| | 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 | |