG_READ_EXPAND_SUPPORTED)
nuclear@1	659 png_ptr->transformations \|= PNG_EXPAND;
nuclear@1	660 #else
nuclear@1	661 {
nuclear@1	662 png_warning(png_ptr,
nuclear@1	663 "Cannot do RGB_TO_GRAY without EXPAND_SUPPORTED.");
nuclear@1	664 png_ptr->transformations &= ~PNG_RGB_TO_GRAY;
nuclear@1	665 }
nuclear@1	666 #endif
nuclear@1	667 {
nuclear@1	668 png_uint_16 red_int, green_int;
nuclear@1	669 if (red < 0 \|\| green < 0)
nuclear@1	670 {
nuclear@1	671 red_int = 6968; /* .212671 * 32768 + .5 */
nuclear@1	672 green_int = 23434; /* .715160 * 32768 + .5 */
nuclear@1	673 }
nuclear@1	674 else if (red + green < 100000L)
nuclear@1	675 {
nuclear@1	676 red_int = (png_uint_16)(((png_uint_32)red*32768L)/100000L);
nuclear@1	677 green_int = (png_uint_16)(((png_uint_32)green*32768L)/100000L);
nuclear@1	678 }
nuclear@1	679 else
nuclear@1	680 {
nuclear@1	681 png_warning(png_ptr, "ignoring out of range rgb_to_gray coefficients");
nuclear@1	682 red_int = 6968;
nuclear@1	683 green_int = 23434;
nuclear@1	684 }
nuclear@1	685 png_ptr->rgb_to_gray_red_coeff = red_int;
nuclear@1	686 png_ptr->rgb_to_gray_green_coeff = green_int;
nuclear@1	687 png_ptr->rgb_to_gray_blue_coeff =
nuclear@1	688 (png_uint_16)(32768 - red_int - green_int);
nuclear@1	689 }
nuclear@1	690 }
nuclear@1	691 #endif
nuclear@1	692
nuclear@1	693 #if defined(PNG_READ_USER_TRANSFORM_SUPPORTED) \|\| \
nuclear@1	694 defined(PNG_WRITE_USER_TRANSFORM_SUPPORTED) \|\| \
nuclear@1	695 defined(PNG_LEGACY_SUPPORTED)
nuclear@1	696 void PNGAPI
nuclear@1	697 png_set_read_user_transform_fn(png_structp png_ptr, png_user_transform_ptr
nuclear@1	698 read_user_transform_fn)
nuclear@1	699 {
nuclear@1	700 png_debug(1, "in png_set_read_user_transform_fn\n");
nuclear@1	701 if (png_ptr == NULL) return;
nuclear@1	702 #if defined(PNG_READ_USER_TRANSFORM_SUPPORTED)
nuclear@1	703 png_ptr->transformations \|= PNG_USER_TRANSFORM;
nuclear@1	704 png_ptr->read_user_transform_fn = read_user_transform_fn;
nuclear@1	705 #endif
nuclear@1	706 #ifdef PNG_LEGACY_SUPPORTED
nuclear@1	707 if (read_user_transform_fn)
nuclear@1	708 png_warning(png_ptr,
nuclear@1	709 "This version of libpng does not support user transforms");
nuclear@1	710 #endif
nuclear@1	711 }
nuclear@1	712 #endif
nuclear@1	713
nuclear@1	714 /* Initialize everything needed for the read. This includes modifying
nuclear@1	715 * the palette.
nuclear@1	716 */
nuclear@1	717 void /* PRIVATE */
nuclear@1	718 png_init_read_transformations(png_structp png_ptr)
nuclear@1	719 {
nuclear@1	720 png_debug(1, "in png_init_read_transformations\n");
nuclear@1	721 #if defined(PNG_USELESS_TESTS_SUPPORTED)
nuclear@1	722 if (png_ptr != NULL)
nuclear@1	723 #endif
nuclear@1	724 {
nuclear@1	725 #if defined(PNG_READ_BACKGROUND_SUPPORTED) \|\| defined(PNG_READ_SHIFT_SUPPORTED) \
nuclear@1	726 \|\| defined(PNG_READ_GAMMA_SUPPORTED)
nuclear@1	727 int color_type = png_ptr->color_type;
nuclear@1	728 #endif
nuclear@1	729
nuclear@1	730 #if defined(PNG_READ_EXPAND_SUPPORTED) && defined(PNG_READ_BACKGROUND_SUPPORTED)
nuclear@1	731
nuclear@1	732 #if defined(PNG_READ_GRAY_TO_RGB_SUPPORTED)
nuclear@1	733 /* Detect gray background and attempt to enable optimization
nuclear@1	734 * for gray --> RGB case */
nuclear@1	735 /* Note: if PNG_BACKGROUND_EXPAND is set and color_type is either RGB or
nuclear@1	736 * RGB_ALPHA (in which case need_expand is superfluous anyway), the
nuclear@1	737 * background color might actually be gray yet not be flagged as such.
nuclear@1	738 * This is not a problem for the current code, which uses
nuclear@1	739 * PNG_BACKGROUND_IS_GRAY only to decide when to do the
nuclear@1	740 * png_do_gray_to_rgb() transformation.
nuclear@1	741 */
nuclear@1	742 if ((png_ptr->transformations & PNG_BACKGROUND_EXPAND) &&
nuclear@1	743 !(color_type & PNG_COLOR_MASK_COLOR))
nuclear@1	744 {
nuclear@1	745 png_ptr->mode \|= PNG_BACKGROUND_IS_GRAY;
nuclear@1	746 } else if ((png_ptr->transformations & PNG_BACKGROUND) &&
nuclear@1	747 !(png_ptr->transformations & PNG_BACKGROUND_EXPAND) &&
nuclear@1	748 (png_ptr->transformations & PNG_GRAY_TO_RGB) &&
nuclear@1	749 png_ptr->background.red == png_ptr->background.green &&
nuclear@1	750 png_ptr->background.red == png_ptr->background.blue)
nuclear@1	751 {
nuclear@1	752 png_ptr->mode \|= PNG_BACKGROUND_IS_GRAY;
nuclear@1	753 png_ptr->background.gray = png_ptr->background.red;
nuclear@1	754 }
nuclear@1	755 #endif
nuclear@1	756
nuclear@1	757 if ((png_ptr->transformations & PNG_BACKGROUND_EXPAND) &&
nuclear@1	758 (png_ptr->transformations & PNG_EXPAND))
nuclear@1	759 {
nuclear@1	760 if (!(color_type & PNG_COLOR_MASK_COLOR)) /* i.e., GRAY or GRAY_ALPHA */
nuclear@1	761 {
nuclear@1	762 /* expand background and tRNS chunks */
nuclear@1	763 switch (png_ptr->bit_depth)
nuclear@1	764 {
nuclear@1	765 case 1:
nuclear@1	766 png_ptr->background.gray *= (png_uint_16)0xff;
nuclear@1	767 png_ptr->background.red = png_ptr->background.green
nuclear@1	768 = png_ptr->background.blue = png_ptr->background.gray;
nuclear@1	769 if (!(png_ptr->transformations & PNG_EXPAND_tRNS))
nuclear@1	770 {
nuclear@1	771 png_ptr->trans_values.gray *= (png_uint_16)0xff;
nuclear@1	772 png_ptr->trans_values.red = png_ptr->trans_values.green
nuclear@1	773 = png_ptr->trans_values.blue = png_ptr->trans_values.gray;
nuclear@1	774 }
nuclear@1	775 break;
nuclear@1	776 case 2:
nuclear@1	777 png_ptr->background.gray *= (png_uint_16)0x55;
nuclear@1	778 png_ptr->background.red = png_ptr->background.green
nuclear@1	779 = png_ptr->background.blue = png_ptr->background.gray;
nuclear@1	780 if (!(png_ptr->transformations & PNG_EXPAND_tRNS))
nuclear@1	781 {
nuclear@1	782 png_ptr->trans_values.gray *= (png_uint_16)0x55;
nuclear@1	783 png_ptr->trans_values.red = png_ptr->trans_values.green
nuclear@1	784 = png_ptr->trans_values.blue = png_ptr->trans_values.gray;
nuclear@1	785 }
nuclear@1	786 break;
nuclear@1	787 case 4:
nuclear@1	788 png_ptr->background.gray *= (png_uint_16)0x11;
nuclear@1	789 png_ptr->background.red = png_ptr->background.green
nuclear@1	790 = png_ptr->background.blue = png_ptr->background.gray;
nuclear@1	791 if (!(png_ptr->transformations & PNG_EXPAND_tRNS))
nuclear@1	792 {
nuclear@1	793 png_ptr->trans_values.gray *= (png_uint_16)0x11;
nuclear@1	794 png_ptr->trans_values.red = png_ptr->trans_values.green
nuclear@1	795 = png_ptr->trans_values.blue = png_ptr->trans_values.gray;
nuclear@1	796 }
nuclear@1	797 break;
nuclear@1	798 case 8:
nuclear@1	799 case 16:
nuclear@1	800 png_ptr->background.red = png_ptr->background.green
nuclear@1	801 = png_ptr->background.blue = png_ptr->background.gray;
nuclear@1	802 break;
nuclear@1	803 }
nuclear@1	804 }
nuclear@1	805 else if (color_type == PNG_COLOR_TYPE_PALETTE)
nuclear@1	806 {
nuclear@1	807 png_ptr->background.red =
nuclear@1	808 png_ptr->palette[png_ptr->background.index].red;
nuclear@1	809 png_ptr->background.green =
nuclear@1	810 png_ptr->palette[png_ptr->background.index].green;
nuclear@1	811 png_ptr->background.blue =
nuclear@1	812 png_ptr->palette[png_ptr->background.index].blue;
nuclear@1	813
nuclear@1	814 #if defined(PNG_READ_INVERT_ALPHA_SUPPORTED)
nuclear@1	815 if (png_ptr->transformations & PNG_INVERT_ALPHA)
nuclear@1	816 {
nuclear@1	817 #if defined(PNG_READ_EXPAND_SUPPORTED)
nuclear@1	818 if (!(png_ptr->transformations & PNG_EXPAND_tRNS))
nuclear@1	819 #endif
nuclear@1	820 {
nuclear@1	821 /* invert the alpha channel (in tRNS) unless the pixels are
nuclear@1	822 going to be expanded, in which case leave it for later */
nuclear@1	823 int i, istop;
nuclear@1	824 istop=(int)png_ptr->num_trans;
nuclear@1	825 for (i=0; i<istop; i++)
nuclear@1	826 png_ptr->trans[i] = (png_byte)(255 - png_ptr->trans[i]);
nuclear@1	827 }
nuclear@1	828 }
nuclear@1	829 #endif
nuclear@1	830
nuclear@1	831 }
nuclear@1	832 }
nuclear@1	833 #endif
nuclear@1	834
nuclear@1	835 #if defined(PNG_READ_BACKGROUND_SUPPORTED) && defined(PNG_READ_GAMMA_SUPPORTED)
nuclear@1	836 png_ptr->background_1 = png_ptr->background;
nuclear@1	837 #endif
nuclear@1	838 #if defined(PNG_READ_GAMMA_SUPPORTED) && defined(PNG_FLOATING_POINT_SUPPORTED)
nuclear@1	839
nuclear@1	840 if ((color_type == PNG_COLOR_TYPE_PALETTE && png_ptr->num_trans != 0)
nuclear@1	841 && (fabs(png_ptr->screen_gamma * png_ptr->gamma - 1.0)
nuclear@1	842 < PNG_GAMMA_THRESHOLD))
nuclear@1	843 {
nuclear@1	844 int i, k;
nuclear@1	845 k=0;
nuclear@1	846 for (i=0; i<png_ptr->num_trans; i++)
nuclear@1	847 {
nuclear@1	848 if (png_ptr->trans[i] != 0 && png_ptr->trans[i] != 0xff)
nuclear@1	849 k=1; /* partial transparency is present */
nuclear@1	850 }
nuclear@1	851 if (k == 0)
nuclear@1	852 png_ptr->transformations &= ~PNG_GAMMA;
nuclear@1	853 }
nuclear@1	854
nuclear@1	855 if ((png_ptr->transformations & (PNG_GAMMA \| PNG_RGB_TO_GRAY)) &&
nuclear@1	856 png_ptr->gamma != 0.0)
nuclear@1	857 {
nuclear@1	858 png_build_gamma_table(png_ptr);
nuclear@1	859 #if defined(PNG_READ_BACKGROUND_SUPPORTED)
nuclear@1	860 if (png_ptr->transformations & PNG_BACKGROUND)
nuclear@1	861 {
nuclear@1	862 if (color_type == PNG_COLOR_TYPE_PALETTE)
nuclear@1	863 {
nuclear@1	864 /* could skip if no transparency and
nuclear@1	865 */
nuclear@1	866 png_color back, back_1;
nuclear@1	867 png_colorp palette = png_ptr->palette;
nuclear@1	868 int num_palette = png_ptr->num_palette;
nuclear@1	869 int i;
nuclear@1	870 if (png_ptr->background_gamma_type == PNG_BACKGROUND_GAMMA_FILE)
nuclear@1	871 {
nuclear@1	872 back.red = png_ptr->gamma_table[png_ptr->background.red];
nuclear@1	873 back.green = png_ptr->gamma_table[png_ptr->background.green];
nuclear@1	874 back.blue = png_ptr->gamma_table[png_ptr->background.blue];
nuclear@1	875
nuclear@1	876 back_1.red = png_ptr->gamma_to_1[png_ptr->background.red];
nuclear@1	877 back_1.green = png_ptr->gamma_to_1[png_ptr->background.green];
nuclear@1	878 back_1.blue = png_ptr->gamma_to_1[png_ptr->background.blue];
nuclear@1	879 }
nuclear@1	880 else
nuclear@1	881 {
nuclear@1	882 double g, gs;
nuclear@1	883
nuclear@1	884 switch (png_ptr->background_gamma_type)
nuclear@1	885 {
nuclear@1	886 case PNG_BACKGROUND_GAMMA_SCREEN:
nuclear@1	887 g = (png_ptr->screen_gamma);
nuclear@1	888 gs = 1.0;
nuclear@1	889 break;
nuclear@1	890 case PNG_BACKGROUND_GAMMA_FILE:
nuclear@1	891 g = 1.0 / (png_ptr->gamma);
nuclear@1	892 gs = 1.0 / (png_ptr->gamma * png_ptr->screen_gamma);
nuclear@1	893 break;
nuclear@1	894 case PNG_BACKGROUND_GAMMA_UNIQUE:
nuclear@1	895 g = 1.0 / (png_ptr->background_gamma);
nuclear@1	896 gs = 1.0 / (png_ptr->background_gamma *
nuclear@1	897 png_ptr->screen_gamma);
nuclear@1	898 break;
nuclear@1	899 default:
nuclear@1	900 g = 1.0; /* back_1 */
nuclear@1	901 gs = 1.0; /* back */
nuclear@1	902 }
nuclear@1	903
nuclear@1	904 if ( fabs(gs - 1.0) < PNG_GAMMA_THRESHOLD)
nuclear@1	905 {
nuclear@1	906 back.red = (png_byte)png_ptr->background.red;
nuclear@1	907 back.green = (png_byte)png_ptr->background.green;
nuclear@1	908 back.blue = (png_byte)png_ptr->background.blue;
nuclear@1	909 }
nuclear@1	910 else
nuclear@1	911 {
nuclear@1	912 back.red = (png_byte)(pow(
nuclear@1	913 (double)png_ptr->background.red/255, gs) * 255.0 + .5);
nuclear@1	914 back.green = (png_byte)(pow(
nuclear@1	915 (double)png_ptr->background.green/255, gs) * 255.0 + .5);
nuclear@1	916 back.blue = (png_byte)(pow(
nuclear@1	917 (double)png_ptr->background.blue/255, gs) * 255.0 + .5);
nuclear@1	918 }
nuclear@1	919
nuclear@1	920 back_1.red = (png_byte)(pow(
nuclear@1	921 (double)png_ptr->background.red/255, g) * 255.0 + .5);
nuclear@1	922 back_1.green = (png_byte)(pow(
nuclear@1	923 (double)png_ptr->background.green/255, g) * 255.0 + .5);
nuclear@1	924 back_1.blue = (png_byte)(pow(
nuclear@1	925 (double)png_ptr->background.blue/255, g) * 255.0 + .5);
nuclear@1	926 }
nuclear@1	927 for (i = 0; i < num_palette; i++)
nuclear@1	928 {
nuclear@1	929 if (i < (int)png_ptr->num_trans && png_ptr->trans[i] != 0xff)
nuclear@1	930 {
nuclear@1	931 if (png_ptr->trans[i] == 0)
nuclear@1	932 {
nuclear@1	933 palette[i] = back;
nuclear@1	934 }
nuclear@1	935 else /* if (png_ptr->trans[i] != 0xff) */
nuclear@1	936 {
nuclear@1	937 png_byte v, w;
nuclear@1	938
nuclear@1	939 v = png_ptr->gamma_to_1[palette[i].red];
nuclear@1	940 png_composite(w, v, png_ptr->trans[i], back_1.red);
nuclear@1	941 palette[i].red = png_ptr->gamma_from_1[w];
nuclear@1	942
nuclear@1	943 v = png_ptr->gamma_to_1[palette[i].green];
nuclear@1	944 png_composite(w, v, png_ptr->trans[i], back_1.green);
nuclear@1	945 palette[i].green = png_ptr->gamma_from_1[w];
nuclear@1	946
nuclear@1	947 v = png_ptr->gamma_to_1[palette[i].blue];
nuclear@1	948 png_composite(w, v, png_ptr->trans[i], back_1.blue);
nuclear@1	949 palette[i].blue = png_ptr->gamma_from_1[w];
nuclear@1	950 }
nuclear@1	951 }
nuclear@1	952 else
nuclear@1	953 {
nuclear@1	954 palette[i].red = png_ptr->gamma_table[palette[i].red];
nuclear@1	955 palette[i].green = png_ptr->gamma_table[palette[i].green];
nuclear@1	956 palette[i].blue = png_ptr->gamma_table[palette[i].blue];
nuclear@1	957 }
nuclear@1	958 }
nuclear@1	959 /* Prevent the transformations being done again, and make sure
nuclear@1	960 * that the now spurious alpha channel is stripped - the code
nuclear@1	961 * has just reduced background composition and gamma correction
nuclear@1	962 * to a simple alpha channel strip.
nuclear@1	963 */
nuclear@1	964 png_ptr->transformations &= ~PNG_BACKGROUND;
nuclear@1	965 png_ptr->transformations &= ~PNG_GAMMA;
nuclear@1	966 png_ptr->transformations \|= PNG_STRIP_ALPHA;
nuclear@1	967 }
nuclear@1	968 /* if (png_ptr->background_gamma_type!=PNG_BACKGROUND_GAMMA_UNKNOWN) */
nuclear@1	969 else
nuclear@1	970 /* color_type != PNG_COLOR_TYPE_PALETTE */
nuclear@1	971 {
nuclear@1	972 double m = (double)(((png_uint_32)1 << png_ptr->bit_depth) - 1);
nuclear@1	973 double g = 1.0;
nuclear@1	974 double gs = 1.0;
nuclear@1	975
nuclear@1	976 switch (png_ptr->background_gamma_type)
nuclear@1	977 {
nuclear@1	978 case PNG_BACKGROUND_GAMMA_SCREEN:
nuclear@1	979 g = (png_ptr->screen_gamma);
nuclear@1	980 gs = 1.0;
nuclear@1	981 break;
nuclear@1	982 case PNG_BACKGROUND_GAMMA_FILE:
nuclear@1	983 g = 1.0 / (png_ptr->gamma);
nuclear@1	984 gs = 1.0 / (png_ptr->gamma * png_ptr->screen_gamma);
nuclear@1	985 break;
nuclear@1	986 case PNG_BACKGROUND_GAMMA_UNIQUE:
nuclear@1	987 g = 1.0 / (png_ptr->background_gamma);
nuclear@1	988 gs = 1.0 / (png_ptr->background_gamma *
nuclear@1	989 png_ptr->screen_gamma);
nuclear@1	990 break;
nuclear@1	991 }
nuclear@1	992
nuclear@1	993 png_ptr->background_1.gray = (png_uint_16)(pow(
nuclear@1	994 (double)png_ptr->background.gray / m, g) * m + .5);
nuclear@1	995 png_ptr->background.gray = (png_uint_16)(pow(
nuclear@1	996 (double)png_ptr->background.gray / m, gs) * m + .5);
nuclear@1	997
nuclear@1	998 if ((png_ptr->background.red != png_ptr->background.green) \|\|
nuclear@1	999 (png_ptr->background.red != png_ptr->background.blue) \|\|
nuclear@1	1000 (png_ptr->background.red != png_ptr->background.gray))
nuclear@1	1001 {
nuclear@1	1002 /* RGB or RGBA with color background */
nuclear@1	1003 png_ptr->background_1.red = (png_uint_16)(pow(
nuclear@1	1004 (double)png_ptr->background.red / m, g) * m + .5);
nuclear@1	1005 png_ptr->background_1.green = (png_uint_16)(pow(
nuclear@1	1006 (double)png_ptr->background.green / m, g) * m + .5);
nuclear@1	1007 png_ptr->background_1.blue = (png_uint_16)(pow(
nuclear@1	1008 (double)png_ptr->background.blue / m, g) * m + .5);
nuclear@1	1009 png_ptr->background.red = (png_uint_16)(pow(
nuclear@1	1010 (double)png_ptr->background.red / m, gs) * m + .5);
nuclear@1	1011 png_ptr->background.green = (png_uint_16)(pow(
nuclear@1	1012 (double)png_ptr->background.green / m, gs) * m + .5);
nuclear@1	1013 png_ptr->background.blue = (png_uint_16)(pow(
nuclear@1	1014 (double)png_ptr->background.blue / m, gs) * m + .5);
nuclear@1	1015 }
nuclear@1	1016 else
nuclear@1	1017 {
nuclear@1	1018 /* GRAY, GRAY ALPHA, RGB, or RGBA with gray background */
nuclear@1	1019 png_ptr->background_1.red = png_ptr->background_1.green
nuclear@1	1020 = png_ptr->background_1.blue = png_ptr->background_1.gray;
nuclear@1	1021 png_ptr->background.red = png_ptr->background.green
nuclear@1	1022 = png_ptr->background.blue = png_ptr->background.gray;
nuclear@1	1023 }
nuclear@1	1024 }
nuclear@1	1025 }
nuclear@1	1026 else
nuclear@1	1027 /* transformation does not include PNG_BACKGROUND */
nuclear@1	1028 #endif /* PNG_READ_BACKGROUND_SUPPORTED */
nuclear@1	1029 if (color_type == PNG_COLOR_TYPE_PALETTE)
nuclear@1	1030 {
nuclear@1	1031 png_colorp palette = png_ptr->palette;
nuclear@1	1032 int num_palette = png_ptr->num_palette;
nuclear@1	1033 int i;
nuclear@1	1034
nuclear@1	1035 for (i = 0; i < num_palette; i++)
nuclear@1	1036 {
nuclear@1	1037 palette[i].red = png_ptr->gamma_table[palette[i].red];
nuclear@1	1038 palette[i].green = png_ptr->gamma_table[palette[i].green];
nuclear@1	1039 palette[i].blue = png_ptr->gamma_table[palette[i].blue];
nuclear@1	1040 }
nuclear@1	1041
nuclear@1	1042 /* Done the gamma correction. */
nuclear@1	1043 png_ptr->transformations &= ~PNG_GAMMA;
nuclear@1	1044 }
nuclear@1	1045 }
nuclear@1	1046 #if defined(PNG_READ_BACKGROUND_SUPPORTED)
nuclear@1	1047 else
nuclear@1	1048 #endif
nuclear@1	1049 #endif /* PNG_READ_GAMMA_SUPPORTED && PNG_FLOATING_POINT_SUPPORTED */
nuclear@1	1050 #if defined(PNG_READ_BACKGROUND_SUPPORTED)
nuclear@1	1051 /* No GAMMA transformation */
nuclear@1	1052 if ((png_ptr->transformations & PNG_BACKGROUND) &&
nuclear@1	1053 (color_type == PNG_COLOR_TYPE_PALETTE))
nuclear@1	1054 {
nuclear@1	1055 int i;
nuclear@1	1056 int istop = (int)png_ptr->num_trans;
nuclear@1	1057 png_color back;
nuclear@1	1058 png_colorp palette = png_ptr->palette;
nuclear@1	1059
nuclear@1	1060 back.red = (png_byte)png_ptr->background.red;
nuclear@1	1061 back.green = (png_byte)png_ptr->background.green;
nuclear@1	1062 back.blue = (png_byte)png_ptr->background.blue;
nuclear@1	1063
nuclear@1	1064 for (i = 0; i < istop; i++)
nuclear@1	1065 {
nuclear@1	1066 if (png_ptr->trans[i] == 0)
nuclear@1	1067 {
nuclear@1	1068 palette[i] = back;
nuclear@1	1069 }
nuclear@1	1070 else if (png_ptr->trans[i] != 0xff)
nuclear@1	1071 {
nuclear@1	1072 /* The png_composite() macro is defined in png.h */
nuclear@1	1073 png_composite(palette[i].red, palette[i].red,
nuclear@1	1074 png_ptr->trans[i], back.red);
nuclear@1	1075 png_composite(palette[i].green, palette[i].green,
nuclear@1	1076 png_ptr->trans[i], back.green);
nuclear@1	1077 png_composite(palette[i].blue, palette[i].blue,
nuclear@1	1078 png_ptr->trans[i], back.blue);
nuclear@1	1079 }
nuclear@1	1080 }
nuclear@1	1081
nuclear@1	1082 /* Handled alpha, still need to strip the channel. */
nuclear@1	1083 png_ptr->transformations &= ~PNG_BACKGROUND;
nuclear@1	1084 png_ptr->transformations \|= PNG_STRIP_ALPHA;
nuclear@1	1085 }
nuclear@1	1086 #endif /* PNG_READ_BACKGROUND_SUPPORTED */
nuclear@1	1087
nuclear@1	1088 #if defined(PNG_READ_SHIFT_SUPPORTED)
nuclear@1	1089 if ((png_ptr->transformations & PNG_SHIFT) &&
nuclear@1	1090 (color_type == PNG_COLOR_TYPE_PALETTE))
nuclear@1	1091 {
nuclear@1	1092 png_uint_16 i;
nuclear@1	1093 png_uint_16 istop = png_ptr->num_palette;
nuclear@1	1094 int sr = 8 - png_ptr->sig_bit.red;
nuclear@1	1095 int sg = 8 - png_ptr->sig_bit.green;
nuclear@1	1096 int sb = 8 - png_ptr->sig_bit.blue;
nuclear@1	1097
nuclear@1	1098 if (sr < 0 \|\| sr > 8)
nuclear@1	1099 sr = 0;
nuclear@1	1100 if (sg < 0 \|\| sg > 8)
nuclear@1	1101 sg = 0;
nuclear@1	1102 if (sb < 0 \|\| sb > 8)
nuclear@1	1103 sb = 0;
nuclear@1	1104 for (i = 0; i < istop; i++)
nuclear@1	1105 {
nuclear@1	1106 png_ptr->palette[i].red >>= sr;
nuclear@1	1107 png_ptr->palette[i].green >>= sg;
nuclear@1	1108 png_ptr->palette[i].blue >>= sb;
nuclear@1	1109 }
nuclear@1	1110 }
nuclear@1	1111 #endif /* PNG_READ_SHIFT_SUPPORTED */
nuclear@1	1112 }
nuclear@1	1113 #if !defined(PNG_READ_GAMMA_SUPPORTED) && !defined(PNG_READ_SHIFT_SUPPORTED) \
nuclear@1	1114 && !defined(PNG_READ_BACKGROUND_SUPPORTED)
nuclear@1	1115 if (png_ptr)
nuclear@1	1116 return;
nuclear@1	1117 #endif
nuclear@1	1118 }
nuclear@1	1119
nuclear@1	1120 /* Modify the info structure to reflect the transformations. The
nuclear@1	1121 * info should be updated so a PNG file could be written with it,
nuclear@1	1122 * assuming the transformations result in valid PNG data.
nuclear@1	1123 */
nuclear@1	1124 void /* PRIVATE */
nuclear@1	1125 png_read_transform_info(png_structp png_ptr, png_infop info_ptr)
nuclear@1	1126 {
nuclear@1	1127 png_debug(1, "in png_read_transform_info\n");
nuclear@1	1128 #if defined(PNG_READ_EXPAND_SUPPORTED)
nuclear@1	1129 if (png_ptr->transformations & PNG_EXPAND)
nuclear@1	1130 {
nuclear@1	1131 if (info_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
nuclear@1	1132 {
nuclear@1	1133 if (png_ptr->num_trans &&
nuclear@1	1134 (png_ptr->transformations & PNG_EXPAND_tRNS))
nuclear@1	1135 info_ptr->color_type = PNG_COLOR_TYPE_RGB_ALPHA;
nuclear@1	1136 else
nuclear@1	1137 info_ptr->color_type = PNG_COLOR_TYPE_RGB;
nuclear@1	1138 info_ptr->bit_depth = 8;
nuclear@1	1139 info_ptr->num_trans = 0;
nuclear@1	1140 }
nuclear@1	1141 else
nuclear@1	1142 {
nuclear@1	1143 if (png_ptr->num_trans)
nuclear@1	1144 {
nuclear@1	1145 if (png_ptr->transformations & PNG_EXPAND_tRNS)
nuclear@1	1146 info_ptr->color_type \|= PNG_COLOR_MASK_ALPHA;
nuclear@1	1147 #if 0 /* Removed from libpng-1.2.27 */
nuclear@1	1148 else
nuclear@1	1149 info_ptr->color_type \|= PNG_COLOR_MASK_COLOR;
nuclear@1	1150 #endif
nuclear@1	1151 }
nuclear@1	1152 if (info_ptr->bit_depth < 8)
nuclear@1	1153 info_ptr->bit_depth = 8;
nuclear@1	1154 info_ptr->num_trans = 0;
nuclear@1	1155 }
nuclear@1	1156 }
nuclear@1	1157 #endif
nuclear@1	1158
nuclear@1	1159 #if defined(PNG_READ_BACKGROUND_SUPPORTED)
nuclear@1	1160 if (png_ptr->transformations & PNG_BACKGROUND)
nuclear@1	1161 {
nuclear@1	1162 info_ptr->color_type &= ~PNG_COLOR_MASK_ALPHA;
nuclear@1	1163 info_ptr->num_trans = 0;
nuclear@1	1164 info_ptr->background = png_ptr->background;
nuclear@1	1165 }
nuclear@1	1166 #endif
nuclear@1	1167
nuclear@1	1168 #if defined(PNG_READ_GAMMA_SUPPORTED)
nuclear@1	1169 if (png_ptr->transformations & PNG_GAMMA)
nuclear@1	1170 {
nuclear@1	1171 #ifdef PNG_FLOATING_POINT_SUPPORTED
nuclear@1	1172 info_ptr->gamma = png_ptr->gamma;
nuclear@1	1173 #endif
nuclear@1	1174 #ifdef PNG_FIXED_POINT_SUPPORTED
nuclear@1	1175 info_ptr->int_gamma = png_ptr->int_gamma;
nuclear@1	1176 #endif
nuclear@1	1177 }
nuclear@1	1178 #endif
nuclear@1	1179
nuclear@1	1180 #if defined(PNG_READ_16_TO_8_SUPPORTED)
nuclear@1	1181 if ((png_ptr->transformations & PNG_16_TO_8) && (info_ptr->bit_depth == 16))
nuclear@1	1182 info_ptr->bit_depth = 8;
nuclear@1	1183 #endif
nuclear@1	1184
nuclear@1	1185 #if defined(PNG_READ_GRAY_TO_RGB_SUPPORTED)
nuclear@1	1186 if (png_ptr->transformations & PNG_GRAY_TO_RGB)
nuclear@1	1187 info_ptr->color_type \|= PNG_COLOR_MASK_COLOR;
nuclear@1	1188 #endif
nuclear@1	1189
nuclear@1	1190 #if defined(PNG_READ_RGB_TO_GRAY_SUPPORTED)
nuclear@1	1191 if (png_ptr->transformations & PNG_RGB_TO_GRAY)
nuclear@1	1192 info_ptr->color_type &= ~PNG_COLOR_MASK_COLOR;
nuclear@1	1193 #endif
nuclear@1	1194
nuclear@1	1195 #if defined(PNG_READ_DITHER_SUPPORTED)
nuclear@1	1196 if (png_ptr->transformations & PNG_DITHER)
nuclear@1	1197 {
nuclear@1	1198 if (((info_ptr->color_type == PNG_COLOR_TYPE_RGB) \|\|
nuclear@1	1199 (info_ptr->color_type == PNG_COLOR_TYPE_RGB_ALPHA)) &&
nuclear@1	1200 png_ptr->palette_lookup && info_ptr->bit_depth == 8)
nuclear@1	1201 {
nuclear@1	1202 info_ptr->color_type = PNG_COLOR_TYPE_PALETTE;
nuclear@1	1203 }
nuclear@1	1204 }
nuclear@1	1205 #endif
nuclear@1	1206
nuclear@1	1207 #if defined(PNG_READ_PACK_SUPPORTED)
nuclear@1	1208 if ((png_ptr->transformations & PNG_PACK) && (info_ptr->bit_depth < 8))
nuclear@1	1209 info_ptr->bit_depth = 8;
nuclear@1	1210 #endif
nuclear@1	1211
nuclear@1	1212 if (info_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
nuclear@1	1213 info_ptr->channels = 1;
nuclear@1	1214 else if (info_ptr->color_type & PNG_COLOR_MASK_COLOR)
nuclear@1	1215 info_ptr->channels = 3;
nuclear@1	1216 else
nuclear@1	1217 info_ptr->channels = 1;
nuclear@1	1218
nuclear@1	1219 #if defined(PNG_READ_STRIP_ALPHA_SUPPORTED)
nuclear@1	1220 if (png_ptr->flags & PNG_FLAG_STRIP_ALPHA)
nuclear@1	1221 info_ptr->color_type &= ~PNG_COLOR_MASK_ALPHA;
nuclear@1	1222 #endif
nuclear@1	1223
nuclear@1	1224 if (info_ptr->color_type & PNG_COLOR_MASK_ALPHA)
nuclear@1	1225 info_ptr->channels++;
nuclear@1	1226
nuclear@1	1227 #if defined(PNG_READ_FILLER_SUPPORTED)
nuclear@1	1228 /* STRIP_ALPHA and FILLER allowed: MASK_ALPHA bit stripped above */
nuclear@1	1229 if ((png_ptr->transformations & PNG_FILLER) &&
nuclear@1	1230 ((info_ptr->color_type == PNG_COLOR_TYPE_RGB) \|\|
nuclear@1	1231 (info_ptr->color_type == PNG_COLOR_TYPE_GRAY)))
nuclear@1	1232 {
nuclear@1	1233 info_ptr->channels++;
nuclear@1	1234 /* if adding a true alpha channel not just filler */
nuclear@1	1235 #if !defined(PNG_1_0_X)
nuclear@1	1236 if (png_ptr->transformations & PNG_ADD_ALPHA)
nuclear@1	1237 info_ptr->color_type \|= PNG_COLOR_MASK_ALPHA;
nuclear@1	1238 #endif
nuclear@1	1239 }
nuclear@1	1240 #endif
nuclear@1	1241
nuclear@1	1242 #if defined(PNG_USER_TRANSFORM_PTR_SUPPORTED) && \
nuclear@1	1243 defined(PNG_READ_USER_TRANSFORM_SUPPORTED)
nuclear@1	1244 if (png_ptr->transformations & PNG_USER_TRANSFORM)
nuclear@1	1245 {
nuclear@1	1246 if (info_ptr->bit_depth < png_ptr->user_transform_depth)
nuclear@1	1247 info_ptr->bit_depth = png_ptr->user_transform_depth;
nuclear@1	1248 if (info_ptr->channels < png_ptr->user_transform_channels)
nuclear@1	1249 info_ptr->channels = png_ptr->user_transform_channels;
nuclear@1	1250 }
nuclear@1	1251 #endif
nuclear@1	1252
nuclear@1	1253 info_ptr->pixel_depth = (png_byte)(info_ptr->channels *
nuclear@1	1254 info_ptr->bit_depth);
nuclear@1	1255
nuclear@1	1256 info_ptr->rowbytes = PNG_ROWBYTES(info_ptr->pixel_depth, info_ptr->width);
nuclear@1	1257
nuclear@1	1258 #if !defined(PNG_READ_EXPAND_SUPPORTED)
nuclear@1	1259 if (png_ptr)
nuclear@1	1260 return;
nuclear@1	1261 #endif
nuclear@1	1262 }
nuclear@1	1263
nuclear@1	1264 /* Transform the row. The order of transformations is significant,
nuclear@1	1265 * and is very touchy. If you add a transformation, take care to
nuclear@1	1266 * decide how it fits in with the other transformations here.
nuclear@1	1267 */
nuclear@1	1268 void /* PRIVATE */
nuclear@1	1269 png_do_read_transformations(png_structp png_ptr)
nuclear@1	1270 {
nuclear@1	1271 png_debug(1, "in png_do_read_transformations\n");
nuclear@1	1272 if (png_ptr->row_buf == NULL)
nuclear@1	1273 {
nuclear@1	1274 #if !defined(PNG_NO_STDIO) && !defined(_WIN32_WCE)
nuclear@1	1275 char msg[50];
nuclear@1	1276
nuclear@1	1277 png_snprintf2(msg, 50,
nuclear@1	1278 "NULL row buffer for row %ld, pass %d", (long)png_ptr->row_number,
nuclear@1	1279 png_ptr->pass);
nuclear@1	1280 png_error(png_ptr, msg);
nuclear@1	1281 #else
nuclear@1	1282 png_error(png_ptr, "NULL row buffer");
nuclear@1	1283 #endif
nuclear@1	1284 }
nuclear@1	1285 #ifdef PNG_WARN_UNINITIALIZED_ROW
nuclear@1	1286 if (!(png_ptr->flags & PNG_FLAG_ROW_INIT))
nuclear@1	1287 /* Application has failed to call either png_read_start_image()
nuclear@1	1288 * or png_read_update_info() after setting transforms that expand
nuclear@1	1289 * pixels. This check added to libpng-1.2.19 */
nuclear@1	1290 #if (PNG_WARN_UNINITIALIZED_ROW==1)
nuclear@1	1291 png_error(png_ptr, "Uninitialized row");
nuclear@1	1292 #else
nuclear@1	1293 png_warning(png_ptr, "Uninitialized row");
nuclear@1	1294 #endif
nuclear@1	1295 #endif
nuclear@1	1296
nuclear@1	1297 #if defined(PNG_READ_EXPAND_SUPPORTED)
nuclear@1	1298 if (png_ptr->transformations & PNG_EXPAND)
nuclear@1	1299 {
nuclear@1	1300 if (png_ptr->row_info.color_type == PNG_COLOR_TYPE_PALETTE)
nuclear@1	1301 {
nuclear@1	1302 png_do_expand_palette(&(png_ptr->row_info), png_ptr->row_buf + 1,
nuclear@1	1303 png_ptr->palette, png_ptr->trans, png_ptr->num_trans);
nuclear@1	1304 }
nuclear@1	1305 else
nuclear@1	1306 {
nuclear@1	1307 if (png_ptr->num_trans &&
nuclear@1	1308 (png_ptr->transformations & PNG_EXPAND_tRNS))
nuclear@1	1309 png_do_expand(&(png_ptr->row_info), png_ptr->row_buf + 1,
nuclear@1	1310 &(png_ptr->trans_values));
nuclear@1	1311 else
nuclear@1	1312 png_do_expand(&(png_ptr->row_info), png_ptr->row_buf + 1,
nuclear@1	1313 NULL);
nuclear@1	1314 }
nuclear@1	1315 }
nuclear@1	1316 #endif
nuclear@1	1317
nuclear@1	1318 #if defined(PNG_READ_STRIP_ALPHA_SUPPORTED)
nuclear@1	1319 if (png_ptr->flags & PNG_FLAG_STRIP_ALPHA)
nuclear@1	1320 png_do_strip_filler(&(png_ptr->row_info), png_ptr->row_buf + 1,
nuclear@1	1321 PNG_FLAG_FILLER_AFTER \| (png_ptr->flags & PNG_FLAG_STRIP_ALPHA));
nuclear@1	1322 #endif
nuclear@1	1323
nuclear@1	1324 #if defined(PNG_READ_RGB_TO_GRAY_SUPPORTED)
nuclear@1	1325 if (png_ptr->transformations & PNG_RGB_TO_GRAY)
nuclear@1	1326 {
nuclear@1	1327 int rgb_error =
nuclear@1	1328 png_do_rgb_to_gray(png_ptr, &(png_ptr->row_info), png_ptr->row_buf + 1);
nuclear@1	1329 if (rgb_error)
nuclear@1	1330 {
nuclear@1	1331 png_ptr->rgb_to_gray_status=1;
nuclear@1	1332 if ((png_ptr->transformations & PNG_RGB_TO_GRAY) ==
nuclear@1	1333 PNG_RGB_TO_GRAY_WARN)
nuclear@1	1334 png_warning(png_ptr, "png_do_rgb_to_gray found nongray pixel");
nuclear@1	1335 if ((png_ptr->transformations & PNG_RGB_TO_GRAY) ==
nuclear@1	1336 PNG_RGB_TO_GRAY_ERR)
nuclear@1	1337 png_error(png_ptr, "png_do_rgb_to_gray found nongray pixel");
nuclear@1	1338 }
nuclear@1	1339 }
nuclear@1	1340 #endif
nuclear@1	1341
nuclear@1	1342 /*
nuclear@1	1343 From Andreas Dilger e-mail to png-implement, 26 March 1998:
nuclear@1	1344
nuclear@1	1345 In most cases, the "simple transparency" should be done prior to doing
nuclear@1	1346 gray-to-RGB, or you will have to test 3x as many bytes to check if a
nuclear@1	1347 pixel is transparent. You would also need to make sure that the
nuclear@1	1348 transparency information is upgraded to RGB.
nuclear@1	1349
nuclear@1	1350 To summarize, the current flow is:
nuclear@1	1351 - Gray + simple transparency -> compare 1 or 2 gray bytes and composite
nuclear@1	1352 with background "in place" if transparent,
nuclear@1	1353 convert to RGB if necessary
nuclear@1	1354 - Gray + alpha -> composite with gray background and remove alpha bytes,
nuclear@1	1355 convert to RGB if necessary
nuclear@1	1356
nuclear@1	1357 To support RGB backgrounds for gray images we need:
nuclear@1	1358 - Gray + simple transparency -> convert to RGB + simple transparency, compare
nuclear@1	1359 3 or 6 bytes and composite with background
nuclear@1	1360 "in place" if transparent (3x compare/pixel
nuclear@1	1361 compared to doing composite with gray bkgrnd)
nuclear@1	1362 - Gray + alpha -> convert to RGB + alpha, composite with background and
nuclear@1	1363 remove alpha bytes (3x float operations/pixel
nuclear@1	1364 compared with composite on gray background)
nuclear@1	1365
nuclear@1	1366 Greg's change will do this. The reason it wasn't done before is for
nuclear@1	1367 performance, as this increases the per-pixel operations. If we would check
nuclear@1	1368 in advance if the background was gray or RGB, and position the gray-to-RGB
nuclear@1	1369 transform appropriately, then it would save a lot of work/time.
nuclear@1	1370 */
nuclear@1	1371
nuclear@1	1372 #if defined(PNG_READ_GRAY_TO_RGB_SUPPORTED)
nuclear@1	1373 /* if gray -> RGB, do so now only if background is non-gray; else do later
nuclear@1	1374 * for performance reasons */
nuclear@1	1375 if ((png_ptr->transformations & PNG_GRAY_TO_RGB) &&
nuclear@1	1376 !(png_ptr->mode & PNG_BACKGROUND_IS_GRAY))
nuclear@1	1377 png_do_gray_to_rgb(&(png_ptr->row_info), png_ptr->row_buf + 1);
nuclear@1	1378 #endif
nuclear@1	1379
nuclear@1	1380 #if defined(PNG_READ_BACKGROUND_SUPPORTED)
nuclear@1	1381 if ((png_ptr->transformations & PNG_BACKGROUND) &&
nuclear@1	1382 ((png_ptr->num_trans != 0 ) \|\|
nuclear@1	1383 (png_ptr->color_type & PNG_COLOR_MASK_ALPHA)))
nuclear@1	1384 png_do_background(&(png_ptr->row_info), png_ptr->row_buf + 1,
nuclear@1	1385 &(png_ptr->trans_values), &(png_ptr->background)
nuclear@1	1386 #if defined(PNG_READ_GAMMA_SUPPORTED)
nuclear@1	1387 , &(png_ptr->background_1),
nuclear@1	1388 png_ptr->gamma_table, png_ptr->gamma_from_1,
nuclear@1	1389 png_ptr->gamma_to_1, png_ptr->gamma_16_table,
nuclear@1	1390 png_ptr->gamma_16_from_1, png_ptr->gamma_16_to_1,
nuclear@1	1391 png_ptr->gamma_shift
nuclear@1	1392 #endif
nuclear@1	1393 );
nuclear@1	1394 #endif
nuclear@1	1395
nuclear@1	1396 #if defined(PNG_READ_GAMMA_SUPPORTED)
nuclear@1	1397 if ((png_ptr->transformations & PNG_GAMMA) &&
nuclear@1	1398 #if defined(PNG_READ_BACKGROUND_SUPPORTED)
nuclear@1	1399 !((png_ptr->transformations & PNG_BACKGROUND) &&
nuclear@1	1400 ((png_ptr->num_trans != 0) \|\|
nuclear@1	1401 (png_ptr->color_type & PNG_COLOR_MASK_ALPHA))) &&
nuclear@1	1402 #endif
nuclear@1	1403 (png_ptr->color_type != PNG_COLOR_TYPE_PALETTE))
nuclear@1	1404 png_do_gamma(&(png_ptr->row_info), png_ptr->row_buf + 1,
nuclear@1	1405 png_ptr->gamma_table, png_ptr->gamma_16_table,
nuclear@1	1406 png_ptr->gamma_shift);
nuclear@1	1407 #endif
nuclear@1	1408
nuclear@1	1409 #if defined(PNG_READ_16_TO_8_SUPPORTED)
nuclear@1	1410 if (png_ptr->transformations & PNG_16_TO_8)
nuclear@1	1411 png_do_chop(&(png_ptr->row_info), png_ptr->row_buf + 1);
nuclear@1	1412 #endif
nuclear@1	1413
nuclear@1	1414 #if defined(PNG_READ_DITHER_SUPPORTED)
nuclear@1	1415 if (png_ptr->transformations & PNG_DITHER)
nuclear@1	1416 {
nuclear@1	1417 png_do_dither((png_row_infop)&(png_ptr->row_info), png_ptr->row_buf + 1,
nuclear@1	1418 png_ptr->palette_lookup, png_ptr->dither_index);
nuclear@1	1419 if (png_ptr->row_info.rowbytes == (png_uint_32)0)
nuclear@1	1420 png_error(png_ptr, "png_do_dither returned rowbytes=0");
nuclear@1	1421 }
nuclear@1	1422 #endif
nuclear@1	1423
nuclear@1	1424 #if defined(PNG_READ_INVERT_SUPPORTED)
nuclear@1	1425 if (png_ptr->transformations & PNG_INVERT_MONO)
nuclear@1	1426 png_do_invert(&(png_ptr->row_info), png_ptr->row_buf + 1);
nuclear@1	1427 #endif
nuclear@1	1428
nuclear@1	1429 #if defined(PNG_READ_SHIFT_SUPPORTED)
nuclear@1	1430 if (png_ptr->transformations & PNG_SHIFT)
nuclear@1	1431 png_do_unshift(&(png_ptr->row_info), png_ptr->row_buf + 1,
nuclear@1	1432 &(png_ptr->shift));
nuclear@1	1433 #endif
nuclear@1	1434
nuclear@1	1435 #if defined(PNG_READ_PACK_SUPPORTED)
nuclear@1	1436 if (png_ptr->transformations & PNG_PACK)
nuclear@1	1437 png_do_unpack(&(png_ptr->row_info), png_ptr->row_buf + 1);
nuclear@1	1438 #endif
nuclear@1	1439
nuclear@1	1440 #if defined(PNG_READ_BGR_SUPPORTED)
nuclear@1	1441 if (png_ptr->transformations & PNG_BGR)
nuclear@1	1442 png_do_bgr(&(png_ptr->row_info), png_ptr->row_buf + 1);
nuclear@1	1443 #endif
nuclear@1	1444
nuclear@1	1445 #if defined(PNG_READ_PACKSWAP_SUPPORTED)
nuclear@1	1446 if (png_ptr->transformations & PNG_PACKSWAP)
nuclear@1	1447 png_do_packswap(&(png_ptr->row_info), png_ptr->row_buf + 1);
nuclear@1	1448 #endif
nuclear@1	1449
nuclear@1	1450 #if defined(PNG_READ_GRAY_TO_RGB_SUPPORTED)
nuclear@1	1451 /* if gray -> RGB, do so now only if we did not do so above */
nuclear@1	1452 if ((png_ptr->transformations & PNG_GRAY_TO_RGB) &&
nuclear@1	1453 (png_ptr->mode & PNG_BACKGROUND_IS_GRAY))
nuclear@1	1454 png_do_gray_to_rgb(&(png_ptr->row_info), png_ptr->row_buf + 1);
nuclear@1	1455 #endif
nuclear@1	1456
nuclear@1	1457 #if defined(PNG_READ_FILLER_SUPPORTED)
nuclear@1	1458 if (png_ptr->transformations & PNG_FILLER)
nuclear@1	1459 png_do_read_filler(&(png_ptr->row_info), png_ptr->row_buf + 1,
nuclear@1	1460 (png_uint_32)png_ptr->filler, png_ptr->flags);
nuclear@1	1461 #endif
nuclear@1	1462
nuclear@1	1463 #if defined(PNG_READ_INVERT_ALPHA_SUPPORTED)
nuclear@1	1464 if (png_ptr->transformations & PNG_INVERT_ALPHA)
nuclear@1	1465 png_do_read_invert_alpha(&(png_ptr->row_info), png_ptr->row_buf + 1);
nuclear@1	1466 #endif
nuclear@1	1467
nuclear@1	1468 #if defined(PNG_READ_SWAP_ALPHA_SUPPORTED)
nuclear@1	1469 if (png_ptr->transformations & PNG_SWAP_ALPHA)
nuclear@1	1470 png_do_read_swap_alpha(&(png_ptr->row_info), png_ptr->row_buf + 1);
nuclear@1	1471 #endif
nuclear@1	1472
nuclear@1	1473 #if defined(PNG_READ_SWAP_SUPPORTED)
nuclear@1	1474 if (png_ptr->transformations & PNG_SWAP_BYTES)
nuclear@1	1475 png_do_swap(&(png_ptr->row_info), png_ptr->row_buf + 1);
nuclear@1	1476 #endif
nuclear@1	1477
nuclear@1	1478 #if defined(PNG_READ_USER_TRANSFORM_SUPPORTED)
nuclear@1	1479 if (png_ptr->transformations & PNG_USER_TRANSFORM)
nuclear@1	1480 {
nuclear@1	1481 if (png_ptr->read_user_transform_fn != NULL)
nuclear@1	1482 ((png_ptr->read_user_transform_fn)) / user read transform function */
nuclear@1	1483 (png_ptr, /* png_ptr */
nuclear@1	1484 &(png_ptr->row_info), /* row_info: */
nuclear@1	1485 /* png_uint_32 width; width of row */
nuclear@1	1486 /* png_uint_32 rowbytes; number of bytes in row */
nuclear@1	1487 /* png_byte color_type; color type of pixels */
nuclear@1	1488 /* png_byte bit_depth; bit depth of samples */
nuclear@1	1489 /* png_byte channels; number of channels (1-4) */
nuclear@1	1490 /* png_byte pixel_depth; bits per pixel (depthchannels) /
nuclear@1	1491 png_ptr->row_buf + 1); /* start of pixel data for row */
nuclear@1	1492 #if defined(PNG_USER_TRANSFORM_PTR_SUPPORTED)
nuclear@1	1493 if (png_ptr->user_transform_depth)
nuclear@1	1494 png_ptr->row_info.bit_depth = png_ptr->user_transform_depth;
nuclear@1	1495 if (png_ptr->user_transform_channels)
nuclear@1	1496 png_ptr->row_info.channels = png_ptr->user_transform_channels;
nuclear@1	1497 #endif
nuclear@1	1498 png_ptr->row_info.pixel_depth = (png_byte)(png_ptr->row_info.bit_depth *
nuclear@1	1499 png_ptr->row_info.channels);
nuclear@1	1500 png_ptr->row_info.rowbytes = PNG_ROWBYTES(png_ptr->row_info.pixel_depth,
nuclear@1	1501 png_ptr->row_info.width);
nuclear@1	1502 }
nuclear@1	1503 #endif
nuclear@1	1504
nuclear@1	1505 }
nuclear@1	1506
nuclear@1	1507 #if defined(PNG_READ_PACK_SUPPORTED)
nuclear@1	1508 /* Unpack pixels of 1, 2, or 4 bits per pixel into 1 byte per pixel,
nuclear@1	1509 * without changing the actual values. Thus, if you had a row with
nuclear@1	1510 * a bit depth of 1, you would end up with bytes that only contained
nuclear@1	1511 * the numbers 0 or 1. If you would rather they contain 0 and 255, use
nuclear@1	1512 * png_do_shift() after this.
nuclear@1	1513 */
nuclear@1	1514 void /* PRIVATE */
nuclear@1	1515 png_do_unpack(png_row_infop row_info, png_bytep row)
nuclear@1	1516 {
nuclear@1	1517 png_debug(1, "in png_do_unpack\n");
nuclear@1	1518 #if defined(PNG_USELESS_TESTS_SUPPORTED)
nuclear@1	1519 if (row != NULL && row_info != NULL && row_info->bit_depth < 8)
nuclear@1	1520 #else
nuclear@1	1521 if (row_info->bit_depth < 8)
nuclear@1	1522 #endif
nuclear@1	1523 {
nuclear@1	1524 png_uint_32 i;
nuclear@1	1525 png_uint_32 row_width=row_info->width;
nuclear@1	1526
nuclear@1	1527 switch (row_info->bit_depth)
nuclear@1	1528 {
nuclear@1	1529 case 1:
nuclear@1	1530 {
nuclear@1	1531 png_bytep sp = row + (png_size_t)((row_width - 1) >> 3);
nuclear@1	1532 png_bytep dp = row + (png_size_t)row_width - 1;
nuclear@1	1533 png_uint_32 shift = 7 - (int)((row_width + 7) & 0x07);
nuclear@1	1534 for (i = 0; i < row_width; i++)
nuclear@1	1535 {
nuclear@1	1536 dp = (png_byte)((sp >> shift) & 0x01);
nuclear@1	1537 if (shift == 7)
nuclear@1	1538 {
nuclear@1	1539 shift = 0;
nuclear@1	1540 sp--;
nuclear@1	1541 }
nuclear@1	1542 else
nuclear@1	1543 shift++;
nuclear@1	1544
nuclear@1	1545 dp--;
nuclear@1	1546 }
nuclear@1	1547 break;
nuclear@1	1548 }
nuclear@1	1549 case 2:
nuclear@1	1550 {
nuclear@1	1551
nuclear@1	1552 png_bytep sp = row + (png_size_t)((row_width - 1) >> 2);
nuclear@1	1553 png_bytep dp = row + (png_size_t)row_width - 1;
nuclear@1	1554 png_uint_32 shift = (int)((3 - ((row_width + 3) & 0x03)) << 1);
nuclear@1	1555 for (i = 0; i < row_width; i++)
nuclear@1	1556 {
nuclear@1	1557 dp = (png_byte)((sp >> shift) & 0x03);
nuclear@1	1558 if (shift == 6)
nuclear@1	1559 {
nuclear@1	1560 shift = 0;
nuclear@1	1561 sp--;
nuclear@1	1562 }
nuclear@1	1563 else
nuclear@1	1564 shift += 2;
nuclear@1	1565
nuclear@1	1566 dp--;
nuclear@1	1567 }
nuclear@1	1568 break;
nuclear@1	1569 }
nuclear@1	1570 case 4:
nuclear@1	1571 {
nuclear@1	1572 png_bytep sp = row + (png_size_t)((row_width - 1) >> 1);
nuclear@1	1573 png_bytep dp = row + (png_size_t)row_width - 1;
nuclear@1	1574 png_uint_32 shift = (int)((1 - ((row_width + 1) & 0x01)) << 2);
nuclear@1	1575 for (i = 0; i < row_width; i++)
nuclear@1	1576 {
nuclear@1	1577 dp = (png_byte)((sp >> shift) & 0x0f);
nuclear@1	1578 if (shift == 4)
nuclear@1	1579 {
nuclear@1	1580 shift = 0;
nuclear@1	1581 sp--;
nuclear@1	1582 }
nuclear@1	1583 else
nuclear@1	1584 shift = 4;
nuclear@1	1585
nuclear@1	1586 dp--;
nuclear@1	1587 }
nuclear@1	1588 break;
nuclear@1	1589 }
nuclear@1	1590 }
nuclear@1	1591 row_info->bit_depth = 8;
nuclear@1	1592 row_info->pixel_depth = (png_byte)(8 * row_info->channels);
nuclear@1	1593 row_info->rowbytes = row_width * row_info->channels;
nuclear@1	1594 }
nuclear@1	1595 }
nuclear@1	1596 #endif
nuclear@1	1597
nuclear@1	1598 #if defined(PNG_READ_SHIFT_SUPPORTED)
nuclear@1	1599 /* Reverse the effects of png_do_shift. This routine merely shifts the
nuclear@1	1600 * pixels back to their significant bits values. Thus, if you have
nuclear@1	1601 * a row of bit depth 8, but only 5 are significant, this will shift
nuclear@1	1602 * the values back to 0 through 31.
nuclear@1	1603 */
nuclear@1	1604 void /* PRIVATE */
nuclear@1	1605 png_do_unshift(png_row_infop row_info, png_bytep row, png_color_8p sig_bits)
nuclear@1	1606 {
nuclear@1	1607 png_debug(1, "in png_do_unshift\n");
nuclear@1	1608 if (
nuclear@1	1609 #if defined(PNG_USELESS_TESTS_SUPPORTED)
nuclear@1	1610 row != NULL && row_info != NULL && sig_bits != NULL &&
nuclear@1	1611 #endif
nuclear@1	1612 row_info->color_type != PNG_COLOR_TYPE_PALETTE)
nuclear@1	1613 {
nuclear@1	1614 int shift[4];
nuclear@1	1615 int channels = 0;
nuclear@1	1616 int c;
nuclear@1	1617 png_uint_16 value = 0;
nuclear@1	1618 png_uint_32 row_width = row_info->width;
nuclear@1	1619
nuclear@1	1620 if (row_info->color_type & PNG_COLOR_MASK_COLOR)
nuclear@1	1621 {
nuclear@1	1622 shift[channels++] = row_info->bit_depth - sig_bits->red;
nuclear@1	1623 shift[channels++] = row_info->bit_depth - sig_bits->green;
nuclear@1	1624 shift[channels++] = row_info->bit_depth - sig_bits->blue;
nuclear@1	1625 }
nuclear@1	1626 else
nuclear@1	1627 {
nuclear@1	1628 shift[channels++] = row_info->bit_depth - sig_bits->gray;
nuclear@1	1629 }
nuclear@1	1630 if (row_info->color_type & PNG_COLOR_MASK_ALPHA)
nuclear@1	1631 {
nuclear@1	1632 shift[channels++] = row_info->bit_depth - sig_bits->alpha;
nuclear@1	1633 }
nuclear@1	1634
nuclear@1	1635 for (c = 0; c < channels; c++)
nuclear@1	1636 {
nuclear@1	1637 if (shift[c] <= 0)
nuclear@1	1638 shift[c] = 0;
nuclear@1	1639 else
nuclear@1	1640 value = 1;
nuclear@1	1641 }
nuclear@1	1642
nuclear@1	1643 if (!value)
nuclear@1	1644 return;
nuclear@1	1645
nuclear@1	1646 switch (row_info->bit_depth)
nuclear@1	1647 {
nuclear@1	1648 case 2:
nuclear@1	1649 {
nuclear@1	1650 png_bytep bp;
nuclear@1	1651 png_uint_32 i;
nuclear@1	1652 png_uint_32 istop = row_info->rowbytes;
nuclear@1	1653
nuclear@1	1654 for (bp = row, i = 0; i < istop; i++)
nuclear@1	1655 {
nuclear@1	1656 *bp >>= 1;
nuclear@1	1657 *bp++ &= 0x55;
nuclear@1	1658 }
nuclear@1	1659 break;
nuclear@1	1660 }
nuclear@1	1661 case 4:
nuclear@1	1662 {
nuclear@1	1663 png_bytep bp = row;
nuclear@1	1664 png_uint_32 i;
nuclear@1	1665 png_uint_32 istop = row_info->rowbytes;
nuclear@1	1666 png_byte mask = (png_byte)((((int)0xf0 >> shift[0]) & (int)0xf0) \|
nuclear@1	1667 (png_byte)((int)0xf >> shift[0]));
nuclear@1	1668
nuclear@1	1669 for (i = 0; i < istop; i++)
nuclear@1	1670 {
nuclear@1	1671 *bp >>= shift[0];
nuclear@1	1672 *bp++ &= mask;
nuclear@1	1673 }
nuclear@1	1674 break;
nuclear@1	1675 }
nuclear@1	1676 case 8:
nuclear@1	1677 {
nuclear@1	1678 png_bytep bp = row;
nuclear@1	1679 png_uint_32 i;
nuclear@1	1680 png_uint_32 istop = row_width * channels;
nuclear@1	1681
nuclear@1	1682 for (i = 0; i < istop; i++)
nuclear@1	1683 {
nuclear@1	1684 *bp++ >>= shift[i%channels];
nuclear@1	1685 }
nuclear@1	1686 break;
nuclear@1	1687 }
nuclear@1	1688 case 16:
nuclear@1	1689 {
nuclear@1	1690 png_bytep bp = row;
nuclear@1	1691 png_uint_32 i;
nuclear@1	1692 png_uint_32 istop = channels * row_width;
nuclear@1	1693
nuclear@1	1694 for (i = 0; i < istop; i++)
nuclear@1	1695 {
nuclear@1	1696 value = (png_uint_16)((bp << 8) + (bp + 1));
nuclear@1	1697 value >>= shift[i%channels];
nuclear@1	1698 *bp++ = (png_byte)(value >> 8);
nuclear@1	1699 *bp++ = (png_byte)(value & 0xff);
nuclear@1	1700 }
nuclear@1	1701 break;
nuclear@1	1702 }
nuclear@1	1703 }
nuclear@1	1704 }
nuclear@1	1705 }
nuclear@1	1706 #endif
nuclear@1	1707
nuclear@1	1708 #if defined(PNG_READ_16_TO_8_SUPPORTED)
nuclear@1	1709 /* chop rows of bit depth 16 down to 8 */
nuclear@1	1710 void /* PRIVATE */
nuclear@1	1711 png_do_chop(png_row_infop row_info, png_bytep row)
nuclear@1	1712 {
nuclear@1	1713 png_debug(1, "in png_do_chop\n");
nuclear@1	1714 #if defined(PNG_USELESS_TESTS_SUPPORTED)
nuclear@1	1715 if (row != NULL && row_info != NULL && row_info->bit_depth == 16)
nuclear@1	1716 #else
nuclear@1	1717 if (row_info->bit_depth == 16)
nuclear@1	1718 #endif
nuclear@1	1719 {
nuclear@1	1720 png_bytep sp = row;
nuclear@1	1721 png_bytep dp = row;
nuclear@1	1722 png_uint_32 i;
nuclear@1	1723 png_uint_32 istop = row_info->width * row_info->channels;
nuclear@1	1724
nuclear@1	1725 for (i = 0; i<istop; i++, sp += 2, dp++)
nuclear@1	1726 {
nuclear@1	1727 #if defined(PNG_READ_16_TO_8_ACCURATE_SCALE_SUPPORTED)
nuclear@1	1728 /* This does a more accurate scaling of the 16-bit color
nuclear@1	1729 * value, rather than a simple low-byte truncation.
nuclear@1	1730 *
nuclear@1	1731 * What the ideal calculation should be:
nuclear@1	1732 * dp = (((((png_uint_32)(sp) << 8) \|
nuclear@1	1733 * (png_uint_32)((sp + 1))) 255 + 127) / (png_uint_32)65535L;
nuclear@1	1734 *
nuclear@1	1735 * GRR: no, I think this is what it really should be:
nuclear@1	1736 * dp = (((((png_uint_32)(sp) << 8) \|
nuclear@1	1737 * (png_uint_32)(*(sp + 1))) + 128L) / (png_uint_32)257L;
nuclear@1	1738 *
nuclear@1	1739 * GRR: here's the exact calculation with shifts:
nuclear@1	1740 * temp = (((png_uint_32)(sp) << 8) \| (png_uint_32)((sp + 1))) + 128L;
nuclear@1	1741 * *dp = (temp - (temp >> 8)) >> 8;
nuclear@1	1742 *
nuclear@1	1743 * Approximate calculation with shift/add instead of multiply/divide:
nuclear@1	1744 * dp = ((((png_uint_32)(sp) << 8) \|
nuclear@1	1745 * (png_uint_32)((int)((sp + 1)) - sp)) + 128) >> 8;
nuclear@1	1746 *
nuclear@1	1747 * What we actually do to avoid extra shifting and conversion:
nuclear@1	1748 */
nuclear@1	1749
nuclear@1	1750 dp = sp + ((((int)((sp + 1)) - sp) > 128) ? 1 : 0);
nuclear@1	1751 #else
nuclear@1	1752 /* Simply discard the low order byte */
nuclear@1	1753 dp = sp;
nuclear@1	1754 #endif
nuclear@1	1755 }
nuclear@1	1756 row_info->bit_depth = 8;
nuclear@1	1757 row_info->pixel_depth = (png_byte)(8 * row_info->channels);
nuclear@1	1758 row_info->rowbytes = row_info->width * row_info->channels;
nuclear@1	1759 }
nuclear@1	1760 }
nuclear@1	1761 #endif
nuclear@1	1762
nuclear@1	1763 #if defined(PNG_READ_SWAP_ALPHA_SUPPORTED)
nuclear@1	1764 void /* PRIVATE */
nuclear@1	1765 png_do_read_swap_alpha(png_row_infop row_info, png_bytep row)
nuclear@1	1766 {
nuclear@1	1767 png_debug(1, "in png_do_read_swap_alpha\n");
nuclear@1	1768 #if defined(PNG_USELESS_TESTS_SUPPORTED)
nuclear@1	1769 if (row != NULL && row_info != NULL)
nuclear@1	1770 #endif
nuclear@1	1771 {
nuclear@1	1772 png_uint_32 row_width = row_info->width;
nuclear@1	1773 if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA)
nuclear@1	1774 {
nuclear@1	1775 /* This converts from RGBA to ARGB */
nuclear@1	1776 if (row_info->bit_depth == 8)
nuclear@1	1777 {
nuclear@1	1778 png_bytep sp = row + row_info->rowbytes;
nuclear@1	1779 png_bytep dp = sp;
nuclear@1	1780 png_byte save;
nuclear@1	1781 png_uint_32 i;
nuclear@1	1782
nuclear@1	1783 for (i = 0; i < row_width; i++)
nuclear@1	1784 {
nuclear@1	1785 save = *(--sp);
nuclear@1	1786 (--dp) = (--sp);
nuclear@1	1787 (--dp) = (--sp);
nuclear@1	1788 (--dp) = (--sp);
nuclear@1	1789 *(--dp) = save;
nuclear@1	1790 }
nuclear@1	1791 }
nuclear@1	1792 /* This converts from RRGGBBAA to AARRGGBB */
nuclear@1	1793 else
nuclear@1	1794 {
nuclear@1	1795 png_bytep sp = row + row_info->rowbytes;
nuclear@1	1796 png_bytep dp = sp;
nuclear@1	1797 png_byte save[2];
nuclear@1	1798 png_uint_32 i;
nuclear@1	1799
nuclear@1	1800 for (i = 0; i < row_width; i++)
nuclear@1	1801 {
nuclear@1	1802 save[0] = *(--sp);
nuclear@1	1803 save[1] = *(--sp);
nuclear@1	1804 (--dp) = (--sp);
nuclear@1	1805 (--dp) = (--sp);
nuclear@1	1806 (--dp) = (--sp);
nuclear@1	1807 (--dp) = (--sp);
nuclear@1	1808 (--dp) = (--sp);
nuclear@1	1809 (--dp) = (--sp);
nuclear@1	1810 *(--dp) = save[0];
nuclear@1	1811 *(--dp) = save[1];
nuclear@1	1812 }
nuclear@1	1813 }
nuclear@1	1814 }
nuclear@1	1815 else if (row_info->color_type == PNG_COLOR_TYPE_GRAY_ALPHA)
nuclear@1	1816 {
nuclear@1	1817 /* This converts from GA to AG */
nuclear@1	1818 if (row_info->bit_depth == 8)
nuclear@1	1819 {
nuclear@1	1820 png_bytep sp = row + row_info->rowbytes;
nuclear@1	1821 png_bytep dp = sp;
nuclear@1	1822 png_byte save;
nuclear@1	1823 png_uint_32 i;
nuclear@1	1824
nuclear@1	1825 for (i = 0; i < row_width; i++)
nuclear@1	1826 {
nuclear@1	1827 save = *(--sp);
nuclear@1	1828 (--dp) = (--sp);
nuclear@1	1829 *(--dp) = save;
nuclear@1	1830 }
nuclear@1	1831 }
nuclear@1	1832 /* This converts from GGAA to AAGG */
nuclear@1	1833 else
nuclear@1	1834 {
nuclear@1	1835 png_bytep sp = row + row_info->rowbytes;
nuclear@1	1836 png_bytep dp = sp;
nuclear@1	1837 png_byte save[2];
nuclear@1	1838 png_uint_32 i;
nuclear@1	1839
nuclear@1	1840 for (i = 0; i < row_width; i++)
nuclear@1	1841 {
nuclear@1	1842 save[0] = *(--sp);
nuclear@1	1843 save[1] = *(--sp);
nuclear@1	1844 (--dp) = (--sp);
nuclear@1	1845 (--dp) = (--sp);
nuclear@1	1846 *(--dp) = save[0];
nuclear@1	1847 *(--dp) = save[1];
nuclear@1	1848 }
nuclear@1	1849 }
nuclear@1	1850 }
nuclear@1	1851 }
nuclear@1	1852 }
nuclear@1	1853 #endif
nuclear@1	1854
nuclear@1	1855 #if defined(PNG_READ_INVERT_ALPHA_SUPPORTED)
nuclear@1	1856 void /* PRIVATE */
nuclear@1	1857 png_do_read_invert_alpha(png_row_infop row_info, png_bytep row)
nuclear@1	1858 {
nuclear@1	1859 png_debug(1, "in png_do_read_invert_alpha\n");
nuclear@1	1860 #if defined(PNG_USELESS_TESTS_SUPPORTED)
nuclear@1	1861 if (row != NULL && row_info != NULL)
nuclear@1	1862 #endif
nuclear@1	1863 {
nuclear@1	1864 png_uint_32 row_width = row_info->width;
nuclear@1	1865 if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA)
nuclear@1	1866 {
nuclear@1	1867 /* This inverts the alpha channel in RGBA */
nuclear@1	1868 if (row_info->bit_depth == 8)
nuclear@1	1869 {
nuclear@1	1870 png_bytep sp = row + row_info->rowbytes;
nuclear@1	1871 png_bytep dp = sp;
nuclear@1	1872 png_uint_32 i;
nuclear@1	1873
nuclear@1	1874 for (i = 0; i < row_width; i++)
nuclear@1	1875 {
nuclear@1	1876 (--dp) = (png_byte)(255 - (--sp));
nuclear@1	1877
nuclear@1	1878 /* This does nothing:
nuclear@1	1879 (--dp) = (--sp);
nuclear@1	1880 (--dp) = (--sp);
nuclear@1	1881 (--dp) = (--sp);
nuclear@1	1882 We can replace it with:
nuclear@1	1883 */
nuclear@1	1884 sp-=3;
nuclear@1	1885 dp=sp;
nuclear@1	1886 }
nuclear@1	1887 }
nuclear@1	1888 /* This inverts the alpha channel in RRGGBBAA */
nuclear@1	1889 else
nuclear@1	1890 {
nuclear@1	1891 png_bytep sp = row + row_info->rowbytes;
nuclear@1	1892 png_bytep dp = sp;
nuclear@1	1893 png_uint_32 i;
nuclear@1	1894
nuclear@1	1895 for (i = 0; i < row_width; i++)
nuclear@1	1896 {
nuclear@1	1897 (--dp) = (png_byte)(255 - (--sp));
nuclear@1	1898 (--dp) = (png_byte)(255 - (--sp));
nuclear@1	1899
nuclear@1	1900 /* This does nothing:
nuclear@1	1901 (--dp) = (--sp);
nuclear@1	1902 (--dp) = (--sp);
nuclear@1	1903 (--dp) = (--sp);
nuclear@1	1904 (--dp) = (--sp);
nuclear@1	1905 (--dp) = (--sp);
nuclear@1	1906 (--dp) = (--sp);
nuclear@1	1907 We can replace it with:
nuclear@1	1908 */
nuclear@1	1909 sp-=6;
nuclear@1	1910 dp=sp;
nuclear@1	1911 }
nuclear@1	1912 }
nuclear@1	1913 }
nuclear@1	1914 else if (row_info->color_type == PNG_COLOR_TYPE_GRAY_ALPHA)
nuclear@1	1915 {
nuclear@1	1916 /* This inverts the alpha channel in GA */
nuclear@1	1917 if (row_info->bit_depth == 8)
nuclear@1	1918 {
nuclear@1	1919 png_bytep sp = row + row_info->rowbytes;
nuclear@1	1920 png_bytep dp = sp;
nuclear@1	1921 png_uint_32 i;
nuclear@1	1922
nuclear@1	1923 for (i = 0; i < row_width; i++)
nuclear@1	1924 {
nuclear@1	1925 (--dp) = (png_byte)(255 - (--sp));
nuclear@1	1926 (--dp) = (--sp);
nuclear@1	1927 }
nuclear@1	1928 }
nuclear@1	1929 /* This inverts the alpha channel in GGAA */
nuclear@1	1930 else
nuclear@1	1931 {
nuclear@1	1932 png_bytep sp = row + row_info->rowbytes;
nuclear@1	1933 png_bytep dp = sp;
nuclear@1	1934 png_uint_32 i;
nuclear@1	1935
nuclear@1	1936 for (i = 0; i < row_width; i++)
nuclear@1	1937 {
nuclear@1	1938 (--dp) = (png_byte)(255 - (--sp));
nuclear@1	1939 (--dp) = (png_byte)(255 - (--sp));
nuclear@1	1940 /*
nuclear@1	1941 (--dp) = (--sp);
nuclear@1	1942 (--dp) = (--sp);
nuclear@1	1943 */
nuclear@1	1944 sp-=2;
nuclear@1	1945 dp=sp;
nuclear@1	1946 }
nuclear@1	1947 }
nuclear@1	1948 }
nuclear@1	1949 }
nuclear@1	1950 }
nuclear@1	1951 #endif
nuclear@1	1952
nuclear@1	1953 #if defined(PNG_READ_FILLER_SUPPORTED)
nuclear@1	1954 /* Add filler channel if we have RGB color */
nuclear@1	1955 void /* PRIVATE */
nuclear@1	1956 png_do_read_filler(png_row_infop row_info, png_bytep row,
nuclear@1	1957 png_uint_32 filler, png_uint_32 flags)
nuclear@1	1958 {
nuclear@1	1959 png_uint_32 i;
nuclear@1	1960 png_uint_32 row_width = row_info->width;
nuclear@1	1961
nuclear@1	1962 png_byte hi_filler = (png_byte)((filler>>8) & 0xff);
nuclear@1	1963 png_byte lo_filler = (png_byte)(filler & 0xff);
nuclear@1	1964
nuclear@1	1965 png_debug(1, "in png_do_read_filler\n");
nuclear@1	1966 if (
nuclear@1	1967 #if defined(PNG_USELESS_TESTS_SUPPORTED)
nuclear@1	1968 row != NULL && row_info != NULL &&
nuclear@1	1969 #endif
nuclear@1	1970 row_info->color_type == PNG_COLOR_TYPE_GRAY)
nuclear@1	1971 {
nuclear@1	1972 if (row_info->bit_depth == 8)
nuclear@1	1973 {
nuclear@1	1974 /* This changes the data from G to GX */
nuclear@1	1975 if (flags & PNG_FLAG_FILLER_AFTER)
nuclear@1	1976 {
nuclear@1	1977 png_bytep sp = row + (png_size_t)row_width;
nuclear@1	1978 png_bytep dp = sp + (png_size_t)row_width;
nuclear@1	1979 for (i = 1; i < row_width; i++)
nuclear@1	1980 {
nuclear@1	1981 *(--dp) = lo_filler;
nuclear@1	1982 (--dp) = (--sp);
nuclear@1	1983 }
nuclear@1	1984 *(--dp) = lo_filler;
nuclear@1	1985 row_info->channels = 2;
nuclear@1	1986 row_info->pixel_depth = 16;
nuclear@1	1987 row_info->rowbytes = row_width * 2;
nuclear@1	1988 }
nuclear@1	1989 /* This changes the data from G to XG */
nuclear@1	1990 else
nuclear@1	1991 {
nuclear@1	1992 png_bytep sp = row + (png_size_t)row_width;
nuclear@1	1993 png_bytep dp = sp + (png_size_t)row_width;
nuclear@1	1994 for (i = 0; i < row_width; i++)
nuclear@1	1995 {
nuclear@1	1996 (--dp) = (--sp);
nuclear@1	1997 *(--dp) = lo_filler;
nuclear@1	1998 }
nuclear@1	1999 row_info->channels = 2;
nuclear@1	2000 row_info->pixel_depth = 16;
nuclear@1	2001 row_info->rowbytes = row_width * 2;
nuclear@1	2002 }
nuclear@1	2003 }
nuclear@1	2004 else if (row_info->bit_depth == 16)
nuclear@1	2005 {
nuclear@1	2006 /* This changes the data from GG to GGXX */
nuclear@1	2007 if (flags & PNG_FLAG_FILLER_AFTER)
nuclear@1	2008 {
nuclear@1	2009 png_bytep sp = row + (png_size_t)row_width * 2;
nuclear@1	2010 png_bytep dp = sp + (png_size_t)row_width * 2;
nuclear@1	2011 for (i = 1; i < row_width; i++)
nuclear@1	2012 {
nuclear@1	2013 *(--dp) = hi_filler;
nuclear@1	2014 *(--dp) = lo_filler;
nuclear@1	2015 (--dp) = (--sp);
nuclear@1	2016 (--dp) = (--sp);
nuclear@1	2017 }
nuclear@1	2018 *(--dp) = hi_filler;
nuclear@1	2019 *(--dp) = lo_filler;
nuclear@1	2020 row_info->channels = 2;
nuclear@1	2021 row_info->pixel_depth = 32;
nuclear@1	2022 row_info->rowbytes = row_width * 4;
nuclear@1	2023 }
nuclear@1	2024 /* This changes the data from GG to XXGG */
nuclear@1	2025 else
nuclear@1	2026 {
nuclear@1	2027 png_bytep sp = row + (png_size_t)row_width * 2;
nuclear@1	2028 png_bytep dp = sp + (png_size_t)row_width * 2;
nuclear@1	2029 for (i = 0; i < row_width; i++)
nuclear@1	2030 {
nuclear@1	2031 (--dp) = (--sp);
nuclear@1	2032 (--dp) = (--sp);
nuclear@1	2033 *(--dp) = hi_filler;
nuclear@1	2034 *(--dp) = lo_filler;
nuclear@1	2035 }
nuclear@1	2036 row_info->channels = 2;
nuclear@1	2037 row_info->pixel_depth = 32;
nuclear@1	2038 row_info->rowbytes = row_width * 4;
nuclear@1	2039 }
nuclear@1	2040 }
nuclear@1	2041 } /* COLOR_TYPE == GRAY */
nuclear@1	2042 else if (row_info->color_type == PNG_COLOR_TYPE_RGB)
nuclear@1	2043 {
nuclear@1	2044 if (row_info->bit_depth == 8)
nuclear@1	2045 {
nuclear@1	2046 /* This changes the data from RGB to RGBX */
nuclear@1	2047 if (flags & PNG_FLAG_FILLER_AFTER)
nuclear@1	2048 {
nuclear@1	2049 png_bytep sp = row + (png_size_t)row_width * 3;
nuclear@1	2050 png_bytep dp = sp + (png_size_t)row_width;
nuclear@1	2051 for (i = 1; i < row_width; i++)
nuclear@1	2052 {
nuclear@1	2053 *(--dp) = lo_filler;
nuclear@1	2054 (--dp) = (--sp);
nuclear@1	2055 (--dp) = (--sp);
nuclear@1	2056 (--dp) = (--sp);
nuclear@1	2057 }
nuclear@1	2058 *(--dp) = lo_filler;
nuclear@1	2059 row_info->channels = 4;
nuclear@1	2060 row_info->pixel_depth = 32;
nuclear@1	2061 row_info->rowbytes = row_width * 4;
nuclear@1	2062 }
nuclear@1	2063 /* This changes the data from RGB to XRGB */
nuclear@1	2064 else
nuclear@1	2065 {
nuclear@1	2066 png_bytep sp = row + (png_size_t)row_width * 3;
nuclear@1	2067 png_bytep dp = sp + (png_size_t)row_width;
nuclear@1	2068 for (i = 0; i < row_width; i++)
nuclear@1	2069 {
nuclear@1	2070 (--dp) = (--sp);
nuclear@1	2071 (--dp) = (--sp);
nuclear@1	2072 (--dp) = (--sp);
nuclear@1	2073 *(--dp) = lo_filler;
nuclear@1	2074 }
nuclear@1	2075 row_info->channels = 4;
nuclear@1	2076 row_info->pixel_depth = 32;
nuclear@1	2077 row_info->rowbytes = row_width * 4;
nuclear@1	2078 }
nuclear@1	2079 }
nuclear@1	2080 else if (row_info->bit_depth == 16)
nuclear@1	2081 {
nuclear@1	2082 /* This changes the data from RRGGBB to RRGGBBXX */
nuclear@1	2083 if (flags & PNG_FLAG_FILLER_AFTER)
nuclear@1	2084 {
nuclear@1	2085 png_bytep sp = row + (png_size_t)row_width * 6;
nuclear@1	2086 png_bytep dp = sp + (png_size_t)row_width * 2;
nuclear@1	2087 for (i = 1; i < row_width; i++)
nuclear@1	2088 {
nuclear@1	2089 *(--dp) = hi_filler;
nuclear@1	2090 *(--dp) = lo_filler;
nuclear@1	2091 (--dp) = (--sp);
nuclear@1	2092 (--dp) = (--sp);
nuclear@1	2093 (--dp) = (--sp);
nuclear@1	2094 (--dp) = (--sp);
nuclear@1	2095 (--dp) = (--sp);
nuclear@1	2096 (--dp) = (--sp);
nuclear@1	2097 }
nuclear@1	2098 *(--dp) = hi_filler;
nuclear@1	2099 *(--dp) = lo_filler;
nuclear@1	2100 row_info->channels = 4;
nuclear@1	2101 row_info->pixel_depth = 64;
nuclear@1	2102 row_info->rowbytes = row_width * 8;
nuclear@1	2103 }
nuclear@1	2104 /* This changes the data from RRGGBB to XXRRGGBB */
nuclear@1	2105 else
nuclear@1	2106 {
nuclear@1	2107 png_bytep sp = row + (png_size_t)row_width * 6;
nuclear@1	2108 png_bytep dp = sp + (png_size_t)row_width * 2;
nuclear@1	2109 for (i = 0; i < row_width; i++)
nuclear@1	2110 {
nuclear@1	2111 (--dp) = (--sp);
nuclear@1	2112 (--dp) = (--sp);
nuclear@1	2113 (--dp) = (--sp);
nuclear@1	2114 (--dp) = (--sp);
nuclear@1	2115 (--dp) = (--sp);
nuclear@1	2116 (--dp) = (--sp);
nuclear@1	2117 *(--dp) = hi_filler;
nuclear@1	2118 *(--dp) = lo_filler;
nuclear@1	2119 }
nuclear@1	2120 row_info->channels = 4;
nuclear@1	2121 row_info->pixel_depth = 64;
nuclear@1	2122 row_info->rowbytes = row_width * 8;
nuclear@1	2123 }
nuclear@1	2124 }
nuclear@1	2125 } /* COLOR_TYPE == RGB */
nuclear@1	2126 }
nuclear@1	2127 #endif
nuclear@1	2128
nuclear@1	2129 #if defined(PNG_READ_GRAY_TO_RGB_SUPPORTED)
nuclear@1	2130 /* expand grayscale files to RGB, with or without alpha */
nuclear@1	2131 void /* PRIVATE */
nuclear@1	2132 png_do_gray_to_rgb(png_row_infop row_info, png_bytep row)
nuclear@1	2133 {
nuclear@1	2134 png_uint_32 i;
nuclear@1	2135 png_uint_32 row_width = row_info->width;
nuclear@1	2136
nuclear@1	2137 png_debug(1, "in png_do_gray_to_rgb\n");
nuclear@1	2138 if (row_info->bit_depth >= 8 &&
nuclear@1	2139 #if defined(PNG_USELESS_TESTS_SUPPORTED)
nuclear@1	2140 row != NULL && row_info != NULL &&
nuclear@1	2141 #endif
nuclear@1	2142 !(row_info->color_type & PNG_COLOR_MASK_COLOR))
nuclear@1	2143 {
nuclear@1	2144 if (row_info->color_type == PNG_COLOR_TYPE_GRAY)
nuclear@1	2145 {
nuclear@1	2146 if (row_info->bit_depth == 8)
nuclear@1	2147 {
nuclear@1	2148 png_bytep sp = row + (png_size_t)row_width - 1;
nuclear@1	2149 png_bytep dp = sp + (png_size_t)row_width * 2;
nuclear@1	2150 for (i = 0; i < row_width; i++)
nuclear@1	2151 {
nuclear@1	2152 (dp--) = sp;
nuclear@1	2153 (dp--) = sp;
nuclear@1	2154 (dp--) = (sp--);
nuclear@1	2155 }
nuclear@1	2156 }
nuclear@1	2157 else
nuclear@1	2158 {
nuclear@1	2159 png_bytep sp = row + (png_size_t)row_width * 2 - 1;
nuclear@1	2160 png_bytep dp = sp + (png_size_t)row_width * 4;
nuclear@1	2161 for (i = 0; i < row_width; i++)
nuclear@1	2162 {
nuclear@1	2163 (dp--) = sp;
nuclear@1	2164 (dp--) = (sp - 1);
nuclear@1	2165 (dp--) = sp;
nuclear@1	2166 (dp--) = (sp - 1);
nuclear@1	2167 (dp--) = (sp--);
nuclear@1	2168 (dp--) = (sp--);
nuclear@1	2169 }
nuclear@1	2170 }
nuclear@1	2171 }
nuclear@1	2172 else if (row_info->color_type == PNG_COLOR_TYPE_GRAY_ALPHA)
nuclear@1	2173 {
nuclear@1	2174 if (row_info->bit_depth == 8)
nuclear@1	2175 {
nuclear@1	2176 png_bytep sp = row + (png_size_t)row_width * 2 - 1;
nuclear@1	2177 png_bytep dp = sp + (png_size_t)row_width * 2;
nuclear@1	2178 for (i = 0; i < row_width; i++)
nuclear@1	2179 {
nuclear@1	2180 (dp--) = (sp--);
nuclear@1	2181 (dp--) = sp;
nuclear@1	2182 (dp--) = sp;
nuclear@1	2183 (dp--) = (sp--);
nuclear@1	2184 }
nuclear@1	2185 }
nuclear@1	2186 else
nuclear@1	2187 {
nuclear@1	2188 png_bytep sp = row + (png_size_t)row_width * 4 - 1;
nuclear@1	2189 png_bytep dp = sp + (png_size_t)row_width * 4;
nuclear@1	2190 for (i = 0; i < row_width; i++)
nuclear@1	2191 {
nuclear@1	2192 (dp--) = (sp--);
nuclear@1	2193 (dp--) = (sp--);
nuclear@1	2194 (dp--) = sp;
nuclear@1	2195 (dp--) = (sp - 1);
nuclear@1	2196 (dp--) = sp;
nuclear@1	2197 (dp--) = (sp - 1);
nuclear@1	2198 (dp--) = (sp--);
nuclear@1	2199 (dp--) = (sp--);
nuclear@1	2200 }
nuclear@1	2201 }
nuclear@1	2202 }
nuclear@1	2203 row_info->channels += (png_byte)2;
nuclear@1	2204 row_info->color_type \|= PNG_COLOR_MASK_COLOR;
nuclear@1	2205 row_info->pixel_depth = (png_byte)(row_info->channels *
nuclear@1	2206 row_info->bit_depth);
nuclear@1	2207 row_info->rowbytes = PNG_ROWBYTES(row_info->pixel_depth, row_width);
nuclear@1	2208 }
nuclear@1	2209 }
nuclear@1	2210 #endif
nuclear@1	2211
nuclear@1	2212 #if defined(PNG_READ_RGB_TO_GRAY_SUPPORTED)
nuclear@1	2213 /* reduce RGB files to grayscale, with or without alpha
nuclear@1	2214 * using the equation given in Poynton's ColorFAQ at
nuclear@1	2215 * <http://www.inforamp.net/~poynton/> (THIS LINK IS DEAD June 2008)
nuclear@1	2216 * New link:
nuclear@1	2217 * <http://www.poynton.com/notes/colour_and_gamma/>
nuclear@1	2218 * Charles Poynton poynton at poynton.com
nuclear@1	2219 *
nuclear@1	2220 * Y = 0.212671 * R + 0.715160 * G + 0.072169 * B
nuclear@1	2221 *
nuclear@1	2222 * We approximate this with
nuclear@1	2223 *
nuclear@1	2224 * Y = 0.21268 * R + 0.7151 * G + 0.07217 * B
nuclear@1	2225 *
nuclear@1	2226 * which can be expressed with integers as
nuclear@1	2227 *
nuclear@1	2228 * Y = (6969 * R + 23434 * G + 2365 * B)/32768
nuclear@1	2229 *
nuclear@1	2230 * The calculation is to be done in a linear colorspace.
nuclear@1	2231 *
nuclear@1	2232 * Other integer coefficents can be used via png_set_rgb_to_gray().
nuclear@1	2233 */
nuclear@1	2234 int /* PRIVATE */
nuclear@1	2235 png_do_rgb_to_gray(png_structp png_ptr, png_row_infop row_info, png_bytep row)
nuclear@1	2236
nuclear@1	2237 {
nuclear@1	2238 png_uint_32 i;
nuclear@1	2239
nuclear@1	2240 png_uint_32 row_width = row_info->width;
nuclear@1	2241 int rgb_error = 0;
nuclear@1	2242
nuclear@1	2243 png_debug(1, "in png_do_rgb_to_gray\n");
nuclear@1	2244 if (
nuclear@1	2245 #if defined(PNG_USELESS_TESTS_SUPPORTED)
nuclear@1	2246 row != NULL && row_info != NULL &&
nuclear@1	2247 #endif
nuclear@1	2248 (row_info->color_type & PNG_COLOR_MASK_COLOR))
nuclear@1	2249 {
nuclear@1	2250 png_uint_32 rc = png_ptr->rgb_to_gray_red_coeff;
nuclear@1	2251 png_uint_32 gc = png_ptr->rgb_to_gray_green_coeff;
nuclear@1	2252 png_uint_32 bc = png_ptr->rgb_to_gray_blue_coeff;
nuclear@1	2253
nuclear@1	2254 if (row_info->color_type == PNG_COLOR_TYPE_RGB)
nuclear@1	2255 {
nuclear@1	2256 if (row_info->bit_depth == 8)
nuclear@1	2257 {
nuclear@1	2258 #if defined(PNG_READ_GAMMA_SUPPORTED) \|\| defined(PNG_READ_BACKGROUND_SUPPORTED)
nuclear@1	2259 if (png_ptr->gamma_from_1 != NULL && png_ptr->gamma_to_1 != NULL)
nuclear@1	2260 {
nuclear@1	2261 png_bytep sp = row;
nuclear@1	2262 png_bytep dp = row;
nuclear@1	2263
nuclear@1	2264 for (i = 0; i < row_width; i++)
nuclear@1	2265 {
nuclear@1	2266 png_byte red = png_ptr->gamma_to_1[*(sp++)];
nuclear@1	2267 png_byte green = png_ptr->gamma_to_1[*(sp++)];
nuclear@1	2268 png_byte blue = png_ptr->gamma_to_1[*(sp++)];
nuclear@1	2269 if (red != green \|\| red != blue)
nuclear@1	2270 {
nuclear@1	2271 rgb_error \|= 1;
nuclear@1	2272 *(dp++) = png_ptr->gamma_from_1[
nuclear@1	2273 (rcred + gcgreen + bc*blue)>>15];
nuclear@1	2274 }
nuclear@1	2275 else
nuclear@1	2276 (dp++) = (sp - 1);
nuclear@1	2277 }
nuclear@1	2278 }
nuclear@1	2279 else
nuclear@1	2280 #endif
nuclear@1	2281 {
nuclear@1	2282 png_bytep sp = row;
nuclear@1	2283 png_bytep dp = row;
nuclear@1	2284 for (i = 0; i < row_width; i++)
nuclear@1	2285 {
nuclear@1	2286 png_byte red = *(sp++);
nuclear@1	2287 png_byte green = *(sp++);
nuclear@1	2288 png_byte blue = *(sp++);
nuclear@1	2289 if (red != green \|\| red != blue)
nuclear@1	2290 {
nuclear@1	2291 rgb_error \|= 1;
nuclear@1	2292 (dp++) = (png_byte)((rcred + gcgreen + bcblue)>>15);
nuclear@1	2293 }
nuclear@1	2294 else
nuclear@1	2295 (dp++) = (sp - 1);
nuclear@1	2296 }
nuclear@1	2297 }
nuclear@1	2298 }
nuclear@1	2299
nuclear@1	2300 else /* RGB bit_depth == 16 */
nuclear@1	2301 {
nuclear@1	2302 #if defined(PNG_READ_GAMMA_SUPPORTED) \|\| defined(PNG_READ_BACKGROUND_SUPPORTED)
nuclear@1	2303 if (png_ptr->gamma_16_to_1 != NULL &&
nuclear@1	2304 png_ptr->gamma_16_from_1 != NULL)
nuclear@1	2305 {
nuclear@1	2306 png_bytep sp = row;
nuclear@1	2307 png_bytep dp = row;
nuclear@1	2308 for (i = 0; i < row_width; i++)
nuclear@1	2309 {
nuclear@1	2310 png_uint_16 red, green, blue, w;
nuclear@1	2311
nuclear@1	2312 red = (png_uint_16)((((sp))<<8) \| (sp+1)); sp+=2;
nuclear@1	2313 green = (png_uint_16)((((sp))<<8) \| (sp+1)); sp+=2;
nuclear@1	2314 blue = (png_uint_16)((((sp))<<8) \| (sp+1)); sp+=2;
nuclear@1	2315
nuclear@1	2316 if (red == green && red == blue)
nuclear@1	2317 w = red;
nuclear@1	2318 else
nuclear@1	2319 {
nuclear@1	2320 png_uint_16 red_1 = png_ptr->gamma_16_to_1[(red&0xff) >>
nuclear@1	2321 png_ptr->gamma_shift][red>>8];
nuclear@1	2322 png_uint_16 green_1 = png_ptr->gamma_16_to_1[(green&0xff) >>
nuclear@1	2323 png_ptr->gamma_shift][green>>8];
nuclear@1	2324 png_uint_16 blue_1 = png_ptr->gamma_16_to_1[(blue&0xff) >>
nuclear@1	2325 png_ptr->gamma_shift][blue>>8];
nuclear@1	2326 png_uint_16 gray16 = (png_uint_16)((rcred_1 + gcgreen_1
nuclear@1	2327 + bc*blue_1)>>15);
nuclear@1	2328 w = png_ptr->gamma_16_from_1[(gray16&0xff) >>
nuclear@1	2329 png_ptr->gamma_shift][gray16 >> 8];
nuclear@1	2330 rgb_error \|= 1;
nuclear@1	2331 }
nuclear@1	2332
nuclear@1	2333 *(dp++) = (png_byte)((w>>8) & 0xff);
nuclear@1	2334 *(dp++) = (png_byte)(w & 0xff);
nuclear@1	2335 }
nuclear@1	2336 }
nuclear@1	2337 else
nuclear@1	2338 #endif
nuclear@1	2339 {
nuclear@1	2340 png_bytep sp = row;
nuclear@1	2341 png_bytep dp = row;
nuclear@1	2342 for (i = 0; i < row_width; i++)
nuclear@1	2343 {
nuclear@1	2344 png_uint_16 red, green, blue, gray16;
nuclear@1	2345
nuclear@1	2346 red = (png_uint_16)((((sp))<<8) \| (sp+1)); sp+=2;
nuclear@1	2347 green = (png_uint_16)((((sp))<<8) \| (sp+1)); sp+=2;
nuclear@1	2348 blue = (png_uint_16)((((sp))<<8) \| (sp+1)); sp+=2;
nuclear@1	2349
nuclear@1	2350 if (red != green \|\| red != blue)
nuclear@1	2351 rgb_error \|= 1;
nuclear@1	2352 gray16 = (png_uint_16)((rcred + gcgreen + bc*blue)>>15);
nuclear@1	2353 *(dp++) = (png_byte)((gray16>>8) & 0xff);
nuclear@1	2354 *(dp++) = (png_byte)(gray16 & 0xff);
nuclear@1	2355 }
nuclear@1	2356 }
nuclear@1	2357 }
nuclear@1	2358 }
nuclear@1	2359 if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA)
nuclear@1	2360 {
nuclear@1	2361 if (row_info->bit_depth == 8)
nuclear@1	2362 {
nuclear@1	2363 #if defined(PNG_READ_GAMMA_SUPPORTED) \|\| defined(PNG_READ_BACKGROUND_SUPPORTED)
nuclear@1	2364 if (png_ptr->gamma_from_1 != NULL && png_ptr->gamma_to_1 != NULL)
nuclear@1	2365 {
nuclear@1	2366 png_bytep sp = row;
nuclear@1	2367 png_bytep dp = row;
nuclear@1	2368 for (i = 0; i < row_width; i++)
nuclear@1	2369 {
nuclear@1	2370 png_byte red = png_ptr->gamma_to_1[*(sp++)];
nuclear@1	2371 png_byte green = png_ptr->gamma_to_1[*(sp++)];
nuclear@1	2372 png_byte blue = png_ptr->gamma_to_1[*(sp++)];
nuclear@1	2373 if (red != green \|\| red != blue)
nuclear@1	2374 rgb_error \|= 1;
nuclear@1	2375 *(dp++) = png_ptr->gamma_from_1
nuclear@1	2376 [(rcred + gcgreen + bc*blue)>>15];
nuclear@1	2377 (dp++) = (sp++); /* alpha */
nuclear@1	2378 }
nuclear@1	2379 }
nuclear@1	2380 else
nuclear@1	2381 #endif
nuclear@1	2382 {
nuclear@1	2383 png_bytep sp = row;
nuclear@1	2384 png_bytep dp = row;
nuclear@1	2385 for (i = 0; i < row_width; i++)
nuclear@1	2386 {
nuclear@1	2387 png_byte red = *(sp++);
nuclear@1	2388 png_byte green = *(sp++);
nuclear@1	2389 png_byte blue = *(sp++);
nuclear@1	2390 if (red != green \|\| red != blue)
nuclear@1	2391 rgb_error \|= 1;
nuclear@1	2392 (dp++) = (png_byte)((rcred + gcgreen + bcblue)>>15);
nuclear@1	2393 (dp++) = (sp++); /* alpha */
nuclear@1	2394 }
nuclear@1	2395 }
nuclear@1	2396 }
nuclear@1	2397 else /* RGBA bit_depth == 16 */
nuclear@1	2398 {
nuclear@1	2399 #if defined(PNG_READ_GAMMA_SUPPORTED) \|\| defined(PNG_READ_BACKGROUND_SUPPORTED)
nuclear@1	2400 if (png_ptr->gamma_16_to_1 != NULL &&
nuclear@1	2401 png_ptr->gamma_16_from_1 != NULL)
nuclear@1	2402 {
nuclear@1	2403 png_bytep sp = row;
nuclear@1	2404 png_bytep dp = row;
nuclear@1	2405 for (i = 0; i < row_width; i++)
nuclear@1	2406 {
nuclear@1	2407 png_uint_16 red, green, blue, w;
nuclear@1	2408
nuclear@1	2409 red = (png_uint_16)((((sp))<<8) \| (sp+1)); sp+=2;
nuclear@1	2410 green = (png_uint_16)((((sp))<<8) \| (sp+1)); sp+=2;
nuclear@1	2411 blue = (png_uint_16)((((sp))<<8) \| (sp+1)); sp+=2;
nuclear@1	2412
nuclear@1	2413 if (red == green && red == blue)
nuclear@1	2414 w = red;
nuclear@1	2415 else
nuclear@1	2416 {
nuclear@1	2417 png_uint_16 red_1 = png_ptr->gamma_16_to_1[(red&0xff) >>
nuclear@1	2418 png_ptr->gamma_shift][red>>8];
nuclear@1	2419 png_uint_16 green_1 = png_ptr->gamma_16_to_1[(green&0xff) >>
nuclear@1	2420 png_ptr->gamma_shift][green>>8];
nuclear@1	2421 png_uint_16 blue_1 = png_ptr->gamma_16_to_1[(blue&0xff) >>
nuclear@1	2422 png_ptr->gamma_shift][blue>>8];
nuclear@1	2423 png_uint_16 gray16 = (png_uint_16)((rc * red_1
nuclear@1	2424 + gc * green_1 + bc * blue_1)>>15);
nuclear@1	2425 w = png_ptr->gamma_16_from_1[(gray16&0xff) >>
nuclear@1	2426 png_ptr->gamma_shift][gray16 >> 8];
nuclear@1	2427 rgb_error \|= 1;
nuclear@1	2428 }
nuclear@1	2429
nuclear@1	2430 *(dp++) = (png_byte)((w>>8) & 0xff);
nuclear@1	2431 *(dp++) = (png_byte)(w & 0xff);
nuclear@1	2432 (dp++) = (sp++); /* alpha */
nuclear@1	2433 (dp++) = (sp++);
nuclear@1	2434 }
nuclear@1	2435 }
nuclear@1	2436 else
nuclear@1	2437 #endif
nuclear@1	2438 {
nuclear@1	2439 png_bytep sp = row;
nuclear@1	2440 png_bytep dp = row;
nuclear@1	2441 for (i = 0; i < row_width; i++)
nuclear@1	2442 {
nuclear@1	2443 png_uint_16 red, green, blue, gray16;
nuclear@1	2444 red = (png_uint_16)(((sp)<<8) \| (sp+1)); sp+=2;
nuclear@1	2445 green = (png_uint_16)(((sp)<<8) \| (sp+1)); sp+=2;
nuclear@1	2446 blue = (png_uint_16)(((sp)<<8) \| (sp+1)); sp+=2;
nuclear@1	2447 if (red != green \|\| red != blue)
nuclear@1	2448 rgb_error \|= 1;
nuclear@1	2449 gray16 = (png_uint_16)((rcred + gcgreen + bc*blue)>>15);
nuclear@1	2450 *(dp++) = (png_byte)((gray16>>8) & 0xff);
nuclear@1	2451 *(dp++) = (png_byte)(gray16 & 0xff);
nuclear@1	2452 (dp++) = (sp++); /* alpha */
nuclear@1	2453 (dp++) = (sp++);
nuclear@1	2454 }
nuclear@1	2455 }
nuclear@1	2456 }
nuclear@1	2457 }
nuclear@1	2458 row_info->channels -= (png_byte)2;
nuclear@1	2459 row_info->color_type &= ~PNG_COLOR_MASK_COLOR;
nuclear@1	2460 row_info->pixel_depth = (png_byte)(row_info->channels *
nuclear@1	2461 row_info->bit_depth);
nuclear@1	2462 row_info->rowbytes = PNG_ROWBYTES(row_info->pixel_depth, row_width);
nuclear@1	2463 }
nuclear@1	2464 return rgb_error;
nuclear@1	2465 }
nuclear@1	2466 #endif
nuclear@1	2467
nuclear@1	2468 /* Build a grayscale palette. Palette is assumed to be 1 << bit_depth
nuclear@1	2469 * large of png_color. This lets grayscale images be treated as
nuclear@1	2470 * paletted. Most useful for gamma correction and simplification
nuclear@1	2471 * of code.
nuclear@1	2472 */
nuclear@1	2473 void PNGAPI
nuclear@1	2474 png_build_grayscale_palette(int bit_depth, png_colorp palette)
nuclear@1	2475 {
nuclear@1	2476 int num_palette;
nuclear@1	2477 int color_inc;
nuclear@1	2478 int i;
nuclear@1	2479 int v;
nuclear@1	2480
nuclear@1	2481 png_debug(1, "in png_do_build_grayscale_palette\n");
nuclear@1	2482 if (palette == NULL)
nuclear@1	2483 return;
nuclear@1	2484
nuclear@1	2485 switch (bit_depth)
nuclear@1	2486 {
nuclear@1	2487 case 1:
nuclear@1	2488 num_palette = 2;
nuclear@1	2489 color_inc = 0xff;
nuclear@1	2490 break;
nuclear@1	2491 case 2:
nuclear@1	2492 num_palette = 4;
nuclear@1	2493 color_inc = 0x55;
nuclear@1	2494 break;
nuclear@1	2495 case 4:
nuclear@1	2496 num_palette = 16;
nuclear@1	2497 color_inc = 0x11;
nuclear@1	2498 break;
nuclear@1	2499 case 8:
nuclear@1	2500 num_palette = 256;
nuclear@1	2501 color_inc = 1;
nuclear@1	2502 break;
nuclear@1	2503 default:
nuclear@1	2504 num_palette = 0;
nuclear@1	2505 color_inc = 0;
nuclear@1	2506 break;
nuclear@1	2507 }
nuclear@1	2508
nuclear@1	2509 for (i = 0, v = 0; i < num_palette; i++, v += color_inc)
nuclear@1	2510 {
nuclear@1	2511 palette[i].red = (png_byte)v;
nuclear@1	2512 palette[i].green = (png_byte)v;
nuclear@1	2513 palette[i].blue = (png_byte)v;
nuclear@1	2514 }
nuclear@1	2515 }
nuclear@1	2516
nuclear@1	2517 /* This function is currently unused. Do we really need it? */
nuclear@1	2518 #if defined(PNG_READ_DITHER_SUPPORTED) && defined(PNG_CORRECT_PALETTE_SUPPORTED)
nuclear@1	2519 void /* PRIVATE */
nuclear@1	2520 png_correct_palette(png_structp png_ptr, png_colorp palette,
nuclear@1	2521 int num_palette)
nuclear@1	2522 {
nuclear@1	2523 png_debug(1, "in png_correct_palette\n");
nuclear@1	2524 #if defined(PNG_READ_BACKGROUND_SUPPORTED) && \
nuclear@1	2525 defined(PNG_READ_GAMMA_SUPPORTED) && defined(PNG_FLOATING_POINT_SUPPORTED)
nuclear@1	2526 if (png_ptr->transformations & (PNG_GAMMA \| PNG_BACKGROUND))
nuclear@1	2527 {
nuclear@1	2528 png_color back, back_1;
nuclear@1	2529
nuclear@1	2530 if (png_ptr->background_gamma_type == PNG_BACKGROUND_GAMMA_FILE)
nuclear@1	2531 {
nuclear@1	2532 back.red = png_ptr->gamma_table[png_ptr->background.red];
nuclear@1	2533 back.green = png_ptr->gamma_table[png_ptr->background.green];
nuclear@1	2534 back.blue = png_ptr->gamma_table[png_ptr->background.blue];
nuclear@1	2535
nuclear@1	2536 back_1.red = png_ptr->gamma_to_1[png_ptr->background.red];
nuclear@1	2537 back_1.green = png_ptr->gamma_to_1[png_ptr->background.green];
nuclear@1	2538 back_1.blue = png_ptr->gamma_to_1[png_ptr->background.blue];
nuclear@1	2539 }
nuclear@1	2540 else
nuclear@1	2541 {
nuclear@1	2542 double g;
nuclear@1	2543
nuclear@1	2544 g = 1.0 / (png_ptr->background_gamma * png_ptr->screen_gamma);
nuclear@1	2545
nuclear@1	2546 if (png_ptr->background_gamma_type == PNG_BACKGROUND_GAMMA_SCREEN \|\|
nuclear@1	2547 fabs(g - 1.0) < PNG_GAMMA_THRESHOLD)
nuclear@1	2548 {
nuclear@1	2549 back.red = png_ptr->background.red;
nuclear@1	2550 back.green = png_ptr->background.green;
nuclear@1	2551 back.blue = png_ptr->background.blue;
nuclear@1	2552 }
nuclear@1	2553 else
nuclear@1	2554 {
nuclear@1	2555 back.red =
nuclear@1	2556 (png_byte)(pow((double)png_ptr->background.red/255, g) *
nuclear@1	2557 255.0 + 0.5);
nuclear@1	2558 back.green =
nuclear@1	2559 (png_byte)(pow((double)png_ptr->background.green/255, g) *
nuclear@1	2560 255.0 + 0.5);
nuclear@1	2561 back.blue =
nuclear@1	2562 (png_byte)(pow((double)png_ptr->background.blue/255, g) *
nuclear@1	2563 255.0 + 0.5);
nuclear@1	2564 }
nuclear@1	2565
nuclear@1	2566 g = 1.0 / png_ptr->background_gamma;
nuclear@1	2567
nuclear@1	2568 back_1.red =
nuclear@1	2569 (png_byte)(pow((double)png_ptr->background.red/255, g) *
nuclear@1	2570 255.0 + 0.5);
nuclear@1	2571 back_1.green =
nuclear@1	2572 (png_byte)(pow((double)png_ptr->background.green/255, g) *
nuclear@1	2573 255.0 + 0.5);
nuclear@1	2574 back_1.blue =
nuclear@1	2575 (png_byte)(pow((double)png_ptr->background.blue/255, g) *
nuclear@1	2576 255.0 + 0.5);
nuclear@1	2577 }
nuclear@1	2578
nuclear@1	2579 if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
nuclear@1	2580 {
nuclear@1	2581 png_uint_32 i;
nuclear@1	2582
nuclear@1	2583 for (i = 0; i < (png_uint_32)num_palette; i++)
nuclear@1	2584 {
nuclear@1	2585 if (i < png_ptr->num_trans && png_ptr->trans[i] == 0)
nuclear@1	2586 {
nuclear@1	2587 palette[i] = back;
nuclear@1	2588 }
nuclear@1	2589 else if (i < png_ptr->num_trans && png_ptr->trans[i] != 0xff)
nuclear@1	2590 {
nuclear@1	2591 png_byte v, w;
nuclear@1	2592
nuclear@1	2593 v = png_ptr->gamma_to_1[png_ptr->palette[i].red];
nuclear@1	2594 png_composite(w, v, png_ptr->trans[i], back_1.red);
nuclear@1	2595 palette[i].red = png_ptr->gamma_from_1[w];
nuclear@1	2596
nuclear@1	2597 v = png_ptr->gamma_to_1[png_ptr->palette[i].green];
nuclear@1	2598 png_composite(w, v, png_ptr->trans[i], back_1.green);
nuclear@1	2599 palette[i].green = png_ptr->gamma_from_1[w];
nuclear@1	2600
nuclear@1	2601 v = png_ptr->gamma_to_1[png_ptr->palette[i].blue];
nuclear@1	2602 png_composite(w, v, png_ptr->trans[i], back_1.blue);
nuclear@1	2603 palette[i].blue = png_ptr->gamma_from_1[w];
nuclear@1	2604 }
nuclear@1	2605 else
nuclear@1	2606 {
nuclear@1	2607 palette[i].red = png_ptr->gamma_table[palette[i].red];
nuclear@1	2608 palette[i].green = png_ptr->gamma_table[palette[i].green];
nuclear@1	2609 palette[i].blue = png_ptr->gamma_table[palette[i].blue];
nuclear@1	2610 }
nuclear@1	2611 }
nuclear@1	2612 }
nuclear@1	2613 else
nuclear@1	2614 {
nuclear@1	2615 int i;
nuclear@1	2616
nuclear@1	2617 for (i = 0; i < num_palette; i++)
nuclear@1	2618 {
nuclear@1	2619 if (palette[i].red == (png_byte)png_ptr->trans_values.gray)
nuclear@1	2620 {
nuclear@1	2621 palette[i] = back;
nuclear@1	2622 }
nuclear@1	2623 else
nuclear@1	2624 {
nuclear@1	2625 palette[i].red = png_ptr->gamma_table[palette[i].red];
nuclear@1	2626 palette[i].green = png_ptr->gamma_table[palette[i].green];
nuclear@1	2627 palette[i].blue = png_ptr->gamma_table[palette[i].blue];
nuclear@1	2628 }
nuclear@1	2629 }
nuclear@1	2630 }
nuclear@1	2631 }
nuclear@1	2632 else
nuclear@1	2633 #endif
nuclear@1	2634 #if defined(PNG_READ_GAMMA_SUPPORTED)
nuclear@1	2635 if (png_ptr->transformations & PNG_GAMMA)
nuclear@1	2636 {
nuclear@1	2637 int i;
nuclear@1	2638
nuclear@1	2639 for (i = 0; i < num_palette; i++)
nuclear@1	2640 {
nuclear@1	2641 palette[i].red = png_ptr->gamma_table[palette[i].red];
nuclear@1	2642 palette[i].green = png_ptr->gamma_table[palette[i].green];
nuclear@1	2643 palette[i].blue = png_ptr->gamma_table[palette[i].blue];
nuclear@1	2644 }
nuclear@1	2645 }
nuclear@1	2646 #if defined(PNG_READ_BACKGROUND_SUPPORTED)
nuclear@1	2647 else
nuclear@1	2648 #endif
nuclear@1	2649 #endif
nuclear@1	2650 #if defined(PNG_READ_BACKGROUND_SUPPORTED)
nuclear@1	2651 if (png_ptr->transformations & PNG_BACKGROUND)
nuclear@1	2652 {
nuclear@1	2653 if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
nuclear@1	2654 {
nuclear@1	2655 png_color back;
nuclear@1	2656
nuclear@1	2657 back.red = (png_byte)png_ptr->background.red;
nuclear@1	2658 back.green = (png_byte)png_ptr->background.green;
nuclear@1	2659 back.blue = (png_byte)png_ptr->background.blue;
nuclear@1	2660
nuclear@1	2661 for (i = 0; i < (int)png_ptr->num_trans; i++)
nuclear@1	2662 {
nuclear@1	2663 if (png_ptr->trans[i] == 0)
nuclear@1	2664 {
nuclear@1	2665 palette[i].red = back.red;
nuclear@1	2666 palette[i].green = back.green;
nuclear@1	2667 palette[i].blue = back.blue;
nuclear@1	2668 }
nuclear@1	2669 else if (png_ptr->trans[i] != 0xff)
nuclear@1	2670 {
nuclear@1	2671 png_composite(palette[i].red, png_ptr->palette[i].red,
nuclear@1	2672 png_ptr->trans[i], back.red);
nuclear@1	2673 png_composite(palette[i].green, png_ptr->palette[i].green,
nuclear@1	2674 png_ptr->trans[i], back.green);
nuclear@1	2675 png_composite(palette[i].blue, png_ptr->palette[i].blue,
nuclear@1	2676 png_ptr->trans[i], back.blue);
nuclear@1	2677 }
nuclear@1	2678 }
nuclear@1	2679 }
nuclear@1	2680 else /* assume grayscale palette (what else could it be?) */
nuclear@1	2681 {
nuclear@1	2682 int i;
nuclear@1	2683
nuclear@1	2684 for (i = 0; i < num_palette; i++)
nuclear@1	2685 {
nuclear@1	2686 if (i == (png_byte)png_ptr->trans_values.gray)
nuclear@1	2687 {
nuclear@1	2688 palette[i].red = (png_byte)png_ptr->background.red;
nuclear@1	2689 palette[i].green = (png_byte)png_ptr->background.green;
nuclear@1	2690 palette[i].blue = (png_byte)png_ptr->background.blue;
nuclear@1	2691 }
nuclear@1	2692 }
nuclear@1	2693 }
nuclear@1	2694 }
nuclear@1	2695 #endif
nuclear@1	2696 }
nuclear@1	2697 #endif
nuclear@1	2698
nuclear@1	2699 #if defined(PNG_READ_BACKGROUND_SUPPORTED)
nuclear@1	2700 /* Replace any alpha or transparency with the supplied background color.
nuclear@1	2701 * "background" is already in the screen gamma, while "background_1" is
nuclear@1	2702 * at a gamma of 1.0. Paletted files have already been taken care of.
nuclear@1	2703 */
nuclear@1	2704 void /* PRIVATE */
nuclear@1	2705 png_do_background(png_row_infop row_info, png_bytep row,
nuclear@1	2706 png_color_16p trans_values, png_color_16p background
nuclear@1	2707 #if defined(PNG_READ_GAMMA_SUPPORTED)
nuclear@1	2708 , png_color_16p background_1,
nuclear@1	2709 png_bytep gamma_table, png_bytep gamma_from_1, png_bytep gamma_to_1,
nuclear@1	2710 png_uint_16pp gamma_16, png_uint_16pp gamma_16_from_1,
nuclear@1	2711 png_uint_16pp gamma_16_to_1, int gamma_shift
nuclear@1	2712 #endif
nuclear@1	2713 )
nuclear@1	2714 {
nuclear@1	2715 png_bytep sp, dp;
nuclear@1	2716 png_uint_32 i;
nuclear@1	2717 png_uint_32 row_width=row_info->width;
nuclear@1	2718 int shift;
nuclear@1	2719
nuclear@1	2720 png_debug(1, "in png_do_background\n");
nuclear@1	2721 if (background != NULL &&
nuclear@1	2722 #if defined(PNG_USELESS_TESTS_SUPPORTED)
nuclear@1	2723 row != NULL && row_info != NULL &&
nuclear@1	2724 #endif
nuclear@1	2725 (!(row_info->color_type & PNG_COLOR_MASK_ALPHA) \|\|
nuclear@1	2726 (row_info->color_type != PNG_COLOR_TYPE_PALETTE && trans_values)))
nuclear@1	2727 {
nuclear@1	2728 switch (row_info->color_type)
nuclear@1	2729 {
nuclear@1	2730 case PNG_COLOR_TYPE_GRAY:
nuclear@1	2731 {
nuclear@1	2732 switch (row_info->bit_depth)
nuclear@1	2733 {
nuclear@1	2734 case 1:
nuclear@1	2735 {
nuclear@1	2736 sp = row;
nuclear@1	2737 shift = 7;
nuclear@1	2738 for (i = 0; i < row_width; i++)
nuclear@1	2739 {
nuclear@1	2740 if ((png_uint_16)((*sp >> shift) & 0x01)
nuclear@1	2741 == trans_values->gray)
nuclear@1	2742 {
nuclear@1	2743 *sp &= (png_byte)((0x7f7f >> (7 - shift)) & 0xff);
nuclear@1	2744 *sp \|= (png_byte)(background->gray << shift);
nuclear@1	2745 }
nuclear@1	2746 if (!shift)
nuclear@1	2747 {
nuclear@1	2748 shift = 7;
nuclear@1	2749 sp++;
nuclear@1	2750 }
nuclear@1	2751 else
nuclear@1	2752 shift--;
nuclear@1	2753 }
nuclear@1	2754 break;
nuclear@1	2755 }
nuclear@1	2756 case 2:
nuclear@1	2757 {
nuclear@1	2758 #if defined(PNG_READ_GAMMA_SUPPORTED)
nuclear@1	2759 if (gamma_table != NULL)
nuclear@1	2760 {
nuclear@1	2761 sp = row;
nuclear@1	2762 shift = 6;
nuclear@1	2763 for (i = 0; i < row_width; i++)
nuclear@1	2764 {
nuclear@1	2765 if ((png_uint_16)((*sp >> shift) & 0x03)
nuclear@1	2766 == trans_values->gray)
nuclear@1	2767 {
nuclear@1	2768 *sp &= (png_byte)((0x3f3f >> (6 - shift)) & 0xff);
nuclear@1	2769 *sp \|= (png_byte)(background->gray << shift);
nuclear@1	2770 }
nuclear@1	2771 else
nuclear@1	2772 {
nuclear@1	2773 png_byte p = (png_byte)((*sp >> shift) & 0x03);
nuclear@1	2774 png_byte g = (png_byte)((gamma_table [p \| (p << 2) \|
nuclear@1	2775 (p << 4) \| (p << 6)] >> 6) & 0x03);
nuclear@1	2776 *sp &= (png_byte)((0x3f3f >> (6 - shift)) & 0xff);
nuclear@1	2777 *sp \|= (png_byte)(g << shift);
nuclear@1	2778 }
nuclear@1	2779 if (!shift)
nuclear@1	2780 {
nuclear@1	2781 shift = 6;
nuclear@1	2782 sp++;
nuclear@1	2783 }
nuclear@1	2784 else
nuclear@1	2785 shift -= 2;
nuclear@1	2786 }
nuclear@1	2787 }
nuclear@1	2788 else
nuclear@1	2789 #endif
nuclear@1	2790 {
nuclear@1	2791 sp = row;
nuclear@1	2792 shift = 6;
nuclear@1	2793 for (i = 0; i < row_width; i++)
nuclear@1	2794 {
nuclear@1	2795 if ((png_uint_16)((*sp >> shift) & 0x03)
nuclear@1	2796 == trans_values->gray)
nuclear@1	2797 {
nuclear@1	2798 *sp &= (png_byte)((0x3f3f >> (6 - shift)) & 0xff);
nuclear@1	2799 *sp \|= (png_byte)(background->gray << shift);
nuclear@1	2800 }
nuclear@1	2801 if (!shift)
nuclear@1	2802 {
nuclear@1	2803 shift = 6;
nuclear@1	2804 sp++;
nuclear@1	2805 }
nuclear@1	2806 else
nuclear@1	2807 shift -= 2;
nuclear@1	2808 }
nuclear@1	2809 }
nuclear@1	2810 break;
nuclear@1	2811 }
nuclear@1	2812 case 4:
nuclear@1	2813 {
nuclear@1	2814 #if defined(PNG_READ_GAMMA_SUPPORTED)
nuclear@1	2815 if (gamma_table != NULL)
nuclear@1	2816 {
nuclear@1	2817 sp = row;
nuclear@1	2818 shift = 4;
nuclear@1	2819 for (i = 0; i < row_width; i++)
nuclear@1	2820 {
nuclear@1	2821 if ((png_uint_16)((*sp >> shift) & 0x0f)
nuclear@1	2822 == trans_values->gray)
nuclear@1	2823 {
nuclear@1	2824 *sp &= (png_byte)((0xf0f >> (4 - shift)) & 0xff);
nuclear@1	2825 *sp \|= (png_byte)(background->gray << shift);
nuclear@1	2826 }
nuclear@1	2827 else
nuclear@1	2828 {
nuclear@1	2829 png_byte p = (png_byte)((*sp >> shift) & 0x0f);
nuclear@1	2830 png_byte g = (png_byte)((gamma_table[p \|
nuclear@1	2831 (p << 4)] >> 4) & 0x0f);
nuclear@1	2832 *sp &= (png_byte)((0xf0f >> (4 - shift)) & 0xff);
nuclear@1	2833 *sp \|= (png_byte)(g << shift);
nuclear@1	2834 }
nuclear@1	2835 if (!shift)
nuclear@1	2836 {
nuclear@1	2837 shift = 4;
nuclear@1	2838 sp++;
nuclear@1	2839 }
nuclear@1	2840 else
nuclear@1	2841 shift -= 4;
nuclear@1	2842 }
nuclear@1	2843 }
nuclear@1	2844 else
nuclear@1	2845 #endif
nuclear@1	2846 {
nuclear@1	2847 sp = row;
nuclear@1	2848 shift = 4;
nuclear@1	2849 for (i = 0; i < row_width; i++)
nuclear@1	2850 {
nuclear@1	2851 if ((png_uint_16)((*sp >> shift) & 0x0f)
nuclear@1	2852 == trans_values->gray)
nuclear@1	2853 {
nuclear@1	2854 *sp &= (png_byte)((0xf0f >> (4 - shift)) & 0xff);
nuclear@1	2855 *sp \|= (png_byte)(background->gray << shift);
nuclear@1	2856 }
nuclear@1	2857 if (!shift)
nuclear@1	2858 {
nuclear@1	2859 shift = 4;
nuclear@1	2860 sp++;
nuclear@1	2861 }
nuclear@1	2862 else
nuclear@1	2863 shift -= 4;
nuclear@1	2864 }
nuclear@1	2865 }
nuclear@1	2866 break;
nuclear@1	2867 }
nuclear@1	2868 case 8:
nuclear@1	2869 {
nuclear@1	2870 #if defined(PNG_READ_GAMMA_SUPPORTED)
nuclear@1	2871 if (gamma_table != NULL)
nuclear@1	2872 {
nuclear@1	2873 sp = row;
nuclear@1	2874 for (i = 0; i < row_width; i++, sp++)
nuclear@1	2875 {
nuclear@1	2876 if (*sp == trans_values->gray)
nuclear@1	2877 {
nuclear@1	2878 *sp = (png_byte)background->gray;
nuclear@1	2879 }
nuclear@1	2880 else
nuclear@1	2881 {
nuclear@1	2882 sp = gamma_table[sp];
nuclear@1	2883 }
nuclear@1	2884 }
nuclear@1	2885 }
nuclear@1	2886 else
nuclear@1	2887 #endif
nuclear@1	2888 {
nuclear@1	2889 sp = row;
nuclear@1	2890 for (i = 0; i < row_width; i++, sp++)
nuclear@1	2891 {
nuclear@1	2892 if (*sp == trans_values->gray)
nuclear@1	2893 {
nuclear@1	2894 *sp = (png_byte)background->gray;
nuclear@1	2895 }
nuclear@1	2896 }
nuclear@1	2897 }
nuclear@1	2898 break;
nuclear@1	2899 }
nuclear@1	2900 case 16:
nuclear@1	2901 {
nuclear@1	2902 #if defined(PNG_READ_GAMMA_SUPPORTED)
nuclear@1	2903 if (gamma_16 != NULL)
nuclear@1	2904 {
nuclear@1	2905 sp = row;
nuclear@1	2906 for (i = 0; i < row_width; i++, sp += 2)
nuclear@1	2907 {
nuclear@1	2908 png_uint_16 v;
nuclear@1	2909
nuclear@1	2910 v = (png_uint_16)(((sp) << 8) + (sp + 1));
nuclear@1	2911 if (v == trans_values->gray)
nuclear@1	2912 {
nuclear@1	2913 /* background is already in screen gamma */
nuclear@1	2914 *sp = (png_byte)((background->gray >> 8) & 0xff);
nuclear@1	2915 *(sp + 1) = (png_byte)(background->gray & 0xff);
nuclear@1	2916 }
nuclear@1	2917 else
nuclear@1	2918 {
nuclear@1	2919 v = gamma_16[(sp + 1) >> gamma_shift][sp];
nuclear@1	2920 *sp = (png_byte)((v >> 8) & 0xff);
nuclear@1	2921 *(sp + 1) = (png_byte)(v & 0xff);
nuclear@1	2922 }
nuclear@1	2923 }
nuclear@1	2924 }
nuclear@1	2925 else
nuclear@1	2926 #endif
nuclear@1	2927 {
nuclear@1	2928 sp = row;
nuclear@1	2929 for (i = 0; i < row_width; i++, sp += 2)
nuclear@1	2930 {
nuclear@1	2931 png_uint_16 v;
nuclear@1	2932
nuclear@1	2933 v = (png_uint_16)(((sp) << 8) + (sp + 1));
nuclear@1	2934 if (v == trans_values->gray)
nuclear@1	2935 {
nuclear@1	2936 *sp = (png_byte)((background->gray >> 8) & 0xff);
nuclear@1	2937 *(sp + 1) = (png_byte)(background->gray & 0xff);
nuclear@1	2938 }
nuclear@1	2939 }
nuclear@1	2940 }
nuclear@1	2941 break;
nuclear@1	2942 }
nuclear@1	2943 }
nuclear@1	2944 break;
nuclear@1	2945 }
nuclear@1	2946 case PNG_COLOR_TYPE_RGB:
nuclear@1	2947 {
nuclear@1	2948 if (row_info->bit_depth == 8)
nuclear@1	2949 {
nuclear@1	2950 #if defined(PNG_READ_GAMMA_SUPPORTED)
nuclear@1	2951 if (gamma_table != NULL)
nuclear@1	2952 {
nuclear@1	2953 sp = row;
nuclear@1	2954 for (i = 0; i < row_width; i++, sp += 3)
nuclear@1	2955 {
nuclear@1	2956 if (*sp == trans_values->red &&
nuclear@1	2957 *(sp + 1) == trans_values->green &&
nuclear@1	2958 *(sp + 2) == trans_values->blue)
nuclear@1	2959 {
nuclear@1	2960 *sp = (png_byte)background->red;
nuclear@1	2961 *(sp + 1) = (png_byte)background->green;
nuclear@1	2962 *(sp + 2) = (png_byte)background->blue;
nuclear@1	2963 }
nuclear@1	2964 else
nuclear@1	2965 {
nuclear@1	2966 sp = gamma_table[sp];
nuclear@1	2967 (sp + 1) = gamma_table[(sp + 1)];
nuclear@1	2968 (sp + 2) = gamma_table[(sp + 2)];
nuclear@1	2969 }
nuclear@1	2970 }
nuclear@1	2971 }
nuclear@1	2972 else
nuclear@1	2973 #endif
nuclear@1	2974 {
nuclear@1	2975 sp = row;
nuclear@1	2976 for (i = 0; i < row_width; i++, sp += 3)
nuclear@1	2977 {
nuclear@1	2978 if (*sp == trans_values->red &&
nuclear@1	2979 *(sp + 1) == trans_values->green &&
nuclear@1	2980 *(sp + 2) == trans_values->blue)
nuclear@1	2981 {
nuclear@1	2982 *sp = (png_byte)background->red;
nuclear@1	2983 *(sp + 1) = (png_byte)background->green;
nuclear@1	2984 *(sp + 2) = (png_byte)background->blue;
nuclear@1	2985 }
nuclear@1	2986 }
nuclear@1	2987 }
nuclear@1	2988 }
nuclear@1	2989 else /* if (row_info->bit_depth == 16) */
nuclear@1	2990 {
nuclear@1	2991 #if defined(PNG_READ_GAMMA_SUPPORTED)
nuclear@1	2992 if (gamma_16 != NULL)
nuclear@1	2993 {
nuclear@1	2994 sp = row;
nuclear@1	2995 for (i = 0; i < row_width; i++, sp += 6)
nuclear@1	2996 {
nuclear@1	2997 png_uint_16 r = (png_uint_16)(((sp) << 8) + (sp + 1));
nuclear@1	2998 png_uint_16 g = (png_uint_16)((((sp+2)) << 8) + (sp+3));
nuclear@1	2999 png_uint_16 b = (png_uint_16)((((sp+4)) << 8) + (sp+5));
nuclear@1	3000 if (r == trans_values->red && g == trans_values->green &&
nuclear@1	3001 b == trans_values->blue)
nuclear@1	3002 {
nuclear@1	3003 /* background is already in screen gamma */
nuclear@1	3004 *sp = (png_byte)((background->red >> 8) & 0xff);
nuclear@1	3005 *(sp + 1) = (png_byte)(background->red & 0xff);
nuclear@1	3006 *(sp + 2) = (png_byte)((background->green >> 8) & 0xff);
nuclear@1	3007 *(sp + 3) = (png_byte)(background->green & 0xff);
nuclear@1	3008 *(sp + 4) = (png_byte)((background->blue >> 8) & 0xff);
nuclear@1	3009 *(sp + 5) = (png_byte)(background->blue & 0xff);
nuclear@1	3010 }
nuclear@1	3011 else
nuclear@1	3012 {
nuclear@1	3013 png_uint_16 v = gamma_16[(sp + 1) >> gamma_shift][sp];
nuclear@1	3014 *sp = (png_byte)((v >> 8) & 0xff);
nuclear@1	3015 *(sp + 1) = (png_byte)(v & 0xff);
nuclear@1	3016 v = gamma_16[(sp + 3) >> gamma_shift][(sp + 2)];
nuclear@1	3017 *(sp + 2) = (png_byte)((v >> 8) & 0xff);
nuclear@1	3018 *(sp + 3) = (png_byte)(v & 0xff);
nuclear@1	3019 v = gamma_16[(sp + 5) >> gamma_shift][(sp + 4)];
nuclear@1	3020 *(sp + 4) = (png_byte)((v >> 8) & 0xff);
nuclear@1	3021 *(sp + 5) = (png_byte)(v & 0xff);
nuclear@1	3022 }
nuclear@1	3023 }
nuclear@1	3024 }
nuclear@1	3025 else
nuclear@1	3026 #endif
nuclear@1	3027 {
nuclear@1	3028 sp = row;
nuclear@1	3029 for (i = 0; i < row_width; i++, sp += 6)
nuclear@1	3030 {
nuclear@1	3031 png_uint_16 r = (png_uint_16)(((sp) << 8) + (sp+1));
nuclear@1	3032 png_uint_16 g = (png_uint_16)((((sp+2)) << 8) + (sp+3));
nuclear@1	3033 png_uint_16 b = (png_uint_16)((((sp+4)) << 8) + (sp+5));
nuclear@1	3034
nuclear@1	3035 if (r == trans_values->red && g == trans_values->green &&
nuclear@1	3036 b == trans_values->blue)
nuclear@1	3037 {
nuclear@1	3038 *sp = (png_byte)((background->red >> 8) & 0xff);
nuclear@1	3039 *(sp + 1) = (png_byte)(background->red & 0xff);
nuclear@1	3040 *(sp + 2) = (png_byte)((background->green >> 8) & 0xff);
nuclear@1	3041 *(sp + 3) = (png_byte)(background->green & 0xff);
nuclear@1	3042 *(sp + 4) = (png_byte)((background->blue >> 8) & 0xff);
nuclear@1	3043 *(sp + 5) = (png_byte)(background->blue & 0xff);
nuclear@1	3044 }
nuclear@1	3045 }
nuclear@1	3046 }
nuclear@1	3047 }
nuclear@1	3048 break;
nuclear@1	3049 }
nuclear@1	3050 case PNG_COLOR_TYPE_GRAY_ALPHA:
nuclear@1	3051 {
nuclear@1	3052 if (row_info->bit_depth == 8)
nuclear@1	3053 {
nuclear@1	3054 #if defined(PNG_READ_GAMMA_SUPPORTED)
nuclear@1	3055 if (gamma_to_1 != NULL && gamma_from_1 != NULL &&
nuclear@1	3056 gamma_table != NULL)
nuclear@1	3057 {
nuclear@1	3058 sp = row;
nuclear@1	3059 dp = row;
nuclear@1	3060 for (i = 0; i < row_width; i++, sp += 2, dp++)
nuclear@1	3061 {
nuclear@1	3062 png_uint_16 a = *(sp + 1);
nuclear@1	3063
nuclear@1	3064 if (a == 0xff)
nuclear@1	3065 {
nuclear@1	3066 dp = gamma_table[sp];
nuclear@1	3067 }
nuclear@1	3068 else if (a == 0)
nuclear@1	3069 {
nuclear@1	3070 /* background is already in screen gamma */
nuclear@1	3071 *dp = (png_byte)background->gray;
nuclear@1	3072 }
nuclear@1	3073 else
nuclear@1	3074 {
nuclear@1	3075 png_byte v, w;
nuclear@1	3076
nuclear@1	3077 v = gamma_to_1[*sp];
nuclear@1	3078 png_composite(w, v, a, background_1->gray);
nuclear@1	3079 *dp = gamma_from_1[w];
nuclear@1	3080 }
nuclear@1	3081 }
nuclear@1	3082 }
nuclear@1	3083 else
nuclear@1	3084 #endif
nuclear@1	3085 {
nuclear@1	3086 sp = row;
nuclear@1	3087 dp = row;
nuclear@1	3088 for (i = 0; i < row_width; i++, sp += 2, dp++)
nuclear@1	3089 {
nuclear@1	3090 png_byte a = *(sp + 1);
nuclear@1	3091
nuclear@1	3092 if (a == 0xff)
nuclear@1	3093 {
nuclear@1	3094 dp = sp;
nuclear@1	3095 }
nuclear@1	3096 #if defined(PNG_READ_GAMMA_SUPPORTED)
nuclear@1	3097 else if (a == 0)
nuclear@1	3098 {
nuclear@1	3099 *dp = (png_byte)background->gray;
nuclear@1	3100 }
nuclear@1	3101 else
nuclear@1	3102 {
nuclear@1	3103 png_composite(dp, sp, a, background_1->gray);
nuclear@1	3104 }
nuclear@1	3105 #else
nuclear@1	3106 *dp = (png_byte)background->gray;
nuclear@1	3107 #endif
nuclear@1	3108 }
nuclear@1	3109 }
nuclear@1	3110 }
nuclear@1	3111 else /* if (png_ptr->bit_depth == 16) */
nuclear@1	3112 {
nuclear@1	3113 #if defined(PNG_READ_GAMMA_SUPPORTED)
nuclear@1	3114 if (gamma_16 != NULL && gamma_16_from_1 != NULL &&
nuclear@1	3115 gamma_16_to_1 != NULL)
nuclear@1	3116 {
nuclear@1	3117 sp = row;
nuclear@1	3118 dp = row;
nuclear@1	3119 for (i = 0; i < row_width; i++, sp += 4, dp += 2)
nuclear@1	3120 {
nuclear@1	3121 png_uint_16 a = (png_uint_16)((((sp+2)) << 8) + (sp+3));
nuclear@1	3122
nuclear@1	3123 if (a == (png_uint_16)0xffff)
nuclear@1	3124 {
nuclear@1	3125 png_uint_16 v;
nuclear@1	3126
nuclear@1	3127 v = gamma_16[(sp + 1) >> gamma_shift][sp];
nuclear@1	3128 *dp = (png_byte)((v >> 8) & 0xff);
nuclear@1	3129 *(dp + 1) = (png_byte)(v & 0xff);
nuclear@1	3130 }
nuclear@1	3131 #if defined(PNG_READ_GAMMA_SUPPORTED)
nuclear@1	3132 else if (a == 0)
nuclear@1	3133 #else
nuclear@1	3134 else
nuclear@1	3135 #endif
nuclear@1	3136 {
nuclear@1	3137 /* background is already in screen gamma */
nuclear@1	3138 *dp = (png_byte)((background->gray >> 8) & 0xff);
nuclear@1	3139 *(dp + 1) = (png_byte)(background->gray & 0xff);
nuclear@1	3140 }
nuclear@1	3141 #if defined(PNG_READ_GAMMA_SUPPORTED)
nuclear@1	3142 else
nuclear@1	3143 {
nuclear@1	3144 png_uint_16 g, v, w;
nuclear@1	3145
nuclear@1	3146 g = gamma_16_to_1[(sp + 1) >> gamma_shift][sp];
nuclear@1	3147 png_composite_16(v, g, a, background_1->gray);
nuclear@1	3148 w = gamma_16_from_1[(v&0xff) >> gamma_shift][v >> 8];
nuclear@1	3149 *dp = (png_byte)((w >> 8) & 0xff);
nuclear@1	3150 *(dp + 1) = (png_byte)(w & 0xff);
nuclear@1	3151 }
nuclear@1	3152 #endif
nuclear@1	3153 }
nuclear@1	3154 }
nuclear@1	3155 else
nuclear@1	3156 #endif
nuclear@1	3157 {
nuclear@1	3158 sp = row;
nuclear@1	3159 dp = row;
nuclear@1	3160 for (i = 0; i < row_width; i++, sp += 4, dp += 2)
nuclear@1	3161 {
nuclear@1	3162 png_uint_16 a = (png_uint_16)((((sp+2)) << 8) + (sp+3));
nuclear@1	3163 if (a == (png_uint_16)0xffff)
nuclear@1	3164 {
nuclear@1	3165 png_memcpy(dp, sp, 2);
nuclear@1	3166 }
nuclear@1	3167 #if defined(PNG_READ_GAMMA_SUPPORTED)
nuclear@1	3168 else if (a == 0)
nuclear@1	3169 #else
nuclear@1	3170 else
nuclear@1	3171 #endif
nuclear@1	3172 {
nuclear@1	3173 *dp = (png_byte)((background->gray >> 8) & 0xff);
nuclear@1	3174 *(dp + 1) = (png_byte)(background->gray & 0xff);
nuclear@1	3175 }
nuclear@1	3176 #if defined(PNG_READ_GAMMA_SUPPORTED)
nuclear@1	3177 else
nuclear@1	3178 {
nuclear@1	3179 png_uint_16 g, v;
nuclear@1	3180
nuclear@1	3181 g = (png_uint_16)(((sp) << 8) + (sp + 1));
nuclear@1	3182 png_composite_16(v, g, a, background_1->gray);
nuclear@1	3183 *dp = (png_byte)((v >> 8) & 0xff);
nuclear@1	3184 *(dp + 1) = (png_byte)(v & 0xff);
nuclear@1	3185 }
nuclear@1	3186 #endif
nuclear@1	3187 }
nuclear@1	3188 }
nuclear@1	3189 }
nuclear@1	3190 break;
nuclear@1	3191 }
nuclear@1	3192 case PNG_COLOR_TYPE_RGB_ALPHA:
nuclear@1	3193 {
nuclear@1	3194 if (row_info->bit_depth == 8)
nuclear@1	3195 {
nuclear@1	3196 #if defined(PNG_READ_GAMMA_SUPPORTED)
nuclear@1	3197 if (gamma_to_1 != NULL && gamma_from_1 != NULL &&
nuclear@1	3198 gamma_table != NULL)
nuclear@1	3199 {
nuclear@1	3200 sp = row;
nuclear@1	3201 dp = row;
nuclear@1	3202 for (i = 0; i < row_width; i++, sp += 4, dp += 3)
nuclear@1	3203 {
nuclear@1	3204 png_byte a = *(sp + 3);
nuclear@1	3205
nuclear@1	3206 if (a == 0xff)
nuclear@1	3207 {
nuclear@1	3208 dp = gamma_table[sp];
nuclear@1	3209 (dp + 1) = gamma_table[(sp + 1)];
nuclear@1	3210 (dp + 2) = gamma_table[(sp + 2)];
nuclear@1	3211 }
nuclear@1	3212 else if (a == 0)
nuclear@1	3213 {
nuclear@1	3214 /* background is already in screen gamma */
nuclear@1	3215 *dp = (png_byte)background->red;
nuclear@1	3216 *(dp + 1) = (png_byte)background->green;
nuclear@1	3217 *(dp + 2) = (png_byte)background->blue;
nuclear@1	3218 }
nuclear@1	3219 else
nuclear@1	3220 {
nuclear@1	3221 png_byte v, w;
nuclear@1	3222
nuclear@1	3223 v = gamma_to_1[*sp];
nuclear@1	3224 png_composite(w, v, a, background_1->red);
nuclear@1	3225 *dp = gamma_from_1[w];
nuclear@1	3226 v = gamma_to_1[*(sp + 1)];
nuclear@1	3227 png_composite(w, v, a, background_1->green);
nuclear@1	3228 *(dp + 1) = gamma_from_1[w];
nuclear@1	3229 v = gamma_to_1[*(sp + 2)];
nuclear@1	3230 png_composite(w, v, a, background_1->blue);
nuclear@1	3231 *(dp + 2) = gamma_from_1[w];
nuclear@1	3232 }
nuclear@1	3233 }
nuclear@1	3234 }
nuclear@1	3235 else
nuclear@1	3236 #endif
nuclear@1	3237 {
nuclear@1	3238 sp = row;
nuclear@1	3239 dp = row;
nuclear@1	3240 for (i = 0; i < row_width; i++, sp += 4, dp += 3)
nuclear@1	3241 {
nuclear@1	3242 png_byte a = *(sp + 3);
nuclear@1	3243
nuclear@1	3244 if (a == 0xff)
nuclear@1	3245 {
nuclear@1	3246 dp = sp;
nuclear@1	3247 (dp + 1) = (sp + 1);
nuclear@1	3248 (dp + 2) = (sp + 2);
nuclear@1	3249 }
nuclear@1	3250 else if (a == 0)
nuclear@1	3251 {
nuclear@1	3252 *dp = (png_byte)background->red;
nuclear@1	3253 *(dp + 1) = (png_byte)background->green;
nuclear@1	3254 *(dp + 2) = (png_byte)background->blue;
nuclear@1	3255 }
nuclear@1	3256 else
nuclear@1	3257 {
nuclear@1	3258 png_composite(dp, sp, a, background->red);
nuclear@1	3259 png_composite((dp + 1), (sp + 1), a,
nuclear@1	3260 background->green);
nuclear@1	3261 png_composite((dp + 2), (sp + 2), a,
nuclear@1	3262 background->blue);
nuclear@1	3263 }
nuclear@1	3264 }
nuclear@1	3265 }
nuclear@1	3266 }
nuclear@1	3267 else /* if (row_info->bit_depth == 16) */
nuclear@1	3268 {
nuclear@1	3269 #if defined(PNG_READ_GAMMA_SUPPORTED)
nuclear@1	3270 if (gamma_16 != NULL && gamma_16_from_1 != NULL &&
nuclear@1	3271 gamma_16_to_1 != NULL)
nuclear@1	3272 {
nuclear@1	3273 sp = row;
nuclear@1	3274 dp = row;
nuclear@1	3275 for (i = 0; i < row_width; i++, sp += 8, dp += 6)
nuclear@1	3276 {
nuclear@1	3277 png_uint_16 a = (png_uint_16)(((png_uint_16)(*(sp + 6))
nuclear@1	3278 << 8) + (png_uint_16)(*(sp + 7)));
nuclear@1	3279 if (a == (png_uint_16)0xffff)
nuclear@1	3280 {
nuclear@1	3281 png_uint_16 v;
nuclear@1	3282
nuclear@1	3283 v = gamma_16[(sp + 1) >> gamma_shift][sp];
nuclear@1	3284 *dp = (png_byte)((v >> 8) & 0xff);
nuclear@1	3285 *(dp + 1) = (png_byte)(v & 0xff);
nuclear@1	3286 v = gamma_16[(sp + 3) >> gamma_shift][(sp + 2)];
nuclear@1	3287 *(dp + 2) = (png_byte)((v >> 8) & 0xff);
nuclear@1	3288 *(dp + 3) = (png_byte)(v & 0xff);
nuclear@1	3289 v = gamma_16[(sp + 5) >> gamma_shift][(sp + 4)];
nuclear@1	3290 *(dp + 4) = (png_byte)((v >> 8) & 0xff);
nuclear@1	3291 *(dp + 5) = (png_byte)(v & 0xff);
nuclear@1	3292 }
nuclear@1	3293 else if (a == 0)
nuclear@1	3294 {
nuclear@1	3295 /* background is already in screen gamma */
nuclear@1	3296 *dp = (png_byte)((background->red >> 8) & 0xff);
nuclear@1	3297 *(dp + 1) = (png_byte)(background->red & 0xff);
nuclear@1	3298 *(dp + 2) = (png_byte)((background->green >> 8) & 0xff);
nuclear@1	3299 *(dp + 3) = (png_byte)(background->green & 0xff);
nuclear@1	3300 *(dp + 4) = (png_byte)((background->blue >> 8) & 0xff);
nuclear@1	3301 *(dp + 5) = (png_byte)(background->blue & 0xff);
nuclear@1	3302 }
nuclear@1	3303 else
nuclear@1	3304 {
nuclear@1	3305 png_uint_16 v, w, x;
nuclear@1	3306
nuclear@1	3307 v = gamma_16_to_1[(sp + 1) >> gamma_shift][sp];
nuclear@1	3308 png_composite_16(w, v, a, background_1->red);
nuclear@1	3309 x = gamma_16_from_1[((w&0xff) >> gamma_shift)][w >> 8];
nuclear@1	3310 *dp = (png_byte)((x >> 8) & 0xff);
nuclear@1	3311 *(dp + 1) = (png_byte)(x & 0xff);
nuclear@1	3312 v = gamma_16_to_1[(sp + 3) >> gamma_shift][(sp + 2)];
nuclear@1	3313 png_composite_16(w, v, a, background_1->green);
nuclear@1	3314 x = gamma_16_from_1[((w&0xff) >> gamma_shift)][w >> 8];
nuclear@1	3315 *(dp + 2) = (png_byte)((x >> 8) & 0xff);
nuclear@1	3316 *(dp + 3) = (png_byte)(x & 0xff);
nuclear@1	3317 v = gamma_16_to_1[(sp + 5) >> gamma_shift][(sp + 4)];
nuclear@1	3318 png_composite_16(w, v, a, background_1->blue);
nuclear@1	3319 x = gamma_16_from_1[(w & 0xff) >> gamma_shift][w >> 8];
nuclear@1	3320 *(dp + 4) = (png_byte)((x >> 8) & 0xff);
nuclear@1	3321 *(dp + 5) = (png_byte)(x & 0xff);
nuclear@1	3322 }
nuclear@1	3323 }
nuclear@1	3324 }
nuclear@1	3325 else
nuclear@1	3326 #endif
nuclear@1	3327 {
nuclear@1	3328 sp = row;
nuclear@1	3329 dp = row;
nuclear@1	3330 for (i = 0; i < row_width; i++, sp += 8, dp += 6)
nuclear@1	3331 {
nuclear@1	3332 png_uint_16 a = (png_uint_16)(((png_uint_16)(*(sp + 6))
nuclear@1	3333 << 8) + (png_uint_16)(*(sp + 7)));
nuclear@1	3334 if (a == (png_uint_16)0xffff)
nuclear@1	3335 {
nuclear@1	3336 png_memcpy(dp, sp, 6);
nuclear@1	3337 }
nuclear@1	3338 else if (a == 0)
nuclear@1	3339 {
nuclear@1	3340 *dp = (png_byte)((background->red >> 8) & 0xff);
nuclear@1	3341 *(dp + 1) = (png_byte)(background->red & 0xff);
nuclear@1	3342 *(dp + 2) = (png_byte)((background->green >> 8) & 0xff);
nuclear@1	3343 *(dp + 3) = (png_byte)(background->green & 0xff);
nuclear@1	3344 *(dp + 4) = (png_byte)((background->blue >> 8) & 0xff);
nuclear@1	3345 *(dp + 5) = (png_byte)(background->blue & 0xff);
nuclear@1	3346 }
nuclear@1	3347 else
nuclear@1	3348 {
nuclear@1	3349 png_uint_16 v;
nuclear@1	3350
nuclear@1	3351 png_uint_16 r = (png_uint_16)(((sp) << 8) + (sp + 1));
nuclear@1	3352 png_uint_16 g = (png_uint_16)(((*(sp + 2)) << 8)
nuclear@1	3353 + *(sp + 3));
nuclear@1	3354 png_uint_16 b = (png_uint_16)(((*(sp + 4)) << 8)
nuclear@1	3355 + *(sp + 5));
nuclear@1	3356
nuclear@1	3357 png_composite_16(v, r, a, background->red);
nuclear@1	3358 *dp = (png_byte)((v >> 8) & 0xff);
nuclear@1	3359 *(dp + 1) = (png_byte)(v & 0xff);
nuclear@1	3360 png_composite_16(v, g, a, background->green);
nuclear@1	3361 *(dp + 2) = (png_byte)((v >> 8) & 0xff);
nuclear@1	3362 *(dp + 3) = (png_byte)(v & 0xff);
nuclear@1	3363 png_composite_16(v, b, a, background->blue);
nuclear@1	3364 *(dp + 4) = (png_byte)((v >> 8) & 0xff);
nuclear@1	3365 *(dp + 5) = (png_byte)(v & 0xff);
nuclear@1	3366 }
nuclear@1	3367 }
nuclear@1	3368 }
nuclear@1	3369 }
nuclear@1	3370 break;
nuclear@1	3371 }
nuclear@1	3372 }
nuclear@1	3373
nuclear@1	3374 if (row_info->color_type & PNG_COLOR_MASK_ALPHA)
nuclear@1	3375 {
nuclear@1	3376 row_info->color_type &= ~PNG_COLOR_MASK_ALPHA;
nuclear@1	3377 row_info->channels--;
nuclear@1	3378 row_info->pixel_depth = (png_byte)(row_info->channels *
nuclear@1	3379 row_info->bit_depth);
nuclear@1	3380 row_info->rowbytes = PNG_ROWBYTES(row_info->pixel_depth, row_width);
nuclear@1	3381 }
nuclear@1	3382 }
nuclear@1	3383 }
nuclear@1	3384 #endif
nuclear@1	3385
nuclear@1	3386 #if defined(PNG_READ_GAMMA_SUPPORTED)
nuclear@1	3387 /* Gamma correct the image, avoiding the alpha channel. Make sure
nuclear@1	3388 * you do this after you deal with the transparency issue on grayscale
nuclear@1	3389 * or RGB images. If your bit depth is 8, use gamma_table, if it
nuclear@1	3390 * is 16, use gamma_16_table and gamma_shift. Build these with
nuclear@1	3391 * build_gamma_table().
nuclear@1	3392 */
nuclear@1	3393 void /* PRIVATE */
nuclear@1	3394 png_do_gamma(png_row_infop row_info, png_bytep row,
nuclear@1	3395 png_bytep gamma_table, png_uint_16pp gamma_16_table,
nuclear@1	3396 int gamma_shift)
nuclear@1	3397 {
nuclear@1	3398 png_bytep sp;
nuclear@1	3399 png_uint_32 i;
nuclear@1	3400 png_uint_32 row_width=row_info->width;
nuclear@1	3401
nuclear@1	3402 png_debug(1, "in png_do_gamma\n");
nuclear@1	3403 if (
nuclear@1	3404 #if defined(PNG_USELESS_TESTS_SUPPORTED)
nuclear@1	3405 row != NULL && row_info != NULL &&
nuclear@1	3406 #endif
nuclear@1	3407 ((row_info->bit_depth <= 8 && gamma_table != NULL) \|\|
nuclear@1	3408 (row_info->bit_depth == 16 && gamma_16_table != NULL)))
nuclear@1	3409 {
nuclear@1	3410 switch (row_info->color_type)
nuclear@1	3411 {
nuclear@1	3412 case PNG_COLOR_TYPE_RGB:
nuclear@1	3413 {
nuclear@1	3414 if (row_info->bit_depth == 8)
nuclear@1	3415 {
nuclear@1	3416 sp = row;
nuclear@1	3417 for (i = 0; i < row_width; i++)
nuclear@1	3418 {
nuclear@1	3419 sp = gamma_table[sp];
nuclear@1	3420 sp++;
nuclear@1	3421 sp = gamma_table[sp];
nuclear@1	3422 sp++;
nuclear@1	3423 sp = gamma_table[sp];
nuclear@1	3424 sp++;
nuclear@1	3425 }
nuclear@1	3426 }
nuclear@1	3427 else /* if (row_info->bit_depth == 16) */
nuclear@1	3428 {
nuclear@1	3429 sp = row;
nuclear@1	3430 for (i = 0; i < row_width; i++)
nuclear@1	3431 {
nuclear@1	3432 png_uint_16 v;
nuclear@1	3433
nuclear@1	3434 v = gamma_16_table[(sp + 1) >> gamma_shift][sp];
nuclear@1	3435 *sp = (png_byte)((v >> 8) & 0xff);
nuclear@1	3436 *(sp + 1) = (png_byte)(v & 0xff);
nuclear@1	3437 sp += 2;
nuclear@1	3438 v = gamma_16_table[(sp + 1) >> gamma_shift][sp];
nuclear@1	3439 *sp = (png_byte)((v >> 8) & 0xff);
nuclear@1	3440 *(sp + 1) = (png_byte)(v & 0xff);
nuclear@1	3441 sp += 2;
nuclear@1	3442 v = gamma_16_table[(sp + 1) >> gamma_shift][sp];
nuclear@1	3443 *sp = (png_byte)((v >> 8) & 0xff);
nuclear@1	3444 *(sp + 1) = (png_byte)(v & 0xff);
nuclear@1	3445 sp += 2;
nuclear@1	3446 }
nuclear@1	3447 }
nuclear@1	3448 break;
nuclear@1	3449 }
nuclear@1	3450 case PNG_COLOR_TYPE_RGB_ALPHA:
nuclear@1	3451 {
nuclear@1	3452 if (row_info->bit_depth == 8)
nuclear@1	3453 {
nuclear@1	3454 sp = row;
nuclear@1	3455 for (i = 0; i < row_width; i++)
nuclear@1	3456 {
nuclear@1	3457 sp = gamma_table[sp];
nuclear@1	3458 sp++;
nuclear@1	3459 sp = gamma_table[sp];
nuclear@1	3460 sp++;
nuclear@1	3461 sp = gamma_table[sp];
nuclear@1	3462 sp++;
nuclear@1	3463 sp++;
nuclear@1	3464 }
nuclear@1	3465 }
nuclear@1	3466 else /* if (row_info->bit_depth == 16) */
nuclear@1	3467 {
nuclear@1	3468 sp = row;
nuclear@1	3469 for (i = 0; i < row_width; i++)
nuclear@1	3470 {
nuclear@1	3471 png_uint_16 v = gamma_16_table[(sp + 1) >> gamma_shift][sp];
nuclear@1	3472 *sp = (png_byte)((v >> 8) & 0xff);
nuclear@1	3473 *(sp + 1) = (png_byte)(v & 0xff);
nuclear@1	3474 sp += 2;
nuclear@1	3475 v = gamma_16_table[(sp + 1) >> gamma_shift][sp];
nuclear@1	3476 *sp = (png_byte)((v >> 8) & 0xff);
nuclear@1	3477 *(sp + 1) = (png_byte)(v & 0xff);
nuclear@1	3478 sp += 2;
nuclear@1	3479 v = gamma_16_table[(sp + 1) >> gamma_shift][sp];
nuclear@1	3480 *sp = (png_byte)((v >> 8) & 0xff);
nuclear@1	3481 *(sp + 1) = (png_byte)(v & 0xff);
nuclear@1	3482 sp += 4;
nuclear@1	3483 }
nuclear@1	3484 }
nuclear@1	3485 break;
nuclear@1	3486 }
nuclear@1	3487 case PNG_COLOR_TYPE_GRAY_ALPHA:
nuclear@1	3488 {
nuclear@1	3489 if (row_info->bit_depth == 8)
nuclear@1	3490 {
nuclear@1	3491 sp = row;
nuclear@1	3492 for (i = 0; i < row_width; i++)
nuclear@1	3493 {
nuclear@1	3494 sp = gamma_table[sp];
nuclear@1	3495 sp += 2;
nuclear@1	3496 }
nuclear@1	3497 }
nuclear@1	3498 else /* if (row_info->bit_depth == 16) */
nuclear@1	3499 {
nuclear@1	3500 sp = row;
nuclear@1	3501 for (i = 0; i < row_width; i++)
nuclear@1	3502 {
nuclear@1	3503 png_uint_16 v = gamma_16_table[(sp + 1) >> gamma_shift][sp];
nuclear@1	3504 *sp = (png_byte)((v >> 8) & 0xff);
nuclear@1	3505 *(sp + 1) = (png_byte)(v & 0xff);
nuclear@1	3506 sp += 4;
nuclear@1	3507 }
nuclear@1	3508 }
nuclear@1	3509 break;
nuclear@1	3510 }
nuclear@1	3511 case PNG_COLOR_TYPE_GRAY:
nuclear@1	3512 {
nuclear@1	3513 if (row_info->bit_depth == 2)
nuclear@1	3514 {
nuclear@1	3515 sp = row;
nuclear@1	3516 for (i = 0; i < row_width; i += 4)
nuclear@1	3517 {
nuclear@1	3518 int a = *sp & 0xc0;
nuclear@1	3519 int b = *sp & 0x30;
nuclear@1	3520 int c = *sp & 0x0c;
nuclear@1	3521 int d = *sp & 0x03;
nuclear@1	3522
nuclear@1	3523 *sp = (png_byte)(
nuclear@1	3524 ((((int)gamma_table[a\|(a>>2)\|(a>>4)\|(a>>6)]) ) & 0xc0)\|
nuclear@1	3525 ((((int)gamma_table[(b<<2)\|b\|(b>>2)\|(b>>4)])>>2) & 0x30)\|
nuclear@1	3526 ((((int)gamma_table[(c<<4)\|(c<<2)\|c\|(c>>2)])>>4) & 0x0c)\|
nuclear@1	3527 ((((int)gamma_table[(d<<6)\|(d<<4)\|(d<<2)\|d])>>6) ));
nuclear@1	3528 sp++;
nuclear@1	3529 }
nuclear@1	3530 }
nuclear@1	3531 if (row_info->bit_depth == 4)
nuclear@1	3532 {
nuclear@1	3533 sp = row;
nuclear@1	3534 for (i = 0; i < row_width; i += 2)
nuclear@1	3535 {
nuclear@1	3536 int msb = *sp & 0xf0;
nuclear@1	3537 int lsb = *sp & 0x0f;
nuclear@1	3538
nuclear@1	3539 *sp = (png_byte)((((int)gamma_table[msb \| (msb >> 4)]) & 0xf0)
nuclear@1	3540 \| (((int)gamma_table[(lsb << 4) \| lsb]) >> 4));
nuclear@1	3541 sp++;
nuclear@1	3542 }
nuclear@1	3543 }
nuclear@1	3544 else if (row_info->bit_depth == 8)
nuclear@1	3545 {
nuclear@1	3546 sp = row;
nuclear@1	3547 for (i = 0; i < row_width; i++)
nuclear@1	3548 {
nuclear@1	3549 sp = gamma_table[sp];
nuclear@1	3550 sp++;
nuclear@1	3551 }
nuclear@1	3552 }
nuclear@1	3553 else if (row_info->bit_depth == 16)
nuclear@1	3554 {
nuclear@1	3555 sp = row;
nuclear@1	3556 for (i = 0; i < row_width; i++)
nuclear@1	3557 {
nuclear@1	3558 png_uint_16 v = gamma_16_table[(sp + 1) >> gamma_shift][sp];
nuclear@1	3559 *sp = (png_byte)((v >> 8) & 0xff);
nuclear@1	3560 *(sp + 1) = (png_byte)(v & 0xff);
nuclear@1	3561 sp += 2;
nuclear@1	3562 }
nuclear@1	3563 }
nuclear@1	3564 break;
nuclear@1	3565 }
nuclear@1	3566 }
nuclear@1	3567 }
nuclear@1	3568 }
nuclear@1	3569 #endif
nuclear@1	3570
nuclear@1	3571 #if defined(PNG_READ_EXPAND_SUPPORTED)
nuclear@1	3572 /* Expands a palette row to an RGB or RGBA row depending
nuclear@1	3573 * upon whether you supply trans and num_trans.
nuclear@1	3574 */
nuclear@1	3575 void /* PRIVATE */
nuclear@1	3576 png_do_expand_palette(png_row_infop row_info, png_bytep row,
nuclear@1	3577 png_colorp palette, png_bytep trans, int num_trans)
nuclear@1	3578 {
nuclear@1	3579 int shift, value;
nuclear@1	3580 png_bytep sp, dp;
nuclear@1	3581 png_uint_32 i;
nuclear@1	3582 png_uint_32 row_width=row_info->width;
nuclear@1	3583
nuclear@1	3584 png_debug(1, "in png_do_expand_palette\n");
nuclear@1	3585 if (
nuclear@1	3586 #if defined(PNG_USELESS_TESTS_SUPPORTED)
nuclear@1	3587 row != NULL && row_info != NULL &&
nuclear@1	3588 #endif
nuclear@1	3589 row_info->color_type == PNG_COLOR_TYPE_PALETTE)
nuclear@1	3590 {
nuclear@1	3591 if (row_info->bit_depth < 8)
nuclear@1	3592 {
nuclear@1	3593 switch (row_info->bit_depth)
nuclear@1	3594 {
nuclear@1	3595 case 1:
nuclear@1	3596 {
nuclear@1	3597 sp = row + (png_size_t)((row_width - 1) >> 3);
nuclear@1	3598 dp = row + (png_size_t)row_width - 1;
nuclear@1	3599 shift = 7 - (int)((row_width + 7) & 0x07);
nuclear@1	3600 for (i = 0; i < row_width; i++)
nuclear@1	3601 {
nuclear@1	3602 if ((*sp >> shift) & 0x01)
nuclear@1	3603 *dp = 1;
nuclear@1	3604 else
nuclear@1	3605 *dp = 0;
nuclear@1	3606 if (shift == 7)
nuclear@1	3607 {
nuclear@1	3608 shift = 0;
nuclear@1	3609 sp--;
nuclear@1	3610 }
nuclear@1	3611 else
nuclear@1	3612 shift++;
nuclear@1	3613
nuclear@1	3614 dp--;
nuclear@1	3615 }
nuclear@1	3616 break;
nuclear@1	3617 }
nuclear@1	3618 case 2:
nuclear@1	3619 {
nuclear@1	3620 sp = row + (png_size_t)((row_width - 1) >> 2);
nuclear@1	3621 dp = row + (png_size_t)row_width - 1;
nuclear@1	3622 shift = (int)((3 - ((row_width + 3) & 0x03)) << 1);
nuclear@1	3623 for (i = 0; i < row_width; i++)
nuclear@1	3624 {
nuclear@1	3625 value = (*sp >> shift) & 0x03;
nuclear@1	3626 *dp = (png_byte)value;
nuclear@1	3627 if (shift == 6)
nuclear@1	3628 {
nuclear@1	3629 shift = 0;
nuclear@1	3630 sp--;
nuclear@1	3631 }
nuclear@1	3632 else
nuclear@1	3633 shift += 2;
nuclear@1	3634
nuclear@1	3635 dp--;
nuclear@1	3636 }
nuclear@1	3637 break;
nuclear@1	3638 }
nuclear@1	3639 case 4:
nuclear@1	3640 {
nuclear@1	3641 sp = row + (png_size_t)((row_width - 1) >> 1);
nuclear@1	3642 dp = row + (png_size_t)row_width - 1;
nuclear@1	3643 shift = (int)((row_width & 0x01) << 2);
nuclear@1	3644 for (i = 0; i < row_width; i++)
nuclear@1	3645 {
nuclear@1	3646 value = (*sp >> shift) & 0x0f;
nuclear@1	3647 *dp = (png_byte)value;
nuclear@1	3648 if (shift == 4)
nuclear@1	3649 {
nuclear@1	3650 shift = 0;
nuclear@1	3651 sp--;
nuclear@1	3652 }
nuclear@1	3653 else
nuclear@1	3654 shift += 4;
nuclear@1	3655
nuclear@1	3656 dp--;
nuclear@1	3657 }
nuclear@1	3658 break;
nuclear@1	3659 }
nuclear@1	3660 }
nuclear@1	3661 row_info->bit_depth = 8;
nuclear@1	3662 row_info->pixel_depth = 8;
nuclear@1	3663 row_info->rowbytes = row_width;
nuclear@1	3664 }
nuclear@1	3665 switch (row_info->bit_depth)
nuclear@1	3666 {
nuclear@1	3667 case 8:
nuclear@1	3668 {
nuclear@1	3669 if (trans != NULL)
nuclear@1	3670 {
nuclear@1	3671 sp = row + (png_size_t)row_width - 1;
nuclear@1	3672 dp = row + (png_size_t)(row_width << 2) - 1;
nuclear@1	3673
nuclear@1	3674 for (i = 0; i < row_width; i++)
nuclear@1	3675 {
nuclear@1	3676 if ((int)(*sp) >= num_trans)
nuclear@1	3677 *dp-- = 0xff;
nuclear@1	3678 else
nuclear@1	3679 dp-- = trans[sp];
nuclear@1	3680 dp-- = palette[sp].blue;
nuclear@1	3681 dp-- = palette[sp].green;
nuclear@1	3682 dp-- = palette[sp].red;
nuclear@1	3683 sp--;
nuclear@1	3684 }
nuclear@1	3685 row_info->bit_depth = 8;
nuclear@1	3686 row_info->pixel_depth = 32;
nuclear@1	3687 row_info->rowbytes = row_width * 4;
nuclear@1	3688 row_info->color_type = 6;
nuclear@1	3689 row_info->channels = 4;
nuclear@1	3690 }
nuclear@1	3691 else
nuclear@1	3692 {
nuclear@1	3693 sp = row + (png_size_t)row_width - 1;
nuclear@1	3694 dp = row + (png_size_t)(row_width * 3) - 1;
nuclear@1	3695
nuclear@1	3696 for (i = 0; i < row_width; i++)
nuclear@1	3697 {
nuclear@1	3698 dp-- = palette[sp].blue;
nuclear@1	3699 dp-- = palette[sp].green;
nuclear@1	3700 dp-- = palette[sp].red;
nuclear@1	3701 sp--;
nuclear@1	3702 }
nuclear@1	3703 row_info->bit_depth = 8;
nuclear@1	3704 row_info->pixel_depth = 24;
nuclear@1	3705 row_info->rowbytes = row_width * 3;
nuclear@1	3706 row_info->color_type = 2;
nuclear@1	3707 row_info->channels = 3;
nuclear@1	3708 }
nuclear@1	3709 break;
nuclear@1	3710 }
nuclear@1	3711 }
nuclear@1	3712 }
nuclear@1	3713 }
nuclear@1	3714
nuclear@1	3715 /* If the bit depth < 8, it is expanded to 8. Also, if the already
nuclear@1	3716 * expanded transparency value is supplied, an alpha channel is built.
nuclear@1	3717 */
nuclear@1	3718 void /* PRIVATE */
nuclear@1	3719 png_do_expand(png_row_infop row_info, png_bytep row,
nuclear@1	3720 png_color_16p trans_value)
nuclear@1	3721 {
nuclear@1	3722 int shift, value;
nuclear@1	3723 png_bytep sp, dp;
nuclear@1	3724 png_uint_32 i;
nuclear@1	3725 png_uint_32 row_width=row_info->width;
nuclear@1	3726
nuclear@1	3727 png_debug(1, "in png_do_expand\n");
nuclear@1	3728 #if defined(PNG_USELESS_TESTS_SUPPORTED)
nuclear@1	3729 if (row != NULL && row_info != NULL)
nuclear@1	3730 #endif
nuclear@1	3731 {
nuclear@1	3732 if (row_info->color_type == PNG_COLOR_TYPE_GRAY)
nuclear@1	3733 {
nuclear@1	3734 png_uint_16 gray = (png_uint_16)(trans_value ? trans_value->gray : 0);
nuclear@1	3735
nuclear@1	3736 if (row_info->bit_depth < 8)
nuclear@1	3737 {
nuclear@1	3738 switch (row_info->bit_depth)
nuclear@1	3739 {
nuclear@1	3740 case 1:
nuclear@1	3741 {
nuclear@1	3742 gray = (png_uint_16)((gray&0x01)*0xff);
nuclear@1	3743 sp = row + (png_size_t)((row_width - 1) >> 3);
nuclear@1	3744 dp = row + (png_size_t)row_width - 1;
nuclear@1	3745 shift = 7 - (int)((row_width + 7) & 0x07);
nuclear@1	3746 for (i = 0; i < row_width; i++)
nuclear@1	3747 {
nuclear@1	3748 if ((*sp >> shift) & 0x01)
nuclear@1	3749 *dp = 0xff;
nuclear@1	3750 else
nuclear@1	3751 *dp = 0;
nuclear@1	3752 if (shift == 7)
nuclear@1	3753 {
nuclear@1	3754 shift = 0;
nuclear@1	3755 sp--;
nuclear@1	3756 }
nuclear@1	3757 else
nuclear@1	3758 shift++;
nuclear@1	3759
nuclear@1	3760 dp--;
nuclear@1	3761 }
nuclear@1	3762 break;
nuclear@1	3763 }
nuclear@1	3764 case 2:
nuclear@1	3765 {
nuclear@1	3766 gray = (png_uint_16)((gray&0x03)*0x55);
nuclear@1	3767 sp = row + (png_size_t)((row_width - 1) >> 2);
nuclear@1	3768 dp = row + (png_size_t)row_width - 1;
nuclear@1	3769 shift = (int)((3 - ((row_width + 3) & 0x03)) << 1);
nuclear@1	3770 for (i = 0; i < row_width; i++)
nuclear@1	3771 {
nuclear@1	3772 value = (*sp >> shift) & 0x03;
nuclear@1	3773 *dp = (png_byte)(value \| (value << 2) \| (value << 4) \|
nuclear@1	3774 (value << 6));
nuclear@1	3775 if (shift == 6)
nuclear@1	3776 {
nuclear@1	3777 shift = 0;
nuclear@1	3778 sp--;
nuclear@1	3779 }
nuclear@1	3780 else
nuclear@1	3781 shift += 2;
nuclear@1	3782
nuclear@1	3783 dp--;
nuclear@1	3784 }
nuclear@1	3785 break;
nuclear@1	3786 }
nuclear@1	3787 case 4:
nuclear@1	3788 {
nuclear@1	3789 gray = (png_uint_16)((gray&0x0f)*0x11);
nuclear@1	3790 sp = row + (png_size_t)((row_width - 1) >> 1);
nuclear@1	3791 dp = row + (png_size_t)row_width - 1;
nuclear@1	3792 shift = (int)((1 - ((row_width + 1) & 0x01)) << 2);
nuclear@1	3793 for (i = 0; i < row_width; i++)
nuclear@1	3794 {
nuclear@1	3795 value = (*sp >> shift) & 0x0f;
nuclear@1	3796 *dp = (png_byte)(value \| (value << 4));
nuclear@1	3797 if (shift == 4)
nuclear@1	3798 {
nuclear@1	3799 shift = 0;
nuclear@1	3800 sp--;
nuclear@1	3801 }
nuclear@1	3802 else
nuclear@1	3803 shift = 4;
nuclear@1	3804
nuclear@1	3805 dp--;
nuclear@1	3806 }
nuclear@1	3807 break;
nuclear@1	3808 }
nuclear@1	3809 }
nuclear@1	3810 row_info->bit_depth = 8;
nuclear@1	3811 row_info->pixel_depth = 8;
nuclear@1	3812 row_info->rowbytes = row_width;
nuclear@1	3813 }
nuclear@1	3814
nuclear@1	3815 if (trans_value != NULL)
nuclear@1	3816 {
nuclear@1	3817 if (row_info->bit_depth == 8)
nuclear@1	3818 {
nuclear@1	3819 gray = gray & 0xff;
nuclear@1	3820 sp = row + (png_size_t)row_width - 1;
nuclear@1	3821 dp = row + (png_size_t)(row_width << 1) - 1;
nuclear@1	3822 for (i = 0; i < row_width; i++)
nuclear@1	3823 {
nuclear@1	3824 if (*sp == gray)
nuclear@1	3825 *dp-- = 0;
nuclear@1	3826 else
nuclear@1	3827 *dp-- = 0xff;
nuclear@1	3828 dp-- = sp--;
nuclear@1	3829 }
nuclear@1	3830 }
nuclear@1	3831 else if (row_info->bit_depth == 16)
nuclear@1	3832 {
nuclear@1	3833 png_byte gray_high = (gray >> 8) & 0xff;
nuclear@1	3834 png_byte gray_low = gray & 0xff;
nuclear@1	3835 sp = row + row_info->rowbytes - 1;
nuclear@1	3836 dp = row + (row_info->rowbytes << 1) - 1;
nuclear@1	3837 for (i = 0; i < row_width; i++)
nuclear@1	3838 {
nuclear@1	3839 if ((sp - 1) == gray_high && (sp) == gray_low)
nuclear@1	3840 {
nuclear@1	3841 *dp-- = 0;
nuclear@1	3842 *dp-- = 0;
nuclear@1	3843 }
nuclear@1	3844 else
nuclear@1	3845 {
nuclear@1	3846 *dp-- = 0xff;
nuclear@1	3847 *dp-- = 0xff;
nuclear@1	3848 }
nuclear@1	3849 dp-- = sp--;
nuclear@1	3850 dp-- = sp--;
nuclear@1	3851 }
nuclear@1	3852 }
nuclear@1	3853 row_info->color_type = PNG_COLOR_TYPE_GRAY_ALPHA;
nuclear@1	3854 row_info->channels = 2;
nuclear@1	3855 row_info->pixel_depth = (png_byte)(row_info->bit_depth << 1);
nuclear@1	3856 row_info->rowbytes = PNG_ROWBYTES(row_info->pixel_depth,
nuclear@1	3857 row_width);
nuclear@1	3858 }
nuclear@1	3859 }
nuclear@1	3860 else if (row_info->color_type == PNG_COLOR_TYPE_RGB && trans_value)
nuclear@1	3861 {
nuclear@1	3862 if (row_info->bit_depth == 8)
nuclear@1	3863 {
nuclear@1	3864 png_byte red = trans_value->red & 0xff;
nuclear@1	3865 png_byte green = trans_value->green & 0xff;
nuclear@1	3866 png_byte blue = trans_value->blue & 0xff;
nuclear@1	3867 sp = row + (png_size_t)row_info->rowbytes - 1;
nuclear@1	3868 dp = row + (png_size_t)(row_width << 2) - 1;
nuclear@1	3869 for (i = 0; i < row_width; i++)
nuclear@1	3870 {
nuclear@1	3871 if ((sp - 2) == red && (sp - 1) == green && *(sp) == blue)
nuclear@1	3872 *dp-- = 0;
nuclear@1	3873 else
nuclear@1	3874 *dp-- = 0xff;
nuclear@1	3875 dp-- = sp--;
nuclear@1	3876 dp-- = sp--;
nuclear@1	3877 dp-- = sp--;
nuclear@1	3878 }
nuclear@1	3879 }
nuclear@1	3880 else if (row_info->bit_depth == 16)
nuclear@1	3881 {
nuclear@1	3882 png_byte red_high = (trans_value->red >> 8) & 0xff;
nuclear@1	3883 png_byte green_high = (trans_value->green >> 8) & 0xff;
nuclear@1	3884 png_byte blue_high = (trans_value->blue >> 8) & 0xff;
nuclear@1	3885 png_byte red_low = trans_value->red & 0xff;
nuclear@1	3886 png_byte green_low = trans_value->green & 0xff;
nuclear@1	3887 png_byte blue_low = trans_value->blue & 0xff;
nuclear@1	3888 sp = row + row_info->rowbytes - 1;
nuclear@1	3889 dp = row + (png_size_t)(row_width << 3) - 1;
nuclear@1	3890 for (i = 0; i < row_width; i++)
nuclear@1	3891 {
nuclear@1	3892 if (*(sp - 5) == red_high &&
nuclear@1	3893 *(sp - 4) == red_low &&
nuclear@1	3894 *(sp - 3) == green_high &&
nuclear@1	3895 *(sp - 2) == green_low &&
nuclear@1	3896 *(sp - 1) == blue_high &&
nuclear@1	3897 *(sp ) == blue_low)
nuclear@1	3898 {
nuclear@1	3899 *dp-- = 0;
nuclear@1	3900 *dp-- = 0;
nuclear@1	3901 }
nuclear@1	3902 else
nuclear@1	3903 {
nuclear@1	3904 *dp-- = 0xff;
nuclear@1	3905 *dp-- = 0xff;
nuclear@1	3906 }
nuclear@1	3907 dp-- = sp--;
nuclear@1	3908 dp-- = sp--;
nuclear@1	3909 dp-- = sp--;
nuclear@1	3910 dp-- = sp--;
nuclear@1	3911 dp-- = sp--;
nuclear@1	3912 dp-- = sp--;
nuclear@1	3913 }
nuclear@1	3914 }
nuclear@1	3915 row_info->color_type = PNG_COLOR_TYPE_RGB_ALPHA;
nuclear@1	3916 row_info->channels = 4;
nuclear@1	3917 row_info->pixel_depth = (png_byte)(row_info->bit_depth << 2);
nuclear@1	3918 row_info->rowbytes = PNG_ROWBYTES(row_info->pixel_depth, row_width);
nuclear@1	3919 }
nuclear@1	3920 }
nuclear@1	3921 }
nuclear@1	3922 #endif
nuclear@1	3923
nuclear@1	3924 #if defined(PNG_READ_DITHER_SUPPORTED)
nuclear@1	3925 void /* PRIVATE */
nuclear@1	3926 png_do_dither(png_row_infop row_info, png_bytep row,
nuclear@1	3927 png_bytep palette_lookup, png_bytep dither_lookup)
nuclear@1	3928 {
nuclear@1	3929 png_bytep sp, dp;
nuclear@1	3930 png_uint_32 i;
nuclear@1	3931 png_uint_32 row_width=row_info->width;
nuclear@1	3932
nuclear@1	3933 png_debug(1, "in png_do_dither\n");
nuclear@1	3934 #if defined(PNG_USELESS_TESTS_SUPPORTED)
nuclear@1	3935 if (row != NULL && row_info != NULL)
nuclear@1	3936 #endif
nuclear@1	3937 {
nuclear@1	3938 if (row_info->color_type == PNG_COLOR_TYPE_RGB &&
nuclear@1	3939 palette_lookup && row_info->bit_depth == 8)
nuclear@1	3940 {
nuclear@1	3941 int r, g, b, p;
nuclear@1	3942 sp = row;
nuclear@1	3943 dp = row;
nuclear@1	3944 for (i = 0; i < row_width; i++)
nuclear@1	3945 {
nuclear@1	3946 r = *sp++;
nuclear@1	3947 g = *sp++;
nuclear@1	3948 b = *sp++;
nuclear@1	3949
nuclear@1	3950 /* this looks real messy, but the compiler will reduce
nuclear@1	3951 it down to a reasonable formula. For example, with
nuclear@1	3952 5 bits per color, we get:
nuclear@1	3953 p = (((r >> 3) & 0x1f) << 10) \|
nuclear@1	3954 (((g >> 3) & 0x1f) << 5) \|
nuclear@1	3955 ((b >> 3) & 0x1f);
nuclear@1	3956 */
nuclear@1	3957 p = (((r >> (8 - PNG_DITHER_RED_BITS)) &
nuclear@1	3958 ((1 << PNG_DITHER_RED_BITS) - 1)) <<
nuclear@1	3959 (PNG_DITHER_GREEN_BITS + PNG_DITHER_BLUE_BITS)) \|
nuclear@1	3960 (((g >> (8 - PNG_DITHER_GREEN_BITS)) &
nuclear@1	3961 ((1 << PNG_DITHER_GREEN_BITS) - 1)) <<
nuclear@1	3962 (PNG_DITHER_BLUE_BITS)) \|
nuclear@1	3963 ((b >> (8 - PNG_DITHER_BLUE_BITS)) &
nuclear@1	3964 ((1 << PNG_DITHER_BLUE_BITS) - 1));
nuclear@1	3965
nuclear@1	3966 *dp++ = palette_lookup[p];
nuclear@1	3967 }
nuclear@1	3968 row_info->color_type = PNG_COLOR_TYPE_PALETTE;
nuclear@1	3969 row_info->channels = 1;
nuclear@1	3970 row_info->pixel_depth = row_info->bit_depth;
nuclear@1	3971 row_info->rowbytes = PNG_ROWBYTES(row_info->pixel_depth, row_width);
nuclear@1	3972 }
nuclear@1	3973 else if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA &&
nuclear@1	3974 palette_lookup != NULL && row_info->bit_depth == 8)
nuclear@1	3975 {
nuclear@1	3976 int r, g, b, p;
nuclear@1	3977 sp = row;
nuclear@1	3978 dp = row;
nuclear@1	3979 for (i = 0; i < row_width; i++)
nuclear@1	3980 {
nuclear@1	3981 r = *sp++;
nuclear@1	3982 g = *sp++;
nuclear@1	3983 b = *sp++;
nuclear@1	3984 sp++;
nuclear@1	3985
nuclear@1	3986 p = (((r >> (8 - PNG_DITHER_RED_BITS)) &
nuclear@1	3987 ((1 << PNG_DITHER_RED_BITS) - 1)) <<
nuclear@1	3988 (PNG_DITHER_GREEN_BITS + PNG_DITHER_BLUE_BITS)) \|
nuclear@1	3989 (((g >> (8 - PNG_DITHER_GREEN_BITS)) &
nuclear@1	3990 ((1 << PNG_DITHER_GREEN_BITS) - 1)) <<
nuclear@1	3991 (PNG_DITHER_BLUE_BITS)) \|
nuclear@1	3992 ((b >> (8 - PNG_DITHER_BLUE_BITS)) &
nuclear@1	3993 ((1 << PNG_DITHER_BLUE_BITS) - 1));
nuclear@1	3994
nuclear@1	3995 *dp++ = palette_lookup[p];
nuclear@1	3996 }
nuclear@1	3997 row_info->color_type = PNG_COLOR_TYPE_PALETTE;
nuclear@1	3998 row_info->channels = 1;
nuclear@1	3999 row_info->pixel_depth = row_info->bit_depth;
nuclear@1	4000 row_info->rowbytes = PNG_ROWBYTES(row_info->pixel_depth, row_width);
nuclear@1	4001 }
nuclear@1	4002 else if (row_info->color_type == PNG_COLOR_TYPE_PALETTE &&
nuclear@1	4003 dither_lookup && row_info->bit_depth == 8)
nuclear@1	4004 {
nuclear@1	4005 sp = row;
nuclear@1	4006 for (i = 0; i < row_width; i++, sp++)
nuclear@1	4007 {
nuclear@1	4008 sp = dither_lookup[sp];
nuclear@1	4009 }
nuclear@1	4010 }
nuclear@1	4011 }
nuclear@1	4012 }
nuclear@1	4013 #endif
nuclear@1	4014
nuclear@1	4015 #ifdef PNG_FLOATING_POINT_SUPPORTED
nuclear@1	4016 #if defined(PNG_READ_GAMMA_SUPPORTED)
nuclear@1	4017 static PNG_CONST int png_gamma_shift[] =
nuclear@1	4018 {0x10, 0x21, 0x42, 0x84, 0x110, 0x248, 0x550, 0xff0, 0x00};
nuclear@1	4019
nuclear@1	4020 /* We build the 8- or 16-bit gamma tables here. Note that for 16-bit
nuclear@1	4021 * tables, we don't make a full table if we are reducing to 8-bit in
nuclear@1	4022 * the future. Note also how the gamma_16 tables are segmented so that
nuclear@1	4023 * we don't need to allocate > 64K chunks for a full 16-bit table.
nuclear@1	4024 */
nuclear@1	4025 void /* PRIVATE */
nuclear@1	4026 png_build_gamma_table(png_structp png_ptr)
nuclear@1	4027 {
nuclear@1	4028 png_debug(1, "in png_build_gamma_table\n");
nuclear@1	4029
nuclear@1	4030 if (png_ptr->bit_depth <= 8)
nuclear@1	4031 {
nuclear@1	4032 int i;
nuclear@1	4033 double g;
nuclear@1	4034
nuclear@1	4035 if (png_ptr->screen_gamma > .000001)
nuclear@1	4036 g = 1.0 / (png_ptr->gamma * png_ptr->screen_gamma);
nuclear@1	4037 else
nuclear@1	4038 g = 1.0;
nuclear@1	4039
nuclear@1	4040 png_ptr->gamma_table = (png_bytep)png_malloc(png_ptr,
nuclear@1	4041 (png_uint_32)256);
nuclear@1	4042
nuclear@1	4043 for (i = 0; i < 256; i++)
nuclear@1	4044 {
nuclear@1	4045 png_ptr->gamma_table[i] = (png_byte)(pow((double)i / 255.0,
nuclear@1	4046 g) * 255.0 + .5);
nuclear@1	4047 }
nuclear@1	4048
nuclear@1	4049 #if defined(PNG_READ_BACKGROUND_SUPPORTED) \|\| \
nuclear@1	4050 defined(PNG_READ_RGB_TO_GRAY_SUPPORTED)
nuclear@1	4051 if (png_ptr->transformations & ((PNG_BACKGROUND) \| PNG_RGB_TO_GRAY))
nuclear@1	4052 {
nuclear@1	4053
nuclear@1	4054 g = 1.0 / (png_ptr->gamma);
nuclear@1	4055
nuclear@1	4056 png_ptr->gamma_to_1 = (png_bytep)png_malloc(png_ptr,
nuclear@1	4057 (png_uint_32)256);
nuclear@1	4058
nuclear@1	4059 for (i = 0; i < 256; i++)
nuclear@1	4060 {
nuclear@1	4061 png_ptr->gamma_to_1[i] = (png_byte)(pow((double)i / 255.0,
nuclear@1	4062 g) * 255.0 + .5);
nuclear@1	4063 }
nuclear@1	4064
nuclear@1	4065
nuclear@1	4066 png_ptr->gamma_from_1 = (png_bytep)png_malloc(png_ptr,
nuclear@1	4067 (png_uint_32)256);
nuclear@1	4068
nuclear@1	4069 if (png_ptr->screen_gamma > 0.000001)
nuclear@1	4070 g = 1.0 / png_ptr->screen_gamma;
nuclear@1	4071 else
nuclear@1	4072 g = png_ptr->gamma; /* probably doing rgb_to_gray */
nuclear@1	4073
nuclear@1	4074 for (i = 0; i < 256; i++)
nuclear@1	4075 {
nuclear@1	4076 png_ptr->gamma_from_1[i] = (png_byte)(pow((double)i / 255.0,
nuclear@1	4077 g) * 255.0 + .5);
nuclear@1	4078
nuclear@1	4079 }
nuclear@1	4080 }
nuclear@1	4081 #endif /* PNG_READ_BACKGROUND_SUPPORTED \|\| PNG_RGB_TO_GRAY_SUPPORTED */
nuclear@1	4082 }
nuclear@1	4083 else
nuclear@1	4084 {
nuclear@1	4085 double g;
nuclear@1	4086 int i, j, shift, num;
nuclear@1	4087 int sig_bit;
nuclear@1	4088 png_uint_32 ig;
nuclear@1	4089
nuclear@1	4090 if (png_ptr->color_type & PNG_COLOR_MASK_COLOR)
nuclear@1	4091 {
nuclear@1	4092 sig_bit = (int)png_ptr->sig_bit.red;
nuclear@1	4093 if ((int)png_ptr->sig_bit.green > sig_bit)
nuclear@1	4094 sig_bit = png_ptr->sig_bit.green;
nuclear@1	4095 if ((int)png_ptr->sig_bit.blue > sig_bit)
nuclear@1	4096 sig_bit = png_ptr->sig_bit.blue;
nuclear@1	4097 }
nuclear@1	4098 else
nuclear@1	4099 {
nuclear@1	4100 sig_bit = (int)png_ptr->sig_bit.gray;
nuclear@1	4101 }
nuclear@1	4102
nuclear@1	4103 if (sig_bit > 0)
nuclear@1	4104 shift = 16 - sig_bit;
nuclear@1	4105 else
nuclear@1	4106 shift = 0;
nuclear@1	4107
nuclear@1	4108 if (png_ptr->transformations & PNG_16_TO_8)
nuclear@1	4109 {
nuclear@1	4110 if (shift < (16 - PNG_MAX_GAMMA_8))
nuclear@1	4111 shift = (16 - PNG_MAX_GAMMA_8);
nuclear@1	4112 }
nuclear@1	4113
nuclear@1	4114 if (shift > 8)
nuclear@1	4115 shift = 8;
nuclear@1	4116 if (shift < 0)
nuclear@1	4117 shift = 0;
nuclear@1	4118
nuclear@1	4119 png_ptr->gamma_shift = (png_byte)shift;
nuclear@1	4120
nuclear@1	4121 num = (1 << (8 - shift));
nuclear@1	4122
nuclear@1	4123 if (png_ptr->screen_gamma > .000001)
nuclear@1	4124 g = 1.0 / (png_ptr->gamma * png_ptr->screen_gamma);
nuclear@1	4125 else
nuclear@1	4126 g = 1.0;
nuclear@1	4127
nuclear@1	4128 png_ptr->gamma_16_table = (png_uint_16pp)png_malloc(png_ptr,
nuclear@1	4129 (png_uint_32)(num * png_sizeof(png_uint_16p)));
nuclear@1	4130
nuclear@1	4131 if (png_ptr->transformations & (PNG_16_TO_8 \| PNG_BACKGROUND))
nuclear@1	4132 {
nuclear@1	4133 double fin, fout;
nuclear@1	4134 png_uint_32 last, max;
nuclear@1	4135
nuclear@1	4136 for (i = 0; i < num; i++)
nuclear@1	4137 {
nuclear@1	4138 png_ptr->gamma_16_table[i] = (png_uint_16p)png_malloc(png_ptr,
nuclear@1	4139 (png_uint_32)(256 * png_sizeof(png_uint_16)));
nuclear@1	4140 }
nuclear@1	4141
nuclear@1	4142 g = 1.0 / g;
nuclear@1	4143 last = 0;
nuclear@1	4144 for (i = 0; i < 256; i++)
nuclear@1	4145 {
nuclear@1	4146 fout = ((double)i + 0.5) / 256.0;
nuclear@1	4147 fin = pow(fout, g);
nuclear@1	4148 max = (png_uint_32)(fin * (double)((png_uint_32)num << 8));
nuclear@1	4149 while (last <= max)
nuclear@1	4150 {
nuclear@1	4151 png_ptr->gamma_16_table[(int)(last & (0xff >> shift))]
nuclear@1	4152 [(int)(last >> (8 - shift))] = (png_uint_16)(
nuclear@1	4153 (png_uint_16)i \| ((png_uint_16)i << 8));
nuclear@1	4154 last++;
nuclear@1	4155 }
nuclear@1	4156 }
nuclear@1	4157 while (last < ((png_uint_32)num << 8))
nuclear@1	4158 {
nuclear@1	4159 png_ptr->gamma_16_table[(int)(last & (0xff >> shift))]
nuclear@1	4160 [(int)(last >> (8 - shift))] = (png_uint_16)65535L;
nuclear@1	4161 last++;
nuclear@1	4162 }
nuclear@1	4163 }
nuclear@1	4164 else
nuclear@1	4165 {
nuclear@1	4166 for (i = 0; i < num; i++)
nuclear@1	4167 {
nuclear@1	4168 png_ptr->gamma_16_table[i] = (png_uint_16p)png_malloc(png_ptr,
nuclear@1	4169 (png_uint_32)(256 * png_sizeof(png_uint_16)));
nuclear@1	4170
nuclear@1	4171 ig = (((png_uint_32)i * (png_uint_32)png_gamma_shift[shift]) >> 4);
nuclear@1	4172 for (j = 0; j < 256; j++)
nuclear@1	4173 {
nuclear@1	4174 png_ptr->gamma_16_table[i][j] =
nuclear@1	4175 (png_uint_16)(pow((double)(ig + ((png_uint_32)j << 8)) /
nuclear@1	4176 65535.0, g) * 65535.0 + .5);
nuclear@1	4177 }
nuclear@1	4178 }
nuclear@1	4179 }
nuclear@1	4180
nuclear@1	4181 #if defined(PNG_READ_BACKGROUND_SUPPORTED) \|\| \
nuclear@1	4182 defined(PNG_READ_RGB_TO_GRAY_SUPPORTED)
nuclear@1	4183 if (png_ptr->transformations & (PNG_BACKGROUND \| PNG_RGB_TO_GRAY))
nuclear@1	4184 {
nuclear@1	4185
nuclear@1	4186 g = 1.0 / (png_ptr->gamma);
nuclear@1	4187
nuclear@1	4188 png_ptr->gamma_16_to_1 = (png_uint_16pp)png_malloc(png_ptr,
nuclear@1	4189 (png_uint_32)(num * png_sizeof(png_uint_16p )));
nuclear@1	4190
nuclear@1	4191 for (i = 0; i < num; i++)
nuclear@1	4192 {
nuclear@1	4193 png_ptr->gamma_16_to_1[i] = (png_uint_16p)png_malloc(png_ptr,
nuclear@1	4194 (png_uint_32)(256 * png_sizeof(png_uint_16)));
nuclear@1	4195
nuclear@1	4196 ig = (((png_uint_32)i *
nuclear@1	4197 (png_uint_32)png_gamma_shift[shift]) >> 4);
nuclear@1	4198 for (j = 0; j < 256; j++)
nuclear@1	4199 {
nuclear@1	4200 png_ptr->gamma_16_to_1[i][j] =
nuclear@1	4201 (png_uint_16)(pow((double)(ig + ((png_uint_32)j << 8)) /
nuclear@1	4202 65535.0, g) * 65535.0 + .5);
nuclear@1	4203 }
nuclear@1	4204 }
nuclear@1	4205
nuclear@1	4206 if (png_ptr->screen_gamma > 0.000001)
nuclear@1	4207 g = 1.0 / png_ptr->screen_gamma;
nuclear@1	4208 else
nuclear@1	4209 g = png_ptr->gamma; /* probably doing rgb_to_gray */
nuclear@1	4210
nuclear@1	4211 png_ptr->gamma_16_from_1 = (png_uint_16pp)png_malloc(png_ptr,
nuclear@1	4212 (png_uint_32)(num * png_sizeof(png_uint_16p)));
nuclear@1	4213
nuclear@1	4214 for (i = 0; i < num; i++)
nuclear@1	4215 {
nuclear@1	4216 png_ptr->gamma_16_from_1[i] = (png_uint_16p)png_malloc(png_ptr,
nuclear@1	4217 (png_uint_32)(256 * png_sizeof(png_uint_16)));
nuclear@1	4218
nuclear@1	4219 ig = (((png_uint_32)i *
nuclear@1	4220 (png_uint_32)png_gamma_shift[shift]) >> 4);
nuclear@1	4221 for (j = 0; j < 256; j++)
nuclear@1	4222 {
nuclear@1	4223 png_ptr->gamma_16_from_1[i][j] =
nuclear@1	4224 (png_uint_16)(pow((double)(ig + ((png_uint_32)j << 8)) /
nuclear@1	4225 65535.0, g) * 65535.0 + .5);
nuclear@1	4226 }
nuclear@1	4227 }
nuclear@1	4228 }
nuclear@1	4229 #endif /* PNG_READ_BACKGROUND_SUPPORTED \|\| PNG_RGB_TO_GRAY_SUPPORTED */
nuclear@1	4230 }
nuclear@1	4231 }
nuclear@1	4232 #endif
nuclear@1	4233 /* To do: install integer version of png_build_gamma_table here */
nuclear@1	4234 #endif
nuclear@1	4235
nuclear@1	4236 #if defined(PNG_MNG_FEATURES_SUPPORTED)
nuclear@1	4237 /* undoes intrapixel differencing */
nuclear@1	4238 void /* PRIVATE */
nuclear@1	4239 png_do_read_intrapixel(png_row_infop row_info, png_bytep row)
nuclear@1	4240 {
nuclear@1	4241 png_debug(1, "in png_do_read_intrapixel\n");
nuclear@1	4242 if (
nuclear@1	4243 #if defined(PNG_USELESS_TESTS_SUPPORTED)
nuclear@1	4244 row != NULL && row_info != NULL &&
nuclear@1	4245 #endif
nuclear@1	4246 (row_info->color_type & PNG_COLOR_MASK_COLOR))
nuclear@1	4247 {
nuclear@1	4248 int bytes_per_pixel;
nuclear@1	4249 png_uint_32 row_width = row_info->width;
nuclear@1	4250 if (row_info->bit_depth == 8)
nuclear@1	4251 {
nuclear@1	4252 png_bytep rp;
nuclear@1	4253 png_uint_32 i;
nuclear@1	4254
nuclear@1	4255 if (row_info->color_type == PNG_COLOR_TYPE_RGB)
nuclear@1	4256 bytes_per_pixel = 3;
nuclear@1	4257 else if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA)
nuclear@1	4258 bytes_per_pixel = 4;
nuclear@1	4259 else
nuclear@1	4260 return;
nuclear@1	4261
nuclear@1	4262 for (i = 0, rp = row; i < row_width; i++, rp += bytes_per_pixel)
nuclear@1	4263 {
nuclear@1	4264 (rp) = (png_byte)((256 + rp + *(rp+1))&0xff);
nuclear@1	4265 (rp+2) = (png_byte)((256 + (rp+2) + *(rp+1))&0xff);
nuclear@1	4266 }
nuclear@1	4267 }
nuclear@1	4268 else if (row_info->bit_depth == 16)
nuclear@1	4269 {
nuclear@1	4270 png_bytep rp;
nuclear@1	4271 png_uint_32 i;
nuclear@1	4272
nuclear@1	4273 if (row_info->color_type == PNG_COLOR_TYPE_RGB)
nuclear@1	4274 bytes_per_pixel = 6;
nuclear@1	4275 else if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA)
nuclear@1	4276 bytes_per_pixel = 8;
nuclear@1	4277 else
nuclear@1	4278 return;
nuclear@1	4279
nuclear@1	4280 for (i = 0, rp = row; i < row_width; i++, rp += bytes_per_pixel)
nuclear@1	4281 {
nuclear@1	4282 png_uint_32 s0 = ((rp ) << 8) \| (rp + 1);
nuclear@1	4283 png_uint_32 s1 = ((rp + 2) << 8) \| (rp + 3);
nuclear@1	4284 png_uint_32 s2 = ((rp + 4) << 8) \| (rp + 5);
nuclear@1	4285 png_uint_32 red = (png_uint_32)((s0 + s1 + 65536L) & 0xffffL);
nuclear@1	4286 png_uint_32 blue = (png_uint_32)((s2 + s1 + 65536L) & 0xffffL);
nuclear@1	4287 *(rp ) = (png_byte)((red >> 8) & 0xff);
nuclear@1	4288 *(rp+1) = (png_byte)(red & 0xff);
nuclear@1	4289 *(rp+4) = (png_byte)((blue >> 8) & 0xff);
nuclear@1	4290 *(rp+5) = (png_byte)(blue & 0xff);
nuclear@1	4291 }
nuclear@1	4292 }
nuclear@1	4293 }
nuclear@1	4294 }
nuclear@1	4295 #endif /* PNG_MNG_FEATURES_SUPPORTED */
nuclear@1	4296 #endif /* PNG_READ_SUPPORTED */