Merge branch 'develop' into feature/cubiquity-version

Conflicts:
	library/PolyVoxCore/include/PolyVoxCore/MarchingCubesSurfaceExtractor.inl

library/PolyVoxCore/include/PolyVoxCore/DefaultMarchingCubesController.h

@@ -103,6 +103,26 @@ namespace PolyVox
 			return 1;
 		}
 
+		/**
+		 * Returns a material which is in some sense a weighted combination of the supplied materials.
+		 *
+		 * The Marching Cubes algotithm generates vertices which lie between voxels, and ideally the material of the vertex should be interpolated from the materials
+		 * of the voxels. In practice, that material type is often an integer identifier (e.g. 1 = rock, 2 = soil, 3 = grass) and an interpolation doean't make sense
+		 * (e.g. soil is not a combination or rock and grass). Therefore this default interpolation just return one material or the other, but if more advanced voxel
+		 * types do support interpolation then it can be implemented in this function.
+		 */
+		MaterialType blendMaterials(MaterialType a, MaterialType b, float weight)
+		{
+			if(weight < 0.5f)
+			{
+				return a;
+			}
+			else
+			{
+				return b;
+			}
+		}
+
 		/**
 		 * Returns the density value which was passed to the constructor.
 		 *

library/PolyVoxCore/include/PolyVoxCore/Density.h

@@ -168,6 +168,11 @@ namespace PolyVox
 			return 1;
 		}
 
+		MaterialType blendMaterials(MaterialType /*a*/, MaterialType /*b*/, float /*weight*/)
+		{
+			return 1;
+		}
+
 		DensityType getThreshold(void)
 		{			
 			return m_tThreshold;

library/PolyVoxCore/include/PolyVoxCore/MaterialDensityPair.h

@@ -132,6 +132,18 @@ namespace PolyVox
 			return voxel.getMaterial();
 		}
 
+		MaterialType blendMaterials(MaterialType a, MaterialType b, float weight)
+		{
+			if(weight < 0.5f)
+			{
+				return a;
+			}
+			else
+			{
+				return b;
+			}
+		}
+
 		DensityType getThreshold(void)
 		{			
 			return m_tThreshold;

tests/TestSurfaceExtractor.cpp

@@ -55,6 +55,11 @@ public:
 		return 1;
 	}
 
+	float blendMaterials(float /*a*/, float /*b*/, float /*weight*/)
+	{
+		return 1;
+	}
+
 	float getThreshold(void)
 	{
 		return 50.0f;