X-Git-Url: https://git.draconx.ca/gitweb/liblbx.git/blobdiff_plain/76e363aa42e94748b34370e7f01aa587e555722c..f5c3db7a3cc9d46f8bb8b2d0d010eb73d68bb9c5:/src/image.c

diff --git a/src/image.c b/src/image.c
index f32a660..fda9dfc 100644
--- a/src/image.c
+++ b/src/image.c
@@ -1,3 +1,21 @@
+/* 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 2 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, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
 #ifdef HAVE_CONFIG_H
 #	include "config.h"
 #endif
@@ -22,9 +40,10 @@ struct lbx_image {
 	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;
@@ -53,12 +72,6 @@ struct lbx_image *lbximg_fopen(FILE *f)
 	tmp.leadin = letohs(tmp.leadin); tmp.foff += sizeof tmp.leadin;
 	tmp.flags  = letohs(tmp.flags);  tmp.foff += sizeof tmp.flags;
 
-	/* Format constraints. */
-	if (tmp.frames <= tmp.leadin) {
-		lbx_errno = LBX_EFORMAT;
-		return NULL;
-	}
-
 	/*
 	 * DEBUG ONLY.  These assertions exist to catch otherwise valid image
 	 * files which differ from what I believe to be true of all LBX images.
@@ -66,6 +79,7 @@ struct lbx_image *lbximg_fopen(FILE *f)
 	 * 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);
@@ -82,6 +96,24 @@ struct lbx_image *lbximg_fopen(FILE *f)
 		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)) {
@@ -290,38 +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])
 {
-	size_t hdrlen = 6*(sizeof img->wtf1)+(img->frames+1)*(sizeof *img->offsets);
 	unsigned int i;
 	size_t rc;
 
-	uint16_t start, count;
 	uint8_t  entry[4];
 
 	/* Do nothing if the image doesn't have embedded palette data. */
 	if (!(img->flags & FLAG_PALETTE))
 		return 0;
 
-	/* Palette data is located right after the header. */
-	if (_lbx_fseek(img->f, &img->foff, hdrlen) == -1)
+	if (_lbx_fseek(img->f, &img->foff, img->paloff) == -1)
 		return -1;
 	
-	/* Palette header */
-	if (fread(&start, sizeof start, 1, img->f) != 1) goto readerr;
-	if (fread(&count, sizeof count, 1, img->f) != 1) goto readerr;
-	start = letohs(start); img->foff += sizeof start;
-	count = letohs(count); img->foff += sizeof count;
-
-	if (start + count > 256) {
-		lbx_errno = LBX_EFORMAT;
-		return -1;
-	}
-
-	if (hdrlen + 2*sizeof start + count*sizeof entry > img->offsets[0]) {
-		lbx_errno = LBX_EFORMAT;
-		return -1;
-	}
-
-	for (i = 0; i < count; i++) {
+	for (i = 0; i < img->palcount; i++) {
 		rc = fread(entry, 1, sizeof entry, img->f);
 		img->foff += rc;
 
@@ -334,7 +347,7 @@ lbximg_getpalette(struct lbx_image *img, struct lbx_colour palette[static 256])
 			return -1;
 		}
 
-		palette[start + i] = (struct lbx_colour){
+		palette[img->palstart + i] = (struct lbx_colour){
 			.red   = entry[1] << 2,
 			.green = entry[2] << 2,
 			.blue  = entry[3] << 2,
@@ -353,7 +366,7 @@ void lbximg_getinfo(struct lbx_image *img, struct lbx_imginfo *info)
 		.width      = img->width,
 		.height     = img->height,
 		.nframes    = img->frames,
-		.haspalette = (_Bool)(img->flags & FLAG_PALETTE),
+		.palettesz  = (img->flags & FLAG_PALETTE) ? img->palcount : 0,
 	};
 
 	/* There seems to be two ways of specifying that an image loops. */