From 125d9000dd03afe1f692e546bd53d31dac43fbba Mon Sep 17 00:00:00 2001
From: unknown <p265186@012987.(none)>
Date: Thu, 9 Aug 2012 16:54:45 +0200
Subject: [PATCH] Started implementing 'IsQuadNeeded' for CubicSurfaceExtractor
 (without normals).

---
 .../PolyVoxCore/CubicSurfaceExtractor.h       |  7 ++++--
 .../PolyVoxCore/CubicSurfaceExtractor.inl     | 25 ++++++++++---------
 .../include/PolyVoxCore/Material.h            | 20 +++++++++++++++
 3 files changed, 38 insertions(+), 14 deletions(-)

diff --git a/library/PolyVoxCore/include/PolyVoxCore/CubicSurfaceExtractor.h b/library/PolyVoxCore/include/PolyVoxCore/CubicSurfaceExtractor.h
index 86922b54..70666f8a 100644
--- a/library/PolyVoxCore/include/PolyVoxCore/CubicSurfaceExtractor.h
+++ b/library/PolyVoxCore/include/PolyVoxCore/CubicSurfaceExtractor.h
@@ -27,11 +27,12 @@ freely, subject to the following restrictions:
 #include "PolyVoxImpl/TypeDef.h"
 
 #include "PolyVoxCore/Array.h"
+#include "PolyVoxCore/DefaultIsQuadNeeded.h"
 #include "PolyVoxCore/SurfaceMesh.h"
 
 namespace PolyVox
 {
-	template<typename VolumeType>
+	template<typename VolumeType, typename IsQuadNeeded = DefaultIsQuadNeeded<typename VolumeType::VoxelType> >
 	class CubicSurfaceExtractor
 	{
 		struct IndexAndMaterial
@@ -57,7 +58,7 @@ namespace PolyVox
 		};
 
 	public:
-		CubicSurfaceExtractor(VolumeType* volData, Region region, SurfaceMesh<PositionMaterial>* result, bool bMergeQuads = true);
+		CubicSurfaceExtractor(VolumeType* volData, Region region, SurfaceMesh<PositionMaterial>* result, bool bMergeQuads = true, IsQuadNeeded isQuadNeeded = IsQuadNeeded());
 
 		void execute();		
 
@@ -66,6 +67,8 @@ namespace PolyVox
 		bool performQuadMerging(std::list<Quad>& quads);
 		bool mergeQuads(Quad& q1, Quad& q2);
 
+		IsQuadNeeded m_funcIsQuadNeededCallback;
+
 		//The volume data and a sampler to access it.
 		VolumeType* m_volData;
 
diff --git a/library/PolyVoxCore/include/PolyVoxCore/CubicSurfaceExtractor.inl b/library/PolyVoxCore/include/PolyVoxCore/CubicSurfaceExtractor.inl
index 5ff1c6ac..9980abcb 100644
--- a/library/PolyVoxCore/include/PolyVoxCore/CubicSurfaceExtractor.inl
+++ b/library/PolyVoxCore/include/PolyVoxCore/CubicSurfaceExtractor.inl
@@ -31,20 +31,21 @@ namespace PolyVox
 	// The vertex position at the center of this group is then going to be used by six quads all with different materials.
 	// One futher note - we can actually have eight quads sharing a vertex position (imagine two 1x1x10 rows of voxels
 	// sharing a common edge) but in this case all eight quads will not have different materials.
-	template<typename VolumeType>
-	const uint32_t CubicSurfaceExtractor<VolumeType>::MaxVerticesPerPosition = 6;
+	template<typename VolumeType, typename IsQuadNeeded>
+	const uint32_t CubicSurfaceExtractor<VolumeType, IsQuadNeeded>::MaxVerticesPerPosition = 6;
 
-	template<typename VolumeType>
-	CubicSurfaceExtractor<VolumeType>::CubicSurfaceExtractor(VolumeType* volData, Region region, SurfaceMesh<PositionMaterial>* result, bool bMergeQuads)
+	template<typename VolumeType, typename IsQuadNeeded>
+	CubicSurfaceExtractor<VolumeType, IsQuadNeeded>::CubicSurfaceExtractor(VolumeType* volData, Region region, SurfaceMesh<PositionMaterial>* result, bool bMergeQuads, IsQuadNeeded isQuadNeeded)
 		:m_volData(volData)
 		,m_regSizeInVoxels(region)
 		,m_meshCurrent(result)
 		,m_bMergeQuads(bMergeQuads)
 	{
+		m_funcIsQuadNeededCallback = isQuadNeeded;
 	}
 
-	template<typename VolumeType>
-	void CubicSurfaceExtractor<VolumeType>::execute()
+	template<typename VolumeType, typename IsQuadNeeded>
+	void CubicSurfaceExtractor<VolumeType, IsQuadNeeded>::execute()
 	{
 		m_meshCurrent->clear();
 
@@ -243,8 +244,8 @@ namespace PolyVox
 		m_meshCurrent->m_vecLodRecords.push_back(lodRecord);
 	}
 
-	template<typename VolumeType>
-	int32_t CubicSurfaceExtractor<VolumeType>::addVertex(float fX, float fY, float fZ, uint32_t uMaterialIn, Array<3, IndexAndMaterial>& existingVertices)
+	template<typename VolumeType, typename IsQuadNeeded>
+	int32_t CubicSurfaceExtractor<VolumeType, IsQuadNeeded>::addVertex(float fX, float fY, float fZ, uint32_t uMaterialIn, Array<3, IndexAndMaterial>& existingVertices)
 	{
 		uint32_t uX = static_cast<uint32_t>(fX + 0.75f);
 		uint32_t uY = static_cast<uint32_t>(fY + 0.75f);
@@ -275,8 +276,8 @@ namespace PolyVox
 		return -1; //Should never happen.
 	}
 
-	template<typename VolumeType>
-	bool CubicSurfaceExtractor<VolumeType>::performQuadMerging(std::list<Quad>& quads)
+	template<typename VolumeType, typename IsQuadNeeded>
+	bool CubicSurfaceExtractor<VolumeType, IsQuadNeeded>::performQuadMerging(std::list<Quad>& quads)
 	{
 		bool bDidMerge = false;
 		for(typename std::list<Quad>::iterator outerIter = quads.begin(); outerIter != quads.end(); outerIter++)
@@ -305,8 +306,8 @@ namespace PolyVox
 		return bDidMerge;
 	}
 
-	template<typename VolumeType>
-	bool CubicSurfaceExtractor<VolumeType>::mergeQuads(Quad& q1, Quad& q2)
+	template<typename VolumeType, typename IsQuadNeeded>
+	bool CubicSurfaceExtractor<VolumeType, IsQuadNeeded>::mergeQuads(Quad& q1, Quad& q2)
 	{
 		//All four vertices of a given quad have the same material,
 		//so just check that the first pair of vertices match.
diff --git a/library/PolyVoxCore/include/PolyVoxCore/Material.h b/library/PolyVoxCore/include/PolyVoxCore/Material.h
index 091e9495..9bbb3bc8 100644
--- a/library/PolyVoxCore/include/PolyVoxCore/Material.h
+++ b/library/PolyVoxCore/include/PolyVoxCore/Material.h
@@ -26,6 +26,8 @@ freely, subject to the following restrictions:
 
 #include "PolyVoxImpl/TypeDef.h"
 
+#include "PolyVoxCore/DefaultIsQuadNeeded.h" //we'll specialise this function for this voxel type
+
 #include <cassert>
 
 namespace PolyVox
@@ -79,6 +81,24 @@ namespace PolyVox
 
 	typedef Material<uint8_t> Material8;
 	typedef Material<uint16_t> Material16;
+
+	template<typename Type>
+	class DefaultIsQuadNeeded< Material<Type> >
+	{
+	public:
+		bool operator()(Material<Type> back, Material<Type> front, float& materialToUse)
+		{
+			if((back.getMaterial() > 0) && (front.getMaterial() == 0))
+			{
+				materialToUse = static_cast<float>(back.getMaterial());
+				return true;
+			}
+			else
+			{
+				return false;
+			}
+		}
+	};
 }
 
 #endif //__PolyVox_Material_H__