dbf-halloween2015

annotate libs/imago/file_png.c @ 3:c37fe5d8a4ed

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windows port
author John Tsiombikas <nuclear@member.fsf.org>
date Sun, 01 Nov 2015 06:04:28 +0200
parents c3f5c32cb210
children
rev   line source
nuclear@1 1 /*
nuclear@1 2 libimago - a multi-format image file input/output library.
nuclear@1 3 Copyright (C) 2010 John Tsiombikas <nuclear@member.fsf.org>
nuclear@1 4
nuclear@1 5 This program is free software: you can redistribute it and/or modify
nuclear@1 6 it under the terms of the GNU Lesser General Public License as published
nuclear@1 7 by the Free Software Foundation, either version 3 of the License, or
nuclear@1 8 (at your option) any later version.
nuclear@1 9
nuclear@1 10 This program is distributed in the hope that it will be useful,
nuclear@1 11 but WITHOUT ANY WARRANTY; without even the implied warranty of
nuclear@1 12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
nuclear@1 13 GNU Lesser General Public License for more details.
nuclear@1 14
nuclear@1 15 You should have received a copy of the GNU Lesser General Public License
nuclear@1 16 along with this program. If not, see <http://www.gnu.org/licenses/>.
nuclear@1 17 */
nuclear@1 18
nuclear@1 19 /* -- PNG module -- */
nuclear@3 20 #include <string.h>
nuclear@1 21 #include <stdlib.h>
nuclear@1 22 #include "png.h"
nuclear@1 23 #include "imago2.h"
nuclear@1 24 #include "ftype_module.h"
nuclear@1 25
nuclear@1 26 static int check_file(struct img_io *io);
nuclear@1 27 static int read_file(struct img_pixmap *img, struct img_io *io);
nuclear@1 28 static int write_file(struct img_pixmap *img, struct img_io *io);
nuclear@1 29
nuclear@1 30 static void read_func(png_struct *png, unsigned char *data, size_t len);
nuclear@1 31 static void write_func(png_struct *png, unsigned char *data, size_t len);
nuclear@1 32 static void flush_func(png_struct *png);
nuclear@1 33
nuclear@1 34 static int png_type_to_fmt(int color_type, int channel_bits);
nuclear@1 35 static int fmt_to_png_type(enum img_fmt fmt);
nuclear@1 36
nuclear@1 37
nuclear@1 38 int img_register_png(void)
nuclear@1 39 {
nuclear@1 40 static struct ftype_module mod = {".png", check_file, read_file, write_file};
nuclear@1 41 return img_register_module(&mod);
nuclear@1 42 }
nuclear@1 43
nuclear@1 44 static int check_file(struct img_io *io)
nuclear@1 45 {
nuclear@1 46 unsigned char sig[8];
nuclear@1 47 int res;
nuclear@1 48 long pos = io->seek(0, SEEK_CUR, io->uptr);
nuclear@1 49
nuclear@1 50 if(io->read(sig, 8, io->uptr) < 8) {
nuclear@1 51 io->seek(pos, SEEK_SET, io->uptr);
nuclear@1 52 return -1;
nuclear@1 53 }
nuclear@1 54
nuclear@1 55 res = png_sig_cmp(sig, 0, 8) == 0 ? 0 : -1;
nuclear@1 56 io->seek(pos, SEEK_SET, io->uptr);
nuclear@1 57 return res;
nuclear@1 58 }
nuclear@1 59
nuclear@1 60 static int read_file(struct img_pixmap *img, struct img_io *io)
nuclear@1 61 {
nuclear@1 62 png_struct *png;
nuclear@1 63 png_info *info;
nuclear@1 64 int channel_bits, color_type, ilace_type, compression, filtering, fmt;
nuclear@1 65 png_uint_32 xsz, ysz;
nuclear@1 66
nuclear@1 67 if(!(png = png_create_read_struct(PNG_LIBPNG_VER_STRING, 0, 0, 0))) {
nuclear@1 68 return -1;
nuclear@1 69 }
nuclear@1 70
nuclear@1 71 if(!(info = png_create_info_struct(png))) {
nuclear@1 72 png_destroy_read_struct(&png, 0, 0);
nuclear@1 73 return -1;
nuclear@1 74 }
nuclear@1 75
nuclear@1 76 if(setjmp(png_jmpbuf(png))) {
nuclear@1 77 png_destroy_read_struct(&png, &info, 0);
nuclear@1 78 return -1;
nuclear@1 79 }
nuclear@1 80
nuclear@1 81 png_set_read_fn(png, io, read_func);
nuclear@1 82 png_set_sig_bytes(png, 0);
nuclear@1 83 png_read_png(png, info, 0, 0);
nuclear@1 84
nuclear@1 85 png_get_IHDR(png, info, &xsz, &ysz, &channel_bits, &color_type, &ilace_type,
nuclear@1 86 &compression, &filtering);
nuclear@1 87 if((fmt = png_type_to_fmt(color_type, channel_bits)) == -1) {
nuclear@1 88 png_destroy_read_struct(&png, &info, 0);
nuclear@1 89 return -1;
nuclear@1 90 }
nuclear@1 91
nuclear@1 92 if(img_set_pixels(img, xsz, ysz, fmt, 0) == -1) {
nuclear@1 93 png_destroy_read_struct(&png, &info, 0);
nuclear@1 94 return -1;
nuclear@1 95 }
nuclear@1 96
nuclear@1 97
nuclear@1 98 if(channel_bits == 8) {
nuclear@1 99 unsigned int i;
nuclear@1 100 unsigned char **lineptr = (unsigned char**)png_get_rows(png, info);
nuclear@1 101 unsigned char *dest = img->pixels;
nuclear@1 102
nuclear@1 103 for(i=0; i<ysz; i++) {
nuclear@1 104 memcpy(dest, lineptr[i], xsz * img->pixelsz);
nuclear@1 105 dest += xsz * img->pixelsz;
nuclear@1 106 }
nuclear@1 107 } else {
nuclear@1 108 unsigned int i, j, num_elem;
nuclear@1 109 unsigned char **lineptr = (unsigned char**)png_get_rows(png, info);
nuclear@1 110 float *dest = img->pixels;
nuclear@1 111
nuclear@1 112 num_elem = img->pixelsz / sizeof(float);
nuclear@1 113 for(i=0; i<ysz; i++) {
nuclear@1 114 for(j=0; j<xsz * num_elem; j++) {
nuclear@1 115 unsigned short val = (lineptr[i][j * 2] << 8) | lineptr[i][j * 2 + 1];
nuclear@1 116 *dest++ = (float)val / 65535.0;
nuclear@1 117 }
nuclear@1 118 }
nuclear@1 119 }
nuclear@1 120
nuclear@1 121
nuclear@1 122 png_destroy_read_struct(&png, &info, 0);
nuclear@1 123 return 0;
nuclear@1 124 }
nuclear@1 125
nuclear@1 126
nuclear@1 127 static int write_file(struct img_pixmap *img, struct img_io *io)
nuclear@1 128 {
nuclear@1 129 png_struct *png;
nuclear@1 130 png_info *info;
nuclear@1 131 png_text txt;
nuclear@1 132 struct img_pixmap tmpimg;
nuclear@1 133 unsigned char **rows;
nuclear@1 134 unsigned char *pixptr;
nuclear@1 135 int i, coltype;
nuclear@1 136
nuclear@1 137 img_init(&tmpimg);
nuclear@1 138
nuclear@1 139 if(!(png = png_create_write_struct(PNG_LIBPNG_VER_STRING, 0, 0, 0))) {
nuclear@1 140 return -1;
nuclear@1 141 }
nuclear@1 142 if(!(info = png_create_info_struct(png))) {
nuclear@1 143 png_destroy_write_struct(&png, 0);
nuclear@1 144 return -1;
nuclear@1 145 }
nuclear@1 146
nuclear@1 147 /* if the input image is floating-point, we need to convert it to integer */
nuclear@1 148 if(img_is_float(img)) {
nuclear@1 149 if(img_copy(&tmpimg, img) == -1) {
nuclear@1 150 return -1;
nuclear@1 151 }
nuclear@1 152 if(img_to_integer(&tmpimg) == -1) {
nuclear@1 153 img_destroy(&tmpimg);
nuclear@1 154 return -1;
nuclear@1 155 }
nuclear@1 156 img = &tmpimg;
nuclear@1 157 }
nuclear@1 158
nuclear@1 159 txt.compression = PNG_TEXT_COMPRESSION_NONE;
nuclear@1 160 txt.key = "Software";
nuclear@1 161 txt.text = "libimago2";
nuclear@1 162 txt.text_length = 0;
nuclear@1 163
nuclear@1 164 if(setjmp(png_jmpbuf(png))) {
nuclear@1 165 png_destroy_write_struct(&png, &info);
nuclear@1 166 img_destroy(&tmpimg);
nuclear@1 167 return -1;
nuclear@1 168 }
nuclear@1 169 png_set_write_fn(png, io, write_func, flush_func);
nuclear@1 170
nuclear@1 171 coltype = fmt_to_png_type(img->fmt);
nuclear@1 172 png_set_IHDR(png, info, img->width, img->height, 8, coltype, PNG_INTERLACE_NONE,
nuclear@1 173 PNG_COMPRESSION_TYPE_DEFAULT, PNG_FILTER_TYPE_DEFAULT);
nuclear@1 174 png_set_text(png, info, &txt, 1);
nuclear@1 175
nuclear@1 176 if(!(rows = malloc(img->height * sizeof *rows))) {
nuclear@1 177 png_destroy_write_struct(&png, &info);
nuclear@1 178 img_destroy(&tmpimg);
nuclear@1 179 return -1;
nuclear@1 180 }
nuclear@1 181
nuclear@1 182 pixptr = img->pixels;
nuclear@1 183 for(i=0; i<img->height; i++) {
nuclear@1 184 rows[i] = pixptr;
nuclear@1 185 pixptr += img->width * img->pixelsz;
nuclear@1 186 }
nuclear@1 187 png_set_rows(png, info, rows);
nuclear@1 188
nuclear@1 189 png_write_png(png, info, 0, 0);
nuclear@1 190 png_write_end(png, info);
nuclear@1 191 png_destroy_write_struct(&png, &info);
nuclear@1 192
nuclear@1 193 free(rows);
nuclear@1 194
nuclear@1 195 img_destroy(&tmpimg);
nuclear@1 196 return 0;
nuclear@1 197 }
nuclear@1 198
nuclear@1 199 static void read_func(png_struct *png, unsigned char *data, size_t len)
nuclear@1 200 {
nuclear@1 201 struct img_io *io = (struct img_io*)png_get_io_ptr(png);
nuclear@1 202
nuclear@1 203 if(io->read(data, len, io->uptr) == -1) {
nuclear@1 204 longjmp(png_jmpbuf(png), 1);
nuclear@1 205 }
nuclear@1 206 }
nuclear@1 207
nuclear@1 208 static void write_func(png_struct *png, unsigned char *data, size_t len)
nuclear@1 209 {
nuclear@1 210 struct img_io *io = (struct img_io*)png_get_io_ptr(png);
nuclear@1 211
nuclear@1 212 if(io->write(data, len, io->uptr) == -1) {
nuclear@1 213 longjmp(png_jmpbuf(png), 1);
nuclear@1 214 }
nuclear@1 215 }
nuclear@1 216
nuclear@1 217 static void flush_func(png_struct *png)
nuclear@1 218 {
nuclear@1 219 /* XXX does it matter that we can't flush? */
nuclear@1 220 }
nuclear@1 221
nuclear@1 222 static int png_type_to_fmt(int color_type, int channel_bits)
nuclear@1 223 {
nuclear@1 224 /* only 8 and 16 bits per channel ar supported at the moment */
nuclear@1 225 if(channel_bits != 8 && channel_bits != 16) {
nuclear@1 226 return -1;
nuclear@1 227 }
nuclear@1 228
nuclear@1 229 switch(color_type) {
nuclear@1 230 case PNG_COLOR_TYPE_RGB:
nuclear@1 231 return channel_bits == 16 ? IMG_FMT_RGBF : IMG_FMT_RGB24;
nuclear@1 232
nuclear@1 233 case PNG_COLOR_TYPE_RGB_ALPHA:
nuclear@1 234 return channel_bits == 16 ? IMG_FMT_RGBAF : IMG_FMT_RGBA32;
nuclear@1 235
nuclear@1 236 case PNG_COLOR_TYPE_GRAY:
nuclear@1 237 return channel_bits == 16 ? IMG_FMT_GREYF : IMG_FMT_GREY8;
nuclear@1 238
nuclear@1 239 default:
nuclear@1 240 break;
nuclear@1 241 }
nuclear@1 242 return -1;
nuclear@1 243 }
nuclear@1 244
nuclear@1 245 static int fmt_to_png_type(enum img_fmt fmt)
nuclear@1 246 {
nuclear@1 247 switch(fmt) {
nuclear@1 248 case IMG_FMT_GREY8:
nuclear@1 249 return PNG_COLOR_TYPE_GRAY;
nuclear@1 250
nuclear@1 251 case IMG_FMT_RGB24:
nuclear@1 252 return PNG_COLOR_TYPE_RGB;
nuclear@1 253
nuclear@1 254 case IMG_FMT_RGBA32:
nuclear@1 255 return PNG_COLOR_TYPE_RGBA;
nuclear@1 256
nuclear@1 257 default:
nuclear@1 258 break;
nuclear@1 259 }
nuclear@1 260 return -1;
nuclear@1 261 }