1 /*------------------------------------- 2 * PNGFILE.C -- Image File Functions 3 *------------------------------------- 4 * 5 * Copyright 2000, Willem van Schaik. 6 * 7 * This code is released under the libpng license. 8 * For conditions of distribution and use, see the disclaimer 9 * and license in png.h 10 */ 11 12 #include <windows.h> 13 #include <commdlg.h> 14 #include <stdio.h> 15 #include <stdlib.h> 16 #include <zlib.h> 17 18 #include "png.h" 19 #include "pngfile.h" 20 #include "cexcept.h" 21 22 define_exception_type(const char *); 23 extern struct exception_context the_exception_context[1]; 24 struct exception_context the_exception_context[1]; 25 png_const_charp msg; 26 27 static OPENFILENAME ofn; 28 29 static png_structp png_ptr = NULL; 30 static png_infop info_ptr = NULL; 31 32 33 /* cexcept interface */ 34 35 static void 36 png_cexcept_error(png_structp png_ptr, png_const_charp msg) 37 { 38 if(png_ptr) 39 ; 40 #ifdef PNG_CONSOLE_IO_SUPPORTED 41 fprintf(stderr, "libpng error: %s\n", msg); 42 #endif 43 { 44 Throw msg; 45 } 46 } 47 48 /* Windows open-file functions */ 49 50 void PngFileInitialize (HWND hwnd) 51 { 52 static TCHAR szFilter[] = TEXT ("PNG Files (*.PNG)\0*.png\0") 53 TEXT ("All Files (*.*)\0*.*\0\0"); 54 55 ofn.lStructSize = sizeof (OPENFILENAME); 56 ofn.hwndOwner = hwnd; 57 ofn.hInstance = NULL; 58 ofn.lpstrFilter = szFilter; 59 ofn.lpstrCustomFilter = NULL; 60 ofn.nMaxCustFilter = 0; 61 ofn.nFilterIndex = 0; 62 ofn.lpstrFile = NULL; /* Set in Open and Close functions */ 63 ofn.nMaxFile = MAX_PATH; 64 ofn.lpstrFileTitle = NULL; /* Set in Open and Close functions */ 65 ofn.nMaxFileTitle = MAX_PATH; 66 ofn.lpstrInitialDir = NULL; 67 ofn.lpstrTitle = NULL; 68 ofn.Flags = 0; /* Set in Open and Close functions */ 69 ofn.nFileOffset = 0; 70 ofn.nFileExtension = 0; 71 ofn.lpstrDefExt = TEXT ("png"); 72 ofn.lCustData = 0; 73 ofn.lpfnHook = NULL; 74 ofn.lpTemplateName = NULL; 75 } 76 77 BOOL PngFileOpenDlg (HWND hwnd, PTSTR pstrFileName, PTSTR pstrTitleName) 78 { 79 ofn.hwndOwner = hwnd; 80 ofn.lpstrFile = pstrFileName; 81 ofn.lpstrFileTitle = pstrTitleName; 82 ofn.Flags = OFN_HIDEREADONLY; 83 84 return GetOpenFileName (&ofn); 85 } 86 87 BOOL PngFileSaveDlg (HWND hwnd, PTSTR pstrFileName, PTSTR pstrTitleName) 88 { 89 ofn.hwndOwner = hwnd; 90 ofn.lpstrFile = pstrFileName; 91 ofn.lpstrFileTitle = pstrTitleName; 92 ofn.Flags = OFN_HIDEREADONLY | OFN_OVERWRITEPROMPT; 93 94 return GetSaveFileName (&ofn); 95 } 96 97 /* PNG image handler functions */ 98 99 BOOL PngLoadImage (PTSTR pstrFileName, png_byte **ppbImageData, 100 int *piWidth, int *piHeight, int *piChannels, png_color *pBkgColor) 101 { 102 static FILE *pfFile; 103 png_byte pbSig[8]; 104 int iBitDepth; 105 int iColorType; 106 double dGamma; 107 png_color_16 *pBackground; 108 png_uint_32 ulChannels; 109 png_uint_32 ulRowBytes; 110 png_byte *pbImageData = *ppbImageData; 111 static png_byte **ppbRowPointers = NULL; 112 int i; 113 114 /* open the PNG input file */ 115 116 if (!pstrFileName) 117 { 118 *ppbImageData = pbImageData = NULL; 119 return FALSE; 120 } 121 122 if (!(pfFile = fopen(pstrFileName, "rb"))) 123 { 124 *ppbImageData = pbImageData = NULL; 125 return FALSE; 126 } 127 128 /* first check the eight byte PNG signature */ 129 130 fread(pbSig, 1, 8, pfFile); 131 if (png_sig_cmp(pbSig, 0, 8)) 132 { 133 *ppbImageData = pbImageData = NULL; 134 return FALSE; 135 } 136 137 /* create the two png(-info) structures */ 138 139 png_ptr = png_create_read_struct(PNG_LIBPNG_VER_STRING, NULL, 140 (png_error_ptr)png_cexcept_error, (png_error_ptr)NULL); 141 if (!png_ptr) 142 { 143 *ppbImageData = pbImageData = NULL; 144 return FALSE; 145 } 146 147 info_ptr = png_create_info_struct(png_ptr); 148 if (!info_ptr) 149 { 150 png_destroy_read_struct(&png_ptr, NULL, NULL); 151 *ppbImageData = pbImageData = NULL; 152 return FALSE; 153 } 154 155 Try 156 { 157 158 /* initialize the png structure */ 159 160 #ifdef PNG_STDIO_SUPPORTED 161 png_init_io(png_ptr, pfFile); 162 #else 163 png_set_read_fn(png_ptr, (png_voidp)pfFile, png_read_data); 164 #endif 165 166 png_set_sig_bytes(png_ptr, 8); 167 168 /* read all PNG info up to image data */ 169 170 png_read_info(png_ptr, info_ptr); 171 172 /* get width, height, bit-depth and color-type */ 173 174 png_get_IHDR(png_ptr, info_ptr, piWidth, piHeight, &iBitDepth, 175 &iColorType, NULL, NULL, NULL); 176 177 /* expand images of all color-type and bit-depth to 3x8-bit RGB */ 178 /* let the library process alpha, transparency, background, etc. */ 179 180 #ifdef PNG_READ_16_TO_8_SUPPORTED 181 if (iBitDepth == 16) 182 # ifdef PNG_READ_SCALE_16_TO_8_SUPPORTED 183 png_set_scale_16(png_ptr); 184 # else 185 png_set_strip_16(png_ptr); 186 # endif 187 #endif 188 if (iColorType == PNG_COLOR_TYPE_PALETTE) 189 png_set_expand(png_ptr); 190 if (iBitDepth < 8) 191 png_set_expand(png_ptr); 192 if (png_get_valid(png_ptr, info_ptr, PNG_INFO_tRNS)) 193 png_set_expand(png_ptr); 194 if (iColorType == PNG_COLOR_TYPE_GRAY || 195 iColorType == PNG_COLOR_TYPE_GRAY_ALPHA) 196 png_set_gray_to_rgb(png_ptr); 197 198 /* set the background color to draw transparent and alpha images over */ 199 if (png_get_bKGD(png_ptr, info_ptr, &pBackground)) 200 { 201 png_set_background(png_ptr, pBackground, PNG_BACKGROUND_GAMMA_FILE, 1, 1.0); 202 pBkgColor->red = (byte) pBackground->red; 203 pBkgColor->green = (byte) pBackground->green; 204 pBkgColor->blue = (byte) pBackground->blue; 205 } 206 else 207 { 208 pBkgColor = NULL; 209 } 210 211 /* if required set gamma conversion */ 212 if (png_get_gAMA(png_ptr, info_ptr, &dGamma)) 213 png_set_gamma(png_ptr, (double) 2.2, dGamma); 214 215 /* after the transformations are registered, update info_ptr data */ 216 217 png_read_update_info(png_ptr, info_ptr); 218 219 /* get again width, height and the new bit-depth and color-type */ 220 221 png_get_IHDR(png_ptr, info_ptr, piWidth, piHeight, &iBitDepth, 222 &iColorType, NULL, NULL, NULL); 223 224 225 /* row_bytes is the width x number of channels */ 226 227 ulRowBytes = png_get_rowbytes(png_ptr, info_ptr); 228 ulChannels = png_get_channels(png_ptr, info_ptr); 229 230 *piChannels = ulChannels; 231 232 /* now we can allocate memory to store the image */ 233 234 if (pbImageData) 235 { 236 free (pbImageData); 237 pbImageData = NULL; 238 } 239 if ((pbImageData = (png_byte *) malloc(ulRowBytes * (*piHeight) 240 * sizeof(png_byte))) == NULL) 241 { 242 png_error(png_ptr, "Visual PNG: out of memory"); 243 } 244 *ppbImageData = pbImageData; 245 246 /* and allocate memory for an array of row-pointers */ 247 248 if ((ppbRowPointers = (png_bytepp) malloc((*piHeight) 249 * sizeof(png_bytep))) == NULL) 250 { 251 png_error(png_ptr, "Visual PNG: out of memory"); 252 } 253 254 /* set the individual row-pointers to point at the correct offsets */ 255 256 for (i = 0; i < (*piHeight); i++) 257 ppbRowPointers[i] = pbImageData + i * ulRowBytes; 258 259 /* now we can go ahead and just read the whole image */ 260 261 png_read_image(png_ptr, ppbRowPointers); 262 263 /* read the additional chunks in the PNG file (not really needed) */ 264 265 png_read_end(png_ptr, NULL); 266 267 /* and we're done */ 268 269 free (ppbRowPointers); 270 ppbRowPointers = NULL; 271 272 /* yepp, done */ 273 } 274 275 Catch (msg) 276 { 277 png_destroy_read_struct(&png_ptr, &info_ptr, NULL); 278 279 *ppbImageData = pbImageData = NULL; 280 281 if(ppbRowPointers) 282 free (ppbRowPointers); 283 284 fclose(pfFile); 285 286 return FALSE; 287 } 288 289 fclose (pfFile); 290 291 return TRUE; 292 } 293 294 295 BOOL PngSaveImage (PTSTR pstrFileName, png_byte *pDiData, 296 int iWidth, int iHeight, png_color bkgColor) 297 { 298 const int ciBitDepth = 8; 299 const int ciChannels = 3; 300 301 static FILE *pfFile; 302 png_uint_32 ulRowBytes; 303 static png_byte **ppbRowPointers = NULL; 304 int i; 305 306 /* open the PNG output file */ 307 308 if (!pstrFileName) 309 return FALSE; 310 311 if (!(pfFile = fopen(pstrFileName, "wb"))) 312 return FALSE; 313 314 /* prepare the standard PNG structures */ 315 316 png_ptr = png_create_write_struct(PNG_LIBPNG_VER_STRING, NULL, 317 (png_error_ptr)png_cexcept_error, (png_error_ptr)NULL); 318 if (!png_ptr) 319 { 320 fclose(pfFile); 321 return FALSE; 322 } 323 324 info_ptr = png_create_info_struct(png_ptr); 325 if (!info_ptr) { 326 fclose(pfFile); 327 png_destroy_write_struct(&png_ptr, (png_infopp) NULL); 328 return FALSE; 329 } 330 331 Try 332 { 333 /* initialize the png structure */ 334 335 #ifdef PNG_STDIO_SUPPORTED 336 png_init_io(png_ptr, pfFile); 337 #else 338 png_set_write_fn(png_ptr, (png_voidp)pfFile, png_write_data, png_flush); 339 #endif 340 341 /* we're going to write a very simple 3x8-bit RGB image */ 342 343 png_set_IHDR(png_ptr, info_ptr, iWidth, iHeight, ciBitDepth, 344 PNG_COLOR_TYPE_RGB, PNG_INTERLACE_NONE, PNG_COMPRESSION_TYPE_BASE, 345 PNG_FILTER_TYPE_BASE); 346 347 /* write the file header information */ 348 349 png_write_info(png_ptr, info_ptr); 350 351 /* swap the BGR pixels in the DiData structure to RGB */ 352 353 png_set_bgr(png_ptr); 354 355 /* row_bytes is the width x number of channels */ 356 357 ulRowBytes = iWidth * ciChannels; 358 359 /* we can allocate memory for an array of row-pointers */ 360 361 if ((ppbRowPointers = (png_bytepp) malloc(iHeight * sizeof(png_bytep))) == NULL) 362 Throw "Visualpng: Out of memory"; 363 364 /* set the individual row-pointers to point at the correct offsets */ 365 366 for (i = 0; i < iHeight; i++) 367 ppbRowPointers[i] = pDiData + i * (((ulRowBytes + 3) >> 2) << 2); 368 369 /* write out the entire image data in one call */ 370 371 png_write_image (png_ptr, ppbRowPointers); 372 373 /* write the additional chunks to the PNG file (not really needed) */ 374 375 png_write_end(png_ptr, info_ptr); 376 377 /* and we're done */ 378 379 free (ppbRowPointers); 380 ppbRowPointers = NULL; 381 382 /* clean up after the write, and free any memory allocated */ 383 384 png_destroy_write_struct(&png_ptr, (png_infopp) NULL); 385 386 /* yepp, done */ 387 } 388 389 Catch (msg) 390 { 391 png_destroy_write_struct(&png_ptr, (png_infopp) NULL); 392 393 if(ppbRowPointers) 394 free (ppbRowPointers); 395 396 fclose(pfFile); 397 398 return FALSE; 399 } 400 401 fclose (pfFile); 402 403 return TRUE; 404 } 405 406 #ifndef PNG_STDIO_SUPPORTED 407 408 static void 409 png_read_data(png_structp png_ptr, png_bytep data, png_size_t length) 410 { 411 png_size_t check; 412 413 /* fread() returns 0 on error, so it is OK to store this in a png_size_t 414 * instead of an int, which is what fread() actually returns. 415 */ 416 check = (png_size_t)fread(data, (png_size_t)1, length, 417 (FILE *)png_ptr->io_ptr); 418 419 if (check != length) 420 { 421 png_error(png_ptr, "Read Error"); 422 } 423 } 424 425 static void 426 png_write_data(png_structp png_ptr, png_bytep data, png_size_t length) 427 { 428 png_uint_32 check; 429 430 check = fwrite(data, 1, length, (FILE *)(png_ptr->io_ptr)); 431 if (check != length) 432 { 433 png_error(png_ptr, "Write Error"); 434 } 435 } 436 437 static void 438 png_flush(png_structp png_ptr) 439 { 440 FILE *io_ptr; 441 io_ptr = (FILE *)CVT_PTR((png_ptr->io_ptr)); 442 if (io_ptr != NULL) 443 fflush(io_ptr); 444 } 445 446 #endif 447 448 /*----------------- 449 * end of source 450 *----------------- 451 */ 452
