gif

commit 92359cc1eb4bcbce821caac0f8f2a29521ef4f28
parent 01e7426b2ea2db4f63047eae652db4239a7b8d93
Author: phoebos <ben@bvnf.space>
Date:   Wed,  1 Sep 2021 17:32:30 +0100

squelch some unused variable warnings, framework for image decoding

Diffstat:
M
gif.c
 | 
28
++++++++++++++++++++++++++--

1 file changed, 26 insertions(+), 2 deletions(-)
diff --git a/gif.c b/gif.c
@@ -33,6 +33,11 @@ struct Gif {
     int colortable_len; /* 2 - 256 */
     unsigned char *pixels; /* array of indices to colors */
 };
+struct Image {
+    int colortable_len; /* 2 - 256 */
+    /*  TODO: local color table */
+    unsigned char *pixels;
+};
 
 void
 print_colortable(struct Gif *g){
@@ -42,11 +47,20 @@ print_colortable(struct Gif *g){
 }
 
 int
+gif_decode_image(struct Image *img, unsigned char *buf){
+    (void) img;
+    (void) buf;
+    return 0;
+}
+
+int
 gif_decode(unsigned char *buf, size_t len){
     struct Gif g = {0 };
+    struct Image *img;
     int cur_block;
     enum { HEAD = 1, SPEC = 2, IMGE = 4 };
     cur_block = HEAD;
+    (void)cur_block;
 
     if (strncmp((char *)buf, "GIF", 3)) return FAIL_GIF;
     buf += 3;
@@ -77,20 +91,30 @@ gif_decode(unsigned char *buf, size_t len){
 
     print_colortable(&g);
 
+    /* END OF HEADER */
+
     while (--len) {
         ++buf;
         switch (*buf) {
             case '!':
-                cur_block = SPEC;
+                if (cur_block != SPEC) {
+                    cur_block = SPEC;
+                }
                 break;
             case ',':
-                cur_block = IMGE;
+                if (cur_block != IMGE) {
+                    cur_block = IMGE;
+                    img = malloc(sizeof(struct Image));
+                    img->colortable_len = g.colortable_len;
+                    gif_decode_image(img, buf);
+                }
                 break;
             case ';':
                 /* last char of image section */
                 return 0;
         }
     }
+    free(img);
 
     return 0;
 }