- start of external Imager API access:
[imager.git] / rgb.c
CommitLineData
92bda632 1#include "imager.h"
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2#include "log.h"
3#include "iolayer.h"
4
5#include <stdlib.h>
6#include <errno.h>
7
8
9/*
10=head1 NAME
11
12rgb.c - implements reading and writing sgi image files, uses io layer.
13
14=head1 SYNOPSIS
15
16 io_glue *ig = io_new_fd( fd );
17 i_img *im = i_readrgb_wiol(ig, -1); // no limit on how much is read
18 // or
19 io_glue *ig = io_new_fd( fd );
20 return_code = i_writergb_wiol(im, ig);
21
22=head1 DESCRIPTION
23
24rgb.c implements the basic functions to read and write portable targa
25files. It uses the iolayer and needs either a seekable source or an
26entire memory mapped buffer.
27
28=head1 FUNCTION REFERENCE
29
30Some of these functions are internal.
31
32=over
33
34=cut
35*/
36
37typedef struct {
38 unsigned short imagic;
39 unsigned char storagetype;
40 unsigned char BPC;
41 unsigned short dimensions;
42 unsigned short xsize, ysize, zsize;
43 unsigned int min, max;
44 char name[80];
45 unsigned int colormap;
46} rgb_header;
47
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48typedef struct {
49 int start, length;
50} stlen_pair;
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51
52typedef enum { NoInit, Raw, Rle } rle_state;
53
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54
55
56typedef struct {
57 int compressed;
58 int bytepp;
59 io_glue *ig;
60} rgb_dest;
61
62
63
64
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65
66
67/*
68=item rgb_header_unpack(header, headbuf)
69
70Unpacks the header structure into from buffer and stores
71in the header structure.
72
73 header - header structure
74 headbuf - buffer to unpack from
75
76=cut
77*/
78
79
80static
81void
82rgb_header_unpack(rgb_header *header, unsigned char *headbuf) {
83 header->imagic = (headbuf[0]<<8) + headbuf[1];
84 header->storagetype = headbuf[2];
85 header->BPC = headbuf[3];
86 header->dimensions = (headbuf[4]<<8) + headbuf[5];
87 header->xsize = (headbuf[6]<<8) + headbuf[7];
88 header->ysize = (headbuf[8]<<8) + headbuf[9];
89 header->zsize = (headbuf[10]<<8) + headbuf[11];
90 header->min = (headbuf[12]<<24) + (headbuf[13]<<16)+(headbuf[14]<<8)+headbuf[15];
91 header->max = (headbuf[16]<<24) + (headbuf[17]<<16)+(headbuf[18]<<8)+headbuf[19];
92 memcpy(header->name,headbuf+20,80);
93 header->colormap = (headbuf[100]<<24) + (headbuf[101]<<16)+(headbuf[102]<<8)+headbuf[103];
94}
95
96
97/*
98=item rgb_header_pack(header, headbuf)
99
100Packs header structure into buffer for writing.
101
102 header - header structure
103 headbuf - buffer to pack into
104
105=cut
106*/
107
108static
109void
110rgb_header_pack(rgb_header *header, unsigned char headbuf[512]) {
111
112 header->imagic = (headbuf[0]<<8) + headbuf[1];
113 header->storagetype = headbuf[2];
114 header->BPC = headbuf[3];
115 header->dimensions = (headbuf[4]<<8) + headbuf[5];
116 header->xsize = (headbuf[6]<<8) + headbuf[7];
117 header->ysize = (headbuf[8]<<8) + headbuf[9];
118 header->zsize = (headbuf[10]<<8) + headbuf[11];
119 header->min = (headbuf[12]<<24) + (headbuf[13]<<16)+(headbuf[14]<<8)+headbuf[15];
120 header->max = (headbuf[16]<<24) + (headbuf[17]<<16)+(headbuf[18]<<8)+headbuf[19];
121 memcpy(header->name,headbuf+20,80);
122 header->colormap = (headbuf[100]<<24) + (headbuf[101]<<16)+(headbuf[102]<<8)+headbuf[103];
123
124}
125
126
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127
128
129
130/*
131=item rgb_dest_write(s, buf, pixels)
132
133Writes pixels from buf to destination s. Takes care of compressing if the
134destination is compressed.
135
136 s - data destination
137 buf - source buffer
138 pixels - number of pixels to put write to destination
139
140=cut
141*/
142
143static
144int
145rgb_dest_write(rgb_dest *s, unsigned char *buf, size_t pixels) {
5ff415bb 146
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147}
148
149
150
151
152
153
154
155
156/*
157=item i_readrgb_wiol(ig, length)
158
159Read in an image from the iolayer data source and return the image structure to it.
160Returns NULL on error.
161
162 ig - io_glue object
163 length - maximum length to read from data source, before closing it -1
164 signifies no limit.
165
166=cut
167*/
168
169i_img *
170i_readrgb_wiol(io_glue *ig, int length) {
171 i_img *img;
a659442a 172 int y, c,i;
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173 int width, height, channels;
174 unsigned long maxlen;
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175
176 int savemask;
5ff415bb 177
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178 rgb_header header;
179 unsigned char headbuf[512];
180 unsigned char *databuf;
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181 unsigned long *starttab, *lengthtab;
182 i_color *linebuf = NULL;
183 i_mempool mp;
184
185 mm_log((1,"i_readrgb(ig %p, length %d)\n", ig, length));
186 i_clear_error();
187 i_mempool_init(&mp);
188
189 io_glue_commit_types(ig);
190
191 if (ig->readcb(ig, headbuf, 512) != 512) {
192 i_push_error(errno, "could not read SGI rgb header");
193 return NULL;
194 }
195
196 rgb_header_unpack(&header, headbuf);
197
198
199 mm_log((1,"imagic: %d\n", header.imagic));
200 mm_log((1,"storagetype: %d\n", header.storagetype));
201 mm_log((1,"BPC: %d\n", header.BPC));
202 mm_log((1,"dimensions: %d\n", header.dimensions));
203 mm_log((1,"xsize: %d\n", header.xsize));
204 mm_log((1,"ysize: %d\n", header.ysize));
205 mm_log((1,"zsize: %d\n", header.zsize));
206 mm_log((1,"min: %d\n", header.min));
207 mm_log((1,"max: %d\n", header.max));
208 mm_log((1,"name [skipped]\n"));
209 mm_log((1,"colormap: %d\n", header.colormap));
210
211 if (header.colormap != 0) {
212 i_push_error(0, "SGI rgb image has a non zero colormap entry - obsolete format");
213 return NULL;
214 }
215
216 if (header.storagetype != 0 && header.storagetype != 1) {
217 i_push_error(0, "SGI rgb image has has invalid storage field");
218 return NULL;
219 }
220
221 width = header.xsize;
222 height = header.ysize;
223 channels = header.zsize;
224
225 img = i_img_empty_ch(NULL, width, height, channels);
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226 if (!img)
227 return NULL;
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228
229 i_tags_add(&img->tags, "rgb_namestr", 0, header.name, 80, 0);
50dc291e 230 i_tags_add(&img->tags, "i_format", 0, "rgb", -1, 0);
da1c841c 231
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232 switch (header.storagetype) {
233 case 0: /* uncompressed */
234
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235 linebuf = i_mempool_alloc(&mp, width*sizeof(i_color));
236 databuf = i_mempool_alloc(&mp, width);
237
238 savemask = i_img_getmask(img);
239
240 for(c=0; c<channels; c++) {
241 i_img_setmask(img, 1<<c);
242 for(y=0; y<height; y++) {
243 int x;
244
245 if (ig->readcb(ig, databuf, width) != width) {
246 i_push_error(0, "SGI rgb: cannot read");
247 goto ErrorReturn;
248 }
249
250 for(x=0; x<width; x++)
251 linebuf[x].channel[c] = databuf[x];
252
253 i_plin(img, 0, width, height-1-y, linebuf);
254 }
255 }
256 i_img_setmask(img, savemask);
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257 break;
258 case 1: /* RLE compressed */
259
260 databuf = i_mempool_alloc(&mp, height*channels*4);
261 starttab = i_mempool_alloc(&mp, height*channels*sizeof(unsigned long));
262 lengthtab = i_mempool_alloc(&mp, height*channels*sizeof(unsigned long));
263 linebuf = i_mempool_alloc(&mp, width*sizeof(i_color));
264
265 /* Read offset table */
266 if (ig->readcb(ig, databuf, height*channels*4) != height*channels*4) goto ErrorReturn;
267 for(i=0; i<height*channels; i++) starttab[i] =
268 (databuf[i*4]<<24) |
269 (databuf[i*4+1]<<16) |
270 (databuf[i*4+2]<<8) |
271 (databuf[i*4+3]);
272
273
274 /* Read length table */
275 if (ig->readcb(ig, databuf, height*channels*4) != height*channels*4) goto ErrorReturn;
276 for(i=0; i<height*channels; i++) lengthtab[i] =
277 (databuf[i*4]<<24)+
278 (databuf[i*4+1]<<16)+
279 (databuf[i*4+2]<<8)+
280 (databuf[i*4+3]);
281
282 mm_log((3, "Offset/length table:\n"));
283 for(i=0; i<height*channels; i++)
284 mm_log((3, "%d: %d/%d\n", i, starttab[i], lengthtab[i]));
285
286
287 /* Find max spanlength if someone is making very badly formed RLE data */
288 maxlen = 0;
289 for(y=0; y<height; y++) maxlen = (maxlen>lengthtab[y])?maxlen:lengthtab[y];
290
291 mm_log((1, "maxlen for an rle buffer: %d\n", maxlen));
292
293 databuf = i_mempool_alloc(&mp, maxlen);
294
295 for(y=0; y<height; y++) {
296 for(c=0; c<channels; c++) {
297 unsigned long iidx = 0, oidx = 0, span = 0;
298 unsigned char cval;
299 int rle = 0;
300 int ci = height*c+y;
301 int datalen = lengthtab[ci];
302
303 if (ig->seekcb(ig, starttab[ci], SEEK_SET) != starttab[ci]) {
304 i_push_error(0, "SGI rgb: cannot seek");
305 goto ErrorReturn;
306 }
307 if (ig->readcb(ig, databuf, datalen) != datalen) {
308 i_push_error(0, "SGI rgb: cannot read");
309 goto ErrorReturn;
310 }
311
312 /*
313 mm_log((1, "Buffer length %d\n", datalen));
314 for(i=0; i<datalen; i++)
315 mm_log((1, "0x%x\n", databuf[i]));
316 */
317
318 while( iidx <= datalen && oidx < width ) {
319 if (!span) {
320 span = databuf[iidx] & 0x7f;
321 rle = !(databuf[iidx++] & 0x80);
322 /* mm_log((1,"new span %d, rle %d\n", span, rle)); */
323 if (rle) {
324 if (iidx==datalen) {
325 i_push_error(0, "SGI rgb: bad rle data");
326 goto ErrorReturn;
327 }
328 cval = databuf[iidx++];
329 /* mm_log((1, "rle value %d\n", cval)); */
330 }
331 }
332 linebuf[oidx++].channel[c] = rle ? cval : databuf[iidx++];
333 span--;
334 /*
335 mm_log((1,"iidx=%d/%d, oidx=%d/%d, linebuf[%d].channel[%d] %d\n", iidx-1, datalen, oidx-1, width, oidx-1, c, linebuf[oidx-1].channel[c]));
336 */
337 }
338 }
339 i_plin(img, 0, width, height-1-y, linebuf);
340 }
341
342 break;
343 }
344
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345 i_tags_add(&img->tags, "i_format", 0, "rgb", -1, 0);
346
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347 i_mempool_destroy(&mp);
348 return img;
349
350 ErrorReturn:
351 i_mempool_destroy(&mp);
352 if (img) i_img_destroy(img);
353 return NULL;
354}
355
356
357
358/*
359=item i_writergb_wiol(img, ig)
360
361Writes an image in targa format. Returns 0 on error.
362
363 img - image to store
364 ig - io_glue object
365
366=cut
367*/
368
369undef_int
370i_writergb_wiol(i_img *img, io_glue *ig, int wierdpack, int compress, char *idstring, size_t idlen) {
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371 i_clear_error();
372 i_push_error(0, "writing SGI RGB files is not implemented");
5ff415bb 373
50dc291e 374 return 0;
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375}
376