1 2 /* pngtrans.c - transforms the data in a row (used by both readers and writers) 3 * 4 * Last changed in libpng 1.2.41 [December 3, 2009] 5 * Copyright (c) 1998-2009 Glenn Randers-Pehrson 6 * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger) 7 * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.) 8 * 9 * This code is released under the libpng license. 10 * For conditions of distribution and use, see the disclaimer 11 * and license in png.h 12 */ 13 14 #define PNG_INTERNAL 15 #define PNG_NO_PEDANTIC_WARNINGS 16 #include "png.h" 17 #if defined(PNG_READ_SUPPORTED) || defined(PNG_WRITE_SUPPORTED) 18 19 #if defined(PNG_READ_BGR_SUPPORTED) || defined(PNG_WRITE_BGR_SUPPORTED) 20 /* Turn on BGR-to-RGB mapping */ 21 void PNGAPI 22 png_set_bgr(png_structp png_ptr) 23 { 24 png_debug(1, "in png_set_bgr"); 25 26 if (png_ptr == NULL) 27 return; 28 png_ptr->transformations |= PNG_BGR; 29 } 30 #endif 31 32 #if defined(PNG_READ_SWAP_SUPPORTED) || defined(PNG_WRITE_SWAP_SUPPORTED) 33 /* Turn on 16 bit byte swapping */ 34 void PNGAPI 35 png_set_swap(png_structp png_ptr) 36 { 37 png_debug(1, "in png_set_swap"); 38 39 if (png_ptr == NULL) 40 return; 41 if (png_ptr->bit_depth == 16) 42 png_ptr->transformations |= PNG_SWAP_BYTES; 43 } 44 #endif 45 46 #if defined(PNG_READ_PACK_SUPPORTED) || defined(PNG_WRITE_PACK_SUPPORTED) 47 /* Turn on pixel packing */ 48 void PNGAPI 49 png_set_packing(png_structp png_ptr) 50 { 51 png_debug(1, "in png_set_packing"); 52 53 if (png_ptr == NULL) 54 return; 55 if (png_ptr->bit_depth < 8) 56 { 57 png_ptr->transformations |= PNG_PACK; 58 png_ptr->usr_bit_depth = 8; 59 } 60 } 61 #endif 62 63 #if defined(PNG_READ_PACKSWAP_SUPPORTED)||defined(PNG_WRITE_PACKSWAP_SUPPORTED) 64 /* Turn on packed pixel swapping */ 65 void PNGAPI 66 png_set_packswap(png_structp png_ptr) 67 { 68 png_debug(1, "in png_set_packswap"); 69 70 if (png_ptr == NULL) 71 return; 72 if (png_ptr->bit_depth < 8) 73 png_ptr->transformations |= PNG_PACKSWAP; 74 } 75 #endif 76 77 #if defined(PNG_READ_SHIFT_SUPPORTED) || defined(PNG_WRITE_SHIFT_SUPPORTED) 78 void PNGAPI 79 png_set_shift(png_structp png_ptr, png_color_8p true_bits) 80 { 81 png_debug(1, "in png_set_shift"); 82 83 if (png_ptr == NULL) 84 return; 85 png_ptr->transformations |= PNG_SHIFT; 86 png_ptr->shift = *true_bits; 87 } 88 #endif 89 90 #if defined(PNG_READ_INTERLACING_SUPPORTED) || \ 91 defined(PNG_WRITE_INTERLACING_SUPPORTED) 92 int PNGAPI 93 png_set_interlace_handling(png_structp png_ptr) 94 { 95 png_debug(1, "in png_set_interlace handling"); 96 97 if (png_ptr && png_ptr->interlaced) 98 { 99 png_ptr->transformations |= PNG_INTERLACE; 100 return (7); 101 } 102 103 return (1); 104 } 105 #endif 106 107 #if defined(PNG_READ_FILLER_SUPPORTED) || defined(PNG_WRITE_FILLER_SUPPORTED) 108 /* Add a filler byte on read, or remove a filler or alpha byte on write. 109 * The filler type has changed in v0.95 to allow future 2-byte fillers 110 * for 48-bit input data, as well as to avoid problems with some compilers 111 * that don't like bytes as parameters. 112 */ 113 void PNGAPI 114 png_set_filler(png_structp png_ptr, png_uint_32 filler, int filler_loc) 115 { 116 png_debug(1, "in png_set_filler"); 117 118 if (png_ptr == NULL) 119 return; 120 png_ptr->transformations |= PNG_FILLER; 121 #ifdef PNG_LEGACY_SUPPORTED 122 png_ptr->filler = (png_byte)filler; 123 #else 124 png_ptr->filler = (png_uint_16)filler; 125 #endif 126 if (filler_loc == PNG_FILLER_AFTER) 127 png_ptr->flags |= PNG_FLAG_FILLER_AFTER; 128 else 129 png_ptr->flags &= ~PNG_FLAG_FILLER_AFTER; 130 131 /* This should probably go in the "do_read_filler" routine. 132 * I attempted to do that in libpng-1.0.1a but that caused problems 133 * so I restored it in libpng-1.0.2a 134 */ 135 136 if (png_ptr->color_type == PNG_COLOR_TYPE_RGB) 137 { 138 png_ptr->usr_channels = 4; 139 } 140 141 /* Also I added this in libpng-1.0.2a (what happens when we expand 142 * a less-than-8-bit grayscale to GA? */ 143 144 if (png_ptr->color_type == PNG_COLOR_TYPE_GRAY && png_ptr->bit_depth >= 8) 145 { 146 png_ptr->usr_channels = 2; 147 } 148 } 149 150 #ifndef PNG_1_0_X 151 /* Added to libpng-1.2.7 */ 152 void PNGAPI 153 png_set_add_alpha(png_structp png_ptr, png_uint_32 filler, int filler_loc) 154 { 155 png_debug(1, "in png_set_add_alpha"); 156 157 if (png_ptr == NULL) 158 return; 159 png_set_filler(png_ptr, filler, filler_loc); 160 png_ptr->transformations |= PNG_ADD_ALPHA; 161 } 162 #endif 163 164 #endif 165 166 #if defined(PNG_READ_SWAP_ALPHA_SUPPORTED) || \ 167 defined(PNG_WRITE_SWAP_ALPHA_SUPPORTED) 168 void PNGAPI 169 png_set_swap_alpha(png_structp png_ptr) 170 { 171 png_debug(1, "in png_set_swap_alpha"); 172 173 if (png_ptr == NULL) 174 return; 175 png_ptr->transformations |= PNG_SWAP_ALPHA; 176 } 177 #endif 178 179 #if defined(PNG_READ_INVERT_ALPHA_SUPPORTED) || \ 180 defined(PNG_WRITE_INVERT_ALPHA_SUPPORTED) 181 void PNGAPI 182 png_set_invert_alpha(png_structp png_ptr) 183 { 184 png_debug(1, "in png_set_invert_alpha"); 185 186 if (png_ptr == NULL) 187 return; 188 png_ptr->transformations |= PNG_INVERT_ALPHA; 189 } 190 #endif 191 192 #if defined(PNG_READ_INVERT_SUPPORTED) || defined(PNG_WRITE_INVERT_SUPPORTED) 193 void PNGAPI 194 png_set_invert_mono(png_structp png_ptr) 195 { 196 png_debug(1, "in png_set_invert_mono"); 197 198 if (png_ptr == NULL) 199 return; 200 png_ptr->transformations |= PNG_INVERT_MONO; 201 } 202 203 /* Invert monochrome grayscale data */ 204 void /* PRIVATE */ 205 png_do_invert(png_row_infop row_info, png_bytep row) 206 { 207 png_debug(1, "in png_do_invert"); 208 209 /* This test removed from libpng version 1.0.13 and 1.2.0: 210 * if (row_info->bit_depth == 1 && 211 */ 212 #ifdef PNG_USELESS_TESTS_SUPPORTED 213 if (row == NULL || row_info == NULL) 214 return; 215 #endif 216 if (row_info->color_type == PNG_COLOR_TYPE_GRAY) 217 { 218 png_bytep rp = row; 219 png_uint_32 i; 220 png_uint_32 istop = row_info->rowbytes; 221 222 for (i = 0; i < istop; i++) 223 { 224 *rp = (png_byte)(~(*rp)); 225 rp++; 226 } 227 } 228 else if (row_info->color_type == PNG_COLOR_TYPE_GRAY_ALPHA && 229 row_info->bit_depth == 8) 230 { 231 png_bytep rp = row; 232 png_uint_32 i; 233 png_uint_32 istop = row_info->rowbytes; 234 235 for (i = 0; i < istop; i+=2) 236 { 237 *rp = (png_byte)(~(*rp)); 238 rp+=2; 239 } 240 } 241 else if (row_info->color_type == PNG_COLOR_TYPE_GRAY_ALPHA && 242 row_info->bit_depth == 16) 243 { 244 png_bytep rp = row; 245 png_uint_32 i; 246 png_uint_32 istop = row_info->rowbytes; 247 248 for (i = 0; i < istop; i+=4) 249 { 250 *rp = (png_byte)(~(*rp)); 251 *(rp+1) = (png_byte)(~(*(rp+1))); 252 rp+=4; 253 } 254 } 255 } 256 #endif 257 258 #if defined(PNG_READ_SWAP_SUPPORTED) || defined(PNG_WRITE_SWAP_SUPPORTED) 259 /* Swaps byte order on 16 bit depth images */ 260 void /* PRIVATE */ 261 png_do_swap(png_row_infop row_info, png_bytep row) 262 { 263 png_debug(1, "in png_do_swap"); 264 265 if ( 266 #ifdef PNG_USELESS_TESTS_SUPPORTED 267 row != NULL && row_info != NULL && 268 #endif 269 row_info->bit_depth == 16) 270 { 271 png_bytep rp = row; 272 png_uint_32 i; 273 png_uint_32 istop= row_info->width * row_info->channels; 274 275 for (i = 0; i < istop; i++, rp += 2) 276 { 277 png_byte t = *rp; 278 *rp = *(rp + 1); 279 *(rp + 1) = t; 280 } 281 } 282 } 283 #endif 284 285 #if defined(PNG_READ_PACKSWAP_SUPPORTED)||defined(PNG_WRITE_PACKSWAP_SUPPORTED) 286 static PNG_CONST png_byte onebppswaptable[256] = { 287 0x00, 0x80, 0x40, 0xC0, 0x20, 0xA0, 0x60, 0xE0, 288 0x10, 0x90, 0x50, 0xD0, 0x30, 0xB0, 0x70, 0xF0, 289 0x08, 0x88, 0x48, 0xC8, 0x28, 0xA8, 0x68, 0xE8, 290 0x18, 0x98, 0x58, 0xD8, 0x38, 0xB8, 0x78, 0xF8, 291 0x04, 0x84, 0x44, 0xC4, 0x24, 0xA4, 0x64, 0xE4, 292 0x14, 0x94, 0x54, 0xD4, 0x34, 0xB4, 0x74, 0xF4, 293 0x0C, 0x8C, 0x4C, 0xCC, 0x2C, 0xAC, 0x6C, 0xEC, 294 0x1C, 0x9C, 0x5C, 0xDC, 0x3C, 0xBC, 0x7C, 0xFC, 295 0x02, 0x82, 0x42, 0xC2, 0x22, 0xA2, 0x62, 0xE2, 296 0x12, 0x92, 0x52, 0xD2, 0x32, 0xB2, 0x72, 0xF2, 297 0x0A, 0x8A, 0x4A, 0xCA, 0x2A, 0xAA, 0x6A, 0xEA, 298 0x1A, 0x9A, 0x5A, 0xDA, 0x3A, 0xBA, 0x7A, 0xFA, 299 0x06, 0x86, 0x46, 0xC6, 0x26, 0xA6, 0x66, 0xE6, 300 0x16, 0x96, 0x56, 0xD6, 0x36, 0xB6, 0x76, 0xF6, 301 0x0E, 0x8E, 0x4E, 0xCE, 0x2E, 0xAE, 0x6E, 0xEE, 302 0x1E, 0x9E, 0x5E, 0xDE, 0x3E, 0xBE, 0x7E, 0xFE, 303 0x01, 0x81, 0x41, 0xC1, 0x21, 0xA1, 0x61, 0xE1, 304 0x11, 0x91, 0x51, 0xD1, 0x31, 0xB1, 0x71, 0xF1, 305 0x09, 0x89, 0x49, 0xC9, 0x29, 0xA9, 0x69, 0xE9, 306 0x19, 0x99, 0x59, 0xD9, 0x39, 0xB9, 0x79, 0xF9, 307 0x05, 0x85, 0x45, 0xC5, 0x25, 0xA5, 0x65, 0xE5, 308 0x15, 0x95, 0x55, 0xD5, 0x35, 0xB5, 0x75, 0xF5, 309 0x0D, 0x8D, 0x4D, 0xCD, 0x2D, 0xAD, 0x6D, 0xED, 310 0x1D, 0x9D, 0x5D, 0xDD, 0x3D, 0xBD, 0x7D, 0xFD, 311 0x03, 0x83, 0x43, 0xC3, 0x23, 0xA3, 0x63, 0xE3, 312 0x13, 0x93, 0x53, 0xD3, 0x33, 0xB3, 0x73, 0xF3, 313 0x0B, 0x8B, 0x4B, 0xCB, 0x2B, 0xAB, 0x6B, 0xEB, 314 0x1B, 0x9B, 0x5B, 0xDB, 0x3B, 0xBB, 0x7B, 0xFB, 315 0x07, 0x87, 0x47, 0xC7, 0x27, 0xA7, 0x67, 0xE7, 316 0x17, 0x97, 0x57, 0xD7, 0x37, 0xB7, 0x77, 0xF7, 317 0x0F, 0x8F, 0x4F, 0xCF, 0x2F, 0xAF, 0x6F, 0xEF, 318 0x1F, 0x9F, 0x5F, 0xDF, 0x3F, 0xBF, 0x7F, 0xFF 319 }; 320 321 static PNG_CONST png_byte twobppswaptable[256] = { 322 0x00, 0x40, 0x80, 0xC0, 0x10, 0x50, 0x90, 0xD0, 323 0x20, 0x60, 0xA0, 0xE0, 0x30, 0x70, 0xB0, 0xF0, 324 0x04, 0x44, 0x84, 0xC4, 0x14, 0x54, 0x94, 0xD4, 325 0x24, 0x64, 0xA4, 0xE4, 0x34, 0x74, 0xB4, 0xF4, 326 0x08, 0x48, 0x88, 0xC8, 0x18, 0x58, 0x98, 0xD8, 327 0x28, 0x68, 0xA8, 0xE8, 0x38, 0x78, 0xB8, 0xF8, 328 0x0C, 0x4C, 0x8C, 0xCC, 0x1C, 0x5C, 0x9C, 0xDC, 329 0x2C, 0x6C, 0xAC, 0xEC, 0x3C, 0x7C, 0xBC, 0xFC, 330 0x01, 0x41, 0x81, 0xC1, 0x11, 0x51, 0x91, 0xD1, 331 0x21, 0x61, 0xA1, 0xE1, 0x31, 0x71, 0xB1, 0xF1, 332 0x05, 0x45, 0x85, 0xC5, 0x15, 0x55, 0x95, 0xD5, 333 0x25, 0x65, 0xA5, 0xE5, 0x35, 0x75, 0xB5, 0xF5, 334 0x09, 0x49, 0x89, 0xC9, 0x19, 0x59, 0x99, 0xD9, 335 0x29, 0x69, 0xA9, 0xE9, 0x39, 0x79, 0xB9, 0xF9, 336 0x0D, 0x4D, 0x8D, 0xCD, 0x1D, 0x5D, 0x9D, 0xDD, 337 0x2D, 0x6D, 0xAD, 0xED, 0x3D, 0x7D, 0xBD, 0xFD, 338 0x02, 0x42, 0x82, 0xC2, 0x12, 0x52, 0x92, 0xD2, 339 0x22, 0x62, 0xA2, 0xE2, 0x32, 0x72, 0xB2, 0xF2, 340 0x06, 0x46, 0x86, 0xC6, 0x16, 0x56, 0x96, 0xD6, 341 0x26, 0x66, 0xA6, 0xE6, 0x36, 0x76, 0xB6, 0xF6, 342 0x0A, 0x4A, 0x8A, 0xCA, 0x1A, 0x5A, 0x9A, 0xDA, 343 0x2A, 0x6A, 0xAA, 0xEA, 0x3A, 0x7A, 0xBA, 0xFA, 344 0x0E, 0x4E, 0x8E, 0xCE, 0x1E, 0x5E, 0x9E, 0xDE, 345 0x2E, 0x6E, 0xAE, 0xEE, 0x3E, 0x7E, 0xBE, 0xFE, 346 0x03, 0x43, 0x83, 0xC3, 0x13, 0x53, 0x93, 0xD3, 347 0x23, 0x63, 0xA3, 0xE3, 0x33, 0x73, 0xB3, 0xF3, 348 0x07, 0x47, 0x87, 0xC7, 0x17, 0x57, 0x97, 0xD7, 349 0x27, 0x67, 0xA7, 0xE7, 0x37, 0x77, 0xB7, 0xF7, 350 0x0B, 0x4B, 0x8B, 0xCB, 0x1B, 0x5B, 0x9B, 0xDB, 351 0x2B, 0x6B, 0xAB, 0xEB, 0x3B, 0x7B, 0xBB, 0xFB, 352 0x0F, 0x4F, 0x8F, 0xCF, 0x1F, 0x5F, 0x9F, 0xDF, 353 0x2F, 0x6F, 0xAF, 0xEF, 0x3F, 0x7F, 0xBF, 0xFF 354 }; 355 356 static PNG_CONST png_byte fourbppswaptable[256] = { 357 0x00, 0x10, 0x20, 0x30, 0x40, 0x50, 0x60, 0x70, 358 0x80, 0x90, 0xA0, 0xB0, 0xC0, 0xD0, 0xE0, 0xF0, 359 0x01, 0x11, 0x21, 0x31, 0x41, 0x51, 0x61, 0x71, 360 0x81, 0x91, 0xA1, 0xB1, 0xC1, 0xD1, 0xE1, 0xF1, 361 0x02, 0x12, 0x22, 0x32, 0x42, 0x52, 0x62, 0x72, 362 0x82, 0x92, 0xA2, 0xB2, 0xC2, 0xD2, 0xE2, 0xF2, 363 0x03, 0x13, 0x23, 0x33, 0x43, 0x53, 0x63, 0x73, 364 0x83, 0x93, 0xA3, 0xB3, 0xC3, 0xD3, 0xE3, 0xF3, 365 0x04, 0x14, 0x24, 0x34, 0x44, 0x54, 0x64, 0x74, 366 0x84, 0x94, 0xA4, 0xB4, 0xC4, 0xD4, 0xE4, 0xF4, 367 0x05, 0x15, 0x25, 0x35, 0x45, 0x55, 0x65, 0x75, 368 0x85, 0x95, 0xA5, 0xB5, 0xC5, 0xD5, 0xE5, 0xF5, 369 0x06, 0x16, 0x26, 0x36, 0x46, 0x56, 0x66, 0x76, 370 0x86, 0x96, 0xA6, 0xB6, 0xC6, 0xD6, 0xE6, 0xF6, 371 0x07, 0x17, 0x27, 0x37, 0x47, 0x57, 0x67, 0x77, 372 0x87, 0x97, 0xA7, 0xB7, 0xC7, 0xD7, 0xE7, 0xF7, 373 0x08, 0x18, 0x28, 0x38, 0x48, 0x58, 0x68, 0x78, 374 0x88, 0x98, 0xA8, 0xB8, 0xC8, 0xD8, 0xE8, 0xF8, 375 0x09, 0x19, 0x29, 0x39, 0x49, 0x59, 0x69, 0x79, 376 0x89, 0x99, 0xA9, 0xB9, 0xC9, 0xD9, 0xE9, 0xF9, 377 0x0A, 0x1A, 0x2A, 0x3A, 0x4A, 0x5A, 0x6A, 0x7A, 378 0x8A, 0x9A, 0xAA, 0xBA, 0xCA, 0xDA, 0xEA, 0xFA, 379 0x0B, 0x1B, 0x2B, 0x3B, 0x4B, 0x5B, 0x6B, 0x7B, 380 0x8B, 0x9B, 0xAB, 0xBB, 0xCB, 0xDB, 0xEB, 0xFB, 381 0x0C, 0x1C, 0x2C, 0x3C, 0x4C, 0x5C, 0x6C, 0x7C, 382 0x8C, 0x9C, 0xAC, 0xBC, 0xCC, 0xDC, 0xEC, 0xFC, 383 0x0D, 0x1D, 0x2D, 0x3D, 0x4D, 0x5D, 0x6D, 0x7D, 384 0x8D, 0x9D, 0xAD, 0xBD, 0xCD, 0xDD, 0xED, 0xFD, 385 0x0E, 0x1E, 0x2E, 0x3E, 0x4E, 0x5E, 0x6E, 0x7E, 386 0x8E, 0x9E, 0xAE, 0xBE, 0xCE, 0xDE, 0xEE, 0xFE, 387 0x0F, 0x1F, 0x2F, 0x3F, 0x4F, 0x5F, 0x6F, 0x7F, 388 0x8F, 0x9F, 0xAF, 0xBF, 0xCF, 0xDF, 0xEF, 0xFF 389 }; 390 391 /* Swaps pixel packing order within bytes */ 392 void /* PRIVATE */ 393 png_do_packswap(png_row_infop row_info, png_bytep row) 394 { 395 png_debug(1, "in png_do_packswap"); 396 397 if ( 398 #ifdef PNG_USELESS_TESTS_SUPPORTED 399 row != NULL && row_info != NULL && 400 #endif 401 row_info->bit_depth < 8) 402 { 403 png_bytep rp, end, table; 404 405 end = row + row_info->rowbytes; 406 407 if (row_info->bit_depth == 1) 408 table = (png_bytep)onebppswaptable; 409 else if (row_info->bit_depth == 2) 410 table = (png_bytep)twobppswaptable; 411 else if (row_info->bit_depth == 4) 412 table = (png_bytep)fourbppswaptable; 413 else 414 return; 415 416 for (rp = row; rp < end; rp++) 417 *rp = table[*rp]; 418 } 419 } 420 #endif /* PNG_READ_PACKSWAP_SUPPORTED or PNG_WRITE_PACKSWAP_SUPPORTED */ 421 422 #if defined(PNG_WRITE_FILLER_SUPPORTED) || \ 423 defined(PNG_READ_STRIP_ALPHA_SUPPORTED) 424 /* Remove filler or alpha byte(s) */ 425 void /* PRIVATE */ 426 png_do_strip_filler(png_row_infop row_info, png_bytep row, png_uint_32 flags) 427 { 428 png_debug(1, "in png_do_strip_filler"); 429 430 #ifdef PNG_USELESS_TESTS_SUPPORTED 431 if (row != NULL && row_info != NULL) 432 #endif 433 { 434 png_bytep sp=row; 435 png_bytep dp=row; 436 png_uint_32 row_width=row_info->width; 437 png_uint_32 i; 438 439 if ((row_info->color_type == PNG_COLOR_TYPE_RGB || 440 (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA && 441 (flags & PNG_FLAG_STRIP_ALPHA))) && 442 row_info->channels == 4) 443 { 444 if (row_info->bit_depth == 8) 445 { 446 /* This converts from RGBX or RGBA to RGB */ 447 if (flags & PNG_FLAG_FILLER_AFTER) 448 { 449 dp+=3; sp+=4; 450 for (i = 1; i < row_width; i++) 451 { 452 *dp++ = *sp++; 453 *dp++ = *sp++; 454 *dp++ = *sp++; 455 sp++; 456 } 457 } 458 /* This converts from XRGB or ARGB to RGB */ 459 else 460 { 461 for (i = 0; i < row_width; i++) 462 { 463 sp++; 464 *dp++ = *sp++; 465 *dp++ = *sp++; 466 *dp++ = *sp++; 467 } 468 } 469 row_info->pixel_depth = 24; 470 row_info->rowbytes = row_width * 3; 471 } 472 else /* if (row_info->bit_depth == 16) */ 473 { 474 if (flags & PNG_FLAG_FILLER_AFTER) 475 { 476 /* This converts from RRGGBBXX or RRGGBBAA to RRGGBB */ 477 sp += 8; dp += 6; 478 for (i = 1; i < row_width; i++) 479 { 480 /* This could be (although png_memcpy is probably slower): 481 png_memcpy(dp, sp, 6); 482 sp += 8; 483 dp += 6; 484 */ 485 486 *dp++ = *sp++; 487 *dp++ = *sp++; 488 *dp++ = *sp++; 489 *dp++ = *sp++; 490 *dp++ = *sp++; 491 *dp++ = *sp++; 492 sp += 2; 493 } 494 } 495 else 496 { 497 /* This converts from XXRRGGBB or AARRGGBB to RRGGBB */ 498 for (i = 0; i < row_width; i++) 499 { 500 /* This could be (although png_memcpy is probably slower): 501 png_memcpy(dp, sp, 6); 502 sp += 8; 503 dp += 6; 504 */ 505 506 sp+=2; 507 *dp++ = *sp++; 508 *dp++ = *sp++; 509 *dp++ = *sp++; 510 *dp++ = *sp++; 511 *dp++ = *sp++; 512 *dp++ = *sp++; 513 } 514 } 515 row_info->pixel_depth = 48; 516 row_info->rowbytes = row_width * 6; 517 } 518 row_info->channels = 3; 519 } 520 else if ((row_info->color_type == PNG_COLOR_TYPE_GRAY || 521 (row_info->color_type == PNG_COLOR_TYPE_GRAY_ALPHA && 522 (flags & PNG_FLAG_STRIP_ALPHA))) && 523 row_info->channels == 2) 524 { 525 if (row_info->bit_depth == 8) 526 { 527 /* This converts from GX or GA to G */ 528 if (flags & PNG_FLAG_FILLER_AFTER) 529 { 530 for (i = 0; i < row_width; i++) 531 { 532 *dp++ = *sp++; 533 sp++; 534 } 535 } 536 /* This converts from XG or AG to G */ 537 else 538 { 539 for (i = 0; i < row_width; i++) 540 { 541 sp++; 542 *dp++ = *sp++; 543 } 544 } 545 row_info->pixel_depth = 8; 546 row_info->rowbytes = row_width; 547 } 548 else /* if (row_info->bit_depth == 16) */ 549 { 550 if (flags & PNG_FLAG_FILLER_AFTER) 551 { 552 /* This converts from GGXX or GGAA to GG */ 553 sp += 4; dp += 2; 554 for (i = 1; i < row_width; i++) 555 { 556 *dp++ = *sp++; 557 *dp++ = *sp++; 558 sp += 2; 559 } 560 } 561 else 562 { 563 /* This converts from XXGG or AAGG to GG */ 564 for (i = 0; i < row_width; i++) 565 { 566 sp += 2; 567 *dp++ = *sp++; 568 *dp++ = *sp++; 569 } 570 } 571 row_info->pixel_depth = 16; 572 row_info->rowbytes = row_width * 2; 573 } 574 row_info->channels = 1; 575 } 576 if (flags & PNG_FLAG_STRIP_ALPHA) 577 row_info->color_type &= ~PNG_COLOR_MASK_ALPHA; 578 } 579 } 580 #endif 581 582 #if defined(PNG_READ_BGR_SUPPORTED) || defined(PNG_WRITE_BGR_SUPPORTED) 583 /* Swaps red and blue bytes within a pixel */ 584 void /* PRIVATE */ 585 png_do_bgr(png_row_infop row_info, png_bytep row) 586 { 587 png_debug(1, "in png_do_bgr"); 588 589 if ( 590 #ifdef PNG_USELESS_TESTS_SUPPORTED 591 row != NULL && row_info != NULL && 592 #endif 593 (row_info->color_type & PNG_COLOR_MASK_COLOR)) 594 { 595 png_uint_32 row_width = row_info->width; 596 if (row_info->bit_depth == 8) 597 { 598 if (row_info->color_type == PNG_COLOR_TYPE_RGB) 599 { 600 png_bytep rp; 601 png_uint_32 i; 602 603 for (i = 0, rp = row; i < row_width; i++, rp += 3) 604 { 605 png_byte save = *rp; 606 *rp = *(rp + 2); 607 *(rp + 2) = save; 608 } 609 } 610 else if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA) 611 { 612 png_bytep rp; 613 png_uint_32 i; 614 615 for (i = 0, rp = row; i < row_width; i++, rp += 4) 616 { 617 png_byte save = *rp; 618 *rp = *(rp + 2); 619 *(rp + 2) = save; 620 } 621 } 622 } 623 else if (row_info->bit_depth == 16) 624 { 625 if (row_info->color_type == PNG_COLOR_TYPE_RGB) 626 { 627 png_bytep rp; 628 png_uint_32 i; 629 630 for (i = 0, rp = row; i < row_width; i++, rp += 6) 631 { 632 png_byte save = *rp; 633 *rp = *(rp + 4); 634 *(rp + 4) = save; 635 save = *(rp + 1); 636 *(rp + 1) = *(rp + 5); 637 *(rp + 5) = save; 638 } 639 } 640 else if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA) 641 { 642 png_bytep rp; 643 png_uint_32 i; 644 645 for (i = 0, rp = row; i < row_width; i++, rp += 8) 646 { 647 png_byte save = *rp; 648 *rp = *(rp + 4); 649 *(rp + 4) = save; 650 save = *(rp + 1); 651 *(rp + 1) = *(rp + 5); 652 *(rp + 5) = save; 653 } 654 } 655 } 656 } 657 } 658 #endif /* PNG_READ_BGR_SUPPORTED or PNG_WRITE_BGR_SUPPORTED */ 659 660 #if defined(PNG_READ_USER_TRANSFORM_SUPPORTED) || \ 661 defined(PNG_LEGACY_SUPPORTED) || \ 662 defined(PNG_WRITE_USER_TRANSFORM_SUPPORTED) 663 void PNGAPI 664 png_set_user_transform_info(png_structp png_ptr, png_voidp 665 user_transform_ptr, int user_transform_depth, int user_transform_channels) 666 { 667 png_debug(1, "in png_set_user_transform_info"); 668 669 if (png_ptr == NULL) 670 return; 671 #ifdef PNG_USER_TRANSFORM_PTR_SUPPORTED 672 png_ptr->user_transform_ptr = user_transform_ptr; 673 png_ptr->user_transform_depth = (png_byte)user_transform_depth; 674 png_ptr->user_transform_channels = (png_byte)user_transform_channels; 675 #else 676 if (user_transform_ptr || user_transform_depth || user_transform_channels) 677 png_warning(png_ptr, 678 "This version of libpng does not support user transform info"); 679 #endif 680 } 681 #endif 682 683 /* This function returns a pointer to the user_transform_ptr associated with 684 * the user transform functions. The application should free any memory 685 * associated with this pointer before png_write_destroy and png_read_destroy 686 * are called. 687 */ 688 png_voidp PNGAPI 689 png_get_user_transform_ptr(png_structp png_ptr) 690 { 691 if (png_ptr == NULL) 692 return (NULL); 693 #ifdef PNG_USER_TRANSFORM_PTR_SUPPORTED 694 return ((png_voidp)png_ptr->user_transform_ptr); 695 #else 696 return (NULL); 697 #endif 698 } 699 #endif /* PNG_READ_SUPPORTED || PNG_WRITE_SUPPORTED */ 700
