/*
* 2ooM: The Master of Orion II Reverse Engineering Project
* Library for working with LBX image files.
* Copyright (C) 2006-2008 Nick Bowler
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see .
*/
#ifdef HAVE_CONFIG_H
# include "config.h"
#endif
#include
#include
#include
#include
#include
#include "byteorder.h"
#include "misc.h"
#include "lbx.h"
#include "image.h"
#define FLAG_OVERWRITE 0x0400 /* Draw each frame on a clean slate (unsure). */
#define FLAG_PALETTE 0x1000 /* Image contains embedded palette. */
#define FLAG_LOOPING 0x2000 /* Loop over all frames in the image (unsure). */
struct lbx_image {
uint16_t width, height;
uint16_t wtf1;
uint16_t frames, leadin;
uint16_t flags;
uint16_t palstart, palcount;
FILE *f;
long foff, paloff;
int currentframe;
int currentx, currenty;
unsigned char **framedata;
unsigned char **mask;
uint32_t offsets[];
};
struct lbx_image *lbximg_fopen(FILE *f)
{
struct lbx_image tmp = {.f = f}, *new = NULL;
size_t rc;
if (fread(&tmp.width, sizeof tmp.width, 1, f) != 1) goto readerr;
if (fread(&tmp.height, sizeof tmp.height, 1, f) != 1) goto readerr;
if (fread(&tmp.wtf1, sizeof tmp.wtf1, 1, f) != 1) goto readerr;
if (fread(&tmp.frames, sizeof tmp.frames, 1, f) != 1) goto readerr;
if (fread(&tmp.leadin, sizeof tmp.leadin, 1, f) != 1) goto readerr;
if (fread(&tmp.flags, sizeof tmp.flags, 1, f) != 1) goto readerr;
tmp.width = letohs(tmp.width); tmp.foff += sizeof tmp.width;
tmp.height = letohs(tmp.height); tmp.foff += sizeof tmp.height;
tmp.wtf1 = letohs(tmp.wtf1); tmp.foff += sizeof tmp.wtf1;
tmp.frames = letohs(tmp.frames); tmp.foff += sizeof tmp.frames;
tmp.leadin = letohs(tmp.leadin); tmp.foff += sizeof tmp.leadin;
tmp.flags = letohs(tmp.flags); tmp.foff += sizeof tmp.flags;
/*
* DEBUG ONLY. These assertions exist to catch otherwise valid image
* files which differ from what I believe to be true of all LBX images.
* If we never find any exceptions, we can replace the assertions with
* assumptions.
*/
_lbx_assert(tmp.wtf1 == 0);
_lbx_assert(tmp.frames > tmp.leadin); /* cmbtshp.lbx breaks this. */
_lbx_assert(!(tmp.flags & ~(FLAG_PALETTE|FLAG_OVERWRITE|FLAG_LOOPING)));
new = malloc(sizeof *new + (tmp.frames+1) * sizeof *new->offsets);
if (!new) {
lbx_errno = -errno;
return NULL;
}
*new = tmp;
new->currentframe = -1;
rc = fread(new->offsets, sizeof *new->offsets, new->frames+1, f);
if (rc < new->frames+1)
goto readerr;
new->foff += sizeof *new->offsets * (new->frames+1);
if (new->flags & FLAG_PALETTE) {
if (fread(&new->palstart, sizeof new->palstart, 1, f) != 1)
goto readerr;
if (fread(&new->palcount, sizeof new->palcount, 1, f) != 1)
goto readerr;
new->palstart = letohs(new->palstart);
new->palcount = letohs(new->palcount);
new->foff += sizeof new->palstart + sizeof new->palcount;
new->paloff = new->foff;
if (new->palstart + new->palcount > 256) {
lbx_errno = LBX_EFORMAT;
free(new);
return NULL;
}
}
return new;
readerr:
if (feof(f)) {
lbx_errno = LBX_EEOF;
} else {
lbx_errno = -errno;
}
free(new);
return NULL;
}
static int _lbx_drawrow(int first, struct lbx_image *img)
{
uint16_t type, yval, count, xval;
unsigned char *pos;
unsigned char abyss;
size_t rc;
assert(img->framedata);
assert(img->mask);
if (fread(&type, sizeof type, 1, img->f) != 1) goto readerr;
type = letohs(type); img->foff += sizeof type;
if (first) {
img->currentx = 0;
img->currenty = 0;
type = 0;
}
if (type == 0) {
if (fread(&yval, sizeof yval, 1, img->f) != 1) goto readerr;
yval = letohs(yval); img->foff += sizeof yval;
if (yval == 1000)
return 1;
if (fread(&count, sizeof count, 1, img->f) != 1) goto readerr;
count = letohs(count); img->foff += sizeof count;
if (fread(&xval, sizeof xval, 1, img->f) != 1) goto readerr;
xval = letohs(xval); img->foff += sizeof xval;
if (xval == 1000)
return 1;
/* Ensure that the row fits in the image. */
if (img->height - img->currenty <= yval || xval >= img->width) {
lbx_errno = LBX_EFORMAT;
return -1;
}
img->currenty += yval;
img->currentx = xval;
} else {
if (fread(&xval, sizeof xval, 1, img->f) != 1) goto readerr;
xval = letohs(xval); img->foff += sizeof xval;
if (img->width - img->currentx <= xval) {
lbx_errno = LBX_EFORMAT;
return -1;
}
img->currentx += xval;
count = type;
}
if (count > img->width - img->currentx) {
lbx_errno = LBX_EFORMAT;
return -1;
}
memset(&img->mask[img->currenty][img->currentx], 1, count);
pos = &img->framedata[img->currenty][img->currentx];
rc = fread(pos, 1, count, img->f);
img->currentx += rc;
img->foff += rc;
if (rc < count)
goto readerr;
if (count % 2) {
if (fread(&abyss, 1, 1, img->f) != 1)
goto readerr;
img->foff += 1;
}
return 0;
readerr:
if (feof(img->f)) {
lbx_errno = LBX_EEOF;
} else {
lbx_errno = -errno;
}
return -1;
}
static unsigned char **allocframebuffer(size_t width, size_t height)
{
unsigned char **new, *tmp;
size_t i;
tmp = calloc(height, width);
if (!tmp) {
lbx_errno = -errno;
return NULL;
}
new = malloc(height * sizeof *new);
if (!new) {
lbx_errno = -errno;
free(tmp);
return NULL;
}
for (i = 0; i < height; i++) {
new[i] = tmp + i * width;
}
return new;
}
unsigned char **lbximg_getframe(struct lbx_image *img, int frame)
{
if (frame >= img->frames || frame < 0) {
lbx_errno = LBX_ERANGE;
return NULL;
}
if (!img->framedata) {
img->framedata = allocframebuffer(img->width, img->height);
if (!img->framedata)
return NULL;
}
if (!img->mask) {
img->mask = allocframebuffer(img->width, img->height);
if (!img->mask)
return NULL;
}
/* Start over if we are backtracking. */
if (img->currentframe > frame)
img->currentframe == -1;
if (img->flags & FLAG_OVERWRITE) {
/* Clear the slate. */
memset(img->framedata[0], 0, img->width * img->height);
memset(img->mask[0], 0, img->width * img->height);
} else {
/* We must have previous frame decoded to continue. */
if (frame > img->currentframe + 1) {
if (!lbximg_getframe(img, frame-1))
return NULL;
}
}
if (img->currentframe != frame) {
int rc, first = 1;
if (_lbx_fseek(img->f, &img->foff, img->offsets[frame]) == -1)
return NULL;
do {
rc = _lbx_drawrow(first, img);
if (rc == -1)
return NULL;
first = 0;
if (!rc && img->foff > img->offsets[frame+1]) {
lbx_errno = LBX_EFORMAT;
return NULL;
}
} while (!rc);
}
img->currentframe = frame;
return img->framedata;
}
int lbximg_loadpalette(FILE *f, struct lbx_colour palette[static 256])
{
uint8_t entry[4];
int i;
for (i = 0; i < 256; i++) {
if (fread(entry, sizeof entry, 1, f) != 1) {
lbx_errno = (feof(f)) ? LBX_EEOF : -errno;
return -1;
}
if (entry[0] != 1) {
lbx_errno = LBX_EFORMAT;
return -1;
}
palette[i] = (struct lbx_colour){
.red = entry[1] << 2,
.green = entry[2] << 2,
.blue = entry[3] << 2,
};
}
return 0;
}
int
lbximg_getpalette(struct lbx_image *img, struct lbx_colour palette[static 256])
{
unsigned int i;
size_t rc;
uint8_t entry[4];
/* Do nothing if the image doesn't have embedded palette data. */
if (!(img->flags & FLAG_PALETTE))
return 0;
if (_lbx_fseek(img->f, &img->foff, img->paloff) == -1)
return -1;
for (i = 0; i < img->palcount; i++) {
rc = fread(entry, 1, sizeof entry, img->f);
img->foff += rc;
if (rc < sizeof entry) {
goto readerr;
}
if (entry[0] != 0) {
lbx_errno = LBX_EFORMAT;
return -1;
}
palette[img->palstart + i] = (struct lbx_colour){
.red = entry[1] << 2,
.green = entry[2] << 2,
.blue = entry[3] << 2,
};
}
return 0;
readerr:
lbx_errno = feof(img->f) ? LBX_EEOF : -errno;
return -1;
}
void lbximg_getinfo(struct lbx_image *img, struct lbx_imginfo *info)
{
*info = (struct lbx_imginfo) {
.width = img->width,
.height = img->height,
.nframes = img->frames,
.palettesz = (img->flags & FLAG_PALETTE) ? img->palcount : 0,
};
/* There seems to be two ways of specifying that an image loops. */
if (img->flags & FLAG_LOOPING) {
info->loopstart = 0;
info->looping = 1;
} else if (img->leadin != img->frames - 1) {
info->loopstart = img->leadin;
info->looping = 1;
}
}
unsigned char **lbximg_getmask(struct lbx_image *img)
{
return img->mask;
}
void lbximg_close(struct lbx_image *img)
{
if (!img) return;
if (img->framedata) {
free(img->framedata[0]);
free(img->framedata);
}
if (img->mask) {
free(img->mask[0]);
free(img->mask);
}
if (img->f) {
fclose(img->f);
}
free(img);
}