/[dtapublic]/projs/trunk/shared_source/c_tk_base_7_5_w_mods/tkimgppm.c
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Revision 69 - (show annotations) (download)
Sat Nov 5 10:54:17 2016 UTC (6 years, 3 months ago) by dashley
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1 /* $Header$ */
2
3 /*
4 * tkImgPPM.c --
5 *
6 * A photo image file handler for PPM (Portable PixMap) files.
7 *
8 * Copyright (c) 1994 The Australian National University.
9 * Copyright (c) 1994-1997 Sun Microsystems, Inc.
10 *
11 * See the file "license.terms" for information on usage and redistribution
12 * of this file, and for a DISCLAIMER OF ALL WARRANTIES.
13 *
14 * Author: Paul Mackerras (paulus@cs.anu.edu.au),
15 * Department of Computer Science,
16 * Australian National University.
17 *
18 * RCS: @(#) $Id: tkimgppm.c,v 1.1.1.1 2001/06/13 05:03:30 dtashley Exp $
19 */
20
21 #define USE_OLD_IMAGE
22
23 #include "tkInt.h"
24 #include "tkPort.h"
25
26 /*
27 * The maximum amount of memory to allocate for data read from the
28 * file. If we need more than this, we do it in pieces.
29 */
30
31 #define MAX_MEMORY 10000 /* don't allocate > 10KB */
32
33 /*
34 * Define PGM and PPM, i.e. gray images and color images.
35 */
36
37 #define PGM 1
38 #define PPM 2
39
40 /*
41 * The format record for the PPM file format:
42 */
43
44 static int FileMatchPPM _ANSI_ARGS_((Tcl_Channel chan,
45 char *fileName, char *formatString,
46 int *widthPtr, int *heightPtr));
47 static int FileReadPPM _ANSI_ARGS_((Tcl_Interp *interp,
48 Tcl_Channel chan, char *fileName,
49 char *formatString, Tk_PhotoHandle imageHandle,
50 int destX, int destY, int width, int height,
51 int srcX, int srcY));
52 static int FileWritePPM _ANSI_ARGS_((Tcl_Interp *interp,
53 char *fileName, char *formatString,
54 Tk_PhotoImageBlock *blockPtr));
55
56 Tk_PhotoImageFormat tkImgFmtPPM = {
57 "PPM", /* name */
58 FileMatchPPM, /* fileMatchProc */
59 NULL, /* stringMatchProc */
60 FileReadPPM, /* fileReadProc */
61 NULL, /* stringReadProc */
62 FileWritePPM, /* fileWriteProc */
63 NULL, /* stringWriteProc */
64 };
65
66 /*
67 * Prototypes for local procedures defined in this file:
68 */
69
70 static int ReadPPMFileHeader _ANSI_ARGS_((Tcl_Channel chan,
71 int *widthPtr, int *heightPtr,
72 int *maxIntensityPtr));
73
74 /*
75 *----------------------------------------------------------------------
76 *
77 * FileMatchPPM --
78 *
79 * This procedure is invoked by the photo image type to see if
80 * a file contains image data in PPM format.
81 *
82 * Results:
83 * The return value is >0 if the first characters in file "f" look
84 * like PPM data, and 0 otherwise.
85 *
86 * Side effects:
87 * The access position in f may change.
88 *
89 *----------------------------------------------------------------------
90 */
91
92 static int
93 FileMatchPPM(chan, fileName, formatString, widthPtr, heightPtr)
94 Tcl_Channel chan; /* The image file, open for reading. */
95 char *fileName; /* The name of the image file. */
96 char *formatString; /* User-specified format string, or NULL. */
97 int *widthPtr, *heightPtr; /* The dimensions of the image are
98 * returned here if the file is a valid
99 * raw PPM file. */
100 {
101 int dummy;
102
103 return ReadPPMFileHeader(chan, widthPtr, heightPtr, &dummy);
104 }
105
106 /*
107 *----------------------------------------------------------------------
108 *
109 * FileReadPPM --
110 *
111 * This procedure is called by the photo image type to read
112 * PPM format data from a file and write it into a given
113 * photo image.
114 *
115 * Results:
116 * A standard TCL completion code. If TCL_ERROR is returned
117 * then an error message is left in the interp's result.
118 *
119 * Side effects:
120 * The access position in file f is changed, and new data is
121 * added to the image given by imageHandle.
122 *
123 *----------------------------------------------------------------------
124 */
125
126 static int
127 FileReadPPM(interp, chan, fileName, formatString, imageHandle, destX, destY,
128 width, height, srcX, srcY)
129 Tcl_Interp *interp; /* Interpreter to use for reporting errors. */
130 Tcl_Channel chan; /* The image file, open for reading. */
131 char *fileName; /* The name of the image file. */
132 char *formatString; /* User-specified format string, or NULL. */
133 Tk_PhotoHandle imageHandle; /* The photo image to write into. */
134 int destX, destY; /* Coordinates of top-left pixel in
135 * photo image to be written to. */
136 int width, height; /* Dimensions of block of photo image to
137 * be written to. */
138 int srcX, srcY; /* Coordinates of top-left pixel to be used
139 * in image being read. */
140 {
141 int fileWidth, fileHeight, maxIntensity;
142 int nLines, nBytes, h, type, count;
143 unsigned char *pixelPtr;
144 Tk_PhotoImageBlock block;
145
146 type = ReadPPMFileHeader(chan, &fileWidth, &fileHeight, &maxIntensity);
147 if (type == 0) {
148 Tcl_AppendResult(interp, "couldn't read raw PPM header from file \"",
149 fileName, "\"", NULL);
150 return TCL_ERROR;
151 }
152 if ((fileWidth <= 0) || (fileHeight <= 0)) {
153 Tcl_AppendResult(interp, "PPM image file \"", fileName,
154 "\" has dimension(s) <= 0", (char *) NULL);
155 return TCL_ERROR;
156 }
157 if ((maxIntensity <= 0) || (maxIntensity >= 256)) {
158 char buffer[TCL_INTEGER_SPACE];
159
160 sprintf(buffer, "%d", maxIntensity);
161 Tcl_AppendResult(interp, "PPM image file \"", fileName,
162 "\" has bad maximum intensity value ", buffer,
163 (char *) NULL);
164 return TCL_ERROR;
165 }
166
167 if ((srcX + width) > fileWidth) {
168 width = fileWidth - srcX;
169 }
170 if ((srcY + height) > fileHeight) {
171 height = fileHeight - srcY;
172 }
173 if ((width <= 0) || (height <= 0)
174 || (srcX >= fileWidth) || (srcY >= fileHeight)) {
175 return TCL_OK;
176 }
177
178 if (type == PGM) {
179 block.pixelSize = 1;
180 block.offset[0] = 0;
181 block.offset[1] = 0;
182 block.offset[2] = 0;
183 }
184 else {
185 block.pixelSize = 3;
186 block.offset[0] = 0;
187 block.offset[1] = 1;
188 block.offset[2] = 2;
189 }
190 block.offset[3] = 0;
191 block.width = width;
192 block.pitch = block.pixelSize * fileWidth;
193
194 Tk_PhotoExpand(imageHandle, destX + width, destY + height);
195
196 if (srcY > 0) {
197 Tcl_Seek(chan, (srcY * block.pitch), SEEK_CUR);
198 }
199
200 nLines = (MAX_MEMORY + block.pitch - 1) / block.pitch;
201 if (nLines > height) {
202 nLines = height;
203 }
204 if (nLines <= 0) {
205 nLines = 1;
206 }
207 nBytes = nLines * block.pitch;
208 pixelPtr = (unsigned char *) ckalloc((unsigned) nBytes);
209 block.pixelPtr = pixelPtr + srcX * block.pixelSize;
210
211 for (h = height; h > 0; h -= nLines) {
212 if (nLines > h) {
213 nLines = h;
214 nBytes = nLines * block.pitch;
215 }
216 count = Tcl_Read(chan, (char *) pixelPtr, nBytes);
217 if (count != nBytes) {
218 Tcl_AppendResult(interp, "error reading PPM image file \"",
219 fileName, "\": ",
220 Tcl_Eof(chan) ? "not enough data" : Tcl_PosixError(interp),
221 (char *) NULL);
222 ckfree((char *) pixelPtr);
223 return TCL_ERROR;
224 }
225 if (maxIntensity != 255) {
226 unsigned char *p;
227
228 for (p = pixelPtr; count > 0; count--, p++) {
229 *p = (((int) *p) * 255)/maxIntensity;
230 }
231 }
232 block.height = nLines;
233 Tk_PhotoPutBlock(imageHandle, &block, destX, destY, width, nLines);
234 destY += nLines;
235 }
236
237 ckfree((char *) pixelPtr);
238 return TCL_OK;
239 }
240
241 /*
242 *----------------------------------------------------------------------
243 *
244 * FileWritePPM --
245 *
246 * This procedure is invoked to write image data to a file in PPM
247 * format.
248 *
249 * Results:
250 * A standard TCL completion code. If TCL_ERROR is returned
251 * then an error message is left in the interp's result.
252 *
253 * Side effects:
254 * Data is written to the file given by "fileName".
255 *
256 *----------------------------------------------------------------------
257 */
258
259 static int
260 FileWritePPM(interp, fileName, formatString, blockPtr)
261 Tcl_Interp *interp;
262 char *fileName;
263 char *formatString;
264 Tk_PhotoImageBlock *blockPtr;
265 {
266 Tcl_Channel chan;
267 int w, h;
268 int greenOffset, blueOffset, nBytes;
269 unsigned char *pixelPtr, *pixLinePtr;
270 char header[16 + TCL_INTEGER_SPACE * 2];
271
272 chan = Tcl_OpenFileChannel(interp, fileName, "w", 0666);
273 if (chan == NULL) {
274 return TCL_ERROR;
275 }
276
277 if (Tcl_SetChannelOption(interp, chan, "-translation", "binary")
278 != TCL_OK) {
279 return TCL_ERROR;
280 }
281 if (Tcl_SetChannelOption(interp, chan, "-encoding", "binary")
282 != TCL_OK) {
283 return TCL_ERROR;
284 }
285
286 sprintf(header, "P6\n%d %d\n255\n", blockPtr->width, blockPtr->height);
287 Tcl_Write(chan, header, -1);
288
289 pixLinePtr = blockPtr->pixelPtr + blockPtr->offset[0];
290 greenOffset = blockPtr->offset[1] - blockPtr->offset[0];
291 blueOffset = blockPtr->offset[2] - blockPtr->offset[0];
292
293 if ((greenOffset == 1) && (blueOffset == 2) && (blockPtr->pixelSize == 3)
294 && (blockPtr->pitch == (blockPtr->width * 3))) {
295 nBytes = blockPtr->height * blockPtr->pitch;
296 if (Tcl_Write(chan, (char *) pixLinePtr, nBytes) != nBytes) {
297 goto writeerror;
298 }
299 } else {
300 for (h = blockPtr->height; h > 0; h--) {
301 pixelPtr = pixLinePtr;
302 for (w = blockPtr->width; w > 0; w--) {
303 if ((Tcl_Write(chan, (char *) &pixelPtr[0], 1) == -1)
304 || (Tcl_Write(chan, (char *) &pixelPtr[greenOffset], 1) == -1)
305 || (Tcl_Write(chan, (char *) &pixelPtr[blueOffset], 1) == -1)) {
306 goto writeerror;
307 }
308 pixelPtr += blockPtr->pixelSize;
309 }
310 pixLinePtr += blockPtr->pitch;
311 }
312 }
313
314 if (Tcl_Close(NULL, chan) == 0) {
315 return TCL_OK;
316 }
317 chan = NULL;
318
319 writeerror:
320 Tcl_AppendResult(interp, "error writing \"", fileName, "\": ",
321 Tcl_PosixError(interp), (char *) NULL);
322 if (chan != NULL) {
323 Tcl_Close(NULL, chan);
324 }
325 return TCL_ERROR;
326 }
327
328 /*
329 *----------------------------------------------------------------------
330 *
331 * ReadPPMFileHeader --
332 *
333 * This procedure reads the PPM header from the beginning of a
334 * PPM file and returns information from the header.
335 *
336 * Results:
337 * The return value is PGM if file "f" appears to start with
338 * a valid PGM header, PPM if "f" appears to start with a valid
339 * PPM header, and 0 otherwise. If the header is valid,
340 * then *widthPtr and *heightPtr are modified to hold the
341 * dimensions of the image and *maxIntensityPtr is modified to
342 * hold the value of a "fully on" intensity value.
343 *
344 * Side effects:
345 * The access position in f advances.
346 *
347 *----------------------------------------------------------------------
348 */
349
350 static int
351 ReadPPMFileHeader(chan, widthPtr, heightPtr, maxIntensityPtr)
352 Tcl_Channel chan; /* Image file to read the header from */
353 int *widthPtr, *heightPtr; /* The dimensions of the image are
354 * returned here. */
355 int *maxIntensityPtr; /* The maximum intensity value for
356 * the image is stored here. */
357 {
358 #define BUFFER_SIZE 1000
359 char buffer[BUFFER_SIZE];
360 int i, numFields;
361 int type = 0;
362 char c;
363
364 /*
365 * Read 4 space-separated fields from the file, ignoring
366 * comments (any line that starts with "#").
367 */
368
369 if (Tcl_Read(chan, &c, 1) != 1) {
370 return 0;
371 }
372 i = 0;
373 for (numFields = 0; numFields < 4; numFields++) {
374 /*
375 * Skip comments and white space.
376 */
377
378 while (1) {
379 while (isspace(UCHAR(c))) {
380 if (Tcl_Read(chan, &c, 1) != 1) {
381 return 0;
382 }
383 }
384 if (c != '#') {
385 break;
386 }
387 do {
388 if (Tcl_Read(chan, &c, 1) != 1) {
389 return 0;
390 }
391 } while (c != '\n');
392 }
393
394 /*
395 * Read a field (everything up to the next white space).
396 */
397
398 while (!isspace(UCHAR(c))) {
399 if (i < (BUFFER_SIZE-2)) {
400 buffer[i] = c;
401 i++;
402 }
403 if (Tcl_Read(chan, &c, 1) != 1) {
404 goto done;
405 }
406 }
407 if (i < (BUFFER_SIZE-1)) {
408 buffer[i] = ' ';
409 i++;
410 }
411 }
412 done:
413 buffer[i] = 0;
414
415 /*
416 * Parse the fields, which are: id, width, height, maxIntensity.
417 */
418
419 if (strncmp(buffer, "P6 ", 3) == 0) {
420 type = PPM;
421 } else if (strncmp(buffer, "P5 ", 3) == 0) {
422 type = PGM;
423 } else {
424 return 0;
425 }
426 if (sscanf(buffer+3, "%d %d %d", widthPtr, heightPtr, maxIntensityPtr)
427 != 3) {
428 return 0;
429 }
430 return type;
431 }
432
433 /* End of tkimgppm.c */

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