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Assets/Alloy/Shaders/Feature/WeightedBlend.cginc

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+// Alloy Physical Shader Framework
+// Copyright 2013-2017 RUST LLC.
+// http://www.alloy.rustltd.com/
+
+/////////////////////////////////////////////////////////////////////////////////
+/// @file WeightedBlend.cginc
+/// @brief Blending with a heightmap, a cutoff value, and the vertex color alpha.
+/////////////////////////////////////////////////////////////////////////////////
+
+#ifndef ALLOY_SHADERS_FEATURE_WEIGHTED_BLEND_CGINC
+#define ALLOY_SHADERS_FEATURE_WEIGHTED_BLEND_CGINC
+
+#include "Assets/Alloy/Shaders/Framework/Feature.cginc"
+
+#ifdef A_WEIGHTED_BLEND_ON
+    /// Heightmap used for blending.
+    /// Expects an RGB data map.
+    A_SAMPLER_2D(_BlendMap);
+    
+    /// Heightmap Blend weight.
+    /// Expects values in the range [0,1].
+    half _BlendScale;
+    
+    /// Height cutoff where blend begins.
+    /// Expects values in the range [0,1].
+    half _BlendCutoff;
+    
+    /// Offset from cutoff where smooth blending occurs.
+    /// Expects values in the range [0.0001,1].
+    half _Blend; 
+    
+    /// Controls how much the vertex color alpha influences the cutoff.
+    /// Expects values in the range [0,1].
+    half _BlendAlphaVertexTint;
+#endif
+
+void aHeightmapBlend(
+    inout ASurface s)
+{
+#ifdef A_WEIGHTED_BLEND_ON
+    float2 blendUv = A_TEX_TRANSFORM_UV(s, _BlendMap);
+    half mask = tex2D(_BlendMap, blendUv).g;
+    
+    aBlendRangeMask(s, mask, _BlendScale, _BlendCutoff, _Blend, _BlendAlphaVertexTint);
+#endif
+}
+
+#endif // ALLOY_SHADERS_FEATURE_WEIGHTED_BLEND_CGINC