/*
* 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 "pack.h"
#include "misc.h"
#include "lbx.h"
#include "image.h"
#define FLAG_OVERWRITE 0x0400 /* Draw each frame on a clean slate (unsure). */
#define FLAG_BUILDING 0x0800 /* Buildings have this, related to shadow? */
#define FLAG_PALETTE 0x1000 /* Image contains embedded palette. */
#define FLAG_LOOPING 0x2000 /* Loop over all frames in the image (unsure). */
#define FLAG_ALL (FLAG_OVERWRITE|FLAG_BUILDING|FLAG_PALETTE|FLAG_LOOPING)
#define HDR_LEN 12
struct lbx_image {
unsigned short width, height;
unsigned short wtf, flags;
unsigned short frames, leadin;
unsigned short palstart, palcount;
const struct lbx_file_ops *fops;
int (*dtor)(void *handle);
void *f;
long paloff;
int currentframe;
int currentx, currenty;
unsigned char **framedata;
unsigned char **mask;
unsigned long offsets[];
};
static struct lbx_image *lbximg_init(unsigned char hdr[static HDR_LEN])
{
unsigned short nframes = unpack_16_le(hdr+6);
struct lbx_image *img;
img = malloc(sizeof *img + sizeof img->offsets[0] * (nframes+1));
if (!img) {
lbx_errno = -errno;
return NULL;
}
*img = (struct lbx_image) {
.width = unpack_16_le(hdr+0),
.height = unpack_16_le(hdr+2),
.wtf = unpack_16_le(hdr+4),
.frames = unpack_16_le(hdr+6),
.leadin = unpack_16_le(hdr+8),
.flags = unpack_16_le(hdr+10),
.currentframe = -1,
};
return img;
}
struct lbx_image *lbximg_open(void *f, const struct lbx_file_ops *fops,
int (*destructor)(void *))
{
unsigned char hdr_buf[HDR_LEN];
struct lbx_image *img;
if (fops->read(hdr_buf, sizeof hdr_buf, f) != sizeof hdr_buf) {
lbx_errno = -errno;
if (fops->eof(f))
lbx_errno = LBX_EEOF;
return NULL;
}
img = lbximg_init(hdr_buf);
if (!img)
return NULL;
img->f = f;
img->fops = fops;
img->dtor = destructor;
/*
* 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(img->wtf == 0); /* version? */
_lbx_assert(img->frames > img->leadin); /* cmbtshp.lbx breaks this. */
_lbx_assert(!(img->flags & ~FLAG_ALL));
/* Read all offsets. Should be merged with identical code in lbx.c */
for (unsigned i = 0; i <= img->frames; i++) {
unsigned char buf[4];
if (fops->read(buf, sizeof buf, f) != sizeof buf) {
lbx_errno = -errno;
if (fops->eof(f))
lbx_errno = LBX_EEOF;
free(img);
return NULL;
}
img->offsets[i] = unpack_32_le(buf);
}
if (img->flags & FLAG_PALETTE) {
unsigned char buf[4];
if (fops->read(buf, sizeof buf, f) != sizeof buf) {
lbx_errno = -errno;
if (fops->eof(f))
lbx_errno = LBX_EEOF;
free(img);
return NULL;
}
img->palstart = unpack_16_le(buf+0);
img->palcount = unpack_16_le(buf+2);
img->paloff = fops->tell(f);
if (img->palstart + img->palcount > 256) {
lbx_errno = LBX_EFORMAT;
free(img);
return NULL;
}
}
return img;
}
struct lbx_image *lbximg_fopen(FILE *f)
{
return lbximg_open(f, &lbx_default_fops, NULL);
}
static int _lbx_drawrow(int first, struct lbx_image *img)
{
unsigned short type, count, yval, xval;
unsigned char buf[4];
unsigned char *pos;
size_t rc;
assert(img->framedata);
assert(img->mask);
if (img->fops->read(buf, sizeof buf, img->f) != sizeof buf)
goto readerr;
type = unpack_16_le(buf+0);
if (first) {
img->currentx = 0;
img->currenty = 0;
type = 0;
}
if (type == 0) {
yval = unpack_16_le(buf+2);
if (yval == 1000)
return 1;
if (img->fops->read(buf, sizeof buf, img->f) != sizeof buf)
goto readerr;
count = unpack_16_le(buf+0);
xval = unpack_16_le(buf+2);
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 {
xval = unpack_16_le(buf+2);
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 = img->fops->read(pos, count, img->f);
img->currentx += rc;
if (rc < count)
goto readerr;
if (count % 2) {
if (img->fops->read(buf, 1, img->f) != 1)
goto readerr;
}
return 0;
readerr:
lbx_errno = -errno;
if (img->fops->eof(img->f))
lbx_errno = LBX_EEOF;
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;
}
if (img->flags & FLAG_OVERWRITE) {
/* Clear the slate. */
img->currentframe = -1;
memset(img->framedata[0], 0, img->width * img->height);
memset(img->mask[0], 0, img->width * img->height);
} else {
/* Start over if we are backtracking. */
if (img->currentframe > frame) {
memset(img->mask[0], 0, img->width * img->height);
img->currentframe = -1;
}
/* 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 (img->fops->seek(img->f, img->offsets[frame], SEEK_SET)) {
lbx_errno = -errno;
return NULL;
}
do {
rc = _lbx_drawrow(first, img);
if (rc == -1)
return NULL;
first = 0;
if (img->fops->tell(img->f) > img->offsets[frame+1]) {
lbx_errno = LBX_EFORMAT;
return NULL;
}
} while (!rc);
}
img->currentframe = frame;
return img->framedata;
}
int
lbximg_loadpalette(void *f, const struct lbx_file_ops *fops,
struct lbx_colour palette[static 256])
{
unsigned char entry[4];
int i;
for (i = 0; i < 256; i++) {
if (fops->read(entry, sizeof entry, f) != sizeof entry) {
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,
.active = 1,
};
}
return 0;
}
int
lbximg_getpalette(struct lbx_image *img, struct lbx_colour palette[static 256])
{
unsigned char entry[4];
unsigned int i;
size_t rc;
/* Do nothing if the image doesn't have embedded palette data. */
if (!(img->flags & FLAG_PALETTE))
return 0;
if (img->fops->seek(img->f, img->paloff, SEEK_SET)) {
lbx_errno = -errno;
return -1;
}
for (i = 0; i < img->palcount; i++) {
rc = img->fops->read(entry, sizeof entry, img->f);
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,
.active = 1,
};
}
return 0;
readerr:
lbx_errno = img->fops->eof(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;
}
int lbximg_close(struct lbx_image *img)
{
int rc = 0;
if (img) {
if (img->framedata) {
free(img->framedata[0]);
free(img->framedata);
}
if (img->mask) {
free(img->mask[0]);
free(img->mask);
}
if (img && img->dtor) {
rc = img->dtor(img->f);
}
free(img);
}
return rc;
}