From cad28a8b35bd51857e5e43ad3aa373dd66f1037f Mon Sep 17 00:00:00 2001
From: ejcoumans <ejcoumans@08e121b0-ae19-0410-a57b-3be3395fd4fd>
Date: Wed, 27 Jun 2007 19:56:18 +0000
Subject: [PATCH] allow for float data, and prepare for 'quad edge flip',
 either re-use the first triangle vertex, or second (re-use index 00 or 01)

---
 Demos/VehicleDemo/VehicleDemo.cpp             |  5 ++-
 .../btHeightfieldTerrainShape.cpp             | 32 +++++++++++++++----
 .../btHeightfieldTerrainShape.h               | 18 ++++++++---
 3 files changed, 43 insertions(+), 12 deletions(-)

diff --git a/Demos/VehicleDemo/VehicleDemo.cpp b/Demos/VehicleDemo/VehicleDemo.cpp
index bc69ad78f..4b5a01d1b 100644
--- a/Demos/VehicleDemo/VehicleDemo.cpp
+++ b/Demos/VehicleDemo/VehicleDemo.cpp
@@ -237,7 +237,10 @@ const float TRIANGLE_SIZE=20.f;
 
 	btScalar maxHeight = 20000.f;
 	
-	groundShape = new btHeightfieldTerrainShape(width,length,heightfieldData,maxHeight,upIndex);
+	bool useFloatDatam=false;
+	bool flipQuadEdges=false;
+
+	groundShape = new btHeightfieldTerrainShape(width,length,heightfieldData,maxHeight,upIndex,useFloatDatam,flipQuadEdges);
 	btVector3 localScaling(20,20,20);
 	localScaling[upIndex]=1.f;
 	groundShape->setLocalScaling(localScaling);
diff --git a/src/BulletCollision/CollisionShapes/btHeightfieldTerrainShape.cpp b/src/BulletCollision/CollisionShapes/btHeightfieldTerrainShape.cpp
index de3f304b3..4e64aef3c 100644
--- a/src/BulletCollision/CollisionShapes/btHeightfieldTerrainShape.cpp
+++ b/src/BulletCollision/CollisionShapes/btHeightfieldTerrainShape.cpp
@@ -18,13 +18,15 @@ subject to the following restrictions:
 #include "LinearMath/btTransformUtil.h"
 
 
-btHeightfieldTerrainShape::btHeightfieldTerrainShape(int width,int length,unsigned char* heightfieldData,btScalar maxHeight,int upAxis)
+btHeightfieldTerrainShape::btHeightfieldTerrainShape(int width,int length,void* heightfieldData,btScalar maxHeight,int upAxis,bool useFloatData,bool flipQuadEdges)
 :m_localScaling(btScalar(1.),btScalar(1.),btScalar(1.)),
 m_width(width),
 m_length(length),
-m_heightfieldData(heightfieldData),
+m_heightfieldDataUnknown(heightfieldData),
 m_maxHeight(maxHeight),
-m_upAxis(upAxis)
+m_upAxis(upAxis),
+m_useFloatData(useFloatData),
+m_flipQuadEdges(flipQuadEdges)
 {
 
 
@@ -108,6 +110,21 @@ void btHeightfieldTerrainShape::getAabb(const btTransform& t,btVector3& aabbMin,
 
 }
 
+btScalar	btHeightfieldTerrainShape::getHeightFieldValue(int x,int y) const
+{
+	btScalar val = 0.f;
+	if (m_useFloatData)
+	{
+		btScalar val = m_heightfieldDataFloat[(y*m_width)+x];
+	} else
+	{
+		unsigned char heightFieldValue = m_heightfieldDataUnsignedChar[(y*m_width)+x];
+		btScalar val = heightFieldValue* (m_maxHeight/btScalar(65535));
+	}
+	return val;
+}
+
+
 
 
 
@@ -119,14 +136,15 @@ void	btHeightfieldTerrainShape::getVertex(int x,int y,btVector3& vertex) const
 	btAssert(x<m_width);
 	btAssert(y<m_length);
 
-	unsigned char heightFieldValue = m_heightfieldData[(y*m_width)+x];
+
+	btScalar	height = getHeightFieldValue(x,y);
 
 	switch (m_upAxis)
 	{
 	case 0:
 		{
 		vertex.setValue(
-			heightFieldValue* (m_maxHeight/btScalar(65535)),
+			height,
 			(-m_width/2 ) + x,
 			(-m_length/2 ) + y
 			);
@@ -136,7 +154,7 @@ void	btHeightfieldTerrainShape::getVertex(int x,int y,btVector3& vertex) const
 		{
 			vertex.setValue(
 			(-m_width/2 ) + x,
-			heightFieldValue* (m_maxHeight/btScalar(65535)),
+			height,
 			(-m_length/2 ) + y
 			);
 			break;
@@ -146,7 +164,7 @@ void	btHeightfieldTerrainShape::getVertex(int x,int y,btVector3& vertex) const
 			vertex.setValue(
 			(-m_width/2 ) + x,
 			(-m_length/2 ) + y,
-			heightFieldValue* (m_maxHeight/btScalar(65535))
+			height
 			);
 			break;
 		}
diff --git a/src/BulletCollision/CollisionShapes/btHeightfieldTerrainShape.h b/src/BulletCollision/CollisionShapes/btHeightfieldTerrainShape.h
index 31bb7121d..1b0ab994c 100644
--- a/src/BulletCollision/CollisionShapes/btHeightfieldTerrainShape.h
+++ b/src/BulletCollision/CollisionShapes/btHeightfieldTerrainShape.h
@@ -29,15 +29,25 @@ protected:
 	int	m_width;
 	int m_length;
 	btScalar	m_maxHeight;
-	unsigned char* m_heightfieldData;
+	union
+	{
+		unsigned char*	m_heightfieldDataUnsignedChar;
+		float*			m_heightfieldDataFloat;
+		void*			m_heightfieldDataUnknown;
+	};
+	
+	bool	m_useFloatData;
+	bool	m_flipQuadEdges;
+
 	int	m_upAxis;
 	
 	btVector3	m_quantization;
 
 	btVector3	m_localScaling;
 
-	void	quantizeWithClamp(short* out, const btVector3& point) const;
-	void	getVertex(int x,int y,btVector3& vertex) const;
+	btScalar	getHeightFieldValue(int x,int y) const;
+	void		quantizeWithClamp(short* out, const btVector3& point) const;
+	void		getVertex(int x,int y,btVector3& vertex) const;
 
 	inline bool testQuantizedAabbAgainstQuantizedAabb(short int* aabbMin1,short int* aabbMax1,const short int* aabbMin2,const short int* aabbMax2) const
 	{
@@ -49,7 +59,7 @@ protected:
 	}
 
 public:
-	btHeightfieldTerrainShape(int width,int height,unsigned char* heightfieldData, btScalar maxHeight,int upAxis);
+	btHeightfieldTerrainShape(int width,int height,void* heightfieldData, btScalar maxHeight,int upAxis,bool useFloatData,bool flipQuadEdges);
 
 	virtual ~btHeightfieldTerrainShape();