| 1 | |
| 2 | /* pngtrans.c - transforms the data in a row (used by both readers and writers) |
| 3 | * |
| 4 | * Last changed in libpng 1.2.30 [August 15, 2008] |
| 5 | * For conditions of distribution and use, see copyright notice in png.h |
| 6 | * Copyright (c) 1998-2008 Glenn Randers-Pehrson |
| 7 | * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger) |
| 8 | * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.) |
| 9 | */ |
| 10 | |
| 11 | #define PNG_INTERNAL |
| 12 | #include "png.h" |
| 13 | #if defined(PNG_READ_SUPPORTED) || defined(PNG_WRITE_SUPPORTED) |
| 14 | |
| 15 | #if defined(PNG_READ_BGR_SUPPORTED) || defined(PNG_WRITE_BGR_SUPPORTED) |
| 16 | /* turn on BGR-to-RGB mapping */ |
| 17 | void PNGAPI |
| 18 | png_set_bgr(png_structp png_ptr) |
| 19 | { |
| 20 | png_debug(1, "in png_set_bgr"); |
| 21 | if (png_ptr == NULL) return; |
| 22 | png_ptr->transformations |= PNG_BGR; |
| 23 | } |
| 24 | #endif |
| 25 | |
| 26 | #if defined(PNG_READ_SWAP_SUPPORTED) || defined(PNG_WRITE_SWAP_SUPPORTED) |
| 27 | /* turn on 16 bit byte swapping */ |
| 28 | void PNGAPI |
| 29 | png_set_swap(png_structp png_ptr) |
| 30 | { |
| 31 | png_debug(1, "in png_set_swap"); |
| 32 | if (png_ptr == NULL) return; |
| 33 | if (png_ptr->bit_depth == 16) |
| 34 | png_ptr->transformations |= PNG_SWAP_BYTES; |
| 35 | } |
| 36 | #endif |
| 37 | |
| 38 | #if defined(PNG_READ_PACK_SUPPORTED) || defined(PNG_WRITE_PACK_SUPPORTED) |
| 39 | /* turn on pixel packing */ |
| 40 | void PNGAPI |
| 41 | png_set_packing(png_structp png_ptr) |
| 42 | { |
| 43 | png_debug(1, "in png_set_packing"); |
| 44 | if (png_ptr == NULL) return; |
| 45 | if (png_ptr->bit_depth < 8) |
| 46 | { |
| 47 | png_ptr->transformations |= PNG_PACK; |
| 48 | png_ptr->usr_bit_depth = 8; |
| 49 | } |
| 50 | } |
| 51 | #endif |
| 52 | |
| 53 | #if defined(PNG_READ_PACKSWAP_SUPPORTED)||defined(PNG_WRITE_PACKSWAP_SUPPORTED) |
| 54 | /* turn on packed pixel swapping */ |
| 55 | void PNGAPI |
| 56 | png_set_packswap(png_structp png_ptr) |
| 57 | { |
| 58 | png_debug(1, "in png_set_packswap"); |
| 59 | if (png_ptr == NULL) return; |
| 60 | if (png_ptr->bit_depth < 8) |
| 61 | png_ptr->transformations |= PNG_PACKSWAP; |
| 62 | } |
| 63 | #endif |
| 64 | |
| 65 | #if defined(PNG_READ_SHIFT_SUPPORTED) || defined(PNG_WRITE_SHIFT_SUPPORTED) |
| 66 | void PNGAPI |
| 67 | png_set_shift(png_structp png_ptr, png_color_8p true_bits) |
| 68 | { |
| 69 | png_debug(1, "in png_set_shift"); |
| 70 | if (png_ptr == NULL) return; |
| 71 | png_ptr->transformations |= PNG_SHIFT; |
| 72 | png_ptr->shift = *true_bits; |
| 73 | } |
| 74 | #endif |
| 75 | |
| 76 | #if defined(PNG_READ_INTERLACING_SUPPORTED) || \ |
| 77 | defined(PNG_WRITE_INTERLACING_SUPPORTED) |
| 78 | int PNGAPI |
| 79 | png_set_interlace_handling(png_structp png_ptr) |
| 80 | { |
| 81 | png_debug(1, "in png_set_interlace handling"); |
| 82 | if (png_ptr && png_ptr->interlaced) |
| 83 | { |
| 84 | png_ptr->transformations |= PNG_INTERLACE; |
| 85 | return (7); |
| 86 | } |
| 87 | |
| 88 | return (1); |
| 89 | } |
| 90 | #endif |
| 91 | |
| 92 | #if defined(PNG_READ_FILLER_SUPPORTED) || defined(PNG_WRITE_FILLER_SUPPORTED) |
| 93 | /* Add a filler byte on read, or remove a filler or alpha byte on write. |
| 94 | * The filler type has changed in v0.95 to allow future 2-byte fillers |
| 95 | * for 48-bit input data, as well as to avoid problems with some compilers |
| 96 | * that don't like bytes as parameters. |
| 97 | */ |
| 98 | void PNGAPI |
| 99 | png_set_filler(png_structp png_ptr, png_uint_32 filler, int filler_loc) |
| 100 | { |
| 101 | png_debug(1, "in png_set_filler"); |
| 102 | if (png_ptr == NULL) return; |
| 103 | png_ptr->transformations |= PNG_FILLER; |
| 104 | png_ptr->filler = (png_byte)filler; |
| 105 | if (filler_loc == PNG_FILLER_AFTER) |
| 106 | png_ptr->flags |= PNG_FLAG_FILLER_AFTER; |
| 107 | else |
| 108 | png_ptr->flags &= ~PNG_FLAG_FILLER_AFTER; |
| 109 | |
| 110 | /* This should probably go in the "do_read_filler" routine. |
| 111 | * I attempted to do that in libpng-1.0.1a but that caused problems |
| 112 | * so I restored it in libpng-1.0.2a |
| 113 | */ |
| 114 | |
| 115 | if (png_ptr->color_type == PNG_COLOR_TYPE_RGB) |
| 116 | { |
| 117 | png_ptr->usr_channels = 4; |
| 118 | } |
| 119 | |
| 120 | /* Also I added this in libpng-1.0.2a (what happens when we expand |
| 121 | * a less-than-8-bit grayscale to GA? */ |
| 122 | |
| 123 | if (png_ptr->color_type == PNG_COLOR_TYPE_GRAY && png_ptr->bit_depth >= 8) |
| 124 | { |
| 125 | png_ptr->usr_channels = 2; |
| 126 | } |
| 127 | } |
| 128 | |
| 129 | #if !defined(PNG_1_0_X) |
| 130 | /* Added to libpng-1.2.7 */ |
| 131 | void PNGAPI |
| 132 | png_set_add_alpha(png_structp png_ptr, png_uint_32 filler, int filler_loc) |
| 133 | { |
| 134 | png_debug(1, "in png_set_add_alpha"); |
| 135 | if (png_ptr == NULL) return; |
| 136 | png_set_filler(png_ptr, filler, filler_loc); |
| 137 | png_ptr->transformations |= PNG_ADD_ALPHA; |
| 138 | } |
| 139 | #endif |
| 140 | |
| 141 | #endif |
| 142 | |
| 143 | #if defined(PNG_READ_SWAP_ALPHA_SUPPORTED) || \ |
| 144 | defined(PNG_WRITE_SWAP_ALPHA_SUPPORTED) |
| 145 | void PNGAPI |
| 146 | png_set_swap_alpha(png_structp png_ptr) |
| 147 | { |
| 148 | png_debug(1, "in png_set_swap_alpha"); |
| 149 | if (png_ptr == NULL) return; |
| 150 | png_ptr->transformations |= PNG_SWAP_ALPHA; |
| 151 | } |
| 152 | #endif |
| 153 | |
| 154 | #if defined(PNG_READ_INVERT_ALPHA_SUPPORTED) || \ |
| 155 | defined(PNG_WRITE_INVERT_ALPHA_SUPPORTED) |
| 156 | void PNGAPI |
| 157 | png_set_invert_alpha(png_structp png_ptr) |
| 158 | { |
| 159 | png_debug(1, "in png_set_invert_alpha"); |
| 160 | if (png_ptr == NULL) return; |
| 161 | png_ptr->transformations |= PNG_INVERT_ALPHA; |
| 162 | } |
| 163 | #endif |
| 164 | |
| 165 | #if defined(PNG_READ_INVERT_SUPPORTED) || defined(PNG_WRITE_INVERT_SUPPORTED) |
| 166 | void PNGAPI |
| 167 | png_set_invert_mono(png_structp png_ptr) |
| 168 | { |
| 169 | png_debug(1, "in png_set_invert_mono"); |
| 170 | if (png_ptr == NULL) return; |
| 171 | png_ptr->transformations |= PNG_INVERT_MONO; |
| 172 | } |
| 173 | |
| 174 | /* invert monochrome grayscale data */ |
| 175 | void /* PRIVATE */ |
| 176 | png_do_invert(png_row_infop row_info, png_bytep row) |
| 177 | { |
| 178 | png_debug(1, "in png_do_invert"); |
| 179 | /* This test removed from libpng version 1.0.13 and 1.2.0: |
| 180 | * if (row_info->bit_depth == 1 && |
| 181 | */ |
| 182 | #if defined(PNG_USELESS_TESTS_SUPPORTED) |
| 183 | if (row == NULL || row_info == NULL) |
| 184 | return; |
| 185 | #endif |
| 186 | if (row_info->color_type == PNG_COLOR_TYPE_GRAY) |
| 187 | { |
| 188 | png_bytep rp = row; |
| 189 | png_uint_32 i; |
| 190 | png_uint_32 istop = row_info->rowbytes; |
| 191 | |
| 192 | for (i = 0; i < istop; i++) |
| 193 | { |
| 194 | *rp = (png_byte)(~(*rp)); |
| 195 | rp++; |
| 196 | } |
| 197 | } |
| 198 | else if (row_info->color_type == PNG_COLOR_TYPE_GRAY_ALPHA && |
| 199 | row_info->bit_depth == 8) |
| 200 | { |
| 201 | png_bytep rp = row; |
| 202 | png_uint_32 i; |
| 203 | png_uint_32 istop = row_info->rowbytes; |
| 204 | |
| 205 | for (i = 0; i < istop; i+=2) |
| 206 | { |
| 207 | *rp = (png_byte)(~(*rp)); |
| 208 | rp+=2; |
| 209 | } |
| 210 | } |
| 211 | else if (row_info->color_type == PNG_COLOR_TYPE_GRAY_ALPHA && |
| 212 | row_info->bit_depth == 16) |
| 213 | { |
| 214 | png_bytep rp = row; |
| 215 | png_uint_32 i; |
| 216 | png_uint_32 istop = row_info->rowbytes; |
| 217 | |
| 218 | for (i = 0; i < istop; i+=4) |
| 219 | { |
| 220 | *rp = (png_byte)(~(*rp)); |
| 221 | *(rp+1) = (png_byte)(~(*(rp+1))); |
| 222 | rp+=4; |
| 223 | } |
| 224 | } |
| 225 | } |
| 226 | #endif |
| 227 | |
| 228 | #if defined(PNG_READ_SWAP_SUPPORTED) || defined(PNG_WRITE_SWAP_SUPPORTED) |
| 229 | /* swaps byte order on 16 bit depth images */ |
| 230 | void /* PRIVATE */ |
| 231 | png_do_swap(png_row_infop row_info, png_bytep row) |
| 232 | { |
| 233 | png_debug(1, "in png_do_swap"); |
| 234 | if ( |
| 235 | #if defined(PNG_USELESS_TESTS_SUPPORTED) |
| 236 | row != NULL && row_info != NULL && |
| 237 | #endif |
| 238 | row_info->bit_depth == 16) |
| 239 | { |
| 240 | png_bytep rp = row; |
| 241 | png_uint_32 i; |
| 242 | png_uint_32 istop= row_info->width * row_info->channels; |
| 243 | |
| 244 | for (i = 0; i < istop; i++, rp += 2) |
| 245 | { |
| 246 | png_byte t = *rp; |
| 247 | *rp = *(rp + 1); |
| 248 | *(rp + 1) = t; |
| 249 | } |
| 250 | } |
| 251 | } |
| 252 | #endif |
| 253 | |
| 254 | #if defined(PNG_READ_PACKSWAP_SUPPORTED)||defined(PNG_WRITE_PACKSWAP_SUPPORTED) |
| 255 | static PNG_CONST png_byte onebppswaptable[256] = { |
| 256 | 0x00, 0x80, 0x40, 0xC0, 0x20, 0xA0, 0x60, 0xE0, |
| 257 | 0x10, 0x90, 0x50, 0xD0, 0x30, 0xB0, 0x70, 0xF0, |
| 258 | 0x08, 0x88, 0x48, 0xC8, 0x28, 0xA8, 0x68, 0xE8, |
| 259 | 0x18, 0x98, 0x58, 0xD8, 0x38, 0xB8, 0x78, 0xF8, |
| 260 | 0x04, 0x84, 0x44, 0xC4, 0x24, 0xA4, 0x64, 0xE4, |
| 261 | 0x14, 0x94, 0x54, 0xD4, 0x34, 0xB4, 0x74, 0xF4, |
| 262 | 0x0C, 0x8C, 0x4C, 0xCC, 0x2C, 0xAC, 0x6C, 0xEC, |
| 263 | 0x1C, 0x9C, 0x5C, 0xDC, 0x3C, 0xBC, 0x7C, 0xFC, |
| 264 | 0x02, 0x82, 0x42, 0xC2, 0x22, 0xA2, 0x62, 0xE2, |
| 265 | 0x12, 0x92, 0x52, 0xD2, 0x32, 0xB2, 0x72, 0xF2, |
| 266 | 0x0A, 0x8A, 0x4A, 0xCA, 0x2A, 0xAA, 0x6A, 0xEA, |
| 267 | 0x1A, 0x9A, 0x5A, 0xDA, 0x3A, 0xBA, 0x7A, 0xFA, |
| 268 | 0x06, 0x86, 0x46, 0xC6, 0x26, 0xA6, 0x66, 0xE6, |
| 269 | 0x16, 0x96, 0x56, 0xD6, 0x36, 0xB6, 0x76, 0xF6, |
| 270 | 0x0E, 0x8E, 0x4E, 0xCE, 0x2E, 0xAE, 0x6E, 0xEE, |
| 271 | 0x1E, 0x9E, 0x5E, 0xDE, 0x3E, 0xBE, 0x7E, 0xFE, |
| 272 | 0x01, 0x81, 0x41, 0xC1, 0x21, 0xA1, 0x61, 0xE1, |
| 273 | 0x11, 0x91, 0x51, 0xD1, 0x31, 0xB1, 0x71, 0xF1, |
| 274 | 0x09, 0x89, 0x49, 0xC9, 0x29, 0xA9, 0x69, 0xE9, |
| 275 | 0x19, 0x99, 0x59, 0xD9, 0x39, 0xB9, 0x79, 0xF9, |
| 276 | 0x05, 0x85, 0x45, 0xC5, 0x25, 0xA5, 0x65, 0xE5, |
| 277 | 0x15, 0x95, 0x55, 0xD5, 0x35, 0xB5, 0x75, 0xF5, |
| 278 | 0x0D, 0x8D, 0x4D, 0xCD, 0x2D, 0xAD, 0x6D, 0xED, |
| 279 | 0x1D, 0x9D, 0x5D, 0xDD, 0x3D, 0xBD, 0x7D, 0xFD, |
| 280 | 0x03, 0x83, 0x43, 0xC3, 0x23, 0xA3, 0x63, 0xE3, |
| 281 | 0x13, 0x93, 0x53, 0xD3, 0x33, 0xB3, 0x73, 0xF3, |
| 282 | 0x0B, 0x8B, 0x4B, 0xCB, 0x2B, 0xAB, 0x6B, 0xEB, |
| 283 | 0x1B, 0x9B, 0x5B, 0xDB, 0x3B, 0xBB, 0x7B, 0xFB, |
| 284 | 0x07, 0x87, 0x47, 0xC7, 0x27, 0xA7, 0x67, 0xE7, |
| 285 | 0x17, 0x97, 0x57, 0xD7, 0x37, 0xB7, 0x77, 0xF7, |
| 286 | 0x0F, 0x8F, 0x4F, 0xCF, 0x2F, 0xAF, 0x6F, 0xEF, |
| 287 | 0x1F, 0x9F, 0x5F, 0xDF, 0x3F, 0xBF, 0x7F, 0xFF |
| 288 | }; |
| 289 | |
| 290 | static PNG_CONST png_byte twobppswaptable[256] = { |
| 291 | 0x00, 0x40, 0x80, 0xC0, 0x10, 0x50, 0x90, 0xD0, |
| 292 | 0x20, 0x60, 0xA0, 0xE0, 0x30, 0x70, 0xB0, 0xF0, |
| 293 | 0x04, 0x44, 0x84, 0xC4, 0x14, 0x54, 0x94, 0xD4, |
| 294 | 0x24, 0x64, 0xA4, 0xE4, 0x34, 0x74, 0xB4, 0xF4, |
| 295 | 0x08, 0x48, 0x88, 0xC8, 0x18, 0x58, 0x98, 0xD8, |
| 296 | 0x28, 0x68, 0xA8, 0xE8, 0x38, 0x78, 0xB8, 0xF8, |
| 297 | 0x0C, 0x4C, 0x8C, 0xCC, 0x1C, 0x5C, 0x9C, 0xDC, |
| 298 | 0x2C, 0x6C, 0xAC, 0xEC, 0x3C, 0x7C, 0xBC, 0xFC, |
| 299 | 0x01, 0x41, 0x81, 0xC1, 0x11, 0x51, 0x91, 0xD1, |
| 300 | 0x21, 0x61, 0xA1, 0xE1, 0x31, 0x71, 0xB1, 0xF1, |
| 301 | 0x05, 0x45, 0x85, 0xC5, 0x15, 0x55, 0x95, 0xD5, |
| 302 | 0x25, 0x65, 0xA5, 0xE5, 0x35, 0x75, 0xB5, 0xF5, |
| 303 | 0x09, 0x49, 0x89, 0xC9, 0x19, 0x59, 0x99, 0xD9, |
| 304 | 0x29, 0x69, 0xA9, 0xE9, 0x39, 0x79, 0xB9, 0xF9, |
| 305 | 0x0D, 0x4D, 0x8D, 0xCD, 0x1D, 0x5D, 0x9D, 0xDD, |
| 306 | 0x2D, 0x6D, 0xAD, 0xED, 0x3D, 0x7D, 0xBD, 0xFD, |
| 307 | 0x02, 0x42, 0x82, 0xC2, 0x12, 0x52, 0x92, 0xD2, |
| 308 | 0x22, 0x62, 0xA2, 0xE2, 0x32, 0x72, 0xB2, 0xF2, |
| 309 | 0x06, 0x46, 0x86, 0xC6, 0x16, 0x56, 0x96, 0xD6, |
| 310 | 0x26, 0x66, 0xA6, 0xE6, 0x36, 0x76, 0xB6, 0xF6, |
| 311 | 0x0A, 0x4A, 0x8A, 0xCA, 0x1A, 0x5A, 0x9A, 0xDA, |
| 312 | 0x2A, 0x6A, 0xAA, 0xEA, 0x3A, 0x7A, 0xBA, 0xFA, |
| 313 | 0x0E, 0x4E, 0x8E, 0xCE, 0x1E, 0x5E, 0x9E, 0xDE, |
| 314 | 0x2E, 0x6E, 0xAE, 0xEE, 0x3E, 0x7E, 0xBE, 0xFE, |
| 315 | 0x03, 0x43, 0x83, 0xC3, 0x13, 0x53, 0x93, 0xD3, |
| 316 | 0x23, 0x63, 0xA3, 0xE3, 0x33, 0x73, 0xB3, 0xF3, |
| 317 | 0x07, 0x47, 0x87, 0xC7, 0x17, 0x57, 0x97, 0xD7, |
| 318 | 0x27, 0x67, 0xA7, 0xE7, 0x37, 0x77, 0xB7, 0xF7, |
| 319 | 0x0B, 0x4B, 0x8B, 0xCB, 0x1B, 0x5B, 0x9B, 0xDB, |
| 320 | 0x2B, 0x6B, 0xAB, 0xEB, 0x3B, 0x7B, 0xBB, 0xFB, |
| 321 | 0x0F, 0x4F, 0x8F, 0xCF, 0x1F, 0x5F, 0x9F, 0xDF, |
| 322 | 0x2F, 0x6F, 0xAF, 0xEF, 0x3F, 0x7F, 0xBF, 0xFF |
| 323 | }; |
| 324 | |
| 325 | static PNG_CONST png_byte fourbppswaptable[256] = { |
| 326 | 0x00, 0x10, 0x20, 0x30, 0x40, 0x50, 0x60, 0x70, |
| 327 | 0x80, 0x90, 0xA0, 0xB0, 0xC0, 0xD0, 0xE0, 0xF0, |
| 328 | 0x01, 0x11, 0x21, 0x31, 0x41, 0x51, 0x61, 0x71, |
| 329 | 0x81, 0x91, 0xA1, 0xB1, 0xC1, 0xD1, 0xE1, 0xF1, |
| 330 | 0x02, 0x12, 0x22, 0x32, 0x42, 0x52, 0x62, 0x72, |
| 331 | 0x82, 0x92, 0xA2, 0xB2, 0xC2, 0xD2, 0xE2, 0xF2, |
| 332 | 0x03, 0x13, 0x23, 0x33, 0x43, 0x53, 0x63, 0x73, |
| 333 | 0x83, 0x93, 0xA3, 0xB3, 0xC3, 0xD3, 0xE3, 0xF3, |
| 334 | 0x04, 0x14, 0x24, 0x34, 0x44, 0x54, 0x64, 0x74, |
| 335 | 0x84, 0x94, 0xA4, 0xB4, 0xC4, 0xD4, 0xE4, 0xF4, |
| 336 | 0x05, 0x15, 0x25, 0x35, 0x45, 0x55, 0x65, 0x75, |
| 337 | 0x85, 0x95, 0xA5, 0xB5, 0xC5, 0xD5, 0xE5, 0xF5, |
| 338 | 0x06, 0x16, 0x26, 0x36, 0x46, 0x56, 0x66, 0x76, |
| 339 | 0x86, 0x96, 0xA6, 0xB6, 0xC6, 0xD6, 0xE6, 0xF6, |
| 340 | 0x07, 0x17, 0x27, 0x37, 0x47, 0x57, 0x67, 0x77, |
| 341 | 0x87, 0x97, 0xA7, 0xB7, 0xC7, 0xD7, 0xE7, 0xF7, |
| 342 | 0x08, 0x18, 0x28, 0x38, 0x48, 0x58, 0x68, 0x78, |
| 343 | 0x88, 0x98, 0xA8, 0xB8, 0xC8, 0xD8, 0xE8, 0xF8, |
| 344 | 0x09, 0x19, 0x29, 0x39, 0x49, 0x59, 0x69, 0x79, |
| 345 | 0x89, 0x99, 0xA9, 0xB9, 0xC9, 0xD9, 0xE9, 0xF9, |
| 346 | 0x0A, 0x1A, 0x2A, 0x3A, 0x4A, 0x5A, 0x6A, 0x7A, |
| 347 | 0x8A, 0x9A, 0xAA, 0xBA, 0xCA, 0xDA, 0xEA, 0xFA, |
| 348 | 0x0B, 0x1B, 0x2B, 0x3B, 0x4B, 0x5B, 0x6B, 0x7B, |
| 349 | 0x8B, 0x9B, 0xAB, 0xBB, 0xCB, 0xDB, 0xEB, 0xFB, |
| 350 | 0x0C, 0x1C, 0x2C, 0x3C, 0x4C, 0x5C, 0x6C, 0x7C, |
| 351 | 0x8C, 0x9C, 0xAC, 0xBC, 0xCC, 0xDC, 0xEC, 0xFC, |
| 352 | 0x0D, 0x1D, 0x2D, 0x3D, 0x4D, 0x5D, 0x6D, 0x7D, |
| 353 | 0x8D, 0x9D, 0xAD, 0xBD, 0xCD, 0xDD, 0xED, 0xFD, |
| 354 | 0x0E, 0x1E, 0x2E, 0x3E, 0x4E, 0x5E, 0x6E, 0x7E, |
| 355 | 0x8E, 0x9E, 0xAE, 0xBE, 0xCE, 0xDE, 0xEE, 0xFE, |
| 356 | 0x0F, 0x1F, 0x2F, 0x3F, 0x4F, 0x5F, 0x6F, 0x7F, |
| 357 | 0x8F, 0x9F, 0xAF, 0xBF, 0xCF, 0xDF, 0xEF, 0xFF |
| 358 | }; |
| 359 | |
| 360 | /* swaps pixel packing order within bytes */ |
| 361 | void /* PRIVATE */ |
| 362 | png_do_packswap(png_row_infop row_info, png_bytep row) |
| 363 | { |
| 364 | png_debug(1, "in png_do_packswap"); |
| 365 | if ( |
| 366 | #if defined(PNG_USELESS_TESTS_SUPPORTED) |
| 367 | row != NULL && row_info != NULL && |
| 368 | #endif |
| 369 | row_info->bit_depth < 8) |
| 370 | { |
| 371 | png_bytep rp, end, table; |
| 372 | |
| 373 | end = row + row_info->rowbytes; |
| 374 | |
| 375 | if (row_info->bit_depth == 1) |
| 376 | table = (png_bytep)onebppswaptable; |
| 377 | else if (row_info->bit_depth == 2) |
| 378 | table = (png_bytep)twobppswaptable; |
| 379 | else if (row_info->bit_depth == 4) |
| 380 | table = (png_bytep)fourbppswaptable; |
| 381 | else |
| 382 | return; |
| 383 | |
| 384 | for (rp = row; rp < end; rp++) |
| 385 | *rp = table[*rp]; |
| 386 | } |
| 387 | } |
| 388 | #endif /* PNG_READ_PACKSWAP_SUPPORTED or PNG_WRITE_PACKSWAP_SUPPORTED */ |
| 389 | |
| 390 | #if defined(PNG_WRITE_FILLER_SUPPORTED) || \ |
| 391 | defined(PNG_READ_STRIP_ALPHA_SUPPORTED) |
| 392 | /* remove filler or alpha byte(s) */ |
| 393 | void /* PRIVATE */ |
| 394 | png_do_strip_filler(png_row_infop row_info, png_bytep row, png_uint_32 flags) |
| 395 | { |
| 396 | png_debug(1, "in png_do_strip_filler"); |
| 397 | #if defined(PNG_USELESS_TESTS_SUPPORTED) |
| 398 | if (row != NULL && row_info != NULL) |
| 399 | #endif |
| 400 | { |
| 401 | png_bytep sp=row; |
| 402 | png_bytep dp=row; |
| 403 | png_uint_32 row_width=row_info->width; |
| 404 | png_uint_32 i; |
| 405 | |
| 406 | if ((row_info->color_type == PNG_COLOR_TYPE_RGB || |
| 407 | (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA && |
| 408 | (flags & PNG_FLAG_STRIP_ALPHA))) && |
| 409 | row_info->channels == 4) |
| 410 | { |
| 411 | if (row_info->bit_depth == 8) |
| 412 | { |
| 413 | /* This converts from RGBX or RGBA to RGB */ |
| 414 | if (flags & PNG_FLAG_FILLER_AFTER) |
| 415 | { |
| 416 | dp+=3; sp+=4; |
| 417 | for (i = 1; i < row_width; i++) |
| 418 | { |
| 419 | *dp++ = *sp++; |
| 420 | *dp++ = *sp++; |
| 421 | *dp++ = *sp++; |
| 422 | sp++; |
| 423 | } |
| 424 | } |
| 425 | /* This converts from XRGB or ARGB to RGB */ |
| 426 | else |
| 427 | { |
| 428 | for (i = 0; i < row_width; i++) |
| 429 | { |
| 430 | sp++; |
| 431 | *dp++ = *sp++; |
| 432 | *dp++ = *sp++; |
| 433 | *dp++ = *sp++; |
| 434 | } |
| 435 | } |
| 436 | row_info->pixel_depth = 24; |
| 437 | row_info->rowbytes = row_width * 3; |
| 438 | } |
| 439 | else /* if (row_info->bit_depth == 16) */ |
| 440 | { |
| 441 | if (flags & PNG_FLAG_FILLER_AFTER) |
| 442 | { |
| 443 | /* This converts from RRGGBBXX or RRGGBBAA to RRGGBB */ |
| 444 | sp += 8; dp += 6; |
| 445 | for (i = 1; i < row_width; i++) |
| 446 | { |
| 447 | /* This could be (although png_memcpy is probably slower): |
| 448 | png_memcpy(dp, sp, 6); |
| 449 | sp += 8; |
| 450 | dp += 6; |
| 451 | */ |
| 452 | |
| 453 | *dp++ = *sp++; |
| 454 | *dp++ = *sp++; |
| 455 | *dp++ = *sp++; |
| 456 | *dp++ = *sp++; |
| 457 | *dp++ = *sp++; |
| 458 | *dp++ = *sp++; |
| 459 | sp += 2; |
| 460 | } |
| 461 | } |
| 462 | else |
| 463 | { |
| 464 | /* This converts from XXRRGGBB or AARRGGBB to RRGGBB */ |
| 465 | for (i = 0; i < row_width; i++) |
| 466 | { |
| 467 | /* This could be (although png_memcpy is probably slower): |
| 468 | png_memcpy(dp, sp, 6); |
| 469 | sp += 8; |
| 470 | dp += 6; |
| 471 | */ |
| 472 | |
| 473 | sp+=2; |
| 474 | *dp++ = *sp++; |
| 475 | *dp++ = *sp++; |
| 476 | *dp++ = *sp++; |
| 477 | *dp++ = *sp++; |
| 478 | *dp++ = *sp++; |
| 479 | *dp++ = *sp++; |
| 480 | } |
| 481 | } |
| 482 | row_info->pixel_depth = 48; |
| 483 | row_info->rowbytes = row_width * 6; |
| 484 | } |
| 485 | row_info->channels = 3; |
| 486 | } |
| 487 | else if ((row_info->color_type == PNG_COLOR_TYPE_GRAY || |
| 488 | (row_info->color_type == PNG_COLOR_TYPE_GRAY_ALPHA && |
| 489 | (flags & PNG_FLAG_STRIP_ALPHA))) && |
| 490 | row_info->channels == 2) |
| 491 | { |
| 492 | if (row_info->bit_depth == 8) |
| 493 | { |
| 494 | /* This converts from GX or GA to G */ |
| 495 | if (flags & PNG_FLAG_FILLER_AFTER) |
| 496 | { |
| 497 | for (i = 0; i < row_width; i++) |
| 498 | { |
| 499 | *dp++ = *sp++; |
| 500 | sp++; |
| 501 | } |
| 502 | } |
| 503 | /* This converts from XG or AG to G */ |
| 504 | else |
| 505 | { |
| 506 | for (i = 0; i < row_width; i++) |
| 507 | { |
| 508 | sp++; |
| 509 | *dp++ = *sp++; |
| 510 | } |
| 511 | } |
| 512 | row_info->pixel_depth = 8; |
| 513 | row_info->rowbytes = row_width; |
| 514 | } |
| 515 | else /* if (row_info->bit_depth == 16) */ |
| 516 | { |
| 517 | if (flags & PNG_FLAG_FILLER_AFTER) |
| 518 | { |
| 519 | /* This converts from GGXX or GGAA to GG */ |
| 520 | sp += 4; dp += 2; |
| 521 | for (i = 1; i < row_width; i++) |
| 522 | { |
| 523 | *dp++ = *sp++; |
| 524 | *dp++ = *sp++; |
| 525 | sp += 2; |
| 526 | } |
| 527 | } |
| 528 | else |
| 529 | { |
| 530 | /* This converts from XXGG or AAGG to GG */ |
| 531 | for (i = 0; i < row_width; i++) |
| 532 | { |
| 533 | sp += 2; |
| 534 | *dp++ = *sp++; |
| 535 | *dp++ = *sp++; |
| 536 | } |
| 537 | } |
| 538 | row_info->pixel_depth = 16; |
| 539 | row_info->rowbytes = row_width * 2; |
| 540 | } |
| 541 | row_info->channels = 1; |
| 542 | } |
| 543 | if (flags & PNG_FLAG_STRIP_ALPHA) |
| 544 | row_info->color_type &= ~PNG_COLOR_MASK_ALPHA; |
| 545 | } |
| 546 | } |
| 547 | #endif |
| 548 | |
| 549 | #if defined(PNG_READ_BGR_SUPPORTED) || defined(PNG_WRITE_BGR_SUPPORTED) |
| 550 | /* swaps red and blue bytes within a pixel */ |
| 551 | void /* PRIVATE */ |
| 552 | png_do_bgr(png_row_infop row_info, png_bytep row) |
| 553 | { |
| 554 | png_debug(1, "in png_do_bgr"); |
| 555 | if ( |
| 556 | #if defined(PNG_USELESS_TESTS_SUPPORTED) |
| 557 | row != NULL && row_info != NULL && |
| 558 | #endif |
| 559 | (row_info->color_type & PNG_COLOR_MASK_COLOR)) |
| 560 | { |
| 561 | png_uint_32 row_width = row_info->width; |
| 562 | if (row_info->bit_depth == 8) |
| 563 | { |
| 564 | if (row_info->color_type == PNG_COLOR_TYPE_RGB) |
| 565 | { |
| 566 | png_bytep rp; |
| 567 | png_uint_32 i; |
| 568 | |
| 569 | for (i = 0, rp = row; i < row_width; i++, rp += 3) |
| 570 | { |
| 571 | png_byte save = *rp; |
| 572 | *rp = *(rp + 2); |
| 573 | *(rp + 2) = save; |
| 574 | } |
| 575 | } |
| 576 | else if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA) |
| 577 | { |
| 578 | png_bytep rp; |
| 579 | png_uint_32 i; |
| 580 | |
| 581 | for (i = 0, rp = row; i < row_width; i++, rp += 4) |
| 582 | { |
| 583 | png_byte save = *rp; |
| 584 | *rp = *(rp + 2); |
| 585 | *(rp + 2) = save; |
| 586 | } |
| 587 | } |
| 588 | } |
| 589 | else if (row_info->bit_depth == 16) |
| 590 | { |
| 591 | if (row_info->color_type == PNG_COLOR_TYPE_RGB) |
| 592 | { |
| 593 | png_bytep rp; |
| 594 | png_uint_32 i; |
| 595 | |
| 596 | for (i = 0, rp = row; i < row_width; i++, rp += 6) |
| 597 | { |
| 598 | png_byte save = *rp; |
| 599 | *rp = *(rp + 4); |
| 600 | *(rp + 4) = save; |
| 601 | save = *(rp + 1); |
| 602 | *(rp + 1) = *(rp + 5); |
| 603 | *(rp + 5) = save; |
| 604 | } |
| 605 | } |
| 606 | else if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA) |
| 607 | { |
| 608 | png_bytep rp; |
| 609 | png_uint_32 i; |
| 610 | |
| 611 | for (i = 0, rp = row; i < row_width; i++, rp += 8) |
| 612 | { |
| 613 | png_byte save = *rp; |
| 614 | *rp = *(rp + 4); |
| 615 | *(rp + 4) = save; |
| 616 | save = *(rp + 1); |
| 617 | *(rp + 1) = *(rp + 5); |
| 618 | *(rp + 5) = save; |
| 619 | } |
| 620 | } |
| 621 | } |
| 622 | } |
| 623 | } |
| 624 | #endif /* PNG_READ_BGR_SUPPORTED or PNG_WRITE_BGR_SUPPORTED */ |
| 625 | |
| 626 | #if defined(PNG_READ_USER_TRANSFORM_SUPPORTED) || \ |
| 627 | defined(PNG_WRITE_USER_TRANSFORM_SUPPORTED) || \ |
| 628 | defined(PNG_LEGACY_SUPPORTED) |
| 629 | void PNGAPI |
| 630 | png_set_user_transform_info(png_structp png_ptr, png_voidp |
| 631 | user_transform_ptr, int user_transform_depth, int user_transform_channels) |
| 632 | { |
| 633 | png_debug(1, "in png_set_user_transform_info"); |
| 634 | if (png_ptr == NULL) return; |
| 635 | #if defined(PNG_USER_TRANSFORM_PTR_SUPPORTED) |
| 636 | png_ptr->user_transform_ptr = user_transform_ptr; |
| 637 | png_ptr->user_transform_depth = (png_byte)user_transform_depth; |
| 638 | png_ptr->user_transform_channels = (png_byte)user_transform_channels; |
| 639 | #else |
| 640 | if (user_transform_ptr || user_transform_depth || user_transform_channels) |
| 641 | png_warning(png_ptr, |
| 642 | "This version of libpng does not support user transform info"); |
| 643 | #endif |
| 644 | } |
| 645 | #endif |
| 646 | |
| 647 | /* This function returns a pointer to the user_transform_ptr associated with |
| 648 | * the user transform functions. The application should free any memory |
| 649 | * associated with this pointer before png_write_destroy and png_read_destroy |
| 650 | * are called. |
| 651 | */ |
| 652 | png_voidp PNGAPI |
| 653 | png_get_user_transform_ptr(png_structp png_ptr) |
| 654 | { |
| 655 | if (png_ptr == NULL) return (NULL); |
| 656 | #if defined(PNG_USER_TRANSFORM_PTR_SUPPORTED) |
| 657 | return ((png_voidp)png_ptr->user_transform_ptr); |
| 658 | #else |
| 659 | return (NULL); |
| 660 | #endif |
| 661 | } |
| 662 | #endif /* PNG_READ_SUPPORTED || PNG_WRITE_SUPPORTED */ |