X-Git-Url: http://git.draconx.ca/gitweb/liblbx.git/blobdiff_plain/ba19b133bf87936dc606dd994f56f433a278b768..a52b40384eb58fc2d7c06c7d46d1c401cde19443:/src/image.c

diff --git a/src/image.c b/src/image.c
index e0ee129..bd207e7 100644
--- a/src/image.c
+++ b/src/image.c
@@ -20,6 +20,7 @@
 #include <stdlib.h>
 #include <string.h>
 #include <assert.h>
+#include <stdbool.h>
 #include <inttypes.h>
 #include <errno.h>
 
@@ -39,23 +40,27 @@
 
 #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;
-
-	int currentframe;
-	int currentx, currenty;
-	unsigned char **framedata;
-	unsigned char **mask;
+	/* State of frame readout */
+	unsigned currentx, currenty, currentn;
+	int read_state;
 
 	unsigned long offsets[];
 };
@@ -80,8 +85,6 @@ static struct lbx_image_priv *lbx_img_init(unsigned char hdr[static HDR_LEN])
 		.pub.leadin = hdr[8],
 		.pub.chunk  = hdr[9],
 		.flags      = unpack_16_le(hdr+10),
-
-		.currentframe = -1,
 	};
 
 	if (img->flags & FLAG_OVERWRITE)
@@ -90,6 +93,12 @@ static struct lbx_image_priv *lbx_img_init(unsigned char hdr[static HDR_LEN])
 	if (img->flags & FLAG_LOOPING)
 		img->pub.leadin = 0;
 
+	if (img->pub.leadin >= img->pub.frames) {
+		lbx_error_raise(LBX_EFORMAT);
+		free(img);
+		return NULL;
+	}
+
 	return img;
 }
 
@@ -121,7 +130,6 @@ 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->pub.leadin);
 	_lbx_assert(!(img->flags & ~FLAG_ALL));
 
 	/* Read all offsets.  Should be merged with identical code in lbx.c */
@@ -138,27 +146,6 @@ struct lbx_image *lbx_img_open(void *f, const struct lbx_file_ops *fops,
 		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;
 }
 
@@ -202,239 +189,170 @@ struct lbx_image *lbx_img_fopen(const char *file)
 	return lbx_img_open(p, &lbx_pipe_fops, pipe_close);
 }
 
-static int _lbx_drawrow(struct lbx_image_priv *img)
+int lbx_img_seek(struct lbx_image *pub, unsigned frame)
 {
-	unsigned short length, offset;
-	unsigned char buf[4];
-	unsigned char *pos;
-	size_t rc;
-
-	assert(img->framedata);
-	assert(img->mask);
-
-	if (img->fops->read(buf, sizeof buf, img->f) != sizeof buf)
-		goto readerr;
-
-	length = unpack_16_le(buf+0);
-	offset = unpack_16_le(buf+2);
-	if (length == 0 && offset == 1000)
-		return 1;
-
-	/* Length of 0 increments Y position */
-	if (!length) {
-		if (offset > img->pub.height - img->currenty) {
-			lbx_error_raise(LBX_EFORMAT);
-			return -1;
-		}
-
-		img->currenty += offset;
-		img->currentx  = 0;
-		return 0;
-	}
+	struct lbx_image_priv *img = (struct lbx_image_priv *)pub;
 
-	/* Otherwise we read pixel data */
-	if (offset > img->pub.width - img->currentx) {
-		lbx_error_raise(LBX_EFORMAT);
+	if (frame >= pub->frames) {
+		lbx_error_raise(LBX_EINVAL);
 		return -1;
 	}
-	img->currentx += offset;
 
-	if (length > img->pub.width - img->currentx) {
-		lbx_error_raise(LBX_EFORMAT);
+	if (img->fops->seek(img->f, img->offsets[frame], SEEK_SET)) {
 		return -1;
 	}
 
-	memset(&img->mask[img->currenty][img->currentx], 1, length);
+	if (!(img->flags & FLAG_RAW)) {
+		unsigned char buf[4];
 
-	pos = &img->framedata[img->currenty][img->currentx];
-	rc  = img->fops->read(pos, length, img->f);
-	img->currentx += rc;
+		/* 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;
+		}
 
-	if (rc < length)
-		goto readerr;
+		if (unpack_16_le(buf) != 1) {
+			lbx_error_raise(LBX_EFORMAT);
+			return -1;
+		}
 
-	/* Skip padding byte, if any */
-	if (length % 2) {
-		if (img->fops->read(buf, 1, img->f) != 1)
-			goto readerr;
+		img->currentx = 0;
+		img->currenty = unpack_16_le(buf+2);
+		if (img->currenty > img->pub.height) {
+			lbx_error_raise(LBX_EFORMAT);
+			return -1;
+		}
 	}
 
+	img->read_state = READ_STATE_HEADER;
 	return 0;
-readerr:
-	if (img->fops->eof(img->f))
-		lbx_error_raise(LBX_EEOF);
-	return -1;
 }
 
-static unsigned char **allocframebuffer(size_t width, size_t height)
+long lbx_img_read_row_header(struct lbx_image *pub, unsigned *x, unsigned *y)
 {
-	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;
-	}
+	struct lbx_image_priv *img = (struct lbx_image_priv *)pub;
+	unsigned short length, offset;
+	unsigned char buf[4];
 
-	new = malloc(height * sizeof *new);
-	if (!new) {
-		lbx_error_raise(LBX_ENOMEM);
-		free(tmp);
-		return NULL;
+	if (img->read_state != READ_STATE_HEADER) {
+		lbx_error_raise(LBX_EINVAL);
+		return -1;
 	}
 
-	for (i = 0; i < height; i++) {
-		new[i] = tmp + i * width;
+	/* 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;
+		}
 	}
 
-	return new;
-}
+	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;
+		}
 
-static unsigned char **read_raw_frame(struct lbx_image_priv *img, int frame)
-{
-	unsigned long size = img->pub.width * img->pub.height;
+		length = unpack_16_le(buf+0);
+		offset = unpack_16_le(buf+2);
 
-	assert(img->flags & FLAG_RAW);
+		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;
+			}
 
-	if (img->fops->seek(img->f, img->offsets[frame], SEEK_SET)) {
-		return NULL;
-	}
+			img->currenty += offset;
+			img->currentx  = 0;
+		}
+	} while (length == 0);
 
-	if (img->fops->read(img->framedata[0], size, img->f) != size) {
-		if (img->fops->eof(img->f))
-			lbx_error_raise(LBX_EEOF);
-		return NULL;
+	if (offset > img->pub.width - img->currentx) {
+		lbx_error_raise(LBX_EFORMAT);
+		return -1;
 	}
-	memset(img->mask[0], 1, size);
+	img->currentx += offset;
 
-	if (img->fops->tell(img->f) > img->offsets[frame+1]) {
+	if (length > img->pub.width - img->currentx) {
 		lbx_error_raise(LBX_EFORMAT);
-		return NULL;
+		return -1;
 	}
+	img->currentn = length;
+
+	img->read_state = READ_STATE_DATA;
+	*x = img->currentx;
+	*y = img->currenty;
 
-	return img->framedata;
+	return img->currentn;
 }
 
-unsigned char **lbx_img_getframe(struct lbx_image *pub, int frame)
+long lbx_img_read_row_data(struct lbx_image *pub, void *buf)
 {
 	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);
-		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->read_state != READ_STATE_DATA) {
+		lbx_error_raise(LBX_EINVAL);
+		return -1;
 	}
 
-	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->fops->read(buf, img->currentn, img->f) != img->currentn) {
+		if (img->fops->eof(img->f))
+			lbx_error_raise(LBX_EEOF);
+		return -1;
 	}
 
-	if (img->currentframe != frame) {
-		int rc;
+	if (!(img->flags & FLAG_RAW) && img->currentn % 2) {
+		unsigned char c;
 
-		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) {
+		/* Skip padding byte */
+		if (img->fops->read(&c, 1, img->f) != 1) {
 			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;
+			return -1;
 		}
-
-		do {
-			rc = _lbx_drawrow(img);
-			if (rc == -1)
-				return NULL;
-
-			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;
+	img->read_state = READ_STATE_HEADER;
+	img->currentx += img->currentn;
+
+	return img->currentn;
 }
 
-int
-lbx_img_loadpalette(void *f, const struct lbx_file_ops *fops,
-                    struct lbx_colour palette[static 256])
+static int read_palette(void *f, const struct lbx_file_ops *fops,
+                        struct lbx_colour *palette, unsigned count,
+			bool external)
 {
-	unsigned char entry[4];
-	int i;
+	assert(count <= 256);
+	for (unsigned i = 0; i < count; i++) {
+		unsigned char buf[4];
 
-	for (i = 0; i < 256; i++) {
-		if (fops->read(entry, sizeof entry, f) != sizeof entry) {
+		if (fops->read(buf, 4, f) != 4) {
 			if (fops->eof(f))
 				lbx_error_raise(LBX_EEOF);
 			return -1;
 		}
 
-		if (entry[0] != 1) {
+		if (buf[0] != external) {
 			lbx_error_raise(LBX_EFORMAT);
 			return -1;
 		}
 
 		palette[i] = (struct lbx_colour) {
-			.red    = entry[1] & 0x3f,
-			.green  = entry[2] & 0x3f,
-			.blue   = entry[3] & 0x3f,
+			.red    = buf[1] & 0x3f,
+			.green  = buf[2] & 0x3f,
+			.blue   = buf[3] & 0x3f,
 			.active = 1,
 		};
 	}
@@ -442,95 +360,63 @@ lbx_img_loadpalette(void *f, const struct lbx_file_ops *fops,
 	return 0;
 }
 
-int
-lbx_img_getpalette(struct lbx_image *pub, struct lbx_colour palette[static 256])
+int lbx_img_loadpalette(void *f, const struct lbx_file_ops *fops,
+                        struct lbx_colour *palette)
+{
+	return read_palette(f, fops, palette, 256, true);
+}
+
+int lbx_img_getpalette(struct lbx_image *pub, struct lbx_colour *out)
 {
 	struct lbx_image_priv *img = (struct lbx_image_priv *)pub;
-	unsigned char entry[4];
-	unsigned int i;
-	size_t rc;
+	unsigned long palette_start, palette_count, palette_offset;
+	unsigned char buf[4];
+	int 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)) {
+	palette_offset = 16 + 4ul * img->pub.frames;
+	if (img->fops->seek(img->f, palette_offset, 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;
-		}
+	/* Read embedded palette header */
+	if (img->fops->read(buf, 4, img->f) < 4)
+		goto readerr;
 
-		if (entry[0] != 0) {
-			lbx_error_raise(LBX_EFORMAT);
-			return -1;
-		}
+	palette_start = unpack_16_le(buf+0);
+	palette_count = unpack_16_le(buf+2);
+	if (palette_start + palette_count > 256) {
+		lbx_error_raise(LBX_EFORMAT);
+		return -1;
+	}
 
-		palette[img->palstart + i] = (struct lbx_colour){
-			.red    = entry[1],
-			.green  = entry[2],
-			.blue   = entry[3],
-			.active = 1,
-		};
+	if (out) {
+		rc = read_palette(img->f, img->fops,
+		                  out+palette_start, palette_count,
+		                  false);
+		if (rc < 0)
+			return -1;
 	}
 
-	return 0;
+	return palette_count;
 readerr:
 	if (img->fops->eof(img->f))
 		lbx_error_raise(LBX_EEOF);
 	return -1;
 }
 
-void lbx_img_getinfo(struct lbx_image *pub, struct lbx_imginfo *info)
-{
-	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);
-		}
-
-		free(img);
+	if (img && img->dtor) {
+		rc = img->dtor(img->f);
 	}
+	free(img);
 
 	return rc;
 }