allow empty canvas w/ no url

1 files changed, 34 insertions, 6 deletions

diff --git a/js/render.js b/js/render.js
index a22c9fe..f6684d7 100644
--- a/js/render.js
+++ b/js/render.js
@@ -9,9 +9,10 @@ function choose (){
   $("#url").val(imageURL)
   loadImage(imageURL, ready)
 }
+
 function load(){
-  loading = true
   var imageURL = $("#url").val()
+  loading = true
   loadImage(imageURL, ready)
 }
 
@@ -25,7 +26,7 @@ function ready(){
       f.cloneData = f.ctx.getImageData(0,0,w,h)
     }
   }
-  else {
+  else if (window.img) {
     fc = cq(img.width, img.height)
     fc.drawImage(img, 0, 0)
     frame = img_frame = { ctx: fc.context }
@@ -33,25 +34,52 @@ function ready(){
     h = cc.canvas.height = frame.ctx.canvas.height
     frame.cloneData = frame.ctx.getImageData(0,0,w,h)
   }
+  else {
+    cc.canvas.width = w
+    cc.canvas.height = h
+    shader_build()
+  }
+	displayWidthHeight(w, h)
 }
 
+function displayWidthHeight(width, height){
+	$("#width").val(width)
+	$("#height").val(height)
+}
+$("#width").change(function(){
+	w = abs(parseInt(this.value,10)) || 1
+	cc.canvas.width = w
+	cc.canvas.height = h
+})
+$("#height").change(function(){
+	h = abs(parseInt(this.value,10)) || 1
+	cc.canvas.width = w
+	cc.canvas.height = h
+})
 function giveFrame(t){
   if (window.gif) {
     if (gif.currentFrame) {
       return gif.frames[gif.currentFrame(t)]
     }
-    else {
+    else if (gif.frames) {
       return gif.frames[0]
     }
   }
-  else if (window.img) {
+  if (window.img) {
     return img_frame
   }
   else {
-    return cq(w, h)
+    return empty_frame()
   }
 }
 
+function empty_frame(){
+	w = w || 400
+	h = h || 266
+	var cx = cq(w, h).fillStyle("rgba(255,255,255,255)").fillRect(0,0,w,h)
+	return { ctx: cx.context, cloneData: cx.getImageData(0,0,w,h) }
+}
+
 function reset(){
   start_t = old_t
   pause_t = 0
@@ -76,7 +104,7 @@ function animate(t){
 
   var step_t = t - old_t
   old_t = t
-  
+
   if (paused || dragging || rendering || scrolling || deferring) {
     pause_t += step_t
     if (scrolling) {