Resolve discrepancies in alpha handling between GL filters and regular filters and minor bugs

Author: David Gillen

src/easeljs/filters/AberrationFilter.js

@@ -161,17 +161,12 @@
 				var grnPixel = ((grnY*width)+grnX)*4;
 				var bluPixel = ((bluY*width)+bluX)*4;
 
-				if(this._alphaMax) {
-					outPixels[pixel] =		refPixels[redPixel];
-					outPixels[pixel+1] =	refPixels[grnPixel+1];
-					outPixels[pixel+2] =	refPixels[bluPixel+2];
-					outPixels[pixel+3] =	refPixels[pixel+3];
-				} else {
-					outPixels[pixel] =		refPixels[redPixel];
-					outPixels[pixel+1] =	refPixels[grnPixel+1];
-					outPixels[pixel+2] =	refPixels[bluPixel+2];
-					outPixels[pixel+3] =	refPixels[pixel+3];
-				}
+				outPixels[pixel] =		refPixels[redPixel];
+				outPixels[pixel+1] =	refPixels[grnPixel+1];
+				outPixels[pixel+2] =	refPixels[bluPixel+2];
+				outPixels[pixel+3] =	this._alphaMax ?
+					Math.max(refPixels[redPixel+3], refPixels[grnPixel+3], refPixels[bluPixel+3]) :
+					(refPixels[redPixel+3] + refPixels[grnPixel+3] + refPixels[bluPixel+3]) / 3;
 			}
 		}
 

src/easeljs/filters/AlphaMapFilter.js

@@ -108,7 +108,8 @@ this.createjs = this.createjs || {};
 
 				// some image formats can have transparent white rgba(1,1,1, 0) when put on the GPU, this means we need a slight tweak
 				// using ceil ensure that the colour will be used so long as it exists but pure transparency will be treated black
-				"gl_FragColor = vec4(color.rgb, color.a * (alphaMap.r * ceil(alphaMap.a)));" +
+				"float newAlpha = alphaMap.r * ceil(alphaMap.a);" +
+				"gl_FragColor = vec4(clamp(color.rgb/color.a, 0.0, 1.0) * newAlpha, newAlpha);" +
 			"}"
 		);
 

src/easeljs/filters/AlphaMaskFilter.js

@@ -91,7 +91,7 @@ this.createjs = this.createjs || {};
 				"vec4 color = texture2D(uSampler, vTextureCoord);" +
 				"vec4 alphaMap = texture2D(uAlphaSampler, vTextureCoord);" +
 
-				"gl_FragColor = vec4(color.rgb, color.a * alphaMap.a);" +
+				"gl_FragColor = vec4(color.rgb * alphaMap.a, color.a * alphaMap.a);" +
 			"}"
 		);
 	}

src/easeljs/filters/DisplacementFilter.js

@@ -116,7 +116,7 @@ this.createjs = this.createjs||{};
 			var canvas = this._dudvCanvas = createjs.createCanvas ? createjs.createCanvas() : document.createElement("canvas");
 			canvas.width = dudvMap.width;
 			canvas.height = dudvMap.height;
-			(this._dudvCtx = canvas.getContext("2d")).drawImage(dudvMap);
+			(this._dudvCtx = canvas.getContext("2d")).drawImage(dudvMap, 0,0);
 		}
 	}
 	var p = createjs.extend(DisplacementFilter, createjs.Filter);