Exposed linear and bilinear interpolation, in addition to trilinear.

Moved them somewhere publically accessable.

library/PolyVoxCore/CMakeLists.txt

@@ -59,6 +59,7 @@ SET(CORE_INC_FILES
 	include/PolyVoxCore/Density.h
 	include/PolyVoxCore/GradientEstimators.h
 	include/PolyVoxCore/GradientEstimators.inl
+	include/PolyVoxCore/Interpolation.h
 	include/PolyVoxCore/IteratorController.h
 	include/PolyVoxCore/IteratorController.inl
 	include/PolyVoxCore/LargeVolume.h

library/PolyVoxCore/include/PolyVoxCore/Interpolation.h

@@ -0,0 +1,82 @@
+/*******************************************************************************
+Copyright (c) 2005-2009 David Williams
+
+This software is provided 'as-is', without any express or implied
+warranty. In no event will the authors be held liable for any damages
+arising from the use of this software.
+
+Permission is granted to anyone to use this software for any purpose,
+including commercial applications, and to alter it and redistribute it
+freely, subject to the following restrictions:
+
+    1. The origin of this software must not be misrepresented; you must not
+    claim that you wrote the original software. If you use this software
+    in a product, an acknowledgment in the product documentation would be
+    appreciated but is not required.
+
+    2. Altered source versions must be plainly marked as such, and must not be
+    misrepresented as being the original software.
+
+    3. This notice may not be removed or altered from any source
+    distribution. 	
+*******************************************************************************/
+
+#ifndef __PolyVox_Interpolation_H__
+#define __PolyVox_Interpolation_H__
+
+#include <cassert>
+
+namespace PolyVox
+{
+	template <typename Type>
+        Type lerp(
+        const Type& v0,const Type& v1,
+        const float x)
+    {
+        assert((x >= 0.0f) && (x <= 1.0f));
+
+		//Interpolate along X
+		Type v0_1 = v0 + x * (v1 - v0);
+
+		return v0_1;
+    }
+
+	template <typename Type>
+        Type bilerp(
+        const Type& v00,const Type& v10,const Type& v01,const Type& v11,
+        const float x, const float y)
+    {
+        assert((x >= 0.0f) && (y >= 0.0f) && 
+            (x <= 1.0f) && (y <= 1.0f));
+
+		// Linearly interpolate along x
+		Type v00_10 = lerp(v00, v10, x);
+		Type v01_11 = lerp(v01, v11, x);
+
+		// And linearly interpolate the results along y
+		Type v00_10__v01_11 = lerp(v00_10, v01_11, y);
+
+		return v00_10__v01_11;
+    }
+
+	template <typename Type>
+        Type trilerp(
+        const Type& v000,const Type& v100,const Type& v010,const Type& v110,
+        const Type& v001,const Type& v101,const Type& v011,const Type& v111,
+        const float x, const float y, const float z)
+    {
+        assert((x >= 0.0f) && (y >= 0.0f) && (z >= 0.0f) && 
+            (x <= 1.0f) && (y <= 1.0f) && (z <= 1.0f));
+
+		// Bilinearly interpolate along Y
+		Type v000_v100__v010_v110 = bilerp(v000, v100, v010, v110, x, y);
+		Type v001_v101__v011_v111 = bilerp(v001, v101, v011, v111, x, y);
+
+		// And linearly interpolate the results along z
+		Type v000_v100__v010_v110____v001_v101__v011_v111 = lerp(v000_v100__v010_v110, v001_v101__v011_v111, z);
+			
+		return v000_v100__v010_v110____v001_v101__v011_v111;
+    }
+}
+
+#endif //__PolyVox_Interpolation_H__

library/PolyVoxCore/include/PolyVoxCore/VolumeResampler.inl

@@ -21,7 +21,7 @@ freely, subject to the following restrictions:
     distribution. 	
 *******************************************************************************/
 
-#include "PolyVoxImpl/Utility.h"
+#include "PolyVoxCore/Interpolation.h"
 
 namespace PolyVox
 {
@@ -125,7 +125,7 @@ namespace PolyVox
 					sy = modf(sy, &dummy);
 					sz = modf(sz, &dummy);
 
-					typename SrcVolumeType::VoxelType tInterpolatedValue = trilinearlyInterpolate<float>(voxel000,voxel100,voxel010,voxel110,voxel001,voxel101,voxel011,voxel111,sx,sy,sz);
+					typename SrcVolumeType::VoxelType tInterpolatedValue = trilerp<float>(voxel000,voxel100,voxel010,voxel110,voxel001,voxel101,voxel011,voxel111,sx,sy,sz);
 
 					typename DstVolumeType::VoxelType result = static_cast<typename DstVolumeType::VoxelType>(tInterpolatedValue);
 					m_pVolDst->setVoxelAt(dx,dy,dz,result);

library/PolyVoxCore/include/PolyVoxImpl/Utility.h

@@ -32,31 +32,6 @@ namespace PolyVox
 {
 	POLYVOX_API uint8_t logBase2(uint32_t uInput);
 	POLYVOX_API bool isPowerOf2(uint32_t uInput);
-
-	template <typename Type>
-        Type trilinearlyInterpolate(
-        const Type& v000,const Type& v100,const Type& v010,const Type& v110,
-        const Type& v001,const Type& v101,const Type& v011,const Type& v111,
-        const float x, const float y, const float z)
-    {
-        assert((x >= 0.0f) && (y >= 0.0f) && (z >= 0.0f) && 
-            (x <= 1.0f) && (y <= 1.0f) && (z <= 1.0f));
-
-		//Interpolate along X
-		Type v000_v100 = (v100 - v000) * x + v000;
-		Type v001_v101 = (v101 - v001) * x + v001;
-		Type v010_v110 = (v110 - v010) * x + v010;
-		Type v011_v111 = (v111 - v011) * x + v011;
-
-		//Interpolate along Y
-		Type v000_v100__v010_v110 = (v010_v110 - v000_v100) * y + v000_v100;
-		Type v001_v101__v011_v111 = (v011_v111 - v001_v101) * y + v001_v101;
-
-		//Interpolate along Z
-		Type v000_v100__v010_v110____v001_v101__v011_v111 = (v001_v101__v011_v111 - v000_v100__v010_v110) * z + v000_v100__v010_v110;
-
-		return v000_v100__v010_v110____v001_v101__v011_v111;
-    }
 }
 
 #endif