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annotate libs/libpng/pngwio.c @ 0:b2f14e535253

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author John Tsiombikas <nuclear@member.fsf.org>
date Sat, 01 Feb 2014 19:58:19 +0200
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nuclear@0 1
nuclear@0 2 /* pngwio.c - functions for data output
nuclear@0 3 *
nuclear@0 4 * Last changed in libpng 1.2.30 [August 15, 2008]
nuclear@0 5 * For conditions of distribution and use, see copyright notice in png.h
nuclear@0 6 * Copyright (c) 1998-2008 Glenn Randers-Pehrson
nuclear@0 7 * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
nuclear@0 8 * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
nuclear@0 9 *
nuclear@0 10 * This file provides a location for all output. Users who need
nuclear@0 11 * special handling are expected to write functions that have the same
nuclear@0 12 * arguments as these and perform similar functions, but that possibly
nuclear@0 13 * use different output methods. Note that you shouldn't change these
nuclear@0 14 * functions, but rather write replacement functions and then change
nuclear@0 15 * them at run time with png_set_write_fn(...).
nuclear@0 16 */
nuclear@0 17
nuclear@0 18 #define PNG_INTERNAL
nuclear@0 19 #include "png.h"
nuclear@0 20 #ifdef PNG_WRITE_SUPPORTED
nuclear@0 21
nuclear@0 22 /* Write the data to whatever output you are using. The default routine
nuclear@0 23 writes to a file pointer. Note that this routine sometimes gets called
nuclear@0 24 with very small lengths, so you should implement some kind of simple
nuclear@0 25 buffering if you are using unbuffered writes. This should never be asked
nuclear@0 26 to write more than 64K on a 16 bit machine. */
nuclear@0 27
nuclear@0 28 void /* PRIVATE */
nuclear@0 29 png_write_data(png_structp png_ptr, png_bytep data, png_size_t length)
nuclear@0 30 {
nuclear@0 31 if (png_ptr->write_data_fn != NULL )
nuclear@0 32 (*(png_ptr->write_data_fn))(png_ptr, data, length);
nuclear@0 33 else
nuclear@0 34 png_error(png_ptr, "Call to NULL write function");
nuclear@0 35 }
nuclear@0 36
nuclear@0 37 #if !defined(PNG_NO_STDIO)
nuclear@0 38 /* This is the function that does the actual writing of data. If you are
nuclear@0 39 not writing to a standard C stream, you should create a replacement
nuclear@0 40 write_data function and use it at run time with png_set_write_fn(), rather
nuclear@0 41 than changing the library. */
nuclear@0 42 #ifndef USE_FAR_KEYWORD
nuclear@0 43 void PNGAPI
nuclear@0 44 png_default_write_data(png_structp png_ptr, png_bytep data, png_size_t length)
nuclear@0 45 {
nuclear@0 46 png_uint_32 check;
nuclear@0 47
nuclear@0 48 if (png_ptr == NULL) return;
nuclear@0 49 #if defined(_WIN32_WCE)
nuclear@0 50 if ( !WriteFile((HANDLE)(png_ptr->io_ptr), data, length, &check, NULL) )
nuclear@0 51 check = 0;
nuclear@0 52 #else
nuclear@0 53 check = fwrite(data, 1, length, (png_FILE_p)(png_ptr->io_ptr));
nuclear@0 54 #endif
nuclear@0 55 if (check != length)
nuclear@0 56 png_error(png_ptr, "Write Error");
nuclear@0 57 }
nuclear@0 58 #else
nuclear@0 59 /* this is the model-independent version. Since the standard I/O library
nuclear@0 60 can't handle far buffers in the medium and small models, we have to copy
nuclear@0 61 the data.
nuclear@0 62 */
nuclear@0 63
nuclear@0 64 #define NEAR_BUF_SIZE 1024
nuclear@0 65 #define MIN(a,b) (a <= b ? a : b)
nuclear@0 66
nuclear@0 67 void PNGAPI
nuclear@0 68 png_default_write_data(png_structp png_ptr, png_bytep data, png_size_t length)
nuclear@0 69 {
nuclear@0 70 png_uint_32 check;
nuclear@0 71 png_byte *near_data; /* Needs to be "png_byte *" instead of "png_bytep" */
nuclear@0 72 png_FILE_p io_ptr;
nuclear@0 73
nuclear@0 74 if (png_ptr == NULL) return;
nuclear@0 75 /* Check if data really is near. If so, use usual code. */
nuclear@0 76 near_data = (png_byte *)CVT_PTR_NOCHECK(data);
nuclear@0 77 io_ptr = (png_FILE_p)CVT_PTR(png_ptr->io_ptr);
nuclear@0 78 if ((png_bytep)near_data == data)
nuclear@0 79 {
nuclear@0 80 #if defined(_WIN32_WCE)
nuclear@0 81 if ( !WriteFile(io_ptr, near_data, length, &check, NULL) )
nuclear@0 82 check = 0;
nuclear@0 83 #else
nuclear@0 84 check = fwrite(near_data, 1, length, io_ptr);
nuclear@0 85 #endif
nuclear@0 86 }
nuclear@0 87 else
nuclear@0 88 {
nuclear@0 89 png_byte buf[NEAR_BUF_SIZE];
nuclear@0 90 png_size_t written, remaining, err;
nuclear@0 91 check = 0;
nuclear@0 92 remaining = length;
nuclear@0 93 do
nuclear@0 94 {
nuclear@0 95 written = MIN(NEAR_BUF_SIZE, remaining);
nuclear@0 96 png_memcpy(buf, data, written); /* copy far buffer to near buffer */
nuclear@0 97 #if defined(_WIN32_WCE)
nuclear@0 98 if ( !WriteFile(io_ptr, buf, written, &err, NULL) )
nuclear@0 99 err = 0;
nuclear@0 100 #else
nuclear@0 101 err = fwrite(buf, 1, written, io_ptr);
nuclear@0 102 #endif
nuclear@0 103 if (err != written)
nuclear@0 104 break;
nuclear@0 105 else
nuclear@0 106 check += err;
nuclear@0 107 data += written;
nuclear@0 108 remaining -= written;
nuclear@0 109 }
nuclear@0 110 while (remaining != 0);
nuclear@0 111 }
nuclear@0 112 if (check != length)
nuclear@0 113 png_error(png_ptr, "Write Error");
nuclear@0 114 }
nuclear@0 115
nuclear@0 116 #endif
nuclear@0 117 #endif
nuclear@0 118
nuclear@0 119 /* This function is called to output any data pending writing (normally
nuclear@0 120 to disk). After png_flush is called, there should be no data pending
nuclear@0 121 writing in any buffers. */
nuclear@0 122 #if defined(PNG_WRITE_FLUSH_SUPPORTED)
nuclear@0 123 void /* PRIVATE */
nuclear@0 124 png_flush(png_structp png_ptr)
nuclear@0 125 {
nuclear@0 126 if (png_ptr->output_flush_fn != NULL)
nuclear@0 127 (*(png_ptr->output_flush_fn))(png_ptr);
nuclear@0 128 }
nuclear@0 129
nuclear@0 130 #if !defined(PNG_NO_STDIO)
nuclear@0 131 void PNGAPI
nuclear@0 132 png_default_flush(png_structp png_ptr)
nuclear@0 133 {
nuclear@0 134 #if !defined(_WIN32_WCE)
nuclear@0 135 png_FILE_p io_ptr;
nuclear@0 136 #endif
nuclear@0 137 if (png_ptr == NULL) return;
nuclear@0 138 #if !defined(_WIN32_WCE)
nuclear@0 139 io_ptr = (png_FILE_p)CVT_PTR((png_ptr->io_ptr));
nuclear@0 140 if (io_ptr != NULL)
nuclear@0 141 fflush(io_ptr);
nuclear@0 142 #endif
nuclear@0 143 }
nuclear@0 144 #endif
nuclear@0 145 #endif
nuclear@0 146
nuclear@0 147 /* This function allows the application to supply new output functions for
nuclear@0 148 libpng if standard C streams aren't being used.
nuclear@0 149
nuclear@0 150 This function takes as its arguments:
nuclear@0 151 png_ptr - pointer to a png output data structure
nuclear@0 152 io_ptr - pointer to user supplied structure containing info about
nuclear@0 153 the output functions. May be NULL.
nuclear@0 154 write_data_fn - pointer to a new output function that takes as its
nuclear@0 155 arguments a pointer to a png_struct, a pointer to
nuclear@0 156 data to be written, and a 32-bit unsigned int that is
nuclear@0 157 the number of bytes to be written. The new write
nuclear@0 158 function should call png_error(png_ptr, "Error msg")
nuclear@0 159 to exit and output any fatal error messages.
nuclear@0 160 flush_data_fn - pointer to a new flush function that takes as its
nuclear@0 161 arguments a pointer to a png_struct. After a call to
nuclear@0 162 the flush function, there should be no data in any buffers
nuclear@0 163 or pending transmission. If the output method doesn't do
nuclear@0 164 any buffering of ouput, a function prototype must still be
nuclear@0 165 supplied although it doesn't have to do anything. If
nuclear@0 166 PNG_WRITE_FLUSH_SUPPORTED is not defined at libpng compile
nuclear@0 167 time, output_flush_fn will be ignored, although it must be
nuclear@0 168 supplied for compatibility. */
nuclear@0 169 void PNGAPI
nuclear@0 170 png_set_write_fn(png_structp png_ptr, png_voidp io_ptr,
nuclear@0 171 png_rw_ptr write_data_fn, png_flush_ptr output_flush_fn)
nuclear@0 172 {
nuclear@0 173 if (png_ptr == NULL) return;
nuclear@0 174 png_ptr->io_ptr = io_ptr;
nuclear@0 175
nuclear@0 176 #if !defined(PNG_NO_STDIO)
nuclear@0 177 if (write_data_fn != NULL)
nuclear@0 178 png_ptr->write_data_fn = write_data_fn;
nuclear@0 179 else
nuclear@0 180 png_ptr->write_data_fn = png_default_write_data;
nuclear@0 181 #else
nuclear@0 182 png_ptr->write_data_fn = write_data_fn;
nuclear@0 183 #endif
nuclear@0 184
nuclear@0 185 #if defined(PNG_WRITE_FLUSH_SUPPORTED)
nuclear@0 186 #if !defined(PNG_NO_STDIO)
nuclear@0 187 if (output_flush_fn != NULL)
nuclear@0 188 png_ptr->output_flush_fn = output_flush_fn;
nuclear@0 189 else
nuclear@0 190 png_ptr->output_flush_fn = png_default_flush;
nuclear@0 191 #else
nuclear@0 192 png_ptr->output_flush_fn = output_flush_fn;
nuclear@0 193 #endif
nuclear@0 194 #endif /* PNG_WRITE_FLUSH_SUPPORTED */
nuclear@0 195
nuclear@0 196 /* It is an error to read while writing a png file */
nuclear@0 197 if (png_ptr->read_data_fn != NULL)
nuclear@0 198 {
nuclear@0 199 png_ptr->read_data_fn = NULL;
nuclear@0 200 png_warning(png_ptr,
nuclear@0 201 "Attempted to set both read_data_fn and write_data_fn in");
nuclear@0 202 png_warning(png_ptr,
nuclear@0 203 "the same structure. Resetting read_data_fn to NULL.");
nuclear@0 204 }
nuclear@0 205 }
nuclear@0 206
nuclear@0 207 #if defined(USE_FAR_KEYWORD)
nuclear@0 208 #if defined(_MSC_VER)
nuclear@0 209 void *png_far_to_near(png_structp png_ptr, png_voidp ptr, int check)
nuclear@0 210 {
nuclear@0 211 void *near_ptr;
nuclear@0 212 void FAR *far_ptr;
nuclear@0 213 FP_OFF(near_ptr) = FP_OFF(ptr);
nuclear@0 214 far_ptr = (void FAR *)near_ptr;
nuclear@0 215 if (check != 0)
nuclear@0 216 if (FP_SEG(ptr) != FP_SEG(far_ptr))
nuclear@0 217 png_error(png_ptr, "segment lost in conversion");
nuclear@0 218 return(near_ptr);
nuclear@0 219 }
nuclear@0 220 # else
nuclear@0 221 void *png_far_to_near(png_structp png_ptr, png_voidp ptr, int check)
nuclear@0 222 {
nuclear@0 223 void *near_ptr;
nuclear@0 224 void FAR *far_ptr;
nuclear@0 225 near_ptr = (void FAR *)ptr;
nuclear@0 226 far_ptr = (void FAR *)near_ptr;
nuclear@0 227 if (check != 0)
nuclear@0 228 if (far_ptr != ptr)
nuclear@0 229 png_error(png_ptr, "segment lost in conversion");
nuclear@0 230 return(near_ptr);
nuclear@0 231 }
nuclear@0 232 # endif
nuclear@0 233 # endif
nuclear@0 234 #endif /* PNG_WRITE_SUPPORTED */