From 7c800a07d6804cd25dc8044d7c959201f95160d6 Mon Sep 17 00:00:00 2001
From: "valtain@gmail.com" <valtain@gmail.com>
Date: Sat, 24 Dec 2016 04:57:23 +0900
Subject: [PATCH] Fixed softmask in scree-space overlay mode of Canvas

---
 Scripts/Effects/SoftMaskScript.cs | 49 ++++++++++---------------
 Shaders/SoftMaskShader.shader     | 59 ++++++++++++++-----------------
 2 files changed, 46 insertions(+), 62 deletions(-)

diff --git a/Scripts/Effects/SoftMaskScript.cs b/Scripts/Effects/SoftMaskScript.cs
index a9dd9e3..2d13b56 100644
--- a/Scripts/Effects/SoftMaskScript.cs
+++ b/Scripts/Effects/SoftMaskScript.cs
@@ -46,19 +46,13 @@ namespace UnityEngine.UI.Extensions
                 MaskArea = myRect;
             }
 
-            if (GetComponent<Graphic>() != null)
-            {
-                mat = new Material(Shader.Find("UI Extensions/SoftMaskShader"));
-                GetComponent<Graphic>().material = mat;
-            }
-
-            if (GetComponent<Text>())
+            var text = GetComponent<Text>();
+            if (text != null)
             {
                 isText = true;
                 mat = new Material(Shader.Find("UI Extensions/SoftMaskShaderText"));
-                GetComponent<Text>().material = mat;
-
-                GetCanvas();
+                text.material = mat;
+                cachedCanvas = text.canvas;
 
                 // For some reason, having the mask control on the parent and disabled stops the mouse interacting
                 // with the texture layer that is not visible.. Not needed for the Image.
@@ -66,24 +60,17 @@ namespace UnityEngine.UI.Extensions
                     transform.parent.gameObject.AddComponent<Mask>();
 
                 transform.parent.GetComponent<Mask>().enabled = false;
+                return;
             }
-        }
 
-        void GetCanvas()
-        {
-            Transform t = transform;
-
-            int lvlLimit = 100;
-            int lvl = 0;
-
-            while (cachedCanvas == null && lvl < lvlLimit)
+            var graphic = GetComponent<Graphic>();
+            if (graphic != null)
             {
-                cachedCanvas = t.gameObject.GetComponent<Canvas>();
-                if (cachedCanvas == null)
-                    t = GetParentTranform(t);
-
-                lvl++;
+                mat = new Material(Shader.Find("UI Extensions/SoftMaskShader"));
+                graphic.material = mat;
+                cachedCanvas = graphic.canvas;
             }
+
         }
 
         Transform GetParentTranform(Transform t)
@@ -93,18 +80,20 @@ namespace UnityEngine.UI.Extensions
 
         void Update()
         {
-            SetMask();
+            if (cachedCanvas != null)
+            {
+                SetMask();
+            }
         }
 
         void SetMask()
         {
             var maskRectXform = MaskArea;
-            
-            MaskArea.GetWorldCorners(worldCorners);
-            
-            var size = (worldCorners[2] - worldCorners[0]);
+            var worldRect = RectTransformUtility.PixelAdjustRect(MaskArea, cachedCanvas);
+
+            var size = worldRect.size;
             maskScale.Set(1.0f / size.x, 1.0f / size.y);
-            maskOffset = -worldCorners[0];
+            maskOffset = -worldRect.min;
             maskOffset.Scale(maskScale);
 
             mat.SetTextureOffset("_AlphaMask", maskOffset);
diff --git a/Shaders/SoftMaskShader.shader b/Shaders/SoftMaskShader.shader
index 6bce499..0accab5 100644
--- a/Shaders/SoftMaskShader.shader
+++ b/Shaders/SoftMaskShader.shader
@@ -90,8 +90,8 @@
 			v2f vert(appdata_t IN)
 			{
 				v2f OUT;
-				float4 wolrdPos = mul(_Object2World, IN.vertex);
-				OUT.maskTexcoord = TRANSFORM_TEX(wolrdPos.xy, _AlphaMask);				
+				float4 wolrdPos = IN.vertex;
+				OUT.maskTexcoord = TRANSFORM_TEX(wolrdPos.xy, _AlphaMask);
 				OUT.vertex = mul(UNITY_MATRIX_MVP, IN.vertex);
 				OUT.texcoord = IN.texcoord;
 
@@ -103,49 +103,44 @@
 				return OUT;
 			}
 
-
-
-
 			float _CutOff;
-
 			bool _HardBlend = false;
 			bool _NoOuterClip = false;
 
 			fixed4 frag(v2f IN) : SV_Target
 			{
 				half4 color = (tex2D(_MainTex, IN.texcoord) + _TextureSampleAdd) * IN.color;
-				 float4 inMask = float4( 
-				 	step(float2(0.0f, 0.0f), IN.maskTexcoord), 
-				 	step(IN.maskTexcoord, float2(1.0f, 1.0f)) );
+				float4 inMask = float4( 
+					step(float2(0.0f, 0.0f), IN.maskTexcoord), 
+					step(IN.maskTexcoord, float2(1.0f, 1.0f)) );
 
-				 // Do we want to clip the image to the Mask Rectangle?
-				 if (_NoOuterClip == false && all(inMask) == false )
-				 {
-				 	color.a = 0;
-				 }
-				 else // It's in the mask rectangle, so apply the alpha of the mask provided.
-				 {
+				// Do we want to clip the image to the Mask Rectangle?
+				if (_NoOuterClip == false && all(inMask) == false )
+				{
+					color.a = 0;
+				}
+				else // It's in the mask rectangle, so apply the alpha of the mask provided.
+				{
 
-				 	float a = tex2D(_AlphaMask, IN.maskTexcoord).a;
+					float a = tex2D(_AlphaMask, IN.maskTexcoord).a;
 
-				 	if (a <= _CutOff)
-				 		a = 0;
-				 	else
-				 	{
-				 		if(_HardBlend)
-				 			a = 1;
-				 	}
+					if (a <= _CutOff)
+						a = 0;
+					else
+					{
+						if(_HardBlend)
+							a = 1;
+					}
 
-				 	if (_FlipAlphaMask == 1)
-				 		a = 1 - a;
+					if (_FlipAlphaMask == 1)
+						a = 1 - a;
 
-				 	color.a *= a;
-				 }
+					color.a *= a;
+				}
 
-				 if (_UseAlphaClip)
-				 	clip(color.a - 0.001);
-
-				 return color;
+				if (_UseAlphaClip)
+					clip(color.a - 0.001);
+				return color;
 			}
 			ENDCG
 		}