X-Git-Url: https://git.draconx.ca/gitweb/liblbx.git/blobdiff_plain/0806586ee10e29b60a77c351d355a00087f81f57..03c280a6c4bec42b1d4617b6d9e0bad1b9bbc80d:/src/image.c

diff --git a/src/image.c b/src/image.c
index 86f6f98..c3abf3f 100644
--- a/src/image.c
+++ b/src/image.c
@@ -1,80 +1,518 @@
-#ifdef HAVE_CONFIG_H
-#	include "config.h"
-#endif
-
+/*
+ * 2ooM: The Master of Orion II Reverse Engineering Project
+ * Library for working with LBX image files.
+ * Copyright © 2006-2011 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 <http://www.gnu.org/licenses/>.
+ */
+#include <config.h>
 #include <stdlib.h>
-#include <stdint.h>
+#include <string.h>
 #include <assert.h>
 #include <errno.h>
 
+#include "pack.h"
+#include "misc.h"
 #include "lbx.h"
-#include "byteorder.h"
+#include "error.h"
+#include "image.h"
 
-struct lbx_image {
-	FILE *f;
-	uint16_t width, height;
-	uint16_t wtf1, wtf2;
-	uint16_t offs, frames;
-	uint32_t offsets[];
+#define FLAG_RAW       0x0100 /* Image is stored as a flat array of bytes. */
+#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_RAW|FLAG_OVERWRITE|FLAG_BUILDING|FLAG_PALETTE|FLAG_LOOPING)
+
+#define HDR_LEN 12
+
+struct lbx_image_priv {
+	struct lbx_image pub;
+
+	unsigned short wtf, flags;
+	unsigned char  wtf2, 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[];
 };
 
-struct lbx_image *lbximg_fopen(FILE *f)
+static struct lbx_image_priv *lbx_img_init(unsigned char hdr[static HDR_LEN])
 {
-	struct lbx_image tmp = {.f = f}, *new;
-
-	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.offs,   sizeof tmp.offs,    1, f) != 1) goto readerr;
-	if (fread(&tmp.frames, sizeof tmp.frames,  1, f) != 1) goto readerr;
-	if (fread(&tmp.wtf2,   sizeof tmp.wtf2,    1, f) != 1) goto readerr;
-
-	tmp.width  = letohs(tmp.width);
-	tmp.height = letohs(tmp.height);
-	tmp.wtf1   = letohs(tmp.wtf1);
-	tmp.offs   = letohs(tmp.offs);
-	tmp.frames = letohs(tmp.frames);
-	tmp.wtf2   = letohs(tmp.wtf2);
+	unsigned short nframes = unpack_16_le(hdr+6);
+	struct lbx_image_priv *img;
+
+	img = malloc(sizeof *img + sizeof img->offsets[0] * (nframes+1));
+	if (!img) {
+		lbx_error_raise(LBX_ENOMEM);
+		return NULL;
+	}
+
+	*img = (struct lbx_image_priv) {
+		.pub.width  = unpack_16_le(hdr+0),
+		.pub.height = unpack_16_le(hdr+2),
+		.wtf        = unpack_16_le(hdr+4),
+		.pub.frames = hdr[6],
+		.wtf2       = hdr[7],
+		.leadin     = hdr[8],
+		.pub.chunk  = hdr[9],
+		.flags      = unpack_16_le(hdr+10),
+
+		.currentframe = -1,
+	};
+
+	return img;
+}
+
+struct lbx_image *lbx_img_open(void *f, const struct lbx_file_ops *fops,
+                               int (*destructor)(void *))
+{
+	unsigned char hdr_buf[HDR_LEN];
+	struct lbx_image_priv *img;
+
+	if (fops->read(hdr_buf, sizeof hdr_buf, f) != sizeof hdr_buf) {
+		if (fops->eof(f))
+			lbx_error_raise(LBX_EEOF);
+		return NULL;
+	}
+
+	img = lbx_img_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.
+	 * When we can decode every image, then these assertions should be
+	 * replaced with constraints.
 	 */
-	assert(tmp.wtf1 == 0);
-	assert(tmp.offs == tmp.frames + 1);
+	_lbx_assert(img->wtf  == 0); /* version? */
+	_lbx_assert(img->wtf2 == 0); /* very likely is simply reserved. */
+	_lbx_assert(img->pub.frames > img->leadin);
+	_lbx_assert(!(img->flags & ~FLAG_ALL));
 
-	new = malloc(sizeof *new + tmp.offs * sizeof *new->offsets);
-	if (!new) {
-		lbx_errno = -errno;
+	/* Read all offsets.  Should be merged with identical code in lbx.c */
+	for (unsigned i = 0; i <= img->pub.frames; i++) {
+		unsigned char buf[4];
+
+		if (fops->read(buf, sizeof buf, f) != sizeof buf) {
+			if (fops->eof(f))
+				lbx_error_raise(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) {
+			if (fops->eof(f))
+				lbx_error_raise(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_error_raise(LBX_EFORMAT);
+			free(img);
+			return NULL;
+		}
+	}
+
+	return &img->pub;
+}
+
+static int pipe_close(void *f)
+{
+	struct lbx_pipe_state *p = f;
+	int rc;
+
+	rc = fclose(p->f);
+	free(p);
+	return rc;
+}
+
+static int file_close(void *f)
+{
+	return fclose((FILE *)f);
+}
+
+struct lbx_image *lbx_img_fopen(const char *file)
+{
+	struct lbx_pipe_state *p;
+	FILE *f;
+
+	f = fopen(file, "rb");
+	if (!f)
+		return NULL;
+
+	if (fseek(f, 0, SEEK_CUR) == 0)
+		return lbx_img_open(f, &lbx_default_fops, file_close);
+
+	p = malloc(sizeof *p);
+	if (!p) {
+		fclose(f);
 		return NULL;
 	}
 
-	*new = tmp;
+	*p = (struct lbx_pipe_state) { .f = f };
+	return lbx_img_open(p, &lbx_pipe_fops, pipe_close);
+}
+
+static int _lbx_drawrow(int first, struct lbx_image_priv *img)
+{
+	unsigned short type, count, yval, xval;
+	unsigned char buf[4];
+	unsigned char *pos;
+	size_t rc;
+
+	assert(img->framedata);
+	assert(img->mask);
 
-	if (fread(new->offsets, sizeof *new->offsets, new->offs, f) != new->offs)
+	if (img->fops->read(buf, sizeof buf, img->f) != sizeof buf)
 		goto readerr;
+	type = unpack_16_le(buf+0);
 
-	return new;
+	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->pub.height - img->currenty <= yval
+		    || xval >= img->pub.width) {
+			lbx_error_raise(LBX_EFORMAT);
+			return -1;
+		}
+
+		img->currenty += yval;
+		img->currentx  = xval;
+	} else {
+		xval = unpack_16_le(buf+2);
+
+		if (img->pub.width - img->currentx <= xval) {
+			lbx_error_raise(LBX_EFORMAT);
+			return -1;
+		}
+		img->currentx += xval;
+
+		count = type;
+	}
+
+	if (count > img->pub.width - img->currentx) {
+		lbx_error_raise(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:
-	if (feof(f)) {
-		lbx_errno = LBX_EEOF;
+	if (img->fops->eof(img->f))
+		lbx_error_raise(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_error_raise(LBX_ENOMEM);
+		return NULL;
+	}
+
+	new = malloc(height * sizeof *new);
+	if (!new) {
+		lbx_error_raise(LBX_ENOMEM);
+		free(tmp);
+		return NULL;
+	}
+
+	for (i = 0; i < height; i++) {
+		new[i] = tmp + i * width;
+	}
+
+	return new;
+}
+
+static unsigned char **read_raw_frame(struct lbx_image_priv *img, int frame)
+{
+	unsigned long size = img->pub.width * img->pub.height;
+
+	assert(img->flags & FLAG_RAW);
+
+	if (img->fops->seek(img->f, img->offsets[frame], SEEK_SET)) {
+		return NULL;
+	}
+
+	if (img->fops->read(img->framedata[0], size, img->f) != size) {
+		if (img->fops->eof(img->f))
+			lbx_error_raise(LBX_EEOF);
+		return NULL;
+	}
+	memset(img->mask[0], 1, size);
+
+	if (img->fops->tell(img->f) > img->offsets[frame+1]) {
+		lbx_error_raise(LBX_EFORMAT);
+		return NULL;
+	}
+
+	return img->framedata;
+}
+
+unsigned char **lbx_img_getframe(struct lbx_image *pub, int frame)
+{
+	struct lbx_image_priv *img = (struct lbx_image_priv *)pub;
+
+	if (frame >= pub->frames || frame < 0) {
+		lbx_error_raise(LBX_ENOENT);
+		return NULL;
+	}
+
+	if (!img->framedata) {
+		img->framedata = allocframebuffer(pub->width, pub->height);
+		if (!img->framedata)
+			return NULL;
+	}
+
+	if (!img->mask) {
+		img->mask = allocframebuffer(pub->width, pub->height);
+		if (!img->mask)
+			return NULL;
+	}
+
+	if (img->flags & FLAG_RAW)
+		return read_raw_frame(img, frame);
+
+	if ((img->flags & FLAG_OVERWRITE)
+	     || (pub->chunk && !(frame % pub->chunk))) {
+		/* Clear the slate. */
+		img->currentframe = -1;
+		memset(img->framedata[0], 0, pub->width * pub->height);
+		memset(img->mask[0],      0, pub->width * pub->height);
 	} else {
-		lbx_errno = -errno;
+		/* Start over if we are backtracking. */
+		if (img->currentframe > frame) {
+			memset(img->mask[0], 0, pub->width * pub->height);
+			img->currentframe = -1;
+		}
+
+		/* We must have previous frame decoded to continue. */
+		if (frame > img->currentframe + 1) {
+			if (!lbx_img_getframe(pub, frame-1))
+				return NULL;
+		}
 	}
 
-	free(new);
-	return NULL;
+	if (img->currentframe != frame) {
+		int rc, first = 1;
+
+		if (img->fops->seek(img->f, img->offsets[frame], SEEK_SET)) {
+			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_error_raise(LBX_EFORMAT);
+				return NULL;
+			}
+		} while (!rc);
+	}
+
+	img->currentframe = frame;
+	return img->framedata;
+}
+
+int
+lbx_img_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) {
+			if (fops->eof(f))
+				lbx_error_raise(LBX_EEOF);
+			return -1;
+		}
+
+		if (entry[0] != 1) {
+			lbx_error_raise(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
+lbx_img_getpalette(struct lbx_image *pub, struct lbx_colour palette[static 256])
+{
+	struct lbx_image_priv *img = (struct lbx_image_priv *)pub;
+	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)) {
+		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_error_raise(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:
+	if (img->fops->eof(img->f))
+		lbx_error_raise(LBX_EEOF);
+	return -1;
 }
 
-void lbximg_close(struct lbx_image *img)
+void lbx_img_getinfo(struct lbx_image *pub, struct lbx_imginfo *info)
 {
-	if (!img) return;
+	struct lbx_image_priv *img = (struct lbx_image_priv *)pub;
+
+	*info = (struct lbx_imginfo) {
+		.width      = pub->width,
+		.height     = pub->height,
+		.nframes    = pub->frames,
+		.chunk      = pub->chunk,
+		.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 != pub->frames - 1) {
+		info->loopstart = img->leadin;
+		info->looping   = 1;
+	}
+}
+
+unsigned char **lbx_img_getmask(struct lbx_image *pub)
+{
+	struct lbx_image_priv *img = (struct lbx_image_priv *)pub;
+
+	return img->mask;
+}
+
+int lbx_img_close(struct lbx_image *pub)
+{
+	struct lbx_image_priv *img = (struct lbx_image_priv *)pub;
+	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);
+		}
 
-	if (img->f) {
-		fclose(img->f);
+		free(img);
 	}
 
-	free(img);
+	return rc;
 }