d07c171f |
1 | /* |
2 | // source code for the BMGLib Utility 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 <stdlib.h> |
29 | #include "BMGUtils.h" |
30 | |
31 | #ifndef _WIN32 |
32 | #include <string.h> |
33 | #endif // _WIN32 |
34 | |
35 | /* error strings for all BMG errors */ |
36 | static char BMGErrorStrings[17][128] = { |
37 | "No Error", |
38 | "Corrupted file or invalid file format", |
39 | "Invalid bits per pixel for this file format", |
40 | "Memory allocation error", |
41 | "Invalid requested image size", |
42 | "Invalid bitmap handle", |
43 | "Windows API Error", /* this will be overwritten */ |
44 | "Unable to open file", |
45 | "Unsupported file format option", |
46 | "Invalid pointer to a BMG image", |
47 | "Unsupported file extension", |
48 | "Error reading file", |
49 | "Error writing to the output file", |
50 | "Invalid pointer to a GeoTIFF structure", |
51 | "The background image is undefined", |
52 | "The background image is too small", |
53 | "Corrupt File" |
54 | }; |
55 | |
56 | /* stores last BMG error */ |
57 | static BMGError LastBMGError; |
58 | |
59 | /* sets the last BMG error */ |
60 | void SetLastBMGError( BMGError err ) |
61 | { |
62 | LastBMGError = err; |
63 | } |
64 | |
65 | /* returns the last error state */ |
66 | BMGError GetLastBMGError(void) |
67 | { |
68 | return LastBMGError; |
69 | } |
70 | /* gets the error message */ |
71 | void GetLastBMGErrorMessage( const char **msg ) |
72 | { |
73 | if ( LastBMGError == errWindowsAPI ) |
74 | { |
75 | char* lpMsgBuf = "Erreur BMG\n"; |
76 | |
77 | /* copy the string. */ |
78 | strcpy( BMGErrorStrings[(int)LastBMGError], (char *)lpMsgBuf ); |
79 | } |
80 | |
81 | *msg = BMGErrorStrings[(int)LastBMGError]; |
82 | } |
83 | |
84 | /* Global background color variables */ |
85 | static unsigned char BackgroundColor[4]; |
86 | static struct BMGImageStruct BackgroundImage; |
87 | |
88 | /* this function simply initializes the background info. It is called from |
89 | the DllEntryPoint function */ |
90 | void InitBackground(void) |
91 | { |
92 | memset( (void *)BackgroundColor, 0xFF, 3 ); /* white */ |
93 | BackgroundColor[3] = 0; /* ignored */ |
94 | InitBMGImage( &BackgroundImage ); |
95 | } |
96 | |
97 | unsigned char *GetBackgroundColor(void) |
98 | { |
99 | return &BackgroundColor[0]; |
100 | } |
101 | |
102 | struct BMGImageStruct *GetBackgroundImage(void) |
103 | { |
104 | return &BackgroundImage; |
105 | } |
106 | |
107 | /* converts an array of 1-bit scanlines to 8-bit scanlines */ |
108 | void Convert1to8( struct BMGImageStruct img, |
109 | unsigned char *out ) |
110 | { |
111 | unsigned char *p, *q, *r, *s, *end; |
112 | int i; |
113 | |
114 | q = out; |
115 | |
116 | for ( s = img.bits; s < img.bits + img.scan_width * img.height; |
117 | s += img.scan_width, q += img.width ) |
118 | { |
119 | i = img.width % 8; |
120 | end = q + img.width - i; |
121 | p = s; |
122 | for ( r = q; r < end; p++ ) |
123 | { |
124 | *r++ = (unsigned char)((*p & 0x80) ? 1 : 0); |
125 | *r++ = (unsigned char)((*p & 0x40) ? 1 : 0); |
126 | *r++ = (unsigned char)((*p & 0x20) ? 1 : 0); |
127 | *r++ = (unsigned char)((*p & 0x10) ? 1 : 0); |
128 | *r++ = (unsigned char)((*p & 0x08) ? 1 : 0); |
129 | *r++ = (unsigned char)((*p & 0x04) ? 1 : 0); |
130 | *r++ = (unsigned char)((*p & 0x02) ? 1 : 0); |
131 | *r++ = (unsigned char)(*p & 0x01); |
132 | } |
133 | |
134 | if ( i-- ) |
135 | { |
136 | *r++ = (unsigned char)((*p & 0x80) ? 1 : 0); |
137 | if ( i-- ) |
138 | { |
139 | *r++ = (unsigned char)((*p & 0x40) ? 1 : 0); |
140 | if ( i-- ) |
141 | { |
142 | *r++ = (unsigned char)((*p & 0x20) ? 1 : 0); |
143 | if ( i-- ) |
144 | { |
145 | *r++ = (unsigned char)((*p & 0x10) ? 1 : 0); |
146 | if ( i-- ) |
147 | { |
148 | *r++ = (unsigned char)((*p & 0x08) ? 1 : 0); |
149 | if ( i-- ) |
150 | { |
151 | *r++ = (unsigned char)((*p & 0x04) ? 1 : 0); |
152 | if ( i ) |
153 | *r = (unsigned char)((*p & 0x02) ? 1:0); |
154 | } |
155 | } |
156 | } |
157 | } |
158 | } |
159 | } |
160 | } |
161 | } |
162 | |
163 | /* converts an array of 4-bit scanlines to 8-bit scanlines */ |
164 | void Convert4to8( struct BMGImageStruct img, |
165 | unsigned char *out ) |
166 | { |
167 | unsigned char *p, *q, *r, *s, *end; |
168 | int i; |
169 | |
170 | q = out; |
171 | |
172 | for ( s = img.bits; s < img.bits + img.scan_width * img.height; |
173 | s += img.scan_width, q += img.width ) |
174 | { |
175 | i = img.width % 2; |
176 | end = q + img.width - i; |
177 | p = s; |
178 | for ( r = q; r < end; p++ ) |
179 | { |
180 | *r++ = (unsigned char)((*p >> 4) & 0x0F); |
181 | *r++ = (unsigned char)(*p & 0x0F); |
182 | } |
183 | |
184 | if ( i ) |
185 | *r = (unsigned char)((*p >> 4) & 0x0F); |
186 | } |
187 | } |
188 | |
189 | /****************************************************************************/ |
190 | /* this function performs alpha blending. It is a variation of a function |
191 | that I found in the PNG example code */ |
192 | unsigned char AlphaComp( unsigned char fg, |
193 | unsigned char alpha, |
194 | unsigned char bg ) |
195 | { |
196 | unsigned char out; |
197 | unsigned short temp; |
198 | |
199 | switch ( alpha ) |
200 | { |
201 | case 0: |
202 | out = bg; |
203 | break; |
204 | case 255: |
205 | out = fg; |
206 | break; |
207 | default: |
208 | temp = ((unsigned short)(fg)*(unsigned short)(alpha) + |
209 | (unsigned short)(bg)*(unsigned short)(255 - |
210 | (unsigned short)(alpha)) + (unsigned short)128); |
211 | out = (unsigned char)((temp + (temp >> 8)) >> 8); |
212 | break; |
213 | } |
214 | return out; |
215 | } |
216 | |
217 | /**************************************************************************** |
218 | // Converts a 16 BPP image to a 24 BPP image |
219 | // returns 1 if successfull, 0 otherwise */ |
220 | BMGError Convert16to24( struct BMGImageStruct *img ) |
221 | { |
222 | unsigned int i; |
223 | unsigned int new_scan_width; |
224 | unsigned char *new_bits; |
225 | |
226 | /* this function will only work with 16 BBP images */ |
227 | if ( img->bits_per_pixel != 16 ) |
228 | return errInvalidPixelFormat; |
229 | |
230 | /* calculate the new scan width */ |
231 | new_scan_width = 3 * img->width; |
232 | if ( new_scan_width % 4 && img->opt_for_bmp ) |
233 | new_scan_width += 4 - new_scan_width % 4; |
234 | |
235 | /* allocate memory for the new pixel values */ |
236 | new_bits = (unsigned char *)calloc( new_scan_width * img->height, sizeof(unsigned char) ); |
237 | if ( new_bits == NULL ) |
238 | return errMemoryAllocation; |
239 | |
240 | /* convert the 16 BPP pixel values to the equivalent 24 BPP values */ |
241 | for ( i = 0; i < img->height; i++ ) |
242 | { |
243 | unsigned char *p24; |
244 | unsigned short *p16 = (unsigned short *)(img->bits + i * img->scan_width); |
245 | unsigned char *start = new_bits + i * new_scan_width; |
246 | unsigned char *end = start + new_scan_width; |
247 | for ( p24 = start; p24 < end; p24 += 3, p16++ ) |
248 | { |
249 | p24[0] = (unsigned char)( (*p16 & 0x001F) << 3 ); |
250 | p24[1] = (unsigned char)( (*p16 & 0x03E0) >> 2 ); |
251 | p24[2] = (unsigned char)( (*p16 & 0x7C00) >> 7 ); |
252 | } |
253 | } |
254 | |
255 | free( img->bits ); |
256 | img->bits = new_bits; |
257 | img->scan_width = new_scan_width; |
258 | img->bits_per_pixel = 24; |
259 | |
260 | return BMG_OK; |
261 | } |
262 | |
263 | /****************************************************************************/ |
264 | /* this function undoes alpha blending - kind-a-sort-of ;-) */ |
265 | unsigned char InverseAlphaComp( unsigned char fg, unsigned char alpha, |
266 | unsigned char bg ) |
267 | { |
268 | unsigned char out; |
269 | short temp; |
270 | |
271 | switch ( alpha ) |
272 | { |
273 | case 0: |
274 | out = bg; |
275 | break; |
276 | case 255: |
277 | out = fg; |
278 | break; |
279 | default: |
280 | temp = (255*fg - bg*(255-alpha))/alpha; |
281 | if ( temp < 0 ) |
282 | temp = 0; |
283 | out = (unsigned char)temp; |
284 | break; |
285 | } |
286 | return out; |
287 | } |
288 | |
289 | /****************************************************************************/ |
290 | /* |
291 | // Creates a BITMAPINFOHEADER for the given width, height, bit count, and |
292 | // compression. Compression must = BI_RGB, BI_BITFIELDS, BI_RLE4, or BI_RLE8. |
293 | */ |
294 | BITMAPINFO InternalCreateBMI( unsigned int dwWidth, /* width */ |
295 | unsigned int dwHeight, /* height */ |
296 | unsigned short wBitCount, /* bit count */ |
297 | int compression ) /* compression type */ |
298 | { |
299 | BITMAPINFO bi; /* bitmap header */ |
300 | unsigned int dwBytesPerLine; /* Number of bytes per scanline */ |
301 | |
302 | /* clear the bitmapinfo structure */ |
303 | memset(&bi, 0, sizeof(BITMAPINFO)); |
304 | |
305 | /* Make sure bits per pixel is valid */ |
306 | if (wBitCount <= 1) |
307 | wBitCount = 1; |
308 | else if (wBitCount <= 4) |
309 | wBitCount = 4; |
310 | else if (wBitCount <= 8) |
311 | wBitCount = 8; |
312 | else if (wBitCount <= 16) |
313 | wBitCount = 16; |
314 | else if (wBitCount <= 24) |
315 | wBitCount = 24; |
316 | else if (wBitCount <= 32) |
317 | wBitCount = 32; |
318 | else |
319 | wBitCount = 8; /* set default value to 8 if parameter is bogus */ |
320 | |
321 | dwBytesPerLine = (((wBitCount * dwWidth) + 31) / 32 * 4); |
322 | |
323 | /* initialize BITMAPINFO */ |
324 | bi.bmiHeader.biSize = sizeof(BITMAPINFOHEADER); |
325 | bi.bmiHeader.biWidth = dwWidth; |
326 | bi.bmiHeader.biHeight = dwHeight; |
327 | bi.bmiHeader.biPlanes = 1; /* must be 1 */ |
328 | bi.bmiHeader.biBitCount = wBitCount; |
329 | bi.bmiHeader.biCompression = compression; |
330 | bi.bmiHeader.biSizeImage = dwBytesPerLine*dwHeight; |
331 | bi.bmiHeader.biXPelsPerMeter = 0; |
332 | bi.bmiHeader.biYPelsPerMeter = 0; |
333 | bi.bmiHeader.biClrUsed = wBitCount <= 8 ? 1U << wBitCount : 0; |
334 | bi.bmiHeader.biClrImportant = bi.bmiHeader.biClrUsed; |
335 | |
336 | return bi; |
337 | } |
338 | |
339 | short SwapShort( short in ) |
340 | { |
341 | char sin[2]; |
342 | char sout[2]; |
343 | |
344 | memcpy( (char *)sin, (char *)&in, 2 ); |
345 | |
346 | sout[0] = sin[1]; |
347 | sout[1] = sin[0]; |
348 | |
349 | return *((short *)sout); |
350 | } |
351 | |
352 | unsigned short SwapUShort( unsigned short in ) |
353 | { |
354 | char sin[2]; |
355 | char sout[2]; |
356 | |
357 | memcpy( (char *)sin, (char *)&in, 2 ); |
358 | |
359 | sout[0] = sin[1]; |
360 | sout[1] = sin[0]; |
361 | |
362 | return *((unsigned short *)sout); |
363 | } |
364 | |
365 | int SwapLong( int in ) |
366 | { |
367 | char sin[4]; |
368 | char sout[4]; |
369 | |
370 | memcpy( (char *)sin, (char *)&in, 4 ); |
371 | |
372 | sout[0] = sin[3]; |
373 | sout[1] = sin[2]; |
374 | sout[2] = sin[1]; |
375 | sout[3] = sin[0]; |
376 | |
377 | return *((int *)sout); |
378 | } |
379 | |
380 | unsigned int SwapULong( unsigned int in ) |
381 | { |
382 | char sin[4]; |
383 | char sout[4]; |
384 | |
385 | memcpy( (char *)sin, (char *)&in, 4 ); |
386 | |
387 | sout[0] = sin[3]; |
388 | sout[1] = sin[2]; |
389 | sout[2] = sin[1]; |
390 | sout[3] = sin[0]; |
391 | |
392 | return *((unsigned int *)sout); |
393 | } |
394 | |