X-Git-Url: http://git.draconx.ca/gitweb/liblbx.git/blobdiff_plain/4a84fce79ab5326aae7aa9f99ccb38b5063b714a..430be3ec2f86aec28fa21558b3141a2e28efd848:/src/image.c

diff --git a/src/image.c b/src/image.c
index 9b9b1dd..0caca96 100644
--- a/src/image.c
+++ b/src/image.c
@@ -1,214 +1,499 @@
-#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, 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
+ * 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 <inttypes.h>
 #include <errno.h>
 
-#include "byteorder.h"
+#include "pack.h"
 #include "misc.h"
 #include "lbx.h"
+#include "error.h"
 #include "image.h"
 
-struct lbx_image {
-	uint16_t width, height;
-	uint16_t wtf1, wtf2;
-	uint16_t offs, frames;
+#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). */
 
-	FILE *f;
-	long foff;
+#define FLAG_ALL (FLAG_RAW|FLAG_OVERWRITE|FLAG_BUILDING|FLAG_PALETTE|FLAG_LOOPING)
+
+#define HDR_LEN 12
+
+/* States for image readout */
+enum {
+	READ_STATE_INIT,
+	READ_STATE_HEADER,
+	READ_STATE_DATA,
+	READ_STATE_DONE,
+};
+
+struct lbx_image_priv {
+	struct lbx_image pub;
+
+	unsigned short wtf, flags;
+	unsigned char  wtf2;
+	unsigned short palstart, palcount;
+
+	const struct lbx_file_ops *fops;
+	int (*dtor)(void *handle);
+	void *f;
+
+	long paloff;
+
+	/* State of frame readout */
+	unsigned currentx, currenty, currentn;
+	int read_state;
 
 	int currentframe;
-	int currentx, currenty;
 	unsigned char **framedata;
+	unsigned char **mask;
 
-	uint32_t offsets[];
+	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.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;
+	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],
+		.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;
+}
+
+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->pub.leadin);
+	_lbx_assert(!(img->flags & ~FLAG_ALL));
+
+	/* 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;
+		}
 
-	new = malloc(sizeof *new + tmp.offs * sizeof *new->offsets);
-	if (!new) {
-		lbx_errno = -errno;
-		return NULL;
+		img->offsets[i] = unpack_32_le(buf);
 	}
 
-	*new = tmp;
-	new->currentframe = -1;
+	if (img->flags & FLAG_PALETTE) {
+		unsigned char buf[4];
 
-	if (fread(new->offsets, sizeof *new->offsets, new->offs, f)!= new->offs)
-		goto readerr;
-	new->foff += sizeof *new->offsets * new->offs;
+		if (fops->read(buf, sizeof buf, f) != sizeof buf) {
+			if (fops->eof(f))
+				lbx_error_raise(LBX_EEOF);
+			free(img);
+			return NULL;
+		}
 
-	return new;
-readerr:
-	if (feof(f)) {
-		lbx_errno = LBX_EEOF;
-	} else {
-		lbx_errno = -errno;
+		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;
+		}
 	}
 
-	free(new);
-	return NULL;
+	return &img->pub;
 }
 
-static int _lbx_drawrow(int first, struct lbx_image *img)
+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) {
+		lbx_error_raise(-errno);
+		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) {
+		lbx_error_raise(LBX_ENOMEM);
+		fclose(f);
+		return NULL;
+	}
+
+	*p = (struct lbx_pipe_state) { .f = f };
+	return lbx_img_open(p, &lbx_pipe_fops, pipe_close);
+}
+
+static int _lbx_drawrow(struct lbx_image_priv *img)
 {
-	uint16_t type, yval, count, xval;
 	unsigned char *pos;
-	unsigned char abyss;
-	size_t rc;
+	unsigned x, y;
+	long 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;
+	rc = lbx_img_read_row_header(&img->pub, &x, &y);
+	if (rc == 0)
+		return 1;
+	else if (rc < 0)
+		return -1;
 
-	if (first) {
-		img->currentx = 0;
-		img->currenty = 0;
-		type = 0;
+	pos = &img->framedata[y][x];
+	rc = lbx_img_read_row_data(&img->pub, pos);
+	if (rc < 0)
+		return -1;
+	memset(&img->mask[y][x], 1, rc);
+
+	return 0;
+}
+
+static unsigned char **allocframebuffer(size_t width, size_t height)
+{
+	unsigned char **new, *tmp;
+	size_t i;
+
+	if (height > SIZE_MAX / sizeof *new) {
+		lbx_error_raise(LBX_ENOMEM);
+		return NULL;
+	}
+
+	/* Ensure that there is at least one row in the framebuffer. */
+	if (height == 0 || width == 0)
+		width = height = 1;
+
+	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;
 	}
 
-	if (type == 0) {
-		if (fread(&yval,  sizeof yval,  1, img->f) != 1) goto readerr;
-		yval = letohs(yval); img->foff += sizeof yval;
+	return new;
+}
 
-		if (yval == 1000)
-			return 1;
+int lbx_img_seek(struct lbx_image *pub, unsigned frame)
+{
+	struct lbx_image_priv *img = (struct lbx_image_priv *)pub;
 
-		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 (frame >= pub->frames) {
+		lbx_error_raise(LBX_EINVAL);
+		return -1;
+	}
 
-		/* Ensure that the row fits in the image. */
-		if (img->height - img->currenty <= yval
-		    || xval >= img->width || count > img->width - xval) {
-			lbx_errno = LBX_EFORMAT;
+	if (img->fops->seek(img->f, img->offsets[frame], SEEK_SET)) {
+		return -1;
+	}
+
+	if (!(img->flags & FLAG_RAW)) {
+		unsigned char buf[4];
+
+		/* Read frame header */
+		if (img->fops->read(buf, 4, img->f) != 4) {
+			if (img->fops->eof(img->f))
+				lbx_error_raise(LBX_EEOF);
 			return -1;
 		}
 
-		img->currenty += yval;
-		img->currentx  = xval;
-	} else {
-		if (fread(&yval,  sizeof yval,  1, img->f) != 1) goto readerr;
-		yval = letohs(yval); img->foff += sizeof yval;
+		if (unpack_16_le(buf) != 1) {
+			lbx_error_raise(LBX_EFORMAT);
+			return -1;
+		}
+
+		img->currentx = 0;
+		img->currenty = unpack_16_le(buf+2);
+		if (img->currenty > img->pub.height) {
+			lbx_error_raise(LBX_EFORMAT);
+			return -1;
+		}
+	}
 
-		/* FIXME Still have to figure out what to do here. */
+	img->read_state = READ_STATE_HEADER;
+	return 0;
+}
 
-		count = type;
+long lbx_img_read_row_header(struct lbx_image *pub, unsigned *x, unsigned *y)
+{
+	struct lbx_image_priv *img = (struct lbx_image_priv *)pub;
+	unsigned short length, offset;
+	unsigned char buf[4];
 
-		if (count > img->width - img->currentx) {
-			lbx_errno = LBX_EFORMAT;
+	if (img->read_state != READ_STATE_HEADER) {
+		lbx_error_raise(LBX_EINVAL);
+		return -1;
+	}
+
+	/* Raw images have no row headers */
+	if (img->flags & FLAG_RAW) {
+		img->currentn = img->pub.width;
+		*y = img->currenty++;
+		*x = 0;
+
+		if (*y < img->pub.height) {
+			img->read_state = READ_STATE_DATA;
+			return img->currentn;
+		} else {
+			img->read_state = READ_STATE_DONE;
+			return 0;
+		}
+	}
+
+	do {
+		if (img->fops->read(buf, sizeof buf, img->f) != sizeof buf) {
+			if (img->fops->eof(img->f))
+				lbx_error_raise(LBX_EEOF);
 			return -1;
 		}
+
+		length = unpack_16_le(buf+0);
+		offset = unpack_16_le(buf+2);
+
+		if (length == 0) {
+			if (offset == 1000) {
+				img->read_state = READ_STATE_DONE;
+				return 0;
+			} else if (offset > img->pub.height - img->currenty) {
+				lbx_error_raise(LBX_EFORMAT);
+				return -1;
+			}
+
+			img->currenty += offset;
+			img->currentx  = 0;
+		}
+	} while (length == 0);
+
+	if (offset > img->pub.width - img->currentx) {
+		lbx_error_raise(LBX_EFORMAT);
+		return -1;
 	}
+	img->currentx += offset;
 
-	pos = &img->framedata[img->currenty][img->currentx];
-	rc  = fread(pos, 1, count, img->f);
-	img->currentx += rc;
-	img->foff     += rc;
+	if (length > img->pub.width - img->currentx) {
+		lbx_error_raise(LBX_EFORMAT);
+		return -1;
+	}
+	img->currentn = length;
 
-	if (rc < count)
-		goto readerr;
+	img->read_state = READ_STATE_DATA;
+	*x = img->currentx;
+	*y = img->currenty;
 
-	if (count % 2) {
-		if (fread(&abyss, 1, 1, img->f) != 1)
-			goto readerr;
-		img->foff += 1;
+	return img->currentn;
+}
+
+long lbx_img_read_row_data(struct lbx_image *pub, void *buf)
+{
+	struct lbx_image_priv *img = (struct lbx_image_priv *)pub;
+
+	if (img->read_state != READ_STATE_DATA) {
+		lbx_error_raise(LBX_EINVAL);
+		return -1;
 	}
 
-	return 0;
-readerr:
-	if (feof(img->f)) {
-		lbx_errno = LBX_EEOF;
-	} else {
-		lbx_errno = -errno;
+	if (img->fops->read(buf, img->currentn, img->f) != img->currentn) {
+		if (img->fops->eof(img->f))
+			lbx_error_raise(LBX_EEOF);
+		return -1;
 	}
-	return -1;
+
+	if (!(img->flags & FLAG_RAW)) {
+		/* Skip padding byte, if any */
+		if (img->currentn % 2) {
+			if (img->fops->seek(img->f, 1, SEEK_CUR))
+				return -1;
+		}
+	}
+
+	img->read_state = READ_STATE_HEADER;
+	img->currentx += img->currentn;
+
+	return img->currentn;
 }
 
-unsigned char **lbximg_getframe(struct lbx_image *img, int frame)
+static unsigned char **read_raw_frame(struct lbx_image_priv *img, int frame)
 {
-	if (frame >= img->frames || frame < 0) {
-		lbx_errno = LBX_ERANGE;
+	unsigned long size = img->pub.width * img->pub.height;
+	int rc;
+
+	assert(img->flags & FLAG_RAW);
+
+	rc = lbx_img_seek(&img->pub, frame);
+	if (rc < 0)
+		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->framedata) {
-		unsigned char *tmp;
-		int i;
+	if (img->fops->tell(img->f) > img->offsets[frame+1]) {
+		lbx_error_raise(LBX_EFORMAT);
+		return NULL;
+	}
 
-		tmp = malloc(img->width * img->height);
-		if (!tmp) {
-			lbx_errno = -errno;
-			return NULL;
-		}
+	return img->framedata;
+}
 
-		img->framedata = malloc(img->height * sizeof *img->framedata);
-		if (!img->framedata) {
-			lbx_errno = -errno;
-			free(tmp);
-			return NULL;
-		}
+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];
 
-		for (i = 0; i < img->height; i++) {
-			img->framedata[i] = tmp + i * img->width;
-		}
+	if (frame >= pub->frames || frame < 0) {
+		lbx_error_raise(LBX_EINVAL);
+		return NULL;
 	}
 
-	/* Start over if we are backtracking. */
-	if (img->currentframe > frame)
-		img->currentframe == -1;
+	if (!img->framedata) {
+		img->framedata = allocframebuffer(pub->width, pub->height);
+		if (!img->framedata)
+			return NULL;
+	}
 
-	/* We must have previous frame decoded to continue. */
-	if (frame > img->currentframe + 1) {
-		if (!lbximg_getframe(img, frame-1))
+	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 {
+		/* 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;
+		}
+	}
+
 	if (img->currentframe != frame) {
-		int rc, first = 1;
+		int rc;
 
-		if (_lbx_fseek(img->f, &img->foff, img->offsets[frame]) == -1)
+		rc = lbx_img_seek(pub, frame);
+		if (rc < 0)
 			return NULL;
 
 		do {
-			rc = _lbx_drawrow(first, img);
+			rc = _lbx_drawrow(img);
 			if (rc == -1)
 				return NULL;
-			first = 0;
 
-			if (img->foff > img->offsets[frame+1]) {
-				lbx_errno = LBX_EFORMAT;
+			if (img->fops->tell(img->f) > img->offsets[frame+1]) {
+				lbx_error_raise(LBX_EFORMAT);
 				return NULL;
 			}
 		} while (!rc);
@@ -218,26 +503,30 @@ unsigned char **lbximg_getframe(struct lbx_image *img, int frame)
 	return img->framedata;
 }
 
-int lbximg_loadpalette(FILE *f, struct lbx_colour palette[static 256])
+int
+lbx_img_loadpalette(void *f, const struct lbx_file_ops *fops,
+                    struct lbx_colour palette[static 256])
 {
-	uint8_t entry[4];
+	unsigned char entry[4];
 	int i;
 
 	for (i = 0; i < 256; i++) {
-		if (fread(entry, sizeof entry, 1, f) != 1) {
-			lbx_errno = (feof(f)) ? LBX_EEOF : -errno;
+		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_errno = LBX_EFORMAT;
+			lbx_error_raise(LBX_EFORMAT);
 			return -1;
 		}
 
-		palette[i] = (struct lbx_colour){
-			.red   = entry[1] << 2,
-			.green = entry[2] << 2,
-			.blue  = entry[3] << 2,
+		palette[i] = (struct lbx_colour) {
+			.red    = entry[1] & 0x3f,
+			.green  = entry[2] & 0x3f,
+			.blue   = entry[3] & 0x3f,
+			.active = 1,
 		};
 	}
 
@@ -245,61 +534,94 @@ int lbximg_loadpalette(FILE *f, struct lbx_colour palette[static 256])
 }
 
 int
-lbximg_getpalette(struct lbx_image *img, struct lbx_colour palette[static 256])
+lbx_img_getpalette(struct lbx_image *pub, struct lbx_colour palette[static 256])
 {
-	int index = 0;
+	struct lbx_image_priv *img = (struct lbx_image_priv *)pub;
+	unsigned char entry[4];
+	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)
+	/* 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;
-	
-	while (img->foff + sizeof entry <= img->offsets[0]) {
-		rc = fread(entry, 1, sizeof entry, img->f);
-		img->foff += rc;
+	}
 
+	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) {
-			index++;
-		} else {
-			index = entry[0];
+		if (entry[0] != 0) {
+			lbx_error_raise(LBX_EFORMAT);
+			return -1;
 		}
 
-		palette[index] = (struct lbx_colour){
-			.red   = entry[1] << 2,
-			.green = entry[2] << 2,
-			.blue  = entry[3] << 2,
+		palette[img->palstart + i] = (struct lbx_colour){
+			.red    = entry[1],
+			.green  = entry[2],
+			.blue   = entry[3],
+			.active = 1,
 		};
 	}
 
 	return 0;
 readerr:
-	if (feof(img->f))
-		lbx_errno = LBX_EEOF;
-	else
-		lbx_errno = -errno;
+	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;
-
-	if (img->framedata) {
-		free(img->framedata[0]);
-		free(img->framedata);
+	struct lbx_image_priv *img = (struct lbx_image_priv *)pub;
+
+	*info = (struct lbx_imginfo) {
+		.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->pub.leadin != pub->frames - 1) {
+		info->loopstart = img->pub.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;
 }