about summary refs log tree commit diff
path: root/lib/libpamwrite.c
blob: dd319d4ac678ddd6604f10c97f0195c19cfb9f99 (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
/*----------------------------------------------------------------------------
                                  libpamwrite.c
------------------------------------------------------------------------------
   These are the library functions, which belong in the libnetpbm library,
   that deal with writing the PAM (Portable Arbitrary Format) image format
   raster (not the header).
-----------------------------------------------------------------------------*/

/* 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 <limits.h>
#include <assert.h>

#include <math.h>

#include "pam.h"


static __inline__ unsigned int
samplesPerPlainLine(sample       const maxval, 
                    unsigned int const depth, 
                    unsigned int const lineLength) {
/*----------------------------------------------------------------------------
   Return the minimum number of samples that should go in a line
   'lineLength' characters long in a plain format non-PBM PNM image
   with depth 'depth' and maxval 'maxval'.

   Note that this number is just for aesthetics; the Netpbm formats allow
   any number of samples per line.
-----------------------------------------------------------------------------*/
    unsigned int const digitsForMaxval = (unsigned int)
        (log(maxval + 0.1 ) / log(10.0));
        /* Number of digits maxval has in decimal */
        /* +0.1 is an adjustment to overcome precision problems */
    unsigned int const fit = lineLength / (digitsForMaxval + 1);
        /* Number of maxval-sized samples that fit in a line */
    unsigned int const retval = (fit > depth) ? (fit - (fit % depth)) : fit;
        /* 'fit', rounded down to a multiple of depth, if possible */

    return retval;
}



static void
writePamPlainPbmRow(const struct pam *  const pamP,
                    const tuple *       const tuplerow) {

    int col;
    unsigned int const samplesPerLine = 70;

    for (col = 0; col < pamP->width; ++col)
        fprintf(pamP->file,  
                ((col+1) % samplesPerLine == 0 || col == pamP->width-1)
                    ? "%1u\n" : "%1u",
                tuplerow[col][0] == PAM_PBM_BLACK ? PBM_BLACK : PBM_WHITE);
}



static void
writePamPlainRow(const struct pam *  const pamP,
                    const tuple *       const tuplerow) {

    int const samplesPerLine = 
        samplesPerPlainLine(pamP->maxval, pamP->depth, 79);

    int col;
    unsigned int samplesInCurrentLine;
        /* number of samples written from start of line  */
    
    samplesInCurrentLine = 0;

    for (col = 0; col < pamP->width; ++col) {
        unsigned int plane;
        for (plane = 0; plane < pamP->depth; ++plane){
            fprintf(pamP->file, "%lu ",tuplerow[col][plane]);

            ++samplesInCurrentLine;

            if (samplesInCurrentLine >= samplesPerLine) {
                fprintf(pamP->file, "\n");
                samplesInCurrentLine = 0;
            }            
        }
    }
    fprintf(pamP->file, "\n");
}



static void
formatPbmRow(const struct pam * const pamP,
             const tuple *      const tuplerow,
             unsigned char *    const outbuf,
             unsigned int *     const rowSizeP) {

    unsigned char accum;
    int col;
    
    accum = 0;  /* initial value */
    
    for (col=0; col < pamP->width; ++col) {
        accum |= 
            (tuplerow[col][0] == PAM_PBM_BLACK ? PBM_BLACK : PBM_WHITE)
                << (7-col%8);
        if (col%8 == 7) {
                outbuf[col/8] = accum;
                accum = 0;
        }
    }
    if (pamP->width % 8 != 0) {
        unsigned int const lastByteIndex = pamP->width/8;
        outbuf[lastByteIndex] = accum;
        *rowSizeP = lastByteIndex + 1;
    } else
        *rowSizeP = pamP->width/8;
}



/* Though it is possible to simplify the sampleToBytesN() and
   formatNBpsRow() functions into a single routine that handles all
   sample widths, we value efficiency higher here.  Earlier versions
   of Netpbm (before 10.25) did that, with a loop, and performance
   suffered visibly.
*/

static __inline__ void
sampleToBytes2(unsigned char       buf[2], 
               sample        const sampleval) {

    buf[0] = (sampleval >> 8) & 0xff;
    buf[1] = (sampleval >> 0) & 0xff;
}



static __inline__ void
sampleToBytes3(unsigned char       buf[3], 
               sample        const sampleval) {

    buf[0] = (sampleval >> 16) & 0xff;
    buf[1] = (sampleval >>  8) & 0xff;
    buf[2] = (sampleval >>  0) & 0xff;
}



static __inline__ void
sampleToBytes4(unsigned char       buf[4], 
               sample        const sampleval) {

    buf[0] = (sampleval >> 24 ) & 0xff;
    buf[1] = (sampleval >> 16 ) & 0xff;
    buf[2] = (sampleval >>  8 ) & 0xff;
    buf[3] = (sampleval >>  0 ) & 0xff;
}



static __inline__ void
format1BpsRow(const struct pam * const pamP,
              const tuple *      const tuplerow,
              unsigned char *    const outbuf,
              unsigned int *     const rowSizeP) {
/*----------------------------------------------------------------------------
   Create the image of a row in the raster of a raw format Netpbm
   image that has one byte per sample (ergo not PBM).

   Put the image at *outbuf; put the number of bytes of it at *rowSizeP.
-----------------------------------------------------------------------------*/
    int col;
    unsigned int bufferCursor;

    bufferCursor = 0;  /* initial value */
    
    for (col = 0; col < pamP->width; ++col) {
        unsigned int plane;
        for (plane=0; plane < pamP->depth; ++plane)
            outbuf[bufferCursor++] = (unsigned char)tuplerow[col][plane];
    }
    *rowSizeP = pamP->width * 1 * pamP->depth;
}



static __inline__ void
format2BpsRow(const struct pam * const pamP,
              const tuple *      const tuplerow,
              unsigned char *    const outbuf,
              unsigned int *     const rowSizeP) {
/*----------------------------------------------------------------------------
  Analogous to format1BpsRow().
-----------------------------------------------------------------------------*/
    unsigned char (* const ob)[2] = (unsigned char (*)[2]) outbuf;

    int col;
    unsigned int bufferCursor;

    bufferCursor = 0;  /* initial value */
    
    for (col=0; col < pamP->width; ++col) {
        unsigned int plane;
        for (plane = 0; plane < pamP->depth; ++plane)
            sampleToBytes2(ob[bufferCursor++], tuplerow[col][plane]);
    }

    *rowSizeP = pamP->width * 2 * pamP->depth;
}



static __inline__ void
format3BpsRow(const struct pam * const pamP,
              const tuple *      const tuplerow,
              unsigned char *    const outbuf,
              unsigned int *     const rowSizeP) {
/*----------------------------------------------------------------------------
  Analogous to format1BpsRow().
-----------------------------------------------------------------------------*/
    unsigned char (* const ob)[3] = (unsigned char (*)[3]) outbuf;

    int col;
    unsigned int bufferCursor;

    bufferCursor = 0;  /* initial value */
    
    for (col=0; col < pamP->width; ++col) {
        unsigned int plane;
        for (plane = 0; plane < pamP->depth; ++plane)
            sampleToBytes3(ob[bufferCursor++], tuplerow[col][plane]);
    }

    *rowSizeP = pamP->width * 3 * pamP->depth;
}



static __inline__ void
format4BpsRow(const struct pam * const pamP,
              const tuple *      const tuplerow,
              unsigned char *    const outbuf,
              unsigned int *     const rowSizeP) {
/*----------------------------------------------------------------------------
  Analogous to format1BpsRow().
-----------------------------------------------------------------------------*/
    unsigned char (* const ob)[4] = (unsigned char (*)[4]) outbuf;

    int col;
    unsigned int bufferCursor;

    bufferCursor = 0;  /* initial value */
    
    for (col=0; col < pamP->width; ++col) {
        unsigned int plane;
        for (plane = 0; plane < pamP->depth; ++plane)
            sampleToBytes4(ob[bufferCursor++], tuplerow[col][plane]);
    }

    *rowSizeP = pamP->width * 4 * pamP->depth;
}



void
pnm_formatpamrow(const struct pam * const pamP,
                 const tuple *      const tuplerow,
                 unsigned char *    const outbuf,
                 unsigned int *     const rowSizeP) {
/*----------------------------------------------------------------------------
   Create the image of a row in the raster of a raw (not plain) format
   Netpbm image, as described by *pamP and tuplerow[].  Put the image
   at *outbuf.

   'outbuf' must be the address of space allocated with pnm_allocrowimage().
   
   We return as *rowSizeP the number of bytes in the row image.
-----------------------------------------------------------------------------*/
    if (PAM_FORMAT_TYPE(pamP->format) == PBM_TYPE)
        formatPbmRow(pamP, tuplerow, outbuf, rowSizeP);
    else {
        switch(pamP->bytes_per_sample){
        case 1: format1BpsRow(pamP, tuplerow, outbuf, rowSizeP); break;
        case 2: format2BpsRow(pamP, tuplerow, outbuf, rowSizeP); break;
        case 3: format3BpsRow(pamP, tuplerow, outbuf, rowSizeP); break;
        case 4: format4BpsRow(pamP, tuplerow, outbuf, rowSizeP); break;
        default:
            pm_error("invalid bytes per sample passed to "
                     "pnm_formatpamrow(): %u",  pamP->bytes_per_sample);
        }
    }
}



static void
writePamRawRow(const struct pam * const pamP,
               const tuple *      const tuplerow,
               unsigned int       const count) {
/*----------------------------------------------------------------------------
   Write mutiple ('count') copies of the same row ('tuplerow') to the file,
   in raw (not plain) format.
-----------------------------------------------------------------------------*/
    jmp_buf jmpbuf;
    jmp_buf * origJmpbufP;
    unsigned int rowImageSize;
    unsigned char * outbuf;  /* malloc'ed */

    outbuf = pnm_allocrowimage(pamP);

    pnm_formatpamrow(pamP, tuplerow, outbuf, &rowImageSize);

    if (setjmp(jmpbuf) != 0) {
        pnm_freerowimage(outbuf);
        pm_setjmpbuf(origJmpbufP);
        pm_longjmp();
    } else {
        unsigned int i;

        pm_setjmpbufsave(&jmpbuf, &origJmpbufP);
        
        for (i = 0; i < count; ++i) {
            size_t bytesWritten;
            
            bytesWritten = fwrite(outbuf, 1, rowImageSize, pamP->file);
            if (bytesWritten != rowImageSize)
                pm_error("fwrite() failed to write an image row to the file.  "
                         "errno=%d (%s)", errno, strerror(errno));
        }
        pm_setjmpbuf(origJmpbufP);
    }
    pnm_freerowimage(outbuf);
}



void 
pnm_writepamrow(const struct pam * const pamP, 
                const tuple *      const tuplerow) {

    /* For speed, we don't check any of the inputs for consistency 
       here (unless it's necessary to avoid crashing).  Any consistency
       checking should have been done by a prior call to 
       pnm_writepaminit().
    */
    
    if (pm_plain_output || pamP->plainformat) {
        switch (PAM_FORMAT_TYPE(pamP->format)) {
        case PBM_TYPE:
            writePamPlainPbmRow(pamP, tuplerow);
            break;
        case PGM_TYPE:
        case PPM_TYPE:
            writePamPlainRow(pamP, tuplerow);
            break;
        case PAM_TYPE:
            /* pm_plain_output is impossible here due to assumption stated
               above about pnm_writepaminit() having checked it.  The
               pamP->plainformat is meaningless for PAM.
            */
            writePamRawRow(pamP, tuplerow, 1);
            break;
        default:
            pm_error("Invalid 'format' value %u in pam structure", 
                     pamP->format);
        }
    } else
        writePamRawRow(pamP, tuplerow, 1);
}



void
pnm_writepamrowmult(const struct pam * const pamP, 
                    const tuple *      const tuplerow,
                    unsigned int       const count) {
/*----------------------------------------------------------------------------
   Write mutiple ('count') copies of the same row ('tuplerow') to the file.
-----------------------------------------------------------------------------*/
   if (pm_plain_output || pamP->plainformat) {
       unsigned int i;
       for (i = 0; i < count; ++i)
           pnm_writepamrow(pamP, tuplerow);
   } else
       /* Simple common case - use fastpath */
       writePamRawRow(pamP, tuplerow, count);
}



void 
pnm_writepam(struct pam * const pamP, 
             tuple **     const tuplearray) {

    int row;

    pnm_writepaminit(pamP);
    
    for (row = 0; row < pamP->height; ++row) 
        pnm_writepamrow(pamP, tuplearray[row]);
}