Guy Schalnat | 0d58058 | 1995-07-20 02:43:20 -0500 | [diff] [blame] | 1 | |
Glenn Randers-Pehrson | b6ce43d | 1998-01-01 07:13:13 -0600 | [diff] [blame] | 2 | /* png.c - location for general purpose libpng functions |
| 3 | * |
Glenn Randers-Pehrson | f9f2fe0 | 1998-03-15 18:20:23 -0600 | [diff] [blame^] | 4 | * libpng 1.0.1 |
Glenn Randers-Pehrson | b6ce43d | 1998-01-01 07:13:13 -0600 | [diff] [blame] | 5 | * For conditions of distribution and use, see copyright notice in png.h |
| 6 | * Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc. |
| 7 | * Copyright (c) 1996, 1997 Andreas Dilger |
Glenn Randers-Pehrson | 2687fcc | 1998-01-07 20:54:20 -0600 | [diff] [blame] | 8 | * Copyright (c) 1998, Glenn Randers-Pehrson |
Glenn Randers-Pehrson | f9f2fe0 | 1998-03-15 18:20:23 -0600 | [diff] [blame^] | 9 | * March 15, 1998 |
Glenn Randers-Pehrson | b6ce43d | 1998-01-01 07:13:13 -0600 | [diff] [blame] | 10 | */ |
Guy Schalnat | 0d58058 | 1995-07-20 02:43:20 -0500 | [diff] [blame] | 11 | |
| 12 | #define PNG_INTERNAL |
| 13 | #define PNG_NO_EXTERN |
| 14 | #include "png.h" |
| 15 | |
Andreas Dilger | 47a0c42 | 1997-05-16 02:46:07 -0500 | [diff] [blame] | 16 | /* Version information for C files. This had better match the version |
Glenn Randers-Pehrson | b6ce43d | 1998-01-01 07:13:13 -0600 | [diff] [blame] | 17 | * string defined in png.h. |
| 18 | */ |
Glenn Randers-Pehrson | f9f2fe0 | 1998-03-15 18:20:23 -0600 | [diff] [blame^] | 19 | char png_libpng_ver[12] = "1.0.1"; |
Guy Schalnat | 51f0eb4 | 1995-09-26 05:22:39 -0500 | [diff] [blame] | 20 | |
Glenn Randers-Pehrson | 46f61e2 | 1998-01-30 21:45:12 -0600 | [diff] [blame] | 21 | /* Place to hold the signature string for a PNG file. */ |
Guy Schalnat | 6d76471 | 1995-12-19 03:22:19 -0600 | [diff] [blame] | 22 | png_byte FARDATA png_sig[8] = {137, 80, 78, 71, 13, 10, 26, 10}; |
Guy Schalnat | 0d58058 | 1995-07-20 02:43:20 -0500 | [diff] [blame] | 23 | |
Glenn Randers-Pehrson | b6ce43d | 1998-01-01 07:13:13 -0600 | [diff] [blame] | 24 | /* Constant strings for known chunk types. If you need to add a chunk, |
| 25 | * add a string holding the name here. If you want to make the code |
| 26 | * portable to EBCDIC machines, use ASCII numbers, not characters. |
| 27 | */ |
Andreas Dilger | 47a0c42 | 1997-05-16 02:46:07 -0500 | [diff] [blame] | 28 | png_byte FARDATA png_IHDR[5] = { 73, 72, 68, 82, '\0'}; |
| 29 | png_byte FARDATA png_IDAT[5] = { 73, 68, 65, 84, '\0'}; |
| 30 | png_byte FARDATA png_IEND[5] = { 73, 69, 78, 68, '\0'}; |
| 31 | png_byte FARDATA png_PLTE[5] = { 80, 76, 84, 69, '\0'}; |
| 32 | png_byte FARDATA png_bKGD[5] = { 98, 75, 71, 68, '\0'}; |
| 33 | png_byte FARDATA png_cHRM[5] = { 99, 72, 82, 77, '\0'}; |
| 34 | png_byte FARDATA png_gAMA[5] = {103, 65, 77, 65, '\0'}; |
| 35 | png_byte FARDATA png_hIST[5] = {104, 73, 83, 84, '\0'}; |
| 36 | png_byte FARDATA png_oFFs[5] = {111, 70, 70, 115, '\0'}; |
| 37 | png_byte FARDATA png_pCAL[5] = {112, 67, 65, 76, '\0'}; |
| 38 | png_byte FARDATA png_pHYs[5] = {112, 72, 89, 115, '\0'}; |
| 39 | png_byte FARDATA png_sBIT[5] = {115, 66, 73, 84, '\0'}; |
Glenn Randers-Pehrson | b6ce43d | 1998-01-01 07:13:13 -0600 | [diff] [blame] | 40 | png_byte FARDATA png_sRGB[5] = {115, 82, 71, 66, '\0'}; |
Andreas Dilger | 47a0c42 | 1997-05-16 02:46:07 -0500 | [diff] [blame] | 41 | png_byte FARDATA png_tEXt[5] = {116, 69, 88, 116, '\0'}; |
| 42 | png_byte FARDATA png_tIME[5] = {116, 73, 77, 69, '\0'}; |
| 43 | png_byte FARDATA png_tRNS[5] = {116, 82, 78, 83, '\0'}; |
| 44 | png_byte FARDATA png_zTXt[5] = {122, 84, 88, 116, '\0'}; |
Guy Schalnat | 0d58058 | 1995-07-20 02:43:20 -0500 | [diff] [blame] | 45 | |
| 46 | /* arrays to facilitate easy interlacing - use pass (0 - 6) as index */ |
| 47 | |
| 48 | /* start of interlace block */ |
Guy Schalnat | 6d76471 | 1995-12-19 03:22:19 -0600 | [diff] [blame] | 49 | int FARDATA png_pass_start[] = {0, 4, 0, 2, 0, 1, 0}; |
Guy Schalnat | 0d58058 | 1995-07-20 02:43:20 -0500 | [diff] [blame] | 50 | |
| 51 | /* offset to next interlace block */ |
Guy Schalnat | 6d76471 | 1995-12-19 03:22:19 -0600 | [diff] [blame] | 52 | int FARDATA png_pass_inc[] = {8, 8, 4, 4, 2, 2, 1}; |
Guy Schalnat | 0d58058 | 1995-07-20 02:43:20 -0500 | [diff] [blame] | 53 | |
| 54 | /* start of interlace block in the y direction */ |
Guy Schalnat | 6d76471 | 1995-12-19 03:22:19 -0600 | [diff] [blame] | 55 | int FARDATA png_pass_ystart[] = {0, 0, 4, 0, 2, 0, 1}; |
Guy Schalnat | 0d58058 | 1995-07-20 02:43:20 -0500 | [diff] [blame] | 56 | |
| 57 | /* offset to next interlace block in the y direction */ |
Guy Schalnat | 6d76471 | 1995-12-19 03:22:19 -0600 | [diff] [blame] | 58 | int FARDATA png_pass_yinc[] = {8, 8, 8, 4, 4, 2, 2}; |
Guy Schalnat | 0d58058 | 1995-07-20 02:43:20 -0500 | [diff] [blame] | 59 | |
Glenn Randers-Pehrson | b6ce43d | 1998-01-01 07:13:13 -0600 | [diff] [blame] | 60 | /* Width of interlace block. This is not currently used - if you need |
| 61 | * it, uncomment it here and in png.h |
Guy Schalnat | 6d76471 | 1995-12-19 03:22:19 -0600 | [diff] [blame] | 62 | int FARDATA png_pass_width[] = {8, 4, 4, 2, 2, 1, 1}; |
Guy Schalnat | 0d58058 | 1995-07-20 02:43:20 -0500 | [diff] [blame] | 63 | */ |
| 64 | |
Glenn Randers-Pehrson | b6ce43d | 1998-01-01 07:13:13 -0600 | [diff] [blame] | 65 | /* Height of interlace block. This is not currently used - if you need |
| 66 | * it, uncomment it here and in png.h |
Guy Schalnat | 6d76471 | 1995-12-19 03:22:19 -0600 | [diff] [blame] | 67 | int FARDATA png_pass_height[] = {8, 8, 4, 4, 2, 2, 1}; |
Guy Schalnat | 0d58058 | 1995-07-20 02:43:20 -0500 | [diff] [blame] | 68 | */ |
| 69 | |
Glenn Randers-Pehrson | b6ce43d | 1998-01-01 07:13:13 -0600 | [diff] [blame] | 70 | /* Mask to determine which pixels are valid in a pass */ |
Guy Schalnat | 6d76471 | 1995-12-19 03:22:19 -0600 | [diff] [blame] | 71 | int FARDATA png_pass_mask[] = {0x80, 0x08, 0x88, 0x22, 0xaa, 0x55, 0xff}; |
Guy Schalnat | 0d58058 | 1995-07-20 02:43:20 -0500 | [diff] [blame] | 72 | |
Glenn Randers-Pehrson | b6ce43d | 1998-01-01 07:13:13 -0600 | [diff] [blame] | 73 | /* Mask to determine which pixels to overwrite while displaying */ |
Guy Schalnat | 6d76471 | 1995-12-19 03:22:19 -0600 | [diff] [blame] | 74 | int FARDATA png_pass_dsp_mask[] = {0xff, 0x0f, 0xff, 0x33, 0xff, 0x55, 0xff}; |
Guy Schalnat | 0d58058 | 1995-07-20 02:43:20 -0500 | [diff] [blame] | 75 | |
| 76 | |
Andreas Dilger | 02ad0ef | 1997-01-17 01:34:35 -0600 | [diff] [blame] | 77 | /* Tells libpng that we have already handled the first "num_bytes" bytes |
| 78 | * of the PNG file signature. If the PNG data is embedded into another |
| 79 | * stream we can set num_bytes = 8 so that libpng will not attempt to read |
| 80 | * or write any of the magic bytes before it starts on the IHDR. |
| 81 | */ |
| 82 | void |
| 83 | png_set_sig_bytes(png_structp png_ptr, int num_bytes) |
| 84 | { |
Andreas Dilger | 47a0c42 | 1997-05-16 02:46:07 -0500 | [diff] [blame] | 85 | png_debug(1, "in png_set_sig_bytes\n"); |
Andreas Dilger | 02ad0ef | 1997-01-17 01:34:35 -0600 | [diff] [blame] | 86 | if (num_bytes > 8) |
| 87 | png_error(png_ptr, "Too many bytes for PNG signature."); |
| 88 | |
| 89 | png_ptr->sig_bytes = num_bytes < 0 ? 0 : num_bytes; |
| 90 | } |
| 91 | |
| 92 | /* Checks whether the supplied bytes match the PNG signature. We allow |
| 93 | * checking less than the full 8-byte signature so that those apps that |
| 94 | * already read the first few bytes of a file to determine the file type |
| 95 | * can simply check the remaining bytes for extra assurance. Returns |
| 96 | * an integer less than, equal to, or greater than zero if sig is found, |
| 97 | * respectively, to be less than, to match, or be greater than the correct |
| 98 | * PNG signature (this is the same behaviour as strcmp, memcmp, etc). |
| 99 | */ |
| 100 | int |
Andreas Dilger | 47a0c42 | 1997-05-16 02:46:07 -0500 | [diff] [blame] | 101 | png_sig_cmp(png_bytep sig, png_size_t start, png_size_t num_to_check) |
Andreas Dilger | 02ad0ef | 1997-01-17 01:34:35 -0600 | [diff] [blame] | 102 | { |
| 103 | if (num_to_check > 8) |
| 104 | num_to_check = 8; |
| 105 | else if (num_to_check < 1) |
Glenn Randers-Pehrson | b212002 | 1998-01-31 20:07:59 -0600 | [diff] [blame] | 106 | return (0); |
Andreas Dilger | 02ad0ef | 1997-01-17 01:34:35 -0600 | [diff] [blame] | 107 | |
Andreas Dilger | 47a0c42 | 1997-05-16 02:46:07 -0500 | [diff] [blame] | 108 | if (start > 7) |
Glenn Randers-Pehrson | b212002 | 1998-01-31 20:07:59 -0600 | [diff] [blame] | 109 | return (0); |
Andreas Dilger | 02ad0ef | 1997-01-17 01:34:35 -0600 | [diff] [blame] | 110 | |
| 111 | if (start + num_to_check > 8) |
| 112 | num_to_check = 8 - start; |
| 113 | |
Glenn Randers-Pehrson | b212002 | 1998-01-31 20:07:59 -0600 | [diff] [blame] | 114 | return ((int)(png_memcmp(&sig[start], &png_sig[start], num_to_check))); |
Andreas Dilger | 02ad0ef | 1997-01-17 01:34:35 -0600 | [diff] [blame] | 115 | } |
| 116 | |
| 117 | /* (Obsolete) function to check signature bytes. It does not allow one |
Glenn Randers-Pehrson | b6ce43d | 1998-01-01 07:13:13 -0600 | [diff] [blame] | 118 | * to check a partial signature. This function will be removed in the |
| 119 | * future - use png_sig_cmp(). |
| 120 | */ |
Guy Schalnat | 0d58058 | 1995-07-20 02:43:20 -0500 | [diff] [blame] | 121 | int |
Guy Schalnat | 6d76471 | 1995-12-19 03:22:19 -0600 | [diff] [blame] | 122 | png_check_sig(png_bytep sig, int num) |
Guy Schalnat | 0d58058 | 1995-07-20 02:43:20 -0500 | [diff] [blame] | 123 | { |
Glenn Randers-Pehrson | b212002 | 1998-01-31 20:07:59 -0600 | [diff] [blame] | 124 | return ((int)!png_sig_cmp(sig, (png_size_t)0, (png_size_t)num)); |
Guy Schalnat | 0d58058 | 1995-07-20 02:43:20 -0500 | [diff] [blame] | 125 | } |
| 126 | |
| 127 | /* Function to allocate memory for zlib. */ |
Guy Schalnat | 51f0eb4 | 1995-09-26 05:22:39 -0500 | [diff] [blame] | 128 | voidpf |
| 129 | png_zalloc(voidpf png_ptr, uInt items, uInt size) |
Guy Schalnat | 0d58058 | 1995-07-20 02:43:20 -0500 | [diff] [blame] | 130 | { |
Guy Schalnat | b2e01bd | 1996-01-26 01:38:47 -0600 | [diff] [blame] | 131 | png_voidp ptr; |
| 132 | png_uint_32 num_bytes; |
Guy Schalnat | 6d76471 | 1995-12-19 03:22:19 -0600 | [diff] [blame] | 133 | |
Andreas Dilger | 47a0c42 | 1997-05-16 02:46:07 -0500 | [diff] [blame] | 134 | num_bytes = (png_uint_32)items * size; |
Glenn Randers-Pehrson | 46f61e2 | 1998-01-30 21:45:12 -0600 | [diff] [blame] | 135 | ptr = (png_voidp)png_malloc((png_structp)png_ptr, num_bytes); |
Andreas Dilger | 47a0c42 | 1997-05-16 02:46:07 -0500 | [diff] [blame] | 136 | if (num_bytes > (png_uint_32)0x8000) |
Guy Schalnat | b2e01bd | 1996-01-26 01:38:47 -0600 | [diff] [blame] | 137 | { |
| 138 | png_memset(ptr, 0, (png_size_t)0x8000L); |
| 139 | png_memset((png_bytep)ptr + (png_size_t)0x8000L, 0, |
| 140 | (png_size_t)(num_bytes - (png_uint_32)0x8000L)); |
| 141 | } |
| 142 | else |
| 143 | { |
| 144 | png_memset(ptr, 0, (png_size_t)num_bytes); |
| 145 | } |
Glenn Randers-Pehrson | b212002 | 1998-01-31 20:07:59 -0600 | [diff] [blame] | 146 | return ((voidpf)ptr); |
Guy Schalnat | 0d58058 | 1995-07-20 02:43:20 -0500 | [diff] [blame] | 147 | } |
| 148 | |
| 149 | /* function to free memory for zlib */ |
| 150 | void |
Guy Schalnat | 51f0eb4 | 1995-09-26 05:22:39 -0500 | [diff] [blame] | 151 | png_zfree(voidpf png_ptr, voidpf ptr) |
Guy Schalnat | 0d58058 | 1995-07-20 02:43:20 -0500 | [diff] [blame] | 152 | { |
Andreas Dilger | 02ad0ef | 1997-01-17 01:34:35 -0600 | [diff] [blame] | 153 | png_free((png_structp)png_ptr, (png_voidp)ptr); |
Guy Schalnat | 0d58058 | 1995-07-20 02:43:20 -0500 | [diff] [blame] | 154 | } |
| 155 | |
Andreas Dilger | 02ad0ef | 1997-01-17 01:34:35 -0600 | [diff] [blame] | 156 | /* Reset the CRC variable to 32 bits of 1's. Care must be taken |
Glenn Randers-Pehrson | b6ce43d | 1998-01-01 07:13:13 -0600 | [diff] [blame] | 157 | * in case CRC is > 32 bits to leave the top bits 0. |
| 158 | */ |
Guy Schalnat | 0d58058 | 1995-07-20 02:43:20 -0500 | [diff] [blame] | 159 | void |
Guy Schalnat | 6d76471 | 1995-12-19 03:22:19 -0600 | [diff] [blame] | 160 | png_reset_crc(png_structp png_ptr) |
Guy Schalnat | 0d58058 | 1995-07-20 02:43:20 -0500 | [diff] [blame] | 161 | { |
Andreas Dilger | 02ad0ef | 1997-01-17 01:34:35 -0600 | [diff] [blame] | 162 | png_ptr->crc = crc32(0, Z_NULL, 0); |
Guy Schalnat | 0d58058 | 1995-07-20 02:43:20 -0500 | [diff] [blame] | 163 | } |
| 164 | |
Andreas Dilger | 47a0c42 | 1997-05-16 02:46:07 -0500 | [diff] [blame] | 165 | /* Calculate the CRC over a section of data. We can only pass as |
Glenn Randers-Pehrson | b6ce43d | 1998-01-01 07:13:13 -0600 | [diff] [blame] | 166 | * much data to this routine as the largest single buffer size. We |
| 167 | * also check that this data will actually be used before going to the |
| 168 | * trouble of calculating it. |
| 169 | */ |
Guy Schalnat | 0d58058 | 1995-07-20 02:43:20 -0500 | [diff] [blame] | 170 | void |
Andreas Dilger | 47a0c42 | 1997-05-16 02:46:07 -0500 | [diff] [blame] | 171 | png_calculate_crc(png_structp png_ptr, png_bytep ptr, png_size_t length) |
Guy Schalnat | 0d58058 | 1995-07-20 02:43:20 -0500 | [diff] [blame] | 172 | { |
Andreas Dilger | 47a0c42 | 1997-05-16 02:46:07 -0500 | [diff] [blame] | 173 | int need_crc = 1; |
| 174 | |
| 175 | if (png_ptr->chunk_name[0] & 0x20) /* ancillary */ |
| 176 | { |
| 177 | if ((png_ptr->flags & PNG_FLAG_CRC_ANCILLARY_MASK) == |
| 178 | (PNG_FLAG_CRC_ANCILLARY_USE | PNG_FLAG_CRC_ANCILLARY_NOWARN)) |
| 179 | need_crc = 0; |
| 180 | } |
| 181 | else /* critical */ |
| 182 | { |
| 183 | if (png_ptr->flags & PNG_FLAG_CRC_CRITICAL_IGNORE) |
| 184 | need_crc = 0; |
| 185 | } |
| 186 | |
| 187 | if (need_crc) |
Glenn Randers-Pehrson | 08a3343 | 1998-03-07 06:06:55 -0600 | [diff] [blame] | 188 | png_ptr->crc = crc32(png_ptr->crc, ptr, (uInt)length); |
Guy Schalnat | 0d58058 | 1995-07-20 02:43:20 -0500 | [diff] [blame] | 189 | } |
Guy Schalnat | e5a3779 | 1996-06-05 15:50:50 -0500 | [diff] [blame] | 190 | |
Andreas Dilger | 02ad0ef | 1997-01-17 01:34:35 -0600 | [diff] [blame] | 191 | /* Allocate the memory for an info_struct for the application. We don't |
Glenn Randers-Pehrson | b6ce43d | 1998-01-01 07:13:13 -0600 | [diff] [blame] | 192 | * really need the png_ptr, but it could potentially be useful in the |
| 193 | * future. This should be used in favour of malloc(sizeof(png_info)) |
| 194 | * and png_info_init() so that applications that want to use a shared |
| 195 | * libpng don't have to be recompiled if png_info changes size. |
| 196 | */ |
Guy Schalnat | e5a3779 | 1996-06-05 15:50:50 -0500 | [diff] [blame] | 197 | png_infop |
| 198 | png_create_info_struct(png_structp png_ptr) |
| 199 | { |
| 200 | png_infop info_ptr; |
| 201 | |
Andreas Dilger | 47a0c42 | 1997-05-16 02:46:07 -0500 | [diff] [blame] | 202 | png_debug(1, "in png_create_info_struct\n"); |
Glenn Randers-Pehrson | a357b99 | 1998-02-08 20:56:40 -0600 | [diff] [blame] | 203 | if(png_ptr == NULL) return (NULL); |
Guy Schalnat | e5a3779 | 1996-06-05 15:50:50 -0500 | [diff] [blame] | 204 | if ((info_ptr = (png_infop)png_create_struct(PNG_STRUCT_INFO)) != NULL) |
| 205 | { |
Andreas Dilger | 02ad0ef | 1997-01-17 01:34:35 -0600 | [diff] [blame] | 206 | png_info_init(info_ptr); |
Guy Schalnat | e5a3779 | 1996-06-05 15:50:50 -0500 | [diff] [blame] | 207 | } |
| 208 | |
Glenn Randers-Pehrson | b212002 | 1998-01-31 20:07:59 -0600 | [diff] [blame] | 209 | return (info_ptr); |
Guy Schalnat | e5a3779 | 1996-06-05 15:50:50 -0500 | [diff] [blame] | 210 | } |
| 211 | |
Andreas Dilger | 02ad0ef | 1997-01-17 01:34:35 -0600 | [diff] [blame] | 212 | /* This function frees the memory associated with a single info struct. |
Glenn Randers-Pehrson | b6ce43d | 1998-01-01 07:13:13 -0600 | [diff] [blame] | 213 | * Normally, one would use either png_destroy_read_struct() or |
| 214 | * png_destroy_write_struct() to free an info struct, but this may be |
| 215 | * useful for some applications. |
| 216 | */ |
Guy Schalnat | 51f0eb4 | 1995-09-26 05:22:39 -0500 | [diff] [blame] | 217 | void |
Andreas Dilger | 02ad0ef | 1997-01-17 01:34:35 -0600 | [diff] [blame] | 218 | png_destroy_info_struct(png_structp png_ptr, png_infopp info_ptr_ptr) |
| 219 | { |
| 220 | png_infop info_ptr = NULL; |
| 221 | |
Andreas Dilger | 47a0c42 | 1997-05-16 02:46:07 -0500 | [diff] [blame] | 222 | png_debug(1, "in png_destroy_info_struct\n"); |
| 223 | if (info_ptr_ptr != NULL) |
Andreas Dilger | 02ad0ef | 1997-01-17 01:34:35 -0600 | [diff] [blame] | 224 | info_ptr = *info_ptr_ptr; |
| 225 | |
Andreas Dilger | 47a0c42 | 1997-05-16 02:46:07 -0500 | [diff] [blame] | 226 | if (info_ptr != NULL) |
Andreas Dilger | 02ad0ef | 1997-01-17 01:34:35 -0600 | [diff] [blame] | 227 | { |
| 228 | png_info_destroy(png_ptr, info_ptr); |
| 229 | |
| 230 | png_destroy_struct((png_voidp)info_ptr); |
| 231 | *info_ptr_ptr = (png_infop)NULL; |
| 232 | } |
| 233 | } |
| 234 | |
| 235 | /* Initialize the info structure. This is now an internal function (0.89) |
Glenn Randers-Pehrson | b6ce43d | 1998-01-01 07:13:13 -0600 | [diff] [blame] | 236 | * and applications using it are urged to use png_create_info_struct() |
| 237 | * instead. |
| 238 | */ |
Andreas Dilger | 02ad0ef | 1997-01-17 01:34:35 -0600 | [diff] [blame] | 239 | void |
| 240 | png_info_init(png_infop info_ptr) |
Guy Schalnat | 51f0eb4 | 1995-09-26 05:22:39 -0500 | [diff] [blame] | 241 | { |
Andreas Dilger | 47a0c42 | 1997-05-16 02:46:07 -0500 | [diff] [blame] | 242 | png_debug(1, "in png_info_init\n"); |
Guy Schalnat | 51f0eb4 | 1995-09-26 05:22:39 -0500 | [diff] [blame] | 243 | /* set everything to 0 */ |
Andreas Dilger | 02ad0ef | 1997-01-17 01:34:35 -0600 | [diff] [blame] | 244 | png_memset(info_ptr, 0, sizeof (png_info)); |
| 245 | } |
| 246 | |
| 247 | /* This is an internal routine to free any memory that the info struct is |
Andreas Dilger | 47a0c42 | 1997-05-16 02:46:07 -0500 | [diff] [blame] | 248 | * pointing to before re-using it or freeing the struct itself. Recall |
| 249 | * that png_free() checks for NULL pointers for us. |
| 250 | */ |
Andreas Dilger | 02ad0ef | 1997-01-17 01:34:35 -0600 | [diff] [blame] | 251 | void |
| 252 | png_info_destroy(png_structp png_ptr, png_infop info_ptr) |
| 253 | { |
| 254 | #if defined(PNG_READ_tEXt_SUPPORTED) || defined(PNG_READ_zTXt_SUPPORTED) |
| 255 | int i; |
| 256 | |
Andreas Dilger | 47a0c42 | 1997-05-16 02:46:07 -0500 | [diff] [blame] | 257 | png_debug(1, "in png_info_destroy\n"); |
| 258 | if (info_ptr->text != NULL) |
Andreas Dilger | 02ad0ef | 1997-01-17 01:34:35 -0600 | [diff] [blame] | 259 | { |
Andreas Dilger | 47a0c42 | 1997-05-16 02:46:07 -0500 | [diff] [blame] | 260 | for (i = 0; i < info_ptr->num_text; i++) |
| 261 | { |
| 262 | png_free(png_ptr, info_ptr->text[i].key); |
| 263 | } |
| 264 | png_free(png_ptr, info_ptr->text); |
Andreas Dilger | 02ad0ef | 1997-01-17 01:34:35 -0600 | [diff] [blame] | 265 | } |
Andreas Dilger | 47a0c42 | 1997-05-16 02:46:07 -0500 | [diff] [blame] | 266 | #endif |
| 267 | #if defined(PNG_READ_pCAL_SUPPORTED) |
| 268 | png_free(png_ptr, info_ptr->pcal_purpose); |
| 269 | png_free(png_ptr, info_ptr->pcal_units); |
| 270 | if (info_ptr->pcal_params != NULL) |
| 271 | { |
Glenn Randers-Pehrson | 0f881d6 | 1998-02-07 10:20:57 -0600 | [diff] [blame] | 272 | for (i = 0; i < (int)info_ptr->pcal_nparams; i++) |
Andreas Dilger | 47a0c42 | 1997-05-16 02:46:07 -0500 | [diff] [blame] | 273 | { |
| 274 | png_free(png_ptr, info_ptr->pcal_params[i]); |
| 275 | } |
| 276 | png_free(png_ptr, info_ptr->pcal_params); |
| 277 | } |
Andreas Dilger | 02ad0ef | 1997-01-17 01:34:35 -0600 | [diff] [blame] | 278 | #endif |
| 279 | |
| 280 | png_info_init(info_ptr); |
Guy Schalnat | 51f0eb4 | 1995-09-26 05:22:39 -0500 | [diff] [blame] | 281 | } |
Guy Schalnat | 0d58058 | 1995-07-20 02:43:20 -0500 | [diff] [blame] | 282 | |
Guy Schalnat | e5a3779 | 1996-06-05 15:50:50 -0500 | [diff] [blame] | 283 | /* This function returns a pointer to the io_ptr associated with the user |
Glenn Randers-Pehrson | b6ce43d | 1998-01-01 07:13:13 -0600 | [diff] [blame] | 284 | * functions. The application should free any memory associated with this |
| 285 | * pointer before png_write_destroy() or png_read_destroy() are called. |
| 286 | */ |
Guy Schalnat | e5a3779 | 1996-06-05 15:50:50 -0500 | [diff] [blame] | 287 | png_voidp |
| 288 | png_get_io_ptr(png_structp png_ptr) |
| 289 | { |
Glenn Randers-Pehrson | b212002 | 1998-01-31 20:07:59 -0600 | [diff] [blame] | 290 | return (png_ptr->io_ptr); |
Guy Schalnat | e5a3779 | 1996-06-05 15:50:50 -0500 | [diff] [blame] | 291 | } |
Andreas Dilger | 47a0c42 | 1997-05-16 02:46:07 -0500 | [diff] [blame] | 292 | |
| 293 | #if !defined(PNG_NO_STDIO) |
| 294 | /* Initialize the default input/output functions for the PNG file. If you |
Glenn Randers-Pehrson | b6ce43d | 1998-01-01 07:13:13 -0600 | [diff] [blame] | 295 | * use your own read or write routines, you can call either png_set_read_fn() |
| 296 | * or png_set_write_fn() instead of png_init_io(). |
| 297 | */ |
Guy Schalnat | e5a3779 | 1996-06-05 15:50:50 -0500 | [diff] [blame] | 298 | void |
| 299 | png_init_io(png_structp png_ptr, FILE *fp) |
| 300 | { |
Andreas Dilger | 47a0c42 | 1997-05-16 02:46:07 -0500 | [diff] [blame] | 301 | png_debug(1, "in png_init_io\n"); |
Guy Schalnat | e5a3779 | 1996-06-05 15:50:50 -0500 | [diff] [blame] | 302 | png_ptr->io_ptr = (png_voidp)fp; |
| 303 | } |
Andreas Dilger | 47a0c42 | 1997-05-16 02:46:07 -0500 | [diff] [blame] | 304 | #endif |