1 /*------------------------------------- 2 * PNGFILE.C -- Image File Functions 3 *------------------------------------- 4 * 5 * Copyright 2000,2017 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 ((*piHeight) > ((size_t)(-1))/ulRowBytes) { 240 { 241 png_error(png_ptr, "Visual PNG: image is too big"); 242 } 243 if ((pbImageData = (png_byte *) malloc(ulRowBytes * (*piHeight) 244 * sizeof(png_byte))) == NULL) 245 { 246 png_error(png_ptr, "Visual PNG: out of memory"); 247 } 248 *ppbImageData = pbImageData; 249 250 /* and allocate memory for an array of row-pointers */ 251 252 if ((ppbRowPointers = (png_bytepp) malloc((*piHeight) 253 * sizeof(png_bytep))) == NULL) 254 { 255 png_error(png_ptr, "Visual PNG: out of memory"); 256 } 257 258 /* set the individual row-pointers to point at the correct offsets */ 259 260 for (i = 0; i < (*piHeight); i++) 261 ppbRowPointers[i] = pbImageData + i * ulRowBytes; 262 263 /* now we can go ahead and just read the whole image */ 264 265 png_read_image(png_ptr, ppbRowPointers); 266 267 /* read the additional chunks in the PNG file (not really needed) */ 268 269 png_read_end(png_ptr, NULL); 270 271 /* and we're done */ 272 273 free (ppbRowPointers); 274 ppbRowPointers = NULL; 275 276 /* yepp, done */ 277 } 278 279 Catch (msg) 280 { 281 png_destroy_read_struct(&png_ptr, &info_ptr, NULL); 282 283 *ppbImageData = pbImageData = NULL; 284 285 if(ppbRowPointers) 286 free (ppbRowPointers); 287 288 fclose(pfFile); 289 290 return FALSE; 291 } 292 293 fclose (pfFile); 294 295 return TRUE; 296 } 297 298 299 BOOL PngSaveImage (PTSTR pstrFileName, png_byte *pDiData, 300 int iWidth, int iHeight, png_color bkgColor) 301 { 302 const int ciBitDepth = 8; 303 const int ciChannels = 3; 304 305 static FILE *pfFile; 306 png_uint_32 ulRowBytes; 307 static png_byte **ppbRowPointers = NULL; 308 int i; 309 310 /* open the PNG output file */ 311 312 if (!pstrFileName) 313 return FALSE; 314 315 if (!(pfFile = fopen(pstrFileName, "wb"))) 316 return FALSE; 317 318 /* prepare the standard PNG structures */ 319 320 png_ptr = png_create_write_struct(PNG_LIBPNG_VER_STRING, NULL, 321 (png_error_ptr)png_cexcept_error, (png_error_ptr)NULL); 322 if (!png_ptr) 323 { 324 fclose(pfFile); 325 return FALSE; 326 } 327 328 info_ptr = png_create_info_struct(png_ptr); 329 if (!info_ptr) { 330 fclose(pfFile); 331 png_destroy_write_struct(&png_ptr, (png_infopp) NULL); 332 return FALSE; 333 } 334 335 Try 336 { 337 /* initialize the png structure */ 338 339 #ifdef PNG_STDIO_SUPPORTED 340 png_init_io(png_ptr, pfFile); 341 #else 342 png_set_write_fn(png_ptr, (png_voidp)pfFile, png_write_data, png_flush); 343 #endif 344 345 /* we're going to write a very simple 3x8-bit RGB image */ 346 347 png_set_IHDR(png_ptr, info_ptr, iWidth, iHeight, ciBitDepth, 348 PNG_COLOR_TYPE_RGB, PNG_INTERLACE_NONE, PNG_COMPRESSION_TYPE_BASE, 349 PNG_FILTER_TYPE_BASE); 350 351 /* write the file header information */ 352 353 png_write_info(png_ptr, info_ptr); 354 355 /* swap the BGR pixels in the DiData structure to RGB */ 356 357 png_set_bgr(png_ptr); 358 359 /* row_bytes is the width x number of channels */ 360 361 ulRowBytes = iWidth * ciChannels; 362 363 /* we can allocate memory for an array of row-pointers */ 364 365 if ((ppbRowPointers = (png_bytepp) malloc(iHeight * sizeof(png_bytep))) == NULL) 366 Throw "Visualpng: Out of memory"; 367 368 /* set the individual row-pointers to point at the correct offsets */ 369 370 for (i = 0; i < iHeight; i++) 371 ppbRowPointers[i] = pDiData + i * (((ulRowBytes + 3) >> 2) << 2); 372 373 /* write out the entire image data in one call */ 374 375 png_write_image (png_ptr, ppbRowPointers); 376 377 /* write the additional chunks to the PNG file (not really needed) */ 378 379 png_write_end(png_ptr, info_ptr); 380 381 /* and we're done */ 382 383 free (ppbRowPointers); 384 ppbRowPointers = NULL; 385 386 /* clean up after the write, and free any memory allocated */ 387 388 png_destroy_write_struct(&png_ptr, (png_infopp) NULL); 389 390 /* yepp, done */ 391 } 392 393 Catch (msg) 394 { 395 png_destroy_write_struct(&png_ptr, (png_infopp) NULL); 396 397 if(ppbRowPointers) 398 free (ppbRowPointers); 399 400 fclose(pfFile); 401 402 return FALSE; 403 } 404 405 fclose (pfFile); 406 407 return TRUE; 408 } 409 410 #ifndef PNG_STDIO_SUPPORTED 411 412 static void 413 png_read_data(png_structp png_ptr, png_bytep data, png_size_t length) 414 { 415 png_size_t check; 416 417 /* fread() returns 0 on error, so it is OK to store this in a png_size_t 418 * instead of an int, which is what fread() actually returns. 419 */ 420 check = (png_size_t)fread(data, (png_size_t)1, length, 421 (FILE *)png_ptr->io_ptr); 422 423 if (check != length) 424 { 425 png_error(png_ptr, "Read Error"); 426 } 427 } 428 429 static void 430 png_write_data(png_structp png_ptr, png_bytep data, png_size_t length) 431 { 432 png_uint_32 check; 433 434 check = fwrite(data, 1, length, (FILE *)(png_ptr->io_ptr)); 435 if (check != length) 436 { 437 png_error(png_ptr, "Write Error"); 438 } 439 } 440 441 static void 442 png_flush(png_structp png_ptr) 443 { 444 FILE *io_ptr; 445 io_ptr = (FILE *)CVT_PTR((png_ptr->io_ptr)); 446 if (io_ptr != NULL) 447 fflush(io_ptr); 448 } 449 450 #endif 451 452 /*----------------- 453 * end of source 454 *----------------- 455 */ 456
