1 files changed, 37 insertions, 0 deletions
diff --git a/gfx/layers/d3d11/mlgshaders/common-ps.hlsl b/gfx/layers/d3d11/mlgshaders/common-ps.hlsl
new file mode 100644
index 0000000000..624f87e2ce
--- /dev/null
+++ b/gfx/layers/d3d11/mlgshaders/common-ps.hlsl
@@ -0,0 +1,37 @@
+/* -*- Mode: C++; tab-width: 20; indent-tabs-mode: nil; c-basic-offset: 4 -*-
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+#include "common.hlsl"
+
+sampler sSampler : register(ps, s0);
+sampler sMaskSampler : register(ps, s1);
+
+Texture2D tMaskTexture : register(ps, t4);
+
+cbuffer MaskInformation : register(b0)
+{
+  float sOpacity : packoffset(c0.x);
+  uint sHasMask : packoffset(c0.y);
+};
+
+float2 MaskCoordsToUV(float3 aMaskCoords)
+{
+  return aMaskCoords.xy / aMaskCoords.z;
+}
+
+float ReadMaskWithOpacity(float3 aMaskCoords, float aOpacity)
+{
+  if (!sHasMask) {
+    return aOpacity;
+  }
+
+  float2 uv = MaskCoordsToUV(aMaskCoords);
+  float r = tMaskTexture.Sample(sMaskSampler, uv).r;
+  return min(aOpacity, r);
+}
+
+float ReadMask(float3 aMaskCoords)
+{
+  return ReadMaskWithOpacity(aMaskCoords, sOpacity);
+}