From: Nick Bowler <draconx@gmail.com>
Date: Sun, 30 Dec 2007 09:02:59 +0000 (-0500)
Subject: Implement functions for loading palettes, and slightly improve the image reader.
X-Git-Url: https://git.draconx.ca/gitweb/liblbx.git/commitdiff_plain/4a84fce79ab5326aae7aa9f99ccb38b5063b714a

Implement functions for loading palettes, and slightly improve the image reader.
---

diff --git a/src/image.c b/src/image.c
index a5b8b05..9b9b1dd 100644
--- a/src/image.c
+++ b/src/image.c
@@ -119,14 +119,17 @@ static int _lbx_drawrow(int first, struct lbx_image *img)
 		img->currenty += yval;
 		img->currentx  = xval;
 	} else {
-		count = 0;
-/*
+		if (fread(&yval,  sizeof yval,  1, img->f) != 1) goto readerr;
+		yval = letohs(yval); img->foff += sizeof yval;
+
+		/* FIXME Still have to figure out what to do here. */
+
 		count = type;
+
 		if (count > img->width - img->currentx) {
 			lbx_errno = LBX_EFORMAT;
 			return -1;
 		}
-*/
 	}
 
 	pos = &img->framedata[img->currenty][img->currentx];
@@ -215,6 +218,76 @@ unsigned char **lbximg_getframe(struct lbx_image *img, int frame)
 	return img->framedata;
 }
 
+int lbximg_loadpalette(FILE *f, struct lbx_colour palette[static 256])
+{
+	uint8_t 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;
+			return -1;
+		}
+
+		if (entry[0] != 1) {
+			lbx_errno = LBX_EFORMAT;
+			return -1;
+		}
+
+		palette[i] = (struct lbx_colour){
+			.red   = entry[1] << 2,
+			.green = entry[2] << 2,
+			.blue  = entry[3] << 2,
+		};
+	}
+
+	return 0;
+}
+
+int
+lbximg_getpalette(struct lbx_image *img, struct lbx_colour palette[static 256])
+{
+	int index = 0;
+	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)
+		return -1;
+	
+	while (img->foff + sizeof entry <= img->offsets[0]) {
+		rc = fread(entry, 1, sizeof entry, img->f);
+		img->foff += rc;
+
+		if (rc < sizeof entry) {
+			goto readerr;
+		}
+
+		if (entry[0] == 0) {
+			index++;
+		} else {
+			index = entry[0];
+		}
+
+		palette[index] = (struct lbx_colour){
+			.red   = entry[1] << 2,
+			.green = entry[2] << 2,
+			.blue  = entry[3] << 2,
+		};
+	}
+
+	return 0;
+readerr:
+	if (feof(img->f))
+		lbx_errno = LBX_EEOF;
+	else
+		lbx_errno = -errno;
+	return -1;
+}
+
 void lbximg_close(struct lbx_image *img)
 {
 	if (!img) return;
diff --git a/src/image.h b/src/image.h
index e9de2bd..83f03de 100644
--- a/src/image.h
+++ b/src/image.h
@@ -5,8 +5,17 @@
 
 typedef struct lbx_image LBXIMG;
 
+struct lbx_colour {
+	unsigned char red;
+	unsigned char green;
+	unsigned char blue;
+};
+
 LBXIMG *lbximg_fopen(FILE *f);
 void    lbximg_close(LBXIMG *img);
 unsigned char **lbximg_getframe(LBXIMG *img, int frame);
 
+int lbximg_loadpalette(FILE *f, struct lbx_colour palette[static 256]);
+int lbximg_getpalette(LBXIMG *img, struct lbx_colour palette[static 256]);
+
 #endif