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