X-Git-Url: https://git.draconx.ca/gitweb/liblbx.git/blobdiff_plain/5057c6695cbe55f5d13e8e10a1e630c7ee00ea12..ba19b133bf87936dc606dd994f56f433a278b768:/src/image.c

diff --git a/src/image.c b/src/image.c
index f68f2da..e0ee129 100644
--- a/src/image.c
+++ b/src/image.c
@@ -1,7 +1,7 @@
 /*
  * 2ooM: The Master of Orion II Reverse Engineering Project
  * Library for working with LBX image files.
- * Copyright © 2006-2011, 2013 Nick Bowler
+ * Copyright © 2006-2011, 2013-2014 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
@@ -43,7 +43,7 @@ struct lbx_image_priv {
 	struct lbx_image pub;
 
 	unsigned short wtf, flags;
-	unsigned char  wtf2, leadin;
+	unsigned char  wtf2;
 	unsigned short palstart, palcount;
 
 	const struct lbx_file_ops *fops;
@@ -77,13 +77,19 @@ static struct lbx_image_priv *lbx_img_init(unsigned char hdr[static HDR_LEN])
 		.wtf        = unpack_16_le(hdr+4),
 		.pub.frames = hdr[6],
 		.wtf2       = hdr[7],
-		.leadin     = hdr[8],
+		.pub.leadin = hdr[8],
 		.pub.chunk  = hdr[9],
 		.flags      = unpack_16_le(hdr+10),
 
 		.currentframe = -1,
 	};
 
+	if (img->flags & FLAG_OVERWRITE)
+		img->pub.chunk = 1;
+
+	if (img->flags & FLAG_LOOPING)
+		img->pub.leadin = 0;
+
 	return img;
 }
 
@@ -115,7 +121,7 @@ struct lbx_image *lbx_img_open(void *f, const struct lbx_file_ops *fops,
 	 */
 	_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->pub.frames > img->pub.leadin);
 	_lbx_assert(!(img->flags & ~FLAG_ALL));
 
 	/* Read all offsets.  Should be merged with identical code in lbx.c */
@@ -196,9 +202,9 @@ struct lbx_image *lbx_img_fopen(const char *file)
 	return lbx_img_open(p, &lbx_pipe_fops, pipe_close);
 }
 
-static int _lbx_drawrow(int first, struct lbx_image_priv *img)
+static int _lbx_drawrow(struct lbx_image_priv *img)
 {
-	unsigned short type, count, yval, xval;
+	unsigned short length, offset;
 	unsigned char buf[4];
 	unsigned char *pos;
 	size_t rc;
@@ -208,63 +214,47 @@ static int _lbx_drawrow(int first, struct lbx_image_priv *img)
 
 	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;
+	length = unpack_16_le(buf+0);
+	offset = unpack_16_le(buf+2);
+	if (length == 0 && offset == 1000)
+		return 1;
 
-		/* Ensure that the row fits in the image. */
-		if (img->pub.height - img->currenty <= yval
-		    || xval >= img->pub.width) {
+	/* Length of 0 increments Y position */
+	if (!length) {
+		if (offset > img->pub.height - img->currenty) {
 			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;
+		img->currenty += offset;
+		img->currentx  = 0;
+		return 0;
+	}
 
-		count = type;
+	/* Otherwise we read pixel data */
+	if (offset > img->pub.width - img->currentx) {
+		lbx_error_raise(LBX_EFORMAT);
+		return -1;
 	}
+	img->currentx += offset;
 
-	if (count > img->pub.width - img->currentx) {
+	if (length > img->pub.width - img->currentx) {
 		lbx_error_raise(LBX_EFORMAT);
 		return -1;
 	}
 
-	memset(&img->mask[img->currenty][img->currentx], 1, count);
+	memset(&img->mask[img->currenty][img->currentx], 1, length);
 
 	pos = &img->framedata[img->currenty][img->currentx];
-	rc  = img->fops->read(pos, count, img->f);
+	rc  = img->fops->read(pos, length, img->f);
 	img->currentx += rc;
 
-	if (rc < count)
+	if (rc < length)
 		goto readerr;
 
-	if (count % 2) {
+	/* Skip padding byte, if any */
+	if (length % 2) {
 		if (img->fops->read(buf, 1, img->f) != 1)
 			goto readerr;
 	}
@@ -338,6 +328,7 @@ static unsigned char **read_raw_frame(struct lbx_image_priv *img, int frame)
 unsigned char **lbx_img_getframe(struct lbx_image *pub, int frame)
 {
 	struct lbx_image_priv *img = (struct lbx_image_priv *)pub;
+	unsigned char buf[4];
 
 	if (frame >= pub->frames || frame < 0) {
 		lbx_error_raise(LBX_ENOENT);
@@ -380,17 +371,35 @@ unsigned char **lbx_img_getframe(struct lbx_image *pub, int frame)
 	}
 
 	if (img->currentframe != frame) {
-		int rc, first = 1;
+		int rc;
 
 		if (img->fops->seek(img->f, img->offsets[frame], SEEK_SET)) {
 			return NULL;
 		}
 
+		/* Read frame header */
+		if (img->fops->read(buf, 4, img->f) != 4) {
+			if (img->fops->eof(img->f))
+				lbx_error_raise(LBX_EEOF);
+			return NULL;
+		}
+
+		if (unpack_16_le(buf) != 1) {
+			lbx_error_raise(LBX_EFORMAT);
+			return NULL;
+		}
+
+		img->currentx = 0;
+		img->currenty = unpack_16_le(buf+2);
+		if (img->currenty > img->pub.height) {
+			lbx_error_raise(LBX_EFORMAT);
+			return NULL;
+		}
+
 		do {
-			rc = _lbx_drawrow(first, img);
+			rc = _lbx_drawrow(img);
 			if (rc == -1)
 				return NULL;
-			first = 0;
 
 			if (img->fops->tell(img->f) > img->offsets[frame+1]) {
 				lbx_error_raise(LBX_EFORMAT);
@@ -487,8 +496,8 @@ void lbx_img_getinfo(struct lbx_image *pub, struct lbx_imginfo *info)
 	if (img->flags & FLAG_LOOPING) {
 		info->loopstart = 0;
 		info->looping   = 1;
-	} else if (img->leadin != pub->frames - 1) {
-		info->loopstart = img->leadin;
+	} else if (img->pub.leadin != pub->frames - 1) {
+		info->loopstart = img->pub.leadin;
 		info->looping   = 1;
 	}
 }