Fix skeleton webgl render command

Author: pandamicro

Diff for: extensions/spine/CCSkeletonWebGLRenderCmd.js

@@ -191,17 +191,11 @@
     proto._updateRegionAttachmentQuad = function(self, slot, quad, premultipliedAlpha) {
         var vertices = {};
         self.computeVertices(slot.bone.skeleton.x, slot.bone.skeleton.y, slot.bone, vertices);
-        var r = slot.bone.skeleton.r * slot.r * 255;
-        var g = slot.bone.skeleton.g * slot.g * 255;
-        var b = slot.bone.skeleton.b * slot.b * 255;
-        var normalizedAlpha = slot.bone.skeleton.a * slot.a;
-
-        if (premultipliedAlpha) {
-            r *= normalizedAlpha;
-            g *= normalizedAlpha;
-            b *= normalizedAlpha;
-        }
-        var a = normalizedAlpha * 255;
+        var a = slot.bone.skeleton.a * slot.a * attachment.a * 255;
+        var multiplier = premultipliedAlpha ? a : 255;
+        var r = slot.bone.skeleton.r * slot.r * attachment.r * multiplier;
+        var g = slot.bone.skeleton.g * slot.g * attachment.g * multiplier;
+        var b = slot.bone.skeleton.b * slot.b * attachment.b * multiplier;
 
         quad.bl.colors.r = quad.tl.colors.r = quad.tr.colors.r = quad.br.colors.r = r;
         quad.bl.colors.g = quad.tl.colors.g = quad.tr.colors.g = quad.br.colors.g = g;