| /* |
| Bullet Continuous Collision Detection and Physics Library |
| Copyright (c) 2003-2009 Erwin Coumans http://bulletphysics.org |
| |
| 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 HEIGHTFIELD_TERRAIN_SHAPE_H |
| #define HEIGHTFIELD_TERRAIN_SHAPE_H |
| |
| #include "btConcaveShape.h" |
| |
| ///btHeightfieldTerrainShape simulates a 2D heightfield terrain |
| /** |
| The caller is responsible for maintaining the heightfield array; this |
| class does not make a copy. |
| |
| The heightfield can be dynamic so long as the min/max height values |
| capture the extremes (heights must always be in that range). |
| |
| The local origin of the heightfield is assumed to be the exact |
| center (as determined by width and length and height, with each |
| axis multiplied by the localScaling). |
| |
| \b NOTE: be careful with coordinates. If you have a heightfield with a local |
| min height of -100m, and a max height of +500m, you may be tempted to place it |
| at the origin (0,0) and expect the heights in world coordinates to be |
| -100 to +500 meters. |
| Actually, the heights will be -300 to +300m, because bullet will re-center |
| the heightfield based on its AABB (which is determined by the min/max |
| heights). So keep in mind that once you create a btHeightfieldTerrainShape |
| object, the heights will be adjusted relative to the center of the AABB. This |
| is different to the behavior of many rendering engines, but is useful for |
| physics engines. |
| |
| Most (but not all) rendering and heightfield libraries assume upAxis = 1 |
| (that is, the y-axis is "up"). This class allows any of the 3 coordinates |
| to be "up". Make sure your choice of axis is consistent with your rendering |
| system. |
| |
| The heightfield heights are determined from the data type used for the |
| heightfieldData array. |
| |
| - PHY_UCHAR: height at a point is the uchar value at the |
| grid point, multipled by heightScale. uchar isn't recommended |
| because of its inability to deal with negative values, and |
| low resolution (8-bit). |
| |
| - PHY_SHORT: height at a point is the short int value at that grid |
| point, multipled by heightScale. |
| |
| - PHY_FLOAT: height at a point is the float value at that grid |
| point. heightScale is ignored when using the float heightfield |
| data type. |
| |
| Whatever the caller specifies as minHeight and maxHeight will be honored. |
| The class will not inspect the heightfield to discover the actual minimum |
| or maximum heights. These values are used to determine the heightfield's |
| axis-aligned bounding box, multiplied by localScaling. |
| |
| For usage and testing see the TerrainDemo. |
| */ |
| class btHeightfieldTerrainShape : public btConcaveShape |
| { |
| protected: |
| btVector3 m_localAabbMin; |
| btVector3 m_localAabbMax; |
| btVector3 m_localOrigin; |
| |
| ///terrain data |
| int m_heightStickWidth; |
| int m_heightStickLength; |
| btScalar m_minHeight; |
| btScalar m_maxHeight; |
| btScalar m_width; |
| btScalar m_length; |
| btScalar m_heightScale; |
| union |
| { |
| unsigned char* m_heightfieldDataUnsignedChar; |
| short* m_heightfieldDataShort; |
| btScalar* m_heightfieldDataFloat; |
| void* m_heightfieldDataUnknown; |
| }; |
| |
| PHY_ScalarType m_heightDataType; |
| bool m_flipQuadEdges; |
| bool m_useDiamondSubdivision; |
| |
| int m_upAxis; |
| |
| btVector3 m_localScaling; |
| |
| virtual btScalar getRawHeightFieldValue(int x,int y) const; |
| void quantizeWithClamp(int* out, const btVector3& point,int isMax) const; |
| void getVertex(int x,int y,btVector3& vertex) const; |
| |
| |
| |
| /// protected initialization |
| /** |
| Handles the work of constructors so that public constructors can be |
| backwards-compatible without a lot of copy/paste. |
| */ |
| void initialize(int heightStickWidth, int heightStickLength, |
| void* heightfieldData, btScalar heightScale, |
| btScalar minHeight, btScalar maxHeight, int upAxis, |
| PHY_ScalarType heightDataType, bool flipQuadEdges); |
| |
| public: |
| /// preferred constructor |
| /** |
| This constructor supports a range of heightfield |
| data types, and allows for a non-zero minimum height value. |
| heightScale is needed for any integer-based heightfield data types. |
| */ |
| btHeightfieldTerrainShape(int heightStickWidth,int heightStickLength, |
| void* heightfieldData, btScalar heightScale, |
| btScalar minHeight, btScalar maxHeight, |
| int upAxis, PHY_ScalarType heightDataType, |
| bool flipQuadEdges); |
| |
| /// legacy constructor |
| /** |
| The legacy constructor assumes the heightfield has a minimum height |
| of zero. Only unsigned char or floats are supported. For legacy |
| compatibility reasons, heightScale is calculated as maxHeight / 65535 |
| (and is only used when useFloatData = false). |
| */ |
| btHeightfieldTerrainShape(int heightStickWidth,int heightStickLength,void* heightfieldData, btScalar maxHeight,int upAxis,bool useFloatData,bool flipQuadEdges); |
| |
| virtual ~btHeightfieldTerrainShape(); |
| |
| |
| void setUseDiamondSubdivision(bool useDiamondSubdivision=true) { m_useDiamondSubdivision = useDiamondSubdivision;} |
| |
| |
| virtual void getAabb(const btTransform& t,btVector3& aabbMin,btVector3& aabbMax) const; |
| |
| virtual void processAllTriangles(btTriangleCallback* callback,const btVector3& aabbMin,const btVector3& aabbMax) const; |
| |
| virtual void calculateLocalInertia(btScalar mass,btVector3& inertia) const; |
| |
| virtual void setLocalScaling(const btVector3& scaling); |
| |
| virtual const btVector3& getLocalScaling() const; |
| |
| //debugging |
| virtual const char* getName()const {return "HEIGHTFIELD";} |
| |
| }; |
| |
| #endif //HEIGHTFIELD_TERRAIN_SHAPE_H |