gifs

.gitignore

@@ -1,2 +1,3 @@
 *.png
-*.so
+*.so
+*.gif

Makefile

@@ -1,2 +1,2 @@
 libguilecgif.so: guile-cgif.c
-	$(CC) `pkg-config --cflags cgif cairo guile-3.0` -shared -fPIC -o $@ $^ `pkg-config --libs cgif cairo guile-3.0`
+	$(CC) `pkg-config --cflags cgif guile-cairo` -g -shared -fPIC -o $@ $^ `pkg-config --libs cgif guile-cairo`

cgif.scm

@@ -1,4 +1,4 @@
 (define-module (cgif)
   :export (make-gif))
 
-(load-extension "./libguilecgif", "init_cgif")
+(load-extension "./libguilecgif" "init_cgif")

graphgif.scm

@@ -1,6 +1,7 @@
 (define-module (graphgif))
 
-(use-modules (cairo))
+(use-modules (cairo)
+	     (cgif))
 
 (re-export (cairo-pattern-create-rgb . create-color))
 
@@ -44,7 +45,7 @@
       (cairo-stroke cr))))
 
 (define-public (draw-abstract-graph graph)
-  (let* ([surface (cairo-image-surface-create 'argb32 400 400)]
+  (let* ([surface (cairo-image-surface-create 'rgb24 400 400)]
 	 [cr (cairo-create surface)])
     (define paint-edges (edge-painter cr graph))
     (define paint-nodes (node-painter cr))
@@ -59,7 +60,7 @@
 
 (define-public (write-graph-to-file graph filename)
   (define my-surface (draw-abstract-graph graph))
-  (cairo-surface-write-to-png my-surface filename)
+  (make-gif `(,my-surface) filename)
   (cairo-surface-destroy my-surface))
 
 

guile-cgif.c

@@ -1,7 +1,7 @@
 #include <stdlib.h>
-#include <libguile.h>
+#include <guile-cairo.h>
 #include <cgif.h>
-#include <cairo.h>
+#include <string.h>
 
 const uint8_t PALETTE[] = {
   0xFF, 0xFF, 0xFF, // WHITE
@@ -9,8 +9,8 @@ const uint8_t PALETTE[] = {
   0xFF, 0x00, 0x00  // RED
 };
 
-#define CAIRO_RED 0x00FF0000
-#define CAIRO_BLACK 0x00FFFFFF
+#define CAIRO_RED   0x00FF0000
+#define CAIRO_BLACK 0x00000000
 
 void encode_frame(cairo_surface_t *surface, CGIF_FrameConfig *frameconfig) {
   // TODO pull colors from cairo
@@ -20,10 +20,10 @@ void encode_frame(cairo_surface_t *surface, CGIF_FrameConfig *frameconfig) {
   frameconfig->pImageData = (uint8_t*)calloc(size, sizeof(uint8_t));
 
   if (cairo_image_surface_get_format(surface) == CAIRO_FORMAT_RGB24) {
-    unsigned char* pen = cairo_image_surface_get_data(surface);
+    uint32_t* pen = (uint32_t*) cairo_image_surface_get_data(surface);
     for (size_t i = 0; i < size; i++) {
-      uint32_t cairo_color = (uint32_t)(*(pen + i * sizeof(uint32_t) * cairo_image_surface_get_stride(surface)));
-      switch (cairo_color) {
+      uint32_t cairo_color = pen[i];
+      switch (cairo_color & 0x00FFFFFF) {
       case CAIRO_BLACK:
 	frameconfig->pImageData[i] = 1;
 	break;
@@ -37,6 +37,7 @@ void encode_frame(cairo_surface_t *surface, CGIF_FrameConfig *frameconfig) {
 
 void make_gif_inner(cairo_surface_t *frames[], size_t n_frames, const char* path) {
   CGIF_Config cgif_config;
+  memset(&cgif_config, 0, sizeof(CGIF_Config));
   cgif_config.path = path;
   cgif_config.attrFlags = CGIF_ATTR_IS_ANIMATED | CGIF_ATTR_NO_GLOBAL_TABLE;
   cgif_config.width = cairo_image_surface_get_width(frames[0]);
@@ -50,6 +51,7 @@ void make_gif_inner(cairo_surface_t *frames[], size_t n_frames, const char* path
     cairo_surface_flush(frame);
 
     CGIF_FrameConfig cgif_frameconfig;
+    memset(&cgif_frameconfig, 0, sizeof(CGIF_FrameConfig));
     cgif_frameconfig.attrFlags = CGIF_FRAME_ATTR_USE_LOCAL_TABLE;
     cgif_frameconfig.delay = 100;
 
@@ -60,16 +62,16 @@ void make_gif_inner(cairo_surface_t *frames[], size_t n_frames, const char* path
   cgif_close(cgif);
 }
 
-void make_gif(SCM frames, SCM path) {
-  size_t c_length = scm_c_array_length(frames);
-  scm_t_array_handle c_array;
-  scm_array_get_handle(frames, &c_array);
-  cairo_surface_t **c_frames = scm_array_handle_uniform_elements(&c_array);
+SCM make_gif(SCM frames, SCM path) {
+  size_t n_frames = scm_to_size_t(scm_length(frames));
+  cairo_surface_t **c_frames = (cairo_surface_t **) malloc(sizeof(cairo_surface_t*) * n_frames);
+  for (size_t i = 0; i < n_frames; i++) {
+    c_frames[i] = scm_to_cairo_surface(scm_list_ref(frames, scm_from_size_t(i)));
+  }
   const char* c_path = scm_to_locale_string(path);
 
-  make_gif_inner(c_frames, c_length, c_path);
-
-  scm_array_handle_release(&c_array);
+  make_gif_inner(c_frames, n_frames, c_path);
+  return SCM_UNSPECIFIED;
 }
 
 void init_cgif() {