| 1 | /* |
| 2 | // source code for the ImageLib PNG functions |
| 3 | // |
| 4 | // Copyright (C) 2001 M. Scott Heiman |
| 5 | // All Rights Reserved |
| 6 | // |
| 7 | // You may use the software for any purpose you see fit. You may modify |
| 8 | // it, incorporate it in a commercial application, use it for school, |
| 9 | // even turn it in as homework. You must keep the Copyright in the |
| 10 | // header and source files. This software is not in the "Public Domain". |
| 11 | // You may use this software at your own risk. I have made a reasonable |
| 12 | // effort to verify that this software works in the manner I expect it to; |
| 13 | // however,... |
| 14 | // |
| 15 | // THE MATERIAL EMBODIED ON THIS SOFTWARE IS PROVIDED TO YOU "AS-IS" AND |
| 16 | // WITHOUT WARRANTY OF ANY KIND, EXPRESS, IMPLIED OR OTHERWISE, INCLUDING |
| 17 | // WITHOUT LIMITATION, ANY WARRANTY OF MERCHANTABILITY OR FITNESS FOR A |
| 18 | // PARTICULAR PURPOSE. IN NO EVENT SHALL MICHAEL S. HEIMAN BE LIABLE TO |
| 19 | // YOU OR ANYONE ELSE FOR ANY DIRECT, SPECIAL, INCIDENTAL, INDIRECT OR |
| 20 | // CONSEQUENTIAL DAMAGES OF ANY KIND, OR ANY DAMAGES WHATSOEVER, INCLUDING |
| 21 | // WITHOUT LIMITATION, LOSS OF PROFIT, LOSS OF USE, SAVINGS OR REVENUE, |
| 22 | // OR THE CLAIMS OF THIRD PARTIES, WHETHER OR NOT MICHAEL S. HEIMAN HAS |
| 23 | // BEEN ADVISED OF THE POSSIBILITY OF SUCH LOSS, HOWEVER CAUSED AND ON |
| 24 | // ANY THEORY OF LIABILITY, ARISING OUT OF OR IN CONNECTION WITH THE |
| 25 | // POSSESSION, USE OR PERFORMANCE OF THIS SOFTWARE. |
| 26 | */ |
| 27 | |
| 28 | #include "BMGUtils.h" |
| 29 | #include <ctype.h> |
| 30 | #include <stdio.h> |
| 31 | #include <stdlib.h> |
| 32 | #ifdef _BMG_LIBPNG_STANDALONE |
| 33 | #include "BMGLibPNG.h" |
| 34 | #else |
| 35 | #include "pngrw.h" |
| 36 | #endif |
| 37 | #include <png.h> |
| 38 | |
| 39 | #ifndef png_jmpbuf |
| 40 | # define png_jmpbuf(png_ptr) ((png_ptr)->jmpbuf) |
| 41 | #endif |
| 42 | |
| 43 | |
| 44 | /* this stuff is necessary because the normal png_init_io() method crashes in Win32 */ |
| 45 | static void user_read_data(png_structp png_read, png_bytep data, png_size_t length) |
| 46 | { |
| 47 | FILE *fPtr = (FILE *) png_get_io_ptr(png_read); |
| 48 | if (fread(data, 1, length, fPtr) != length) |
| 49 | fprintf(stderr, "Failed to read %i bytes from PNG file.\n", (int) length); |
| 50 | } |
| 51 | |
| 52 | static void user_write_data(png_structp png_write, png_bytep data, png_size_t length) |
| 53 | { |
| 54 | FILE *fPtr = (FILE *) png_get_io_ptr(png_write); |
| 55 | if (fwrite(data, 1, length, fPtr) != length) |
| 56 | fprintf(stderr, "Failed to write %i bytes to PNG file.\n", (int) length); |
| 57 | } |
| 58 | |
| 59 | static void user_flush_data(png_structp png_read) |
| 60 | { |
| 61 | FILE *fPtr = (FILE *) png_get_io_ptr(png_read); |
| 62 | fflush(fPtr); |
| 63 | } |
| 64 | |
| 65 | /* |
| 66 | ReadPNG - Reads the contents of a PNG file and stores the contents into |
| 67 | BMGImageStruct |
| 68 | |
| 69 | Inputs: |
| 70 | filename - the name of the file to be opened |
| 71 | |
| 72 | Outputs: |
| 73 | img - the BMGImageStruct containing the image data |
| 74 | |
| 75 | Returns: |
| 76 | BMGError - if the file could not be read or a resource error occurred |
| 77 | BMG_OK - if the file was read and the data was stored in img |
| 78 | |
| 79 | Limitations: |
| 80 | None. |
| 81 | |
| 82 | Comments: |
| 83 | 2-bit images are converted to 4-bit images. |
| 84 | 16-bit images are converted to 8-bit images. |
| 85 | gray scale images with alpha components are converted to 32-bit images |
| 86 | */ |
| 87 | BMGError ReadPNG( const char *filename, |
| 88 | struct BMGImageStruct * volatile img ) |
| 89 | { |
| 90 | jmp_buf err_jmp; |
| 91 | int error; |
| 92 | |
| 93 | FILE * volatile file = NULL; |
| 94 | int BitDepth; |
| 95 | int ColorType; |
| 96 | int InterlaceType; |
| 97 | unsigned char signature[8]; |
| 98 | png_structp volatile png_ptr = NULL; |
| 99 | png_infop volatile info_ptr = NULL; |
| 100 | png_infop volatile end_info = NULL; |
| 101 | png_color_16 *ImageBackground = NULL; |
| 102 | png_bytep trns = NULL; |
| 103 | int NumTrans = 0; |
| 104 | int i, k; |
| 105 | png_color_16p TransColors = NULL; |
| 106 | png_uint_32 Width, Height; |
| 107 | |
| 108 | unsigned char *bits; |
| 109 | unsigned char** volatile rows = NULL; |
| 110 | |
| 111 | BMGError tmp; |
| 112 | |
| 113 | /* error handler */ |
| 114 | error = setjmp( err_jmp ); |
| 115 | if (error != 0) |
| 116 | { |
| 117 | if (end_info != NULL) |
| 118 | png_destroy_read_struct((png_structp *) &png_ptr, (png_infop *) &info_ptr, (png_infop *) &end_info); |
| 119 | else if (info_ptr != NULL) |
| 120 | png_destroy_read_struct((png_structp *) &png_ptr, (png_infop *) &info_ptr, NULL); |
| 121 | else if (png_ptr != NULL) |
| 122 | png_destroy_read_struct((png_structp *) &png_ptr, NULL, NULL); |
| 123 | if (rows) |
| 124 | { |
| 125 | if (rows[0]) |
| 126 | free(rows[0]); |
| 127 | free(rows); |
| 128 | } |
| 129 | if (img) |
| 130 | FreeBMGImage(img); |
| 131 | if (file) |
| 132 | fclose(file); |
| 133 | SetLastBMGError((BMGError) error); |
| 134 | return (BMGError) error; |
| 135 | } |
| 136 | |
| 137 | if ( img == NULL ) |
| 138 | longjmp ( err_jmp, (int)errInvalidBMGImage ); |
| 139 | |
| 140 | file = fopen( filename, "rb" ); |
| 141 | if ( !file || fread( signature, 1, 8, file ) != 8) |
| 142 | longjmp ( err_jmp, (int)errFileOpen ); |
| 143 | |
| 144 | /* check the signature */ |
| 145 | if ( png_sig_cmp( signature, 0, 8 ) != 0 ) |
| 146 | longjmp( err_jmp, (int)errUnsupportedFileFormat ); |
| 147 | |
| 148 | /* create a pointer to the png read structure */ |
| 149 | png_ptr = png_create_read_struct( PNG_LIBPNG_VER_STRING, NULL, NULL, NULL ); |
| 150 | if ( !png_ptr ) |
| 151 | longjmp( err_jmp, (int)errMemoryAllocation ); |
| 152 | |
| 153 | /* create a pointer to the png info structure */ |
| 154 | info_ptr = png_create_info_struct( png_ptr ); |
| 155 | if ( !info_ptr ) |
| 156 | longjmp( err_jmp, (int)errMemoryAllocation ); |
| 157 | |
| 158 | /* create a pointer to the png end-info structure */ |
| 159 | end_info = png_create_info_struct(png_ptr); |
| 160 | if (!end_info) |
| 161 | longjmp( err_jmp, (int)errMemoryAllocation ); |
| 162 | |
| 163 | /* bamboozle the PNG longjmp buffer */ |
| 164 | /*generic PNG error handler*/ |
| 165 | /* error will always == 1 which == errLib */ |
| 166 | // error = png_setjmp(png_ptr); |
| 167 | error = setjmp( png_jmpbuf( png_ptr ) ); |
| 168 | if ( error > 0 ) |
| 169 | longjmp( err_jmp, error ); |
| 170 | |
| 171 | /* set function pointers in the PNG library, for read callbacks */ |
| 172 | png_set_read_fn(png_ptr, (png_voidp) file, user_read_data); |
| 173 | |
| 174 | /*let the read functions know that we have already read the 1st 8 bytes */ |
| 175 | png_set_sig_bytes( png_ptr, 8 ); |
| 176 | |
| 177 | /* read all PNG data up to the image data */ |
| 178 | png_read_info( png_ptr, info_ptr ); |
| 179 | |
| 180 | /* extract the data we need to form the HBITMAP from the PNG header */ |
| 181 | png_get_IHDR( png_ptr, info_ptr, &Width, &Height, &BitDepth, &ColorType, |
| 182 | &InterlaceType, NULL, NULL); |
| 183 | |
| 184 | img->width = (unsigned int) Width; |
| 185 | img->height = (unsigned int) Height; |
| 186 | |
| 187 | img->bits_per_pixel = (unsigned char)32; |
| 188 | img->scan_width = Width * 4; |
| 189 | |
| 190 | /* convert 16-bit images to 8-bit images */ |
| 191 | if (BitDepth == 16) |
| 192 | png_set_strip_16(png_ptr); |
| 193 | |
| 194 | /* These are not really required per Rice format spec, |
| 195 | * but is done just in case someone uses them. |
| 196 | */ |
| 197 | /* convert palette color to rgb color */ |
| 198 | if (ColorType == PNG_COLOR_TYPE_PALETTE) { |
| 199 | png_set_palette_to_rgb(png_ptr); |
| 200 | ColorType = PNG_COLOR_TYPE_RGB; |
| 201 | } |
| 202 | |
| 203 | /* expand 1,2,4 bit gray scale to 8 bit gray scale */ |
| 204 | if (ColorType == PNG_COLOR_TYPE_GRAY && BitDepth < 8) |
| 205 | png_set_expand_gray_1_2_4_to_8(png_ptr); |
| 206 | |
| 207 | /* convert gray scale or gray scale + alpha to rgb color */ |
| 208 | if (ColorType == PNG_COLOR_TYPE_GRAY || |
| 209 | ColorType == PNG_COLOR_TYPE_GRAY_ALPHA) { |
| 210 | png_set_gray_to_rgb(png_ptr); |
| 211 | ColorType = PNG_COLOR_TYPE_RGB; |
| 212 | } |
| 213 | |
| 214 | /* add alpha channel if any */ |
| 215 | if (png_get_valid(png_ptr, info_ptr, PNG_INFO_tRNS)) { |
| 216 | png_set_tRNS_to_alpha(png_ptr); |
| 217 | ColorType = PNG_COLOR_TYPE_RGB_ALPHA; |
| 218 | } |
| 219 | |
| 220 | /* convert rgb to rgba */ |
| 221 | if (ColorType == PNG_COLOR_TYPE_RGB) { |
| 222 | png_set_filler(png_ptr, 0xff, PNG_FILLER_AFTER); |
| 223 | ColorType = PNG_COLOR_TYPE_RGB_ALPHA; |
| 224 | } |
| 225 | |
| 226 | png_set_bgr(png_ptr); |
| 227 | |
| 228 | /* set the background color if one is found */ |
| 229 | if ( png_get_valid(png_ptr, info_ptr, PNG_INFO_bKGD) ) |
| 230 | png_get_bKGD(png_ptr, info_ptr, &ImageBackground); |
| 231 | |
| 232 | /* get the transparent color if one is there */ |
| 233 | if ( png_get_valid( png_ptr, info_ptr, PNG_INFO_tRNS ) ) |
| 234 | png_get_tRNS( png_ptr, info_ptr, &trns, &NumTrans, &TransColors ); |
| 235 | |
| 236 | img->palette_size = (unsigned short)0; |
| 237 | img->bytes_per_palette_entry = 4U; |
| 238 | |
| 239 | tmp = AllocateBMGImage( img ); |
| 240 | if ( tmp != BMG_OK ) |
| 241 | longjmp( err_jmp, (int)tmp ); |
| 242 | |
| 243 | png_read_update_info( png_ptr, info_ptr ); |
| 244 | |
| 245 | /* create buffer to read data to */ |
| 246 | rows = (unsigned char **)malloc(Height*sizeof(unsigned char *)); |
| 247 | if ( !rows ) |
| 248 | longjmp( err_jmp, (int)errMemoryAllocation ); |
| 249 | |
| 250 | k = png_get_rowbytes( png_ptr, info_ptr ); |
| 251 | rows[0] = (unsigned char *)malloc( Height*k*sizeof(char)); |
| 252 | if ( !rows[0] ) |
| 253 | longjmp( err_jmp, (int)errMemoryAllocation ); |
| 254 | |
| 255 | for ( i = 1; i < (int)Height; i++ ) |
| 256 | rows[i] = rows[i-1] + k; |
| 257 | |
| 258 | /* read the entire image into rows */ |
| 259 | png_read_image( png_ptr, rows ); |
| 260 | |
| 261 | bits = img->bits + (Height - 1) * img->scan_width; |
| 262 | for ( i = 0; i < (int)Height; i++ ) |
| 263 | { |
| 264 | memcpy(bits, rows[i], 4*Width); |
| 265 | bits -= img->scan_width; |
| 266 | } |
| 267 | |
| 268 | free( rows[0] ); |
| 269 | free( rows ); |
| 270 | png_read_end( png_ptr, info_ptr ); |
| 271 | png_destroy_read_struct((png_structp *) &png_ptr, (png_infop *) &info_ptr, (png_infop *) &end_info); |
| 272 | fclose( file ); |
| 273 | |
| 274 | return BMG_OK; |
| 275 | } |
| 276 | |
| 277 | BMGError ReadPNGInfo( const char *filename, |
| 278 | struct BMGImageStruct * volatile img ) |
| 279 | { |
| 280 | jmp_buf err_jmp; |
| 281 | int error; |
| 282 | |
| 283 | FILE * volatile file = NULL; |
| 284 | int BitDepth; |
| 285 | int ColorType; |
| 286 | int InterlaceType; |
| 287 | unsigned char signature[8]; |
| 288 | png_structp volatile png_ptr = NULL; |
| 289 | png_infop volatile info_ptr = NULL; |
| 290 | png_infop volatile end_info = NULL; |
| 291 | png_uint_32 Width, Height; |
| 292 | |
| 293 | /* error handler */ |
| 294 | error = setjmp( err_jmp ); |
| 295 | if (error != 0) |
| 296 | { |
| 297 | if (end_info != NULL) |
| 298 | png_destroy_read_struct((png_structp *) &png_ptr, (png_infop *) &info_ptr, (png_infop *) &end_info); |
| 299 | else if (info_ptr != NULL) |
| 300 | png_destroy_read_struct((png_structp *) &png_ptr, (png_infop *) &info_ptr, NULL); |
| 301 | else if (png_ptr != NULL) |
| 302 | png_destroy_read_struct((png_structp *) &png_ptr, NULL, NULL); |
| 303 | if (img) |
| 304 | FreeBMGImage(img); |
| 305 | if (file) |
| 306 | fclose(file); |
| 307 | SetLastBMGError((BMGError) error); |
| 308 | return (BMGError) error; |
| 309 | } |
| 310 | |
| 311 | if ( img == NULL ) |
| 312 | longjmp ( err_jmp, (int)errInvalidBMGImage ); |
| 313 | |
| 314 | file = fopen( filename, "rb" ); |
| 315 | if ( !file || fread( signature, 1, 8, file ) != 8) |
| 316 | longjmp ( err_jmp, (int)errFileOpen ); |
| 317 | |
| 318 | /* check the signature */ |
| 319 | if ( png_sig_cmp( signature, 0, 8 ) != 0 ) |
| 320 | longjmp( err_jmp, (int)errUnsupportedFileFormat ); |
| 321 | |
| 322 | /* create a pointer to the png read structure */ |
| 323 | png_ptr = png_create_read_struct( PNG_LIBPNG_VER_STRING, NULL, NULL, NULL ); |
| 324 | if ( !png_ptr ) |
| 325 | longjmp( err_jmp, (int)errMemoryAllocation ); |
| 326 | |
| 327 | /* create a pointer to the png info structure */ |
| 328 | info_ptr = png_create_info_struct( png_ptr ); |
| 329 | if ( !info_ptr ) |
| 330 | longjmp( err_jmp, (int)errMemoryAllocation ); |
| 331 | |
| 332 | /* create a pointer to the png end-info structure */ |
| 333 | end_info = png_create_info_struct(png_ptr); |
| 334 | if (!end_info) |
| 335 | longjmp( err_jmp, (int)errMemoryAllocation ); |
| 336 | |
| 337 | /* bamboozle the PNG longjmp buffer */ |
| 338 | /*generic PNG error handler*/ |
| 339 | /* error will always == 1 which == errLib */ |
| 340 | // error = png_setjmp(png_ptr); |
| 341 | error = setjmp( png_jmpbuf( png_ptr ) ); |
| 342 | if ( error > 0 ) |
| 343 | longjmp( err_jmp, error ); |
| 344 | |
| 345 | /* set function pointers in the PNG library, for read callbacks */ |
| 346 | png_set_read_fn(png_ptr, (png_voidp) file, user_read_data); |
| 347 | |
| 348 | /*let the read functions know that we have already read the 1st 8 bytes */ |
| 349 | png_set_sig_bytes( png_ptr, 8 ); |
| 350 | |
| 351 | /* read all PNG data up to the image data */ |
| 352 | png_read_info( png_ptr, info_ptr ); |
| 353 | |
| 354 | /* extract the data we need to form the HBITMAP from the PNG header */ |
| 355 | png_get_IHDR( png_ptr, info_ptr, &Width, &Height, &BitDepth, &ColorType, |
| 356 | &InterlaceType, NULL, NULL); |
| 357 | |
| 358 | img->width = (unsigned int) Width; |
| 359 | img->height = (unsigned int) Height; |
| 360 | |
| 361 | img->bits_per_pixel = (unsigned char)32; |
| 362 | img->scan_width = Width * 4; |
| 363 | |
| 364 | img->palette_size = (unsigned short)0; |
| 365 | img->bytes_per_palette_entry = 4U; |
| 366 | img->bits = NULL; |
| 367 | |
| 368 | png_destroy_read_struct((png_structp *) &png_ptr, (png_infop *) &info_ptr, (png_infop *) &end_info); |
| 369 | fclose( file ); |
| 370 | |
| 371 | return BMG_OK; |
| 372 | } |
| 373 | |
| 374 | /* |
| 375 | WritePNG - writes the contents of a BMGImageStruct to a PNG file. |
| 376 | |
| 377 | Inputs: |
| 378 | filename - the name of the file to be opened |
| 379 | img - the BMGImageStruct containing the image data |
| 380 | |
| 381 | Returns: |
| 382 | 0 - if the file could not be written or a resource error occurred |
| 383 | 1 - if the file was written |
| 384 | |
| 385 | Comments: |
| 386 | 16-BPP BMG Images are converted to 24-BPP images |
| 387 | |
| 388 | Limitations: |
| 389 | Color Type is limited to PNG_COLOR_TYPE_GRAY, PNG_COLOR_TYPE_RGB_ALPHA, |
| 390 | PNG_COLOR_TYPE_RGB, & PNG_COLOR_TYPE_PALETTE; |
| 391 | */ |
| 392 | BMGError WritePNG( const char *filename, struct BMGImageStruct img ) |
| 393 | { |
| 394 | jmp_buf err_jmp; |
| 395 | int error = 0; |
| 396 | int BitDepth = 0; |
| 397 | int ColorType = 0; |
| 398 | png_structp png_ptr = NULL; |
| 399 | png_infop info_ptr = NULL; |
| 400 | png_colorp PNGPalette = NULL; |
| 401 | |
| 402 | unsigned char *bits, *p, *q; |
| 403 | unsigned char **rows = NULL; |
| 404 | volatile int GrayScale, NumColors; // mark as volatile so GCC won't throw warning with -Wclobbered |
| 405 | |
| 406 | int DIBScanWidth; |
| 407 | FILE *outfile = NULL; |
| 408 | int i; |
| 409 | BMGError tmp; |
| 410 | |
| 411 | /* error handler */ |
| 412 | error = setjmp( err_jmp ); |
| 413 | fprintf(stderr,"Writing PNG file %s.\n", filename); |
| 414 | if ( error != 0 ) |
| 415 | { |
| 416 | if ( png_ptr != NULL ) |
| 417 | png_destroy_write_struct( &png_ptr, NULL ); |
| 418 | if ( rows ) |
| 419 | { |
| 420 | if ( rows[0] ) |
| 421 | { |
| 422 | free( rows[0] ); |
| 423 | } |
| 424 | free( rows ); |
| 425 | } |
| 426 | if ( PNGPalette ) |
| 427 | free( PNGPalette ); |
| 428 | if (outfile) |
| 429 | { |
| 430 | fclose( outfile ); |
| 431 | } |
| 432 | SetLastBMGError( (BMGError)error ); |
| 433 | return (BMGError)error; |
| 434 | } |
| 435 | |
| 436 | SetLastBMGError( BMG_OK ); |
| 437 | /* open the file */ |
| 438 | if ((outfile = fopen(filename, "wb")) == NULL) |
| 439 | { |
| 440 | fprintf(stderr, "Error opening %s for reading.\n", filename); |
| 441 | longjmp( err_jmp, (int)errFileOpen ); |
| 442 | } |
| 443 | |
| 444 | /* 16 BPP DIBS do not have palettes. libPNG expects 16 BPP images to have |
| 445 | a palette. To correct this situation we must convert 16 BPP images to |
| 446 | 24 BPP images before saving the data to the file */ |
| 447 | if ( img.bits_per_pixel == 16 ) |
| 448 | { |
| 449 | tmp = Convert16to24( &img ); |
| 450 | if ( tmp != BMG_OK ) |
| 451 | longjmp( err_jmp, (int)tmp ); |
| 452 | } |
| 453 | |
| 454 | GrayScale = 0; |
| 455 | NumColors = 0; |
| 456 | if (img.bits_per_pixel <= 8) // has palette |
| 457 | { |
| 458 | NumColors = img.palette_size; |
| 459 | /* if this is a grayscale image then set the flag and delete the palette*/ |
| 460 | i = 0; |
| 461 | bits = img.palette; |
| 462 | while ( i < NumColors && bits[0] == bits[1] && bits[0] == bits[2] ) |
| 463 | { |
| 464 | i++; |
| 465 | bits += img.bytes_per_palette_entry; |
| 466 | } |
| 467 | GrayScale = (i == NumColors); |
| 468 | } |
| 469 | |
| 470 | /* dimensions */ |
| 471 | DIBScanWidth = ( img.width * img.bits_per_pixel + 7 ) / 8; |
| 472 | |
| 473 | /* create the png pointer */ |
| 474 | png_ptr = png_create_write_struct( PNG_LIBPNG_VER_STRING, NULL, NULL, NULL); |
| 475 | if ( !png_ptr ) |
| 476 | longjmp( err_jmp, (int)errMemoryAllocation ); |
| 477 | |
| 478 | /* create the info pointer */ |
| 479 | info_ptr = png_create_info_struct( png_ptr ); |
| 480 | if ( !info_ptr ) |
| 481 | longjmp( err_jmp, (int)errMemoryAllocation ); |
| 482 | |
| 483 | /* bamboozle the png error handler */ |
| 484 | /* error will always == 1 which equals errLib */ |
| 485 | // error = png_setjmp(png_ptr); |
| 486 | error = setjmp( png_jmpbuf( png_ptr ) ); |
| 487 | if ( error > 0 ) |
| 488 | longjmp( err_jmp, error ); |
| 489 | |
| 490 | /* set function pointers in the PNG library, for write callbacks */ |
| 491 | png_set_write_fn(png_ptr, (png_voidp) outfile, user_write_data, user_flush_data); |
| 492 | |
| 493 | /* prepare variables needed to create PNG header */ |
| 494 | BitDepth = img.bits_per_pixel < 8 ? img.bits_per_pixel : 8; |
| 495 | |
| 496 | /* determine color type */ |
| 497 | if ( GrayScale ) |
| 498 | ColorType = PNG_COLOR_TYPE_GRAY; |
| 499 | else if ( img.bits_per_pixel == 32 ) |
| 500 | ColorType = PNG_COLOR_TYPE_RGB_ALPHA; |
| 501 | else if ( img.bits_per_pixel == 24 ) |
| 502 | ColorType = PNG_COLOR_TYPE_RGB; |
| 503 | else |
| 504 | ColorType = PNG_COLOR_TYPE_PALETTE; |
| 505 | |
| 506 | /* create the PNG header */ |
| 507 | png_set_IHDR( png_ptr, info_ptr, img.width, img.height, BitDepth, ColorType, PNG_INTERLACE_NONE, PNG_COMPRESSION_TYPE_BASE, PNG_FILTER_TYPE_BASE ); |
| 508 | |
| 509 | /* store the palette information if there is any */ |
| 510 | if ( img.palette != NULL && !GrayScale ) |
| 511 | { |
| 512 | PNGPalette = (png_colorp)png_malloc( png_ptr, |
| 513 | NumColors*sizeof(png_color)); |
| 514 | if ( PNGPalette ) |
| 515 | { |
| 516 | bits = img.palette; |
| 517 | for ( i = 0; i < NumColors; i++, bits += img.bytes_per_palette_entry ) |
| 518 | { |
| 519 | PNGPalette[i].red = bits[2]; |
| 520 | PNGPalette[i].green = bits[1]; |
| 521 | PNGPalette[i].blue = bits[0]; |
| 522 | } |
| 523 | png_set_PLTE( png_ptr, info_ptr, PNGPalette, NumColors ); |
| 524 | } |
| 525 | else |
| 526 | longjmp( err_jmp, (int)errMemoryAllocation ); |
| 527 | } |
| 528 | |
| 529 | /* write the file header information */ |
| 530 | png_write_info( png_ptr, info_ptr ); |
| 531 | |
| 532 | /* create array to store data in */ |
| 533 | rows = (unsigned char **)malloc(sizeof(unsigned char*)); |
| 534 | if ( !rows ) |
| 535 | longjmp( err_jmp, (int)errMemoryAllocation ); |
| 536 | rows[0] = (unsigned char *)malloc( DIBScanWidth * sizeof(unsigned char)); |
| 537 | if ( !rows[0] ) |
| 538 | longjmp( err_jmp, (int)errMemoryAllocation ); |
| 539 | |
| 540 | /* point to the bottom row of the DIB data. DIBs are stored bottom-to-top, |
| 541 | PNGs are stored top-to-bottom. */ |
| 542 | bits = img.bits + (img.height - 1) * img.scan_width; |
| 543 | |
| 544 | /* store bits */ |
| 545 | for ( i = 0; i < (int)img.height; i++ ) |
| 546 | { |
| 547 | switch ( img.bits_per_pixel ) |
| 548 | { |
| 549 | case 1: |
| 550 | case 4: |
| 551 | case 8: |
| 552 | memcpy( (void *)rows[0], (void *)bits, DIBScanWidth ); |
| 553 | break; |
| 554 | case 24: |
| 555 | q = bits; |
| 556 | for ( p = rows[0]; p < rows[0] + DIBScanWidth; p += 3, q += 3 ) |
| 557 | { |
| 558 | p[0] = q[2]; |
| 559 | p[1] = q[1]; |
| 560 | p[2] = q[0]; |
| 561 | } |
| 562 | break; |
| 563 | case 32: |
| 564 | q = bits; |
| 565 | for ( p = rows[0]; p < rows[0] + DIBScanWidth; p += 4, q += 4 ) |
| 566 | { |
| 567 | p[3] = q[3]; |
| 568 | p[0] = q[2]; |
| 569 | p[1] = q[1]; |
| 570 | p[2] = q[0]; |
| 571 | } |
| 572 | break; |
| 573 | } |
| 574 | |
| 575 | png_write_rows( png_ptr, rows, 1 ); |
| 576 | bits -= img.scan_width; |
| 577 | } |
| 578 | |
| 579 | /* finish writing the rest of the file */ |
| 580 | png_write_end( png_ptr, info_ptr ); |
| 581 | |
| 582 | /* clean up and exit */ |
| 583 | if ( PNGPalette ) |
| 584 | free( PNGPalette ); |
| 585 | free( rows[0] ); |
| 586 | free( rows ); |
| 587 | png_destroy_write_struct( &png_ptr, NULL ); |
| 588 | fclose( outfile ); |
| 589 | |
| 590 | return BMG_OK; |
| 591 | } |
| 592 | |
| 593 | #ifdef _BMG_LIBPNG_STANDALONE |
| 594 | #pragma message ("Creating BMGLibPNG functions") |
| 595 | |
| 596 | #ifdef _WIN32 |
| 597 | /* saves the contents of an HBITMAP to a file. returns 1 if successfull, |
| 598 | // 0 otherwise */ |
| 599 | BMGError SaveBitmapToPNGFile( HBITMAP hBitmap, /* bitmap to be saved */ |
| 600 | const char *filename) /* name of output file */ |
| 601 | { |
| 602 | struct BMGImageStruct img; |
| 603 | char msg[256], ext[4], *period; |
| 604 | BMGError out = BMG_OK; |
| 605 | |
| 606 | InitBMGImage( &img ); |
| 607 | |
| 608 | /* determine the file type by using the extension */ |
| 609 | strcpy( msg, filename ); |
| 610 | period = strrchr( msg, '.' ); |
| 611 | if ( period != NULL ) |
| 612 | { |
| 613 | period++; |
| 614 | strcpy( ext, period ); |
| 615 | ext[0] = toupper( ext[0] ); |
| 616 | ext[1] = toupper( ext[1] ); |
| 617 | ext[2] = toupper( ext[2] ); |
| 618 | ext[3] = 0; |
| 619 | } |
| 620 | else |
| 621 | { |
| 622 | strcat( msg, ".PNG" ); |
| 623 | strcpy( ext, "PNG" ); |
| 624 | } |
| 625 | |
| 626 | if ( strcmp( ext, "PNG" ) == 0 ) |
| 627 | { |
| 628 | /* extract data from the bitmap. We assume that 32 bit images have been |
| 629 | // blended with the background (unless this is a DDB - see GetDataFromBitmap |
| 630 | // for more details) */ |
| 631 | out = GetDataFromBitmap( hBitmap, &img, 1 ); |
| 632 | if ( out == BMG_OK ) |
| 633 | { |
| 634 | out = WritePNG( msg, img ); |
| 635 | } |
| 636 | FreeBMGImage( &img ); |
| 637 | } |
| 638 | else |
| 639 | { |
| 640 | out = errInvalidFileExtension; |
| 641 | } |
| 642 | |
| 643 | SetLastBMGError( out ); |
| 644 | return out; |
| 645 | } |
| 646 | #endif // _WIN32 |
| 647 | |
| 648 | /* Creates an HBITMAP to an image file. returns an HBITMAP if successfull, |
| 649 | // NULL otherwise */ |
| 650 | HBITMAP CreateBitmapFromPNGFile( const char *filename, |
| 651 | int blend ) |
| 652 | { |
| 653 | char ext[4], msg[256]; |
| 654 | char *period; |
| 655 | BMGError out = BMG_OK; |
| 656 | struct BMGImageStruct img; |
| 657 | HBITMAP hBitmap = NULL; |
| 658 | |
| 659 | InitBMGImage( &img ); |
| 660 | img.opt_for_bmp = 1; |
| 661 | |
| 662 | strcpy( msg, filename ); |
| 663 | period = strrchr( msg, '.' ); |
| 664 | if ( period != NULL ) |
| 665 | { |
| 666 | period++; |
| 667 | strncpy( ext, period, 3 ); |
| 668 | ext[0] = toupper( ext[0] ); |
| 669 | ext[1] = toupper( ext[1] ); |
| 670 | ext[2] = toupper( ext[2] ); |
| 671 | ext[3] = 0; |
| 672 | } |
| 673 | else |
| 674 | { |
| 675 | strcat( msg, ".PNG" ); |
| 676 | strcpy( ext, "PNG" ); |
| 677 | } |
| 678 | |
| 679 | if ( strcmp( ext, "PNG" ) == 0 ) |
| 680 | { |
| 681 | out = ReadPNG( msg, &img ); |
| 682 | if ( out == BMG_OK ) |
| 683 | { |
| 684 | hBitmap = CreateBitmapFromData( img, blend ); |
| 685 | } |
| 686 | FreeBMGImage( &img ); |
| 687 | } |
| 688 | else |
| 689 | { |
| 690 | out = errInvalidFileExtension; |
| 691 | } |
| 692 | |
| 693 | SetLastBMGError( out ); |
| 694 | return hBitmap; |
| 695 | } |
| 696 | |
| 697 | #endif |
| 698 | |