2 * 2ooM: The Master of Orion II Reverse Engineering Project
3 * Library for working with LBX image files.
4 * Copyright (C) 2006-2008 Nick Bowler
6 * This program is free software: you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation, either version 3 of the License, or
9 * (at your option) any later version.
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
16 * You should have received a copy of the GNU General Public License
17 * along with this program. If not, see <http://www.gnu.org/licenses/>.
33 #define FLAG_RAW 0x0100 /* Image is stored as a flat array of bytes. */
34 #define FLAG_OVERWRITE 0x0400 /* Draw each frame on a clean slate (unsure). */
35 #define FLAG_BUILDING 0x0800 /* Buildings have this, related to shadow? */
36 #define FLAG_PALETTE 0x1000 /* Image contains embedded palette. */
37 #define FLAG_LOOPING 0x2000 /* Loop over all frames in the image (unsure). */
39 #define FLAG_ALL (FLAG_RAW|FLAG_OVERWRITE|FLAG_BUILDING|FLAG_PALETTE|FLAG_LOOPING)
44 unsigned short width, height;
45 unsigned short wtf, flags;
46 unsigned short frames, leadin;
47 unsigned short palstart, palcount;
49 const struct lbx_file_ops *fops;
50 int (*dtor)(void *handle);
56 int currentx, currenty;
57 unsigned char **framedata;
60 unsigned long offsets[];
63 static struct lbx_image *lbximg_init(unsigned char hdr[static HDR_LEN])
65 unsigned short nframes = unpack_16_le(hdr+6);
66 struct lbx_image *img;
68 img = malloc(sizeof *img + sizeof img->offsets[0] * (nframes+1));
74 *img = (struct lbx_image) {
75 .width = unpack_16_le(hdr+0),
76 .height = unpack_16_le(hdr+2),
77 .wtf = unpack_16_le(hdr+4),
78 .frames = unpack_16_le(hdr+6),
79 .leadin = unpack_16_le(hdr+8),
80 .flags = unpack_16_le(hdr+10),
88 struct lbx_image *lbximg_open(void *f, const struct lbx_file_ops *fops,
89 int (*destructor)(void *))
91 unsigned char hdr_buf[HDR_LEN];
92 struct lbx_image *img;
94 if (fops->read(hdr_buf, sizeof hdr_buf, f) != sizeof hdr_buf) {
101 img = lbximg_init(hdr_buf);
107 img->dtor = destructor;
110 * DEBUG ONLY. These assertions exist to catch otherwise valid image
111 * files which differ from what I believe to be true of all LBX images.
112 * If we never find any exceptions, we can replace the assertions with
115 _lbx_assert(img->wtf == 0); /* version? */
116 _lbx_assert(img->frames > img->leadin); /* cmbtshp.lbx breaks this. */
117 _lbx_assert(!(img->flags & ~FLAG_ALL));
119 /* Read all offsets. Should be merged with identical code in lbx.c */
120 for (unsigned i = 0; i <= img->frames; i++) {
121 unsigned char buf[4];
123 if (fops->read(buf, sizeof buf, f) != sizeof buf) {
126 lbx_errno = LBX_EEOF;
131 img->offsets[i] = unpack_32_le(buf);
134 if (img->flags & FLAG_PALETTE) {
135 unsigned char buf[4];
137 if (fops->read(buf, sizeof buf, f) != sizeof buf) {
140 lbx_errno = LBX_EEOF;
145 img->palstart = unpack_16_le(buf+0);
146 img->palcount = unpack_16_le(buf+2);
147 img->paloff = fops->tell(f);
149 if (img->palstart + img->palcount > 256) {
150 lbx_errno = LBX_EFORMAT;
159 struct lbx_image *lbximg_fopen(FILE *f)
161 return lbximg_open(f, &lbx_default_fops, NULL);
164 static int _lbx_drawrow(int first, struct lbx_image *img)
166 unsigned short type, count, yval, xval;
167 unsigned char buf[4];
171 assert(img->framedata);
174 if (img->fops->read(buf, sizeof buf, img->f) != sizeof buf)
176 type = unpack_16_le(buf+0);
185 yval = unpack_16_le(buf+2);
189 if (img->fops->read(buf, sizeof buf, img->f) != sizeof buf)
191 count = unpack_16_le(buf+0);
193 xval = unpack_16_le(buf+2);
197 /* Ensure that the row fits in the image. */
198 if (img->height - img->currenty <= yval || xval >= img->width) {
199 lbx_errno = LBX_EFORMAT;
203 img->currenty += yval;
204 img->currentx = xval;
206 xval = unpack_16_le(buf+2);
208 if (img->width - img->currentx <= xval) {
209 lbx_errno = LBX_EFORMAT;
212 img->currentx += xval;
217 if (count > img->width - img->currentx) {
218 lbx_errno = LBX_EFORMAT;
222 memset(&img->mask[img->currenty][img->currentx], 1, count);
224 pos = &img->framedata[img->currenty][img->currentx];
225 rc = img->fops->read(pos, count, img->f);
232 if (img->fops->read(buf, 1, img->f) != 1)
239 if (img->fops->eof(img->f))
240 lbx_errno = LBX_EEOF;
244 static unsigned char **allocframebuffer(size_t width, size_t height)
246 unsigned char **new, *tmp;
249 tmp = calloc(height, width);
255 new = malloc(height * sizeof *new);
262 for (i = 0; i < height; i++) {
263 new[i] = tmp + i * width;
269 static unsigned char **read_raw_frame(struct lbx_image *img, int frame)
271 unsigned long size = img->width * img->height;
273 assert(img->flags & FLAG_RAW);
275 if (img->fops->seek(img->f, img->offsets[frame], SEEK_SET)) {
280 if (img->fops->read(img->framedata[0], size, img->f) != size) {
282 if (img->fops->eof(img->f))
283 lbx_errno = LBX_EEOF;
286 memset(img->mask[0], 1, size);
288 if (img->fops->tell(img->f) > img->offsets[frame+1]) {
289 lbx_errno = LBX_EFORMAT;
293 return img->framedata;
296 unsigned char **lbximg_getframe(struct lbx_image *img, int frame)
298 if (frame >= img->frames || frame < 0) {
299 lbx_errno = LBX_ERANGE;
303 if (!img->framedata) {
304 img->framedata = allocframebuffer(img->width, img->height);
310 img->mask = allocframebuffer(img->width, img->height);
315 if (img->flags & FLAG_RAW)
316 return read_raw_frame(img, frame);
318 if (img->flags & FLAG_OVERWRITE) {
319 /* Clear the slate. */
320 img->currentframe = -1;
321 memset(img->framedata[0], 0, img->width * img->height);
322 memset(img->mask[0], 0, img->width * img->height);
324 /* Start over if we are backtracking. */
325 if (img->currentframe > frame) {
326 memset(img->mask[0], 0, img->width * img->height);
327 img->currentframe = -1;
330 /* We must have previous frame decoded to continue. */
331 if (frame > img->currentframe + 1) {
332 if (!lbximg_getframe(img, frame-1))
337 if (img->currentframe != frame) {
340 if (img->fops->seek(img->f, img->offsets[frame], SEEK_SET)) {
346 rc = _lbx_drawrow(first, img);
351 if (img->fops->tell(img->f) > img->offsets[frame+1]) {
352 lbx_errno = LBX_EFORMAT;
358 img->currentframe = frame;
359 return img->framedata;
363 lbximg_loadpalette(void *f, const struct lbx_file_ops *fops,
364 struct lbx_colour palette[static 256])
366 unsigned char entry[4];
369 for (i = 0; i < 256; i++) {
370 if (fops->read(entry, sizeof entry, f) != sizeof entry) {
371 lbx_errno = (feof(f)) ? LBX_EEOF : -errno;
376 lbx_errno = LBX_EFORMAT;
380 palette[i] = (struct lbx_colour) {
381 .red = entry[1] << 2,
382 .green = entry[2] << 2,
383 .blue = entry[3] << 2,
392 lbximg_getpalette(struct lbx_image *img, struct lbx_colour palette[static 256])
394 unsigned char entry[4];
398 /* Do nothing if the image doesn't have embedded palette data. */
399 if (!(img->flags & FLAG_PALETTE))
402 if (img->fops->seek(img->f, img->paloff, SEEK_SET)) {
407 for (i = 0; i < img->palcount; i++) {
408 rc = img->fops->read(entry, sizeof entry, img->f);
409 if (rc < sizeof entry) {
414 lbx_errno = LBX_EFORMAT;
418 palette[img->palstart + i] = (struct lbx_colour){
419 .red = entry[1] << 2,
420 .green = entry[2] << 2,
421 .blue = entry[3] << 2,
428 lbx_errno = img->fops->eof(img->f) ? LBX_EEOF : -errno;
432 void lbximg_getinfo(struct lbx_image *img, struct lbx_imginfo *info)
434 *info = (struct lbx_imginfo) {
436 .height = img->height,
437 .nframes = img->frames,
438 .palettesz = (img->flags & FLAG_PALETTE) ? img->palcount : 0,
441 /* There seems to be two ways of specifying that an image loops. */
442 if (img->flags & FLAG_LOOPING) {
445 } else if (img->leadin != img->frames - 1) {
446 info->loopstart = img->leadin;
451 unsigned char **lbximg_getmask(struct lbx_image *img)
456 int lbximg_close(struct lbx_image *img)
461 if (img->framedata) {
462 free(img->framedata[0]);
463 free(img->framedata);
471 if (img && img->dtor) {
472 rc = img->dtor(img->f);