2 files changed, 7 insertions, 2 deletions
diff --git a/js/util.js b/js/util.js
index 3a03f55..fb15fb5 100644
--- a/js/util.js
+++ b/js/util.js
@@ -40,7 +40,7 @@ function randint(n){ return rand(n)|0 }
 function choice(a){ return a[randint(a.length)] }
 function deg(n){ return n*180/PI }
 function rad(n){ return n*PI/180 }
-function pixel(x,y){ return 4*(y*w+x) }
+function pixel(x,y){ return 4*(mod(y,h)*w+mod(x,w)) }
 function rgbpixel(d,x,y){
   var p = pixel(x,y)
   r = d[p]
diff --git a/shader-gif.html b/shader-gif.html
index 9f7e398..59d2add 100644
--- a/shader-gif.html
+++ b/shader-gif.html
@@ -189,7 +189,12 @@ function draw(t) {
 var frame, img_frame;
 function giveFrame(t){
   if (window.gif) {
-    return gif.frames[gif.currentFrame(t)]
+    if (gif.currentFrame) {
+      return gif.frames[gif.currentFrame(t)]
+    }
+    else {
+      return gif.frames[0]
+    }
   }
   else if (window.img) {
     return img_frame