about summary refs log tree commit diff
path: root/lib/libppm1.c
blob: a3be5d3b0b536e5668a85323572c8ffbf4c98cc0 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
/* libppm1.c - ppm utility library part 1
**
** Copyright (C) 1989 by Jef Poskanzer.
**
** Permission to use, copy, modify, and distribute this software and its
** documentation for any purpose and without fee is hereby granted, provided
** that the above copyright notice appear in all copies and that both that
** copyright notice and this permission notice appear in supporting
** documentation.  This software is provided "as is" without express or
** implied warranty.
*/

/* See pmfileio.c for the complicated explanation of this 32/64 bit file
   offset stuff.
*/
#define _FILE_OFFSET_BITS 64
#define _LARGE_FILES  

#include <string.h>
#include <stdio.h>
#include <errno.h>

#include "netpbm/mallocvar.h"
#include "netpbm/nstring.h"
#include "ppm.h"
#include "libppm.h"
#include "pgm.h"
#include "libpgm.h"
#include "pbm.h"
#include "libpbm.h"
#include "pam.h"
#include "libpam.h"
#include "fileio.h"


pixel *
ppm_allocrow(unsigned int const cols) {

    pixel * pixelrow;

    MALLOCARRAY(pixelrow, cols);

    if (pixelrow == 0)
        pm_error("Unable to allocate space for a %u-column pixel row", cols);

    return pixelrow;
}



void
ppm_init( argcP, argv )
    int* argcP;
    char* argv[];
    {
    pgm_init( argcP, argv );
    }

void
ppm_nextimage(FILE * const fileP, 
              int *  const eofP) {
    pm_nextimage(fileP, eofP);
}



void
ppm_readppminitrest(FILE *   const fileP, 
                    int *    const colsP, 
                    int *    const rowsP, 
                    pixval * const maxvalP) {
    unsigned int maxval;

    /* Read size. */
    *colsP = (int)pm_getuint(fileP);
    *rowsP = (int)pm_getuint(fileP);

    /* Read maxval. */
    maxval = pm_getuint(fileP);
    if (maxval > PPM_OVERALLMAXVAL)
        pm_error("maxval of input image (%u) is too large.  "
                 "The maximum allowed by the PPM format is %u.",
                 maxval, PPM_OVERALLMAXVAL); 
    if (maxval == 0)
        pm_error("maxval of input image is zero.");

    *maxvalP = maxval;
}



static void
validateComputableSize(unsigned int const cols,
                       unsigned int const rows) {
/*----------------------------------------------------------------------------
   Validate that the dimensions of the image are such that it can be
   processed in typical ways on this machine without worrying about
   overflows.  Note that in C, arithmetic is always modulus
   arithmetic, so if your values are too big, the result is not what
   you expect.  That failed expectation can be disastrous if you use
   it to allocate memory.

   It is very normal to allocate space for a pixel row, so we make sure
   the size of a pixel row, in bytes, can be represented by an 'int'.

   A common operation is adding 1 or 2 to the highest row or
   column number in the image, so we make sure that's possible.
-----------------------------------------------------------------------------*/
    if (cols > INT_MAX/(sizeof(pixval) * 3) || cols > INT_MAX - 2)
        pm_error("image width (%u) too large to be processed", cols);
    if (rows > INT_MAX - 2)
        pm_error("image height (%u) too large to be processed", rows);
}



void
ppm_readppminit(FILE *   const fileP, 
                int *    const colsP, 
                int *    const rowsP, 
                pixval * const maxvalP, 
                int *    const formatP) {

    int realFormat;

    /* Check magic number. */
    realFormat = pm_readmagicnumber(fileP);
    switch (PAM_FORMAT_TYPE(realFormat)) {
    case PPM_TYPE:
        *formatP = realFormat;
        ppm_readppminitrest(fileP, colsP, rowsP, maxvalP);
        break;

    case PGM_TYPE:
        *formatP = realFormat;
        pgm_readpgminitrest(fileP, colsP, rowsP, maxvalP);
        break;

    case PBM_TYPE:
        *formatP = realFormat;
        /* See comment in pgm_readpgminit() about this maxval */
        *maxvalP = PPM_MAXMAXVAL;
        pbm_readpbminitrest(fileP, colsP, rowsP);
        break;

    case PAM_TYPE:
        pnm_readpaminitrestaspnm(fileP, colsP, rowsP, maxvalP, formatP);
        break;

    default:
        pm_error("bad magic number 0x%x - not a PPM, PGM, PBM, or PAM file",
                 realFormat);
    }
    validateComputableSize(*colsP, *rowsP);
}



static void
readPpmRow(FILE *       const fileP, 
           pixel *      const pixelrow, 
           unsigned int const cols, 
           pixval       const maxval, 
           int          const format) {

    unsigned int col;

    for (col = 0; col < cols; ++col) {
        pixval const r = pm_getuint(fileP);
        pixval const g = pm_getuint(fileP);
        pixval const b = pm_getuint(fileP);
        
        if (r > maxval)
            pm_error("Red sample value %u is greater than maxval (%u)",
                     r, maxval);
        if (g > maxval)
            pm_error("Green sample value %u is greater than maxval (%u)",
                     g, maxval);
        if (b > maxval)
            pm_error("Blue sample value %u is greater than maxval (%u)",
                     b, maxval);
        
        PPM_ASSIGN(pixelrow[col], r, g, b);
    }
}



static void
interpRasterRowRaw(const unsigned char * const rowBuffer,
                   pixel *               const pixelrow,
                   unsigned int          const cols,
                   unsigned int          const bytesPerSample) {

    unsigned int bufferCursor;

    bufferCursor = 0;  /* start at beginning of rowBuffer[] */
        
    if (bytesPerSample == 1) {
        unsigned int col;
        for (col = 0; col < cols; ++col) {
            pixval const r = rowBuffer[bufferCursor++];
            pixval const g = rowBuffer[bufferCursor++];
            pixval const b = rowBuffer[bufferCursor++];
            PPM_ASSIGN(pixelrow[col], r, g, b);
        }
    } else  {
        /* two byte samples */
        unsigned int col;
        for (col = 0; col < cols; ++col) {
            pixval r, g, b;
                    
            r = rowBuffer[bufferCursor++] << 8;
            r |= rowBuffer[bufferCursor++];
                    
            g = rowBuffer[bufferCursor++] << 8;
            g |= rowBuffer[bufferCursor++];
                    
            b = rowBuffer[bufferCursor++] << 8;
            b |= rowBuffer[bufferCursor++];
                    
            PPM_ASSIGN(pixelrow[col], r, g, b);
        }
    }
}



static void
validateRppmRow(pixel *       const pixelrow,
                unsigned int  const cols,
                pixval        const maxval,
                const char ** const errorP) {
/*----------------------------------------------------------------------------
  Check for sample values above maxval in input.  

  Note: a program that wants to deal with invalid sample values itself can
  simply make sure it uses a sufficiently high maxval on the read function
  call, so this validation never fails.
-----------------------------------------------------------------------------*/
    if (maxval == 255 || maxval == 65535) {
        /* There's no way a sample can be invalid, so we don't need to look at
           the samples individually.
        */
        *errorP = NULL;
    } else {
        unsigned int col;

        for (col = 0, *errorP = NULL; col < cols && !*errorP; ++col) {
            pixval const r = PPM_GETR(pixelrow[col]);
            pixval const g = PPM_GETG(pixelrow[col]);
            pixval const b = PPM_GETB(pixelrow[col]);

            if (r > maxval)
                pm_asprintf(
                    errorP,
                    "Red sample value %u is greater than maxval (%u)",
                    r, maxval);
            else if (g > maxval)
                pm_asprintf(
                    errorP,
                    "Green sample value %u is greater than maxval (%u)",
                    g, maxval);
            else if (b > maxval)
                pm_asprintf(
                    errorP,
                    "Blue sample value %u is greater than maxval (%u)",
                    b, maxval);
        }
    }
}



static void
readRppmRow(FILE *       const fileP, 
            pixel *      const pixelrow, 
            unsigned int const cols, 
            pixval       const maxval, 
            int          const format) {

    unsigned int const bytesPerSample = maxval < 256 ? 1 : 2;
    unsigned int const bytesPerRow    = cols * 3 * bytesPerSample;
        
    unsigned char * rowBuffer;
    const char * error;
    
    MALLOCARRAY(rowBuffer, bytesPerRow);
        
    if (rowBuffer == NULL)
        pm_asprintf(&error, "Unable to allocate memory for row buffer "
                    "for %u columns", cols);
    else {
        ssize_t rc;

        rc = fread(rowBuffer, 1, bytesPerRow, fileP);
    
        if (feof(fileP))
            pm_asprintf(&error, "Unexpected EOF reading row of PPM image.");
        else if (ferror(fileP))
            pm_asprintf(&error, "Error reading row.  fread() errno=%d (%s)",
                        errno, strerror(errno));
        else {
            size_t const bytesRead = rc;
            if (bytesRead != bytesPerRow)
                pm_asprintf(&error,
                            "Error reading row.  Short read of %u bytes "
                            "instead of %u", (unsigned)bytesRead, bytesPerRow);
            else {
                interpRasterRowRaw(rowBuffer, pixelrow, cols, bytesPerSample);

                validateRppmRow(pixelrow, cols, maxval, &error);
            }
        }
        free(rowBuffer);
    }
    if (error) {
        pm_errormsg("%s", error);
        pm_strfree(error);
        pm_longjmp();
    }
}



static void
readPgmRow(FILE *       const fileP, 
           pixel *      const pixelrow, 
           unsigned int const cols, 
           pixval       const maxval, 
           int          const format) {

    jmp_buf jmpbuf;
    jmp_buf * origJmpbufP;
    gray * grayrow;

    grayrow = pgm_allocrow(cols);

    if (setjmp(jmpbuf) != 0) {
        pgm_freerow(grayrow);
        pm_setjmpbuf(origJmpbufP);
        pm_longjmp();
    } else {
        unsigned int col;
    
        pm_setjmpbufsave(&jmpbuf, &origJmpbufP);

        pgm_readpgmrow(fileP, grayrow, cols, maxval, format);

        for (col = 0; col < cols; ++col) {
            pixval const g = grayrow[col];
            PPM_ASSIGN(pixelrow[col], g, g, g);
        }
        pm_setjmpbuf(origJmpbufP);
    }
    pgm_freerow(grayrow);
}



static void
readPbmRow(FILE *       const fileP, 
           pixel *      const pixelrow, 
           unsigned int const cols, 
           pixval       const maxval, 
           int          const format) {

    jmp_buf jmpbuf;
    jmp_buf * origJmpbufP;
    bit * bitrow;

    bitrow = pbm_allocrow_packed(cols);

    if (setjmp(jmpbuf) != 0) {
        pbm_freerow_packed(bitrow);
        pm_setjmpbuf(origJmpbufP);
        pm_longjmp();
    } else {
        unsigned int col;

        pm_setjmpbufsave(&jmpbuf, &origJmpbufP);

        pbm_readpbmrow_packed(fileP, bitrow, cols, format);

        for (col = 0; col < cols; ++col) {
            pixval const g =
                ((bitrow[col/8] >> (7 - col%8)) & 0x1) == PBM_WHITE ?
                maxval : 0;
            PPM_ASSIGN(pixelrow[col], g, g, g);
        }
        pm_setjmpbuf(origJmpbufP);
    }
    pbm_freerow(bitrow);
}



void
ppm_readppmrow(FILE *  const fileP, 
               pixel * const pixelrow, 
               int     const cols, 
               pixval  const maxval, 
               int     const format) {

    switch (format) {
    case PPM_FORMAT:
        readPpmRow(fileP, pixelrow, cols, maxval, format);
        break;

    /* For PAM, we require a depth of 3, which means the raster format
       is identical to Raw PPM!  How convenient.
    */
    case PAM_FORMAT:
    case RPPM_FORMAT:
        readRppmRow(fileP, pixelrow, cols, maxval, format);
        break;

    case PGM_FORMAT:
    case RPGM_FORMAT:
        readPgmRow(fileP, pixelrow, cols, maxval, format);
        break;

    case PBM_FORMAT:
    case RPBM_FORMAT:
        readPbmRow(fileP, pixelrow, cols, maxval, format);
        break;

    default:
        pm_error("Invalid format code");
    }
}



pixel**
ppm_readppm(FILE *   const fileP, 
            int *    const colsP, 
            int *    const rowsP, 
            pixval * const maxvalP) {

    jmp_buf jmpbuf;
    jmp_buf * origJmpbufP;
    pixel ** pixels;
    int cols, rows;
    pixval maxval;
    int format;

    ppm_readppminit(fileP, &cols, &rows, &maxval, &format);

    pixels = ppm_allocarray(cols, rows);

    if (setjmp(jmpbuf) != 0) {
        ppm_freearray(pixels, rows);
        pm_setjmpbuf(origJmpbufP);
        pm_longjmp();
    } else {
        unsigned int row;

        pm_setjmpbufsave(&jmpbuf, &origJmpbufP);

        for (row = 0; row < rows; ++row)
            ppm_readppmrow(fileP, pixels[row], cols, maxval, format);

        *colsP = cols;
        *rowsP = rows;
        *maxvalP = maxval;

        pm_setjmpbuf(origJmpbufP);
    }
    return pixels;
}



void
ppm_check(FILE *               const fileP, 
          enum pm_check_type   const checkType, 
          int                  const format, 
          int                  const cols, 
          int                  const rows, 
          pixval               const maxval,
          enum pm_check_code * const retvalP) {

    if (rows < 0)
        pm_error("Invalid number of rows passed to ppm_check(): %d", rows);
    if (cols < 0)
        pm_error("Invalid number of columns passed to ppm_check(): %d", cols);
    
    if (checkType != PM_CHECK_BASIC) {
        if (retvalP)
            *retvalP = PM_CHECK_UNKNOWN_TYPE;
    } else if (PPM_FORMAT_TYPE(format) == PBM_TYPE) {
        pbm_check(fileP, checkType, format, cols, rows, retvalP);
    } else if (PPM_FORMAT_TYPE(format) == PGM_TYPE) {
        pgm_check(fileP, checkType, format, cols, rows, maxval, retvalP);
    } else if (format != RPPM_FORMAT) {
        if (retvalP)
            *retvalP = PM_CHECK_UNCHECKABLE;
    } else {        
        pm_filepos const bytesPerRow    = cols * 3 * (maxval > 255 ? 2 : 1);
        pm_filepos const needRasterSize = rows * bytesPerRow;
        
        pm_check(fileP, checkType, needRasterSize, retvalP);
    }
}