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annotate libs/libpng/pngwio.c @ 35:643f4ab609a4

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added readme and license
author John Tsiombikas <nuclear@member.fsf.org>
date Sat, 31 Oct 2015 05:45:35 +0200
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nuclear@2 1
nuclear@2 2 /* pngwio.c - functions for data output
nuclear@2 3 *
nuclear@2 4 * Last changed in libpng 1.2.30 [August 15, 2008]
nuclear@2 5 * For conditions of distribution and use, see copyright notice in png.h
nuclear@2 6 * Copyright (c) 1998-2008 Glenn Randers-Pehrson
nuclear@2 7 * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
nuclear@2 8 * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
nuclear@2 9 *
nuclear@2 10 * This file provides a location for all output. Users who need
nuclear@2 11 * special handling are expected to write functions that have the same
nuclear@2 12 * arguments as these and perform similar functions, but that possibly
nuclear@2 13 * use different output methods. Note that you shouldn't change these
nuclear@2 14 * functions, but rather write replacement functions and then change
nuclear@2 15 * them at run time with png_set_write_fn(...).
nuclear@2 16 */
nuclear@2 17
nuclear@2 18 #define PNG_INTERNAL
nuclear@2 19 #include "png.h"
nuclear@2 20 #ifdef PNG_WRITE_SUPPORTED
nuclear@2 21
nuclear@2 22 /* Write the data to whatever output you are using. The default routine
nuclear@2 23 writes to a file pointer. Note that this routine sometimes gets called
nuclear@2 24 with very small lengths, so you should implement some kind of simple
nuclear@2 25 buffering if you are using unbuffered writes. This should never be asked
nuclear@2 26 to write more than 64K on a 16 bit machine. */
nuclear@2 27
nuclear@2 28 void /* PRIVATE */
nuclear@2 29 png_write_data(png_structp png_ptr, png_bytep data, png_size_t length)
nuclear@2 30 {
nuclear@2 31 if (png_ptr->write_data_fn != NULL )
nuclear@2 32 (*(png_ptr->write_data_fn))(png_ptr, data, length);
nuclear@2 33 else
nuclear@2 34 png_error(png_ptr, "Call to NULL write function");
nuclear@2 35 }
nuclear@2 36
nuclear@2 37 #if !defined(PNG_NO_STDIO)
nuclear@2 38 /* This is the function that does the actual writing of data. If you are
nuclear@2 39 not writing to a standard C stream, you should create a replacement
nuclear@2 40 write_data function and use it at run time with png_set_write_fn(), rather
nuclear@2 41 than changing the library. */
nuclear@2 42 #ifndef USE_FAR_KEYWORD
nuclear@2 43 void PNGAPI
nuclear@2 44 png_default_write_data(png_structp png_ptr, png_bytep data, png_size_t length)
nuclear@2 45 {
nuclear@2 46 png_uint_32 check;
nuclear@2 47
nuclear@2 48 if (png_ptr == NULL) return;
nuclear@2 49 #if defined(_WIN32_WCE)
nuclear@2 50 if ( !WriteFile((HANDLE)(png_ptr->io_ptr), data, length, &check, NULL) )
nuclear@2 51 check = 0;
nuclear@2 52 #else
nuclear@2 53 check = fwrite(data, 1, length, (png_FILE_p)(png_ptr->io_ptr));
nuclear@2 54 #endif
nuclear@2 55 if (check != length)
nuclear@2 56 png_error(png_ptr, "Write Error");
nuclear@2 57 }
nuclear@2 58 #else
nuclear@2 59 /* this is the model-independent version. Since the standard I/O library
nuclear@2 60 can't handle far buffers in the medium and small models, we have to copy
nuclear@2 61 the data.
nuclear@2 62 */
nuclear@2 63
nuclear@2 64 #define NEAR_BUF_SIZE 1024
nuclear@2 65 #define MIN(a,b) (a <= b ? a : b)
nuclear@2 66
nuclear@2 67 void PNGAPI
nuclear@2 68 png_default_write_data(png_structp png_ptr, png_bytep data, png_size_t length)
nuclear@2 69 {
nuclear@2 70 png_uint_32 check;
nuclear@2 71 png_byte *near_data; /* Needs to be "png_byte *" instead of "png_bytep" */
nuclear@2 72 png_FILE_p io_ptr;
nuclear@2 73
nuclear@2 74 if (png_ptr == NULL) return;
nuclear@2 75 /* Check if data really is near. If so, use usual code. */
nuclear@2 76 near_data = (png_byte *)CVT_PTR_NOCHECK(data);
nuclear@2 77 io_ptr = (png_FILE_p)CVT_PTR(png_ptr->io_ptr);
nuclear@2 78 if ((png_bytep)near_data == data)
nuclear@2 79 {
nuclear@2 80 #if defined(_WIN32_WCE)
nuclear@2 81 if ( !WriteFile(io_ptr, near_data, length, &check, NULL) )
nuclear@2 82 check = 0;
nuclear@2 83 #else
nuclear@2 84 check = fwrite(near_data, 1, length, io_ptr);
nuclear@2 85 #endif
nuclear@2 86 }
nuclear@2 87 else
nuclear@2 88 {
nuclear@2 89 png_byte buf[NEAR_BUF_SIZE];
nuclear@2 90 png_size_t written, remaining, err;
nuclear@2 91 check = 0;
nuclear@2 92 remaining = length;
nuclear@2 93 do
nuclear@2 94 {
nuclear@2 95 written = MIN(NEAR_BUF_SIZE, remaining);
nuclear@2 96 png_memcpy(buf, data, written); /* copy far buffer to near buffer */
nuclear@2 97 #if defined(_WIN32_WCE)
nuclear@2 98 if ( !WriteFile(io_ptr, buf, written, &err, NULL) )
nuclear@2 99 err = 0;
nuclear@2 100 #else
nuclear@2 101 err = fwrite(buf, 1, written, io_ptr);
nuclear@2 102 #endif
nuclear@2 103 if (err != written)
nuclear@2 104 break;
nuclear@2 105 else
nuclear@2 106 check += err;
nuclear@2 107 data += written;
nuclear@2 108 remaining -= written;
nuclear@2 109 }
nuclear@2 110 while (remaining != 0);
nuclear@2 111 }
nuclear@2 112 if (check != length)
nuclear@2 113 png_error(png_ptr, "Write Error");
nuclear@2 114 }
nuclear@2 115
nuclear@2 116 #endif
nuclear@2 117 #endif
nuclear@2 118
nuclear@2 119 /* This function is called to output any data pending writing (normally
nuclear@2 120 to disk). After png_flush is called, there should be no data pending
nuclear@2 121 writing in any buffers. */
nuclear@2 122 #if defined(PNG_WRITE_FLUSH_SUPPORTED)
nuclear@2 123 void /* PRIVATE */
nuclear@2 124 png_flush(png_structp png_ptr)
nuclear@2 125 {
nuclear@2 126 if (png_ptr->output_flush_fn != NULL)
nuclear@2 127 (*(png_ptr->output_flush_fn))(png_ptr);
nuclear@2 128 }
nuclear@2 129
nuclear@2 130 #if !defined(PNG_NO_STDIO)
nuclear@2 131 void PNGAPI
nuclear@2 132 png_default_flush(png_structp png_ptr)
nuclear@2 133 {
nuclear@2 134 #if !defined(_WIN32_WCE)
nuclear@2 135 png_FILE_p io_ptr;
nuclear@2 136 #endif
nuclear@2 137 if (png_ptr == NULL) return;
nuclear@2 138 #if !defined(_WIN32_WCE)
nuclear@2 139 io_ptr = (png_FILE_p)CVT_PTR((png_ptr->io_ptr));
nuclear@2 140 if (io_ptr != NULL)
nuclear@2 141 fflush(io_ptr);
nuclear@2 142 #endif
nuclear@2 143 }
nuclear@2 144 #endif
nuclear@2 145 #endif
nuclear@2 146
nuclear@2 147 /* This function allows the application to supply new output functions for
nuclear@2 148 libpng if standard C streams aren't being used.
nuclear@2 149
nuclear@2 150 This function takes as its arguments:
nuclear@2 151 png_ptr - pointer to a png output data structure
nuclear@2 152 io_ptr - pointer to user supplied structure containing info about
nuclear@2 153 the output functions. May be NULL.
nuclear@2 154 write_data_fn - pointer to a new output function that takes as its
nuclear@2 155 arguments a pointer to a png_struct, a pointer to
nuclear@2 156 data to be written, and a 32-bit unsigned int that is
nuclear@2 157 the number of bytes to be written. The new write
nuclear@2 158 function should call png_error(png_ptr, "Error msg")
nuclear@2 159 to exit and output any fatal error messages.
nuclear@2 160 flush_data_fn - pointer to a new flush function that takes as its
nuclear@2 161 arguments a pointer to a png_struct. After a call to
nuclear@2 162 the flush function, there should be no data in any buffers
nuclear@2 163 or pending transmission. If the output method doesn't do
nuclear@2 164 any buffering of ouput, a function prototype must still be
nuclear@2 165 supplied although it doesn't have to do anything. If
nuclear@2 166 PNG_WRITE_FLUSH_SUPPORTED is not defined at libpng compile
nuclear@2 167 time, output_flush_fn will be ignored, although it must be
nuclear@2 168 supplied for compatibility. */
nuclear@2 169 void PNGAPI
nuclear@2 170 png_set_write_fn(png_structp png_ptr, png_voidp io_ptr,
nuclear@2 171 png_rw_ptr write_data_fn, png_flush_ptr output_flush_fn)
nuclear@2 172 {
nuclear@2 173 if (png_ptr == NULL) return;
nuclear@2 174 png_ptr->io_ptr = io_ptr;
nuclear@2 175
nuclear@2 176 #if !defined(PNG_NO_STDIO)
nuclear@2 177 if (write_data_fn != NULL)
nuclear@2 178 png_ptr->write_data_fn = write_data_fn;
nuclear@2 179 else
nuclear@2 180 png_ptr->write_data_fn = png_default_write_data;
nuclear@2 181 #else
nuclear@2 182 png_ptr->write_data_fn = write_data_fn;
nuclear@2 183 #endif
nuclear@2 184
nuclear@2 185 #if defined(PNG_WRITE_FLUSH_SUPPORTED)
nuclear@2 186 #if !defined(PNG_NO_STDIO)
nuclear@2 187 if (output_flush_fn != NULL)
nuclear@2 188 png_ptr->output_flush_fn = output_flush_fn;
nuclear@2 189 else
nuclear@2 190 png_ptr->output_flush_fn = png_default_flush;
nuclear@2 191 #else
nuclear@2 192 png_ptr->output_flush_fn = output_flush_fn;
nuclear@2 193 #endif
nuclear@2 194 #endif /* PNG_WRITE_FLUSH_SUPPORTED */
nuclear@2 195
nuclear@2 196 /* It is an error to read while writing a png file */
nuclear@2 197 if (png_ptr->read_data_fn != NULL)
nuclear@2 198 {
nuclear@2 199 png_ptr->read_data_fn = NULL;
nuclear@2 200 png_warning(png_ptr,
nuclear@2 201 "Attempted to set both read_data_fn and write_data_fn in");
nuclear@2 202 png_warning(png_ptr,
nuclear@2 203 "the same structure. Resetting read_data_fn to NULL.");
nuclear@2 204 }
nuclear@2 205 }
nuclear@2 206
nuclear@2 207 #if defined(USE_FAR_KEYWORD)
nuclear@2 208 #if defined(_MSC_VER)
nuclear@2 209 void *png_far_to_near(png_structp png_ptr, png_voidp ptr, int check)
nuclear@2 210 {
nuclear@2 211 void *near_ptr;
nuclear@2 212 void FAR *far_ptr;
nuclear@2 213 FP_OFF(near_ptr) = FP_OFF(ptr);
nuclear@2 214 far_ptr = (void FAR *)near_ptr;
nuclear@2 215 if (check != 0)
nuclear@2 216 if (FP_SEG(ptr) != FP_SEG(far_ptr))
nuclear@2 217 png_error(png_ptr, "segment lost in conversion");
nuclear@2 218 return(near_ptr);
nuclear@2 219 }
nuclear@2 220 # else
nuclear@2 221 void *png_far_to_near(png_structp png_ptr, png_voidp ptr, int check)
nuclear@2 222 {
nuclear@2 223 void *near_ptr;
nuclear@2 224 void FAR *far_ptr;
nuclear@2 225 near_ptr = (void FAR *)ptr;
nuclear@2 226 far_ptr = (void FAR *)near_ptr;
nuclear@2 227 if (check != 0)
nuclear@2 228 if (far_ptr != ptr)
nuclear@2 229 png_error(png_ptr, "segment lost in conversion");
nuclear@2 230 return(near_ptr);
nuclear@2 231 }
nuclear@2 232 # endif
nuclear@2 233 # endif
nuclear@2 234 #endif /* PNG_WRITE_SUPPORTED */