From b1b4eca3755ee0062a6d9595a377ebf26bd02d74 Mon Sep 17 00:00:00 2001
From: ippo615 <acippolit@gmail.com>
Date: Tue, 3 Dec 2013 19:20:34 -0500
Subject: [PATCH] Fixed bug in Flip filter, works on single buffer

---
 src/filters/Flip.js            | 48 +++++++++++++++++++++++++++++-----
 test/unit/filters/Flip-test.js | 42 +++++++++++++++++++++++++++++
 2 files changed, 84 insertions(+), 6 deletions(-)

diff --git a/src/filters/Flip.js b/src/filters/Flip.js
index aad863fb..8ba6adf8 100644
--- a/src/filters/Flip.js
+++ b/src/filters/Flip.js
@@ -16,16 +16,27 @@
     var srcPixels = src.data,
       dstPixels = dst.data,
       xSize = src.width,
+      xEnd = Math.ceil(0.5*xSize),
       ySize = src.height,
-      i, m, x, y;
-    for (x = 0; x < xSize; x += 1) {
+      i, m, x, y, r,g,b,a;
+    for (x = 0; x < xEnd; x += 1) {
       for (y = 0; y < ySize; y += 1) {
         i = (y * xSize + x) * 4; // original 
         m = (y * xSize + (xSize-1) - x) * 4; // flipped
+        // Instead of copying each row from the source to the destiation
+        // swap rows - this let's us achive a full flip in a single buffer
+        r = srcPixels[m + 0];
+        g = srcPixels[m + 1];
+        b = srcPixels[m + 2];
+        a = srcPixels[m + 3];
         dstPixels[m + 0] = srcPixels[i + 0];
         dstPixels[m + 1] = srcPixels[i + 1];
         dstPixels[m + 2] = srcPixels[i + 2];
         dstPixels[m + 3] = srcPixels[i + 3];
+        dstPixels[i + 0] = r;
+        dstPixels[i + 1] = g;
+        dstPixels[i + 2] = b;
+        dstPixels[i + 3] = a;
       }
     }
   };
@@ -47,19 +58,44 @@
       dstPixels = dst.data,
       xSize = src.width,
       ySize = src.height,
-      i, m, x, y;
+      yEnd = Math.ceil(0.5*ySize),
+      i, m, x, y, r,g,b,a;
     for (x = 0; x < xSize; x += 1) {
-      for (y = 0; y < ySize; y += 1) {
+      for (y = 0; y < yEnd; y += 1) {
         i = (y * xSize + x) * 4; // original 
         m = ((ySize-1 - y) * xSize + x) * 4; // flipped
+        // Instead of copying each row from the source to the destiation
+        // swap rows - this let's us achive a full flip in a single buffer
+        r = srcPixels[m + 0];
+        g = srcPixels[m + 1];
+        b = srcPixels[m + 2];
+        a = srcPixels[m + 3];
         dstPixels[m + 0] = srcPixels[i + 0];
         dstPixels[m + 1] = srcPixels[i + 1];
         dstPixels[m + 2] = srcPixels[i + 2];
         dstPixels[m + 3] = srcPixels[i + 3];
+        dstPixels[i + 0] = r;
+        dstPixels[i + 1] = g;
+        dstPixels[i + 2] = b;
+        dstPixels[i + 3] = a;
       }
     }
   };
 
-  Kinetic.Filters.FlipX = Kinetic.Util._FilterWrapSingleBuffer(FlipX);
-  Kinetic.Filters.FlipY = Kinetic.Util._FilterWrapSingleBuffer(FlipY);
+  Kinetic.Filters.FlipX = function(src,dst,opt){
+    if( this === Kinetic.Filters ){
+      FlipX(src, dst||src, opt );
+    }else{
+      FlipX.call(this, src, dst||src, opt);
+    }
+  };
+
+  Kinetic.Filters.FlipY = function(src,dst,opt){
+    if( this === Kinetic.Filters ){
+      FlipY(src, dst||src, opt );
+    }else{
+      FlipY.call(this, src, dst||src, opt);
+    }
+  };
+
 })();
diff --git a/test/unit/filters/Flip-test.js b/test/unit/filters/Flip-test.js
index 437112e2..d1750cbb 100644
--- a/test/unit/filters/Flip-test.js
+++ b/test/unit/filters/Flip-test.js
@@ -224,4 +224,46 @@ suite('Flip', function () {
         done();
     });
 
+    // ======================================================
+    test('on image', function(done) {
+        var stage = addStage();
+
+        var imageObj = new Image();
+        imageObj.onload = function() {
+            
+            var layer = new Kinetic.Layer();
+            var xFlip = new Kinetic.Image({
+                x: 160,
+                y: 10,
+                image: imageObj,
+                draggable: true,
+                filter: Kinetic.Filters.FlipX
+            });
+            var yFlip = new Kinetic.Image({
+                x: 320,
+                y: 10,
+                image: imageObj,
+                draggable: true,
+                filter: Kinetic.Filters.FlipY
+            });
+            var noFlip = new Kinetic.Image({
+                x: 0,
+                y: 10,
+                image: imageObj,
+                draggable: true
+            });
+
+            layer.add(noFlip);
+            layer.add(xFlip);
+            layer.add(yFlip);
+            stage.add(layer);
+
+            layer.draw();
+
+            done();
+        };
+        imageObj.src = 'assets/lion.png';
+
+    });
+
 });