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/>.
31 #define FLAG_RAW 0x0100 /* Image is stored as a flat array of bytes. */
32 #define FLAG_OVERWRITE 0x0400 /* Draw each frame on a clean slate (unsure). */
33 #define FLAG_BUILDING 0x0800 /* Buildings have this, related to shadow? */
34 #define FLAG_PALETTE 0x1000 /* Image contains embedded palette. */
35 #define FLAG_LOOPING 0x2000 /* Loop over all frames in the image (unsure). */
37 #define FLAG_ALL (FLAG_RAW|FLAG_OVERWRITE|FLAG_BUILDING|FLAG_PALETTE|FLAG_LOOPING)
42 unsigned short width, height;
43 unsigned short wtf, flags;
44 unsigned char frames, wtf2, leadin, chunk;
45 unsigned short palstart, palcount;
47 const struct lbx_file_ops *fops;
48 int (*dtor)(void *handle);
54 int currentx, currenty;
55 unsigned char **framedata;
58 unsigned long offsets[];
61 static struct lbx_image *lbximg_init(unsigned char hdr[static HDR_LEN])
63 unsigned short nframes = unpack_16_le(hdr+6);
64 struct lbx_image *img;
66 img = malloc(sizeof *img + sizeof img->offsets[0] * (nframes+1));
68 lbx_error_raise(LBX_ENOMEM);
72 *img = (struct lbx_image) {
73 .width = unpack_16_le(hdr+0),
74 .height = unpack_16_le(hdr+2),
75 .wtf = unpack_16_le(hdr+4),
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) {
96 lbx_error_raise(LBX_EEOF);
100 img = lbximg_init(hdr_buf);
106 img->dtor = destructor;
109 * DEBUG ONLY. These assertions exist to catch otherwise valid image
110 * files which differ from what I believe to be true of all LBX images.
111 * When we can decode every image, then these assertions should be
112 * replaced with constraints.
114 _lbx_assert(img->wtf == 0); /* version? */
115 _lbx_assert(img->wtf2 == 0); /* very likely is simply reserved. */
116 _lbx_assert(img->frames > img->leadin);
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) {
125 lbx_error_raise(LBX_EEOF);
130 img->offsets[i] = unpack_32_le(buf);
133 if (img->flags & FLAG_PALETTE) {
134 unsigned char buf[4];
136 if (fops->read(buf, sizeof buf, f) != sizeof buf) {
138 lbx_error_raise(LBX_EEOF);
143 img->palstart = unpack_16_le(buf+0);
144 img->palcount = unpack_16_le(buf+2);
145 img->paloff = fops->tell(f);
147 if (img->palstart + img->palcount > 256) {
148 lbx_error_raise(LBX_EFORMAT);
157 static int pipe_close(void *f)
159 struct lbx_pipe_state *p = f;
167 static int file_close(void *f)
169 return fclose((FILE *)f);
172 struct lbx_image *lbximg_fopen(const char *file)
174 struct lbx_pipe_state *p;
177 f = fopen(file, "rb");
181 if (fseek(f, 0, SEEK_CUR) == 0)
182 return lbximg_open(f, &lbx_default_fops, file_close);
184 p = malloc(sizeof *p);
190 *p = (struct lbx_pipe_state) { .f = f };
191 return lbximg_open(p, &lbx_pipe_fops, pipe_close);
194 static int _lbx_drawrow(int first, struct lbx_image *img)
196 unsigned short type, count, yval, xval;
197 unsigned char buf[4];
201 assert(img->framedata);
204 if (img->fops->read(buf, sizeof buf, img->f) != sizeof buf)
206 type = unpack_16_le(buf+0);
215 yval = unpack_16_le(buf+2);
219 if (img->fops->read(buf, sizeof buf, img->f) != sizeof buf)
221 count = unpack_16_le(buf+0);
223 xval = unpack_16_le(buf+2);
227 /* Ensure that the row fits in the image. */
228 if (img->height - img->currenty <= yval || xval >= img->width) {
229 lbx_error_raise(LBX_EFORMAT);
233 img->currenty += yval;
234 img->currentx = xval;
236 xval = unpack_16_le(buf+2);
238 if (img->width - img->currentx <= xval) {
239 lbx_error_raise(LBX_EFORMAT);
242 img->currentx += xval;
247 if (count > img->width - img->currentx) {
248 lbx_error_raise(LBX_EFORMAT);
252 memset(&img->mask[img->currenty][img->currentx], 1, count);
254 pos = &img->framedata[img->currenty][img->currentx];
255 rc = img->fops->read(pos, count, img->f);
262 if (img->fops->read(buf, 1, img->f) != 1)
268 if (img->fops->eof(img->f))
269 lbx_error_raise(LBX_EEOF);
273 static unsigned char **allocframebuffer(size_t width, size_t height)
275 unsigned char **new, *tmp;
278 tmp = calloc(height, width);
280 lbx_error_raise(LBX_ENOMEM);
284 new = malloc(height * sizeof *new);
286 lbx_error_raise(LBX_ENOMEM);
291 for (i = 0; i < height; i++) {
292 new[i] = tmp + i * width;
298 static unsigned char **read_raw_frame(struct lbx_image *img, int frame)
300 unsigned long size = img->width * img->height;
302 assert(img->flags & FLAG_RAW);
304 if (img->fops->seek(img->f, img->offsets[frame], SEEK_SET)) {
308 if (img->fops->read(img->framedata[0], size, img->f) != size) {
309 if (img->fops->eof(img->f))
310 lbx_error_raise(LBX_EEOF);
313 memset(img->mask[0], 1, size);
315 if (img->fops->tell(img->f) > img->offsets[frame+1]) {
316 lbx_error_raise(LBX_EFORMAT);
320 return img->framedata;
323 unsigned char **lbximg_getframe(struct lbx_image *img, int frame)
325 if (frame >= img->frames || frame < 0) {
326 lbx_error_raise(LBX_ENOENT);
330 if (!img->framedata) {
331 img->framedata = allocframebuffer(img->width, img->height);
337 img->mask = allocframebuffer(img->width, img->height);
342 if (img->flags & FLAG_RAW)
343 return read_raw_frame(img, frame);
345 if ((img->flags & FLAG_OVERWRITE)
346 || (img->chunk && !(frame % img->chunk))) {
347 /* Clear the slate. */
348 img->currentframe = -1;
349 memset(img->framedata[0], 0, img->width * img->height);
350 memset(img->mask[0], 0, img->width * img->height);
352 /* Start over if we are backtracking. */
353 if (img->currentframe > frame) {
354 memset(img->mask[0], 0, img->width * img->height);
355 img->currentframe = -1;
358 /* We must have previous frame decoded to continue. */
359 if (frame > img->currentframe + 1) {
360 if (!lbximg_getframe(img, frame-1))
365 if (img->currentframe != frame) {
368 if (img->fops->seek(img->f, img->offsets[frame], SEEK_SET)) {
373 rc = _lbx_drawrow(first, img);
378 if (img->fops->tell(img->f) > img->offsets[frame+1]) {
379 lbx_error_raise(LBX_EFORMAT);
385 img->currentframe = frame;
386 return img->framedata;
390 lbximg_loadpalette(void *f, const struct lbx_file_ops *fops,
391 struct lbx_colour palette[static 256])
393 unsigned char entry[4];
396 for (i = 0; i < 256; i++) {
397 if (fops->read(entry, sizeof entry, f) != sizeof entry) {
399 lbx_error_raise(LBX_EEOF);
404 lbx_error_raise(LBX_EFORMAT);
408 palette[i] = (struct lbx_colour) {
409 .red = entry[1] << 2,
410 .green = entry[2] << 2,
411 .blue = entry[3] << 2,
420 lbximg_getpalette(struct lbx_image *img, struct lbx_colour palette[static 256])
422 unsigned char entry[4];
426 /* Do nothing if the image doesn't have embedded palette data. */
427 if (!(img->flags & FLAG_PALETTE))
430 if (img->fops->seek(img->f, img->paloff, SEEK_SET)) {
434 for (i = 0; i < img->palcount; i++) {
435 rc = img->fops->read(entry, sizeof entry, img->f);
436 if (rc < sizeof entry) {
441 lbx_error_raise(LBX_EFORMAT);
445 palette[img->palstart + i] = (struct lbx_colour){
446 .red = entry[1] << 2,
447 .green = entry[2] << 2,
448 .blue = entry[3] << 2,
455 if (img->fops->eof(img->f))
456 lbx_error_raise(LBX_EEOF);
460 void lbximg_getinfo(struct lbx_image *img, struct lbx_imginfo *info)
462 *info = (struct lbx_imginfo) {
464 .height = img->height,
465 .nframes = img->frames,
467 .palettesz = (img->flags & FLAG_PALETTE) ? img->palcount : 0,
470 /* There seems to be two ways of specifying that an image loops. */
471 if (img->flags & FLAG_LOOPING) {
474 } else if (img->leadin != img->frames - 1) {
475 info->loopstart = img->leadin;
480 unsigned char **lbximg_getmask(struct lbx_image *img)
485 int lbximg_close(struct lbx_image *img)
490 if (img->framedata) {
491 free(img->framedata[0]);
492 free(img->framedata);
500 if (img && img->dtor) {
501 rc = img->dtor(img->f);