1 files changed, 29 insertions, 0 deletions

diff --git a/src/blender/blender.c b/src/blender/blender.c
index 0e0835d..738811d 100644
--- a/src/blender/blender.c
+++ b/src/blender/blender.c
@@ -1,6 +1,7 @@
 #include "blender/blender.h"
 #include <assert.h>
 #include <math.h>
+#include "morpher/morpher.h"
 
 static ColorComponent blend_components(ColorComponent origin, ColorComponent target, TimeVector frame) {
   return (ColorComponent) sqrt((TIME_UNIT - frame) * pow(origin, 2) + frame * pow(target, 2));
@@ -13,3 +14,31 @@ Color blender_blend_colors(Color origin, Color target, TimeVector frame) {
                    blend_components(origin.rgba.b, target.rgba.b, frame),
                    blend_components(origin.rgba.a, target.rgba.a, frame)}};
 }
+
+void blender_blend_canvas(Canvas *canvas, Canvas *source, Canvas *target, Morphing *morphing, TimeVector frame) {
+  IntVector flat_dim;
+  CartesianVector dim, point;
+  CartesianMapping mapping;
+  Color pixel;
+
+  dim = morpher_get_dim(morphing);
+
+  assert(dim.x > 0 && dim.y > 0);
+  assert(vector_equals(dim, canvas_get_dim(canvas)));
+  assert(vector_equals(dim, canvas_get_dim(source)));
+  assert(vector_equals(dim, canvas_get_dim(target)));
+  assert(frame >= TIME_ORIGIN && frame <= TIME_UNIT);
+
+  for (flat_dim = (dim.x - 1) * (dim.y - 1); flat_dim >= 0; --flat_dim) {
+    point.x = flat_dim % dim.y;
+    point.y = flat_dim / dim.y;
+
+    mapping = morpher_get_point_mapping(morphing, point, frame);
+
+    pixel = blender_blend_colors(canvas_get_pixel(source, mapping.origin),
+                                 canvas_get_pixel(target, mapping.target),
+                                 frame);
+
+    canvas_set_pixel(canvas, point, pixel);
+  }
+}