2 * 2ooM: The Master of Orion II Reverse Engineering Project
3 * Library for working with LBX image files.
4 * Copyright (C) 2006-2010 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/>.
34 #define FLAG_RAW 0x0100 /* Image is stored as a flat array of bytes. */
35 #define FLAG_OVERWRITE 0x0400 /* Draw each frame on a clean slate (unsure). */
36 #define FLAG_BUILDING 0x0800 /* Buildings have this, related to shadow? */
37 #define FLAG_PALETTE 0x1000 /* Image contains embedded palette. */
38 #define FLAG_LOOPING 0x2000 /* Loop over all frames in the image (unsure). */
40 #define FLAG_ALL (FLAG_RAW|FLAG_OVERWRITE|FLAG_BUILDING|FLAG_PALETTE|FLAG_LOOPING)
45 unsigned short width, height;
46 unsigned short wtf, flags;
47 unsigned char frames, wtf2, leadin, chunk;
48 unsigned short palstart, palcount;
50 const struct lbx_file_ops *fops;
51 int (*dtor)(void *handle);
57 int currentx, currenty;
58 unsigned char **framedata;
61 unsigned long offsets[];
64 static struct lbx_image *lbximg_init(unsigned char hdr[static HDR_LEN])
66 unsigned short nframes = unpack_16_le(hdr+6);
67 struct lbx_image *img;
69 img = malloc(sizeof *img + sizeof img->offsets[0] * (nframes+1));
71 lbx_error_raise(LBX_ENOMEM);
75 *img = (struct lbx_image) {
76 .width = unpack_16_le(hdr+0),
77 .height = unpack_16_le(hdr+2),
78 .wtf = unpack_16_le(hdr+4),
83 .flags = unpack_16_le(hdr+10),
91 struct lbx_image *lbximg_open(void *f, const struct lbx_file_ops *fops,
92 int (*destructor)(void *))
94 unsigned char hdr_buf[HDR_LEN];
95 struct lbx_image *img;
97 if (fops->read(hdr_buf, sizeof hdr_buf, f) != sizeof hdr_buf) {
99 lbx_error_raise(LBX_EEOF);
103 img = lbximg_init(hdr_buf);
109 img->dtor = destructor;
112 * DEBUG ONLY. These assertions exist to catch otherwise valid image
113 * files which differ from what I believe to be true of all LBX images.
114 * When we can decode every image, then these assertions should be
115 * replaced with constraints.
117 _lbx_assert(img->wtf == 0); /* version? */
118 _lbx_assert(img->wtf2 == 0); /* very likely is simply reserved. */
119 _lbx_assert(img->frames > img->leadin);
120 _lbx_assert(!(img->flags & ~FLAG_ALL));
122 /* Read all offsets. Should be merged with identical code in lbx.c */
123 for (unsigned i = 0; i <= img->frames; i++) {
124 unsigned char buf[4];
126 if (fops->read(buf, sizeof buf, f) != sizeof buf) {
128 lbx_error_raise(LBX_EEOF);
133 img->offsets[i] = unpack_32_le(buf);
136 if (img->flags & FLAG_PALETTE) {
137 unsigned char buf[4];
139 if (fops->read(buf, sizeof buf, f) != sizeof buf) {
141 lbx_error_raise(LBX_EEOF);
146 img->palstart = unpack_16_le(buf+0);
147 img->palcount = unpack_16_le(buf+2);
148 img->paloff = fops->tell(f);
150 if (img->palstart + img->palcount > 256) {
151 lbx_error_raise(LBX_EFORMAT);
160 static int pipe_close(void *f)
162 struct lbx_pipe_state *p = f;
170 static int file_close(void *f)
172 return fclose((FILE *)f);
175 struct lbx_image *lbximg_fopen(const char *file)
177 struct lbx_pipe_state *p;
180 f = fopen(file, "rb");
184 if (fseek(f, 0, SEEK_CUR) == 0)
185 return lbximg_open(f, &lbx_default_fops, file_close);
187 p = malloc(sizeof *p);
193 *p = (struct lbx_pipe_state) { .f = f };
194 return lbximg_open(p, &lbx_pipe_fops, pipe_close);
197 static int _lbx_drawrow(int first, struct lbx_image *img)
199 unsigned short type, count, yval, xval;
200 unsigned char buf[4];
204 assert(img->framedata);
207 if (img->fops->read(buf, sizeof buf, img->f) != sizeof buf)
209 type = unpack_16_le(buf+0);
218 yval = unpack_16_le(buf+2);
222 if (img->fops->read(buf, sizeof buf, img->f) != sizeof buf)
224 count = unpack_16_le(buf+0);
226 xval = unpack_16_le(buf+2);
230 /* Ensure that the row fits in the image. */
231 if (img->height - img->currenty <= yval || xval >= img->width) {
232 lbx_error_raise(LBX_EFORMAT);
236 img->currenty += yval;
237 img->currentx = xval;
239 xval = unpack_16_le(buf+2);
241 if (img->width - img->currentx <= xval) {
242 lbx_error_raise(LBX_EFORMAT);
245 img->currentx += xval;
250 if (count > img->width - img->currentx) {
251 lbx_error_raise(LBX_EFORMAT);
255 memset(&img->mask[img->currenty][img->currentx], 1, count);
257 pos = &img->framedata[img->currenty][img->currentx];
258 rc = img->fops->read(pos, count, img->f);
265 if (img->fops->read(buf, 1, img->f) != 1)
271 if (img->fops->eof(img->f))
272 lbx_error_raise(LBX_EEOF);
276 static unsigned char **allocframebuffer(size_t width, size_t height)
278 unsigned char **new, *tmp;
281 tmp = calloc(height, width);
283 lbx_error_raise(LBX_ENOMEM);
287 new = malloc(height * sizeof *new);
289 lbx_error_raise(LBX_ENOMEM);
294 for (i = 0; i < height; i++) {
295 new[i] = tmp + i * width;
301 static unsigned char **read_raw_frame(struct lbx_image *img, int frame)
303 unsigned long size = img->width * img->height;
305 assert(img->flags & FLAG_RAW);
307 if (img->fops->seek(img->f, img->offsets[frame], SEEK_SET)) {
311 if (img->fops->read(img->framedata[0], size, img->f) != size) {
312 if (img->fops->eof(img->f))
313 lbx_error_raise(LBX_EEOF);
316 memset(img->mask[0], 1, size);
318 if (img->fops->tell(img->f) > img->offsets[frame+1]) {
319 lbx_error_raise(LBX_EFORMAT);
323 return img->framedata;
326 unsigned char **lbximg_getframe(struct lbx_image *img, int frame)
328 if (frame >= img->frames || frame < 0) {
329 lbx_error_raise(LBX_ENOENT);
333 if (!img->framedata) {
334 img->framedata = allocframebuffer(img->width, img->height);
340 img->mask = allocframebuffer(img->width, img->height);
345 if (img->flags & FLAG_RAW)
346 return read_raw_frame(img, frame);
348 if ((img->flags & FLAG_OVERWRITE)
349 || (img->chunk && !(frame % img->chunk))) {
350 /* Clear the slate. */
351 img->currentframe = -1;
352 memset(img->framedata[0], 0, img->width * img->height);
353 memset(img->mask[0], 0, img->width * img->height);
355 /* Start over if we are backtracking. */
356 if (img->currentframe > frame) {
357 memset(img->mask[0], 0, img->width * img->height);
358 img->currentframe = -1;
361 /* We must have previous frame decoded to continue. */
362 if (frame > img->currentframe + 1) {
363 if (!lbximg_getframe(img, frame-1))
368 if (img->currentframe != frame) {
371 if (img->fops->seek(img->f, img->offsets[frame], SEEK_SET)) {
376 rc = _lbx_drawrow(first, img);
381 if (img->fops->tell(img->f) > img->offsets[frame+1]) {
382 lbx_error_raise(LBX_EFORMAT);
388 img->currentframe = frame;
389 return img->framedata;
393 lbximg_loadpalette(void *f, const struct lbx_file_ops *fops,
394 struct lbx_colour palette[static 256])
396 unsigned char entry[4];
399 for (i = 0; i < 256; i++) {
400 if (fops->read(entry, sizeof entry, f) != sizeof entry) {
402 lbx_error_raise(LBX_EEOF);
407 lbx_error_raise(LBX_EFORMAT);
411 palette[i] = (struct lbx_colour) {
412 .red = entry[1] << 2,
413 .green = entry[2] << 2,
414 .blue = entry[3] << 2,
423 lbximg_getpalette(struct lbx_image *img, struct lbx_colour palette[static 256])
425 unsigned char entry[4];
429 /* Do nothing if the image doesn't have embedded palette data. */
430 if (!(img->flags & FLAG_PALETTE))
433 if (img->fops->seek(img->f, img->paloff, SEEK_SET)) {
437 for (i = 0; i < img->palcount; i++) {
438 rc = img->fops->read(entry, sizeof entry, img->f);
439 if (rc < sizeof entry) {
444 lbx_error_raise(LBX_EFORMAT);
448 palette[img->palstart + i] = (struct lbx_colour){
449 .red = entry[1] << 2,
450 .green = entry[2] << 2,
451 .blue = entry[3] << 2,
458 if (img->fops->eof(img->f))
459 lbx_error_raise(LBX_EEOF);
463 void lbximg_getinfo(struct lbx_image *img, struct lbx_imginfo *info)
465 *info = (struct lbx_imginfo) {
467 .height = img->height,
468 .nframes = img->frames,
470 .palettesz = (img->flags & FLAG_PALETTE) ? img->palcount : 0,
473 /* There seems to be two ways of specifying that an image loops. */
474 if (img->flags & FLAG_LOOPING) {
477 } else if (img->leadin != img->frames - 1) {
478 info->loopstart = img->leadin;
483 unsigned char **lbximg_getmask(struct lbx_image *img)
488 int lbximg_close(struct lbx_image *img)
493 if (img->framedata) {
494 free(img->framedata[0]);
495 free(img->framedata);
503 if (img && img->dtor) {
504 rc = img->dtor(img->f);