From 1d617214b4afb8dbf3f973c8f85d5b03f4be50d7 Mon Sep 17 00:00:00 2001
From: Paul Kaplan <pkaplan@media.mit.edu>
Date: Mon, 11 Feb 2019 09:28:16 -0500
Subject: [PATCH] Simplify disposal method handling
---
src/lib/gif-decoder.js | 7 +------
1 file changed, 1 insertion(+), 6 deletions(-)
diff --git a/src/lib/gif-decoder.js b/src/lib/gif-decoder.js
index c6cc50ece..91466eaa4 100644
--- a/src/lib/gif-decoder.js
+++ b/src/lib/gif-decoder.js
@@ -34,10 +34,6 @@ export default (arrayBuffer, {onFrame, onDone}) => {
const dataUrl = canvas.toDataURL();
switch (disposal) {
- case 0:
- case 1: // Both are "keep previous frame"
- previousData = ctx.getImageData(0, 0, canvas.width, canvas.height);
- break;
case 2: // "Return to background", blank out the current frame
ctx.clearRect(x, y, width, height);
imageData = ctx.getImageData(0, 0, canvas.width, canvas.height);
@@ -46,8 +42,7 @@ export default (arrayBuffer, {onFrame, onDone}) => {
imageData = ctx.createImageData(canvas.width, canvas.height);
imageData.data.set(previousData.data);
break;
- default:
- // Not defined, treat like do-not-dispose
+ default: // 0 and 1, as well as 4+ modes = do-not-dispose, so cache frame
previousData = ctx.getImageData(0, 0, canvas.width, canvas.height);
break;
--
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