X-Git-Url: https://git.draconx.ca/gitweb/liblbx.git/blobdiff_plain/210202b952fe47685635f812d85779f7a8ce5354..f228da9594290408ee03ffddbd01eadefbf06f1d:/src/image.c

diff --git a/src/image.c b/src/image.c
index 336cd98..3043861 100644
--- a/src/image.c
+++ b/src/image.c
@@ -1,9 +1,28 @@
+/*
+ *  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 <http://www.gnu.org/licenses/>.
+ */
 #ifdef HAVE_CONFIG_H
 #	include "config.h"
 #endif
 
 #include <stdlib.h>
 #include <stdint.h>
+#include <string.h>
 #include <assert.h>
 #include <errno.h>
 
@@ -12,38 +31,46 @@
 #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, wtf2;
-	uint16_t offs, frames;
+	uint16_t wtf1;
+	uint16_t frames, leadin;
+	uint16_t flags;
+	uint16_t palstart, palcount;
 
 	FILE *f;
-	long foff;
+	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;
+	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.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;
+	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.offs   = letohs(tmp.offs);   tmp.foff += sizeof tmp.offs;
 	tmp.frames = letohs(tmp.frames); tmp.foff += sizeof tmp.frames;
-	tmp.wtf2   = letohs(tmp.wtf2);   tmp.foff += sizeof tmp.wtf2;
+	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
@@ -51,10 +78,11 @@ struct lbx_image *lbximg_fopen(FILE *f)
 	 * If we never find any exceptions, we can replace the assertions with
 	 * assumptions.
 	 */
-	assert(tmp.wtf1 == 0);
-	assert(tmp.offs == tmp.frames + 1);
+	_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.offs * sizeof *new->offsets);
+	new = malloc(sizeof *new + (tmp.frames+1) * sizeof *new->offsets);
 	if (!new) {
 		lbx_errno = -errno;
 		return NULL;
@@ -63,9 +91,28 @@ struct lbx_image *lbximg_fopen(FILE *f)
 	*new = tmp;
 	new->currentframe = -1;
 
-	if (fread(new->offsets, sizeof *new->offsets, new->offs, f)!= new->offs)
+	rc = fread(new->offsets, sizeof *new->offsets, new->frames+1, f);
+	if (rc < new->frames+1)
 		goto readerr;
-	new->foff += sizeof *new->offsets * new->offs;
+	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:
@@ -87,6 +134,7 @@ static int _lbx_drawrow(int first, struct lbx_image *img)
 	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;
@@ -100,14 +148,14 @@ static int _lbx_drawrow(int first, struct lbx_image *img)
 	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) {
@@ -136,6 +184,8 @@ static int _lbx_drawrow(int first, struct lbx_image *img)
 		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;
@@ -160,6 +210,31 @@ readerr:
 	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) {
@@ -168,35 +243,31 @@ unsigned char **lbximg_getframe(struct lbx_image *img, int frame)
 	}
 
 	if (!img->framedata) {
-		unsigned char *tmp;
-		int i;
-
-		tmp = malloc(img->width * img->height);
-		if (!tmp) {
-			lbx_errno = -errno;
+		img->framedata = allocframebuffer(img->width, img->height);
+		if (!img->framedata)
 			return NULL;
-		}
+	}
 
-		img->framedata = malloc(img->height * sizeof *img->framedata);
-		if (!img->framedata) {
-			lbx_errno = -errno;
-			free(tmp);
+	if (!img->mask) {
+		img->mask = allocframebuffer(img->width, img->height);
+		if (!img->mask)
 			return NULL;
-		}
-
-		for (i = 0; i < img->height; i++) {
-			img->framedata[i] = tmp + i * img->width;
-		}
 	}
 
 	/* Start over if we are backtracking. */
 	if (img->currentframe > frame)
 		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->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) {
@@ -211,7 +282,7 @@ unsigned char **lbximg_getframe(struct lbx_image *img, int frame)
 				return NULL;
 			first = 0;
 
-			if (img->foff > img->offsets[frame+1]) {
+			if (!rc && img->foff > img->offsets[frame+1]) {
 				lbx_errno = LBX_EFORMAT;
 				return NULL;
 			}
@@ -251,18 +322,19 @@ int lbximg_loadpalette(FILE *f, struct lbx_colour palette[static 256])
 int
 lbximg_getpalette(struct lbx_image *img, struct lbx_colour palette[static 256])
 {
-	int index = 0;
+	unsigned int i;
 	size_t rc;
-	size_t hdrlen = 6*(sizeof img->width)
-	                + (img->offs)*(sizeof *img->offsets);
-	
-	uint8_t entry[4];
 
-	/* Palette data is located right after the header. */
-	if (_lbx_fseek(img->f, &img->foff, hdrlen) == -1)
+	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;
 	
-	while (img->foff + sizeof entry <= img->offsets[0]) {
+	for (i = 0; i < img->palcount; i++) {
 		rc = fread(entry, 1, sizeof entry, img->f);
 		img->foff += rc;
 
@@ -270,13 +342,12 @@ lbximg_getpalette(struct lbx_image *img, struct lbx_colour palette[static 256])
 			goto readerr;
 		}
 
-		if (entry[0] == 0) {
-			index++;
-		} else {
-			index = entry[0];
+		if (entry[0] != 0) {
+			lbx_errno = LBX_EFORMAT;
+			return -1;
 		}
 
-		palette[index] = (struct lbx_colour){
+		palette[img->palstart + i] = (struct lbx_colour){
 			.red   = entry[1] << 2,
 			.green = entry[2] << 2,
 			.blue  = entry[3] << 2,
@@ -285,13 +356,34 @@ lbximg_getpalette(struct lbx_image *img, struct lbx_colour palette[static 256])
 
 	return 0;
 readerr:
-	if (feof(img->f))
-		lbx_errno = LBX_EEOF;
-	else
-		lbx_errno = -errno;
+	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;
@@ -301,6 +393,11 @@ void lbximg_close(struct lbx_image *img)
 		free(img->framedata);
 	}
 
+	if (img->mask) {
+		free(img->mask[0]);
+		free(img->mask);
+	}
+
 	if (img->f) {
 		fclose(img->f);
 	}