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source: code/trunk/src/bullet/BulletCollision/CollisionShapes/btHeightfieldTerrainShape.h @ 2732

Last change on this file since 2732 was 2662, checked in by rgrieder, 16 years ago

Merged presentation branch back to trunk.

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1/*
2Bullet Continuous Collision Detection and Physics Library
3Copyright (c) 2003-2006 Erwin Coumans  http://continuousphysics.com/Bullet/
4
5This software is provided 'as-is', without any express or implied warranty.
6In no event will the authors be held liable for any damages arising from the use of this software.
7Permission is granted to anyone to use this software for any purpose,
8including commercial applications, and to alter it and redistribute it freely,
9subject to the following restrictions:
10
111. 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.
122. Altered source versions must be plainly marked as such, and must not be misrepresented as being the original software.
133. This notice may not be removed or altered from any source distribution.
14*/
15
16#ifndef HEIGHTFIELD_TERRAIN_SHAPE_H
17#define HEIGHTFIELD_TERRAIN_SHAPE_H
18
19#include "btConcaveShape.h"
20
21///btHeightfieldTerrainShape simulates a 2D heightfield terrain
22/**
23  The caller is responsible for maintaining the heightfield array; this
24  class does not make a copy.
25
26  The heightfield can be dynamic so long as the min/max height values
27  capture the extremes (heights must always be in that range).
28
29  The local origin of the heightfield is assumed to be the exact
30  center (as determined by width and length and height, with each
31  axis multiplied by the localScaling).
32
33  Most (but not all) rendering and heightfield libraries assume upAxis = 1
34  (that is, the y-axis is "up").  This class allows any of the 3 coordinates
35  to be "up".  Make sure your choice of axis is consistent with your rendering
36  system.
37
38  The heightfield heights are determined from the data type used for the
39  heightfieldData array. 
40
41   - PHY_UCHAR: height at a point is the uchar value at the
42       grid point, multipled by heightScale.  uchar isn't recommended
43       because of its inability to deal with negative values, and
44       low resolution (8-bit).
45
46   - PHY_SHORT: height at a point is the short int value at that grid
47       point, multipled by heightScale.
48
49   - PHY_FLOAT: height at a point is the float value at that grid
50       point.  heightScale is ignored when using the float heightfield
51       data type.
52
53  Whatever the caller specifies as minHeight and maxHeight will be honored.
54  The class will not inspect the heightfield to discover the actual minimum
55  or maximum heights.  These values are used to determine the heightfield's
56  axis-aligned bounding box, multiplied by localScaling.
57
58  For usage and testing see the TerrainDemo.
59 */
60class btHeightfieldTerrainShape : public btConcaveShape
61{
62protected:
63        btVector3       m_localAabbMin;
64        btVector3       m_localAabbMax;
65        btVector3       m_localOrigin;
66
67        ///terrain data
68        int     m_heightStickWidth;
69        int m_heightStickLength;
70        btScalar        m_minHeight;
71        btScalar        m_maxHeight;
72        btScalar m_width;
73        btScalar m_length;
74        btScalar m_heightScale;
75        union
76        {
77                unsigned char*  m_heightfieldDataUnsignedChar;
78                short*          m_heightfieldDataShort;
79                btScalar*                       m_heightfieldDataFloat;
80                void*                   m_heightfieldDataUnknown;
81        };
82
83        PHY_ScalarType  m_heightDataType;       
84        bool    m_flipQuadEdges;
85  bool  m_useDiamondSubdivision;
86
87        int     m_upAxis;
88       
89        btVector3       m_localScaling;
90
91        virtual btScalar        getHeightFieldValue(int x,int y) const;
92        void            quantizeWithClamp(int* out, const btVector3& point,int isMax) const;
93        void            getVertex(int x,int y,btVector3& vertex) const;
94
95
96
97        /// protected initialization
98        /**
99          Handles the work of constructors so that public constructors can be
100          backwards-compatible without a lot of copy/paste.
101         */
102        void initialize(int heightStickWidth, int heightStickLength,
103                        void* heightfieldData, btScalar heightScale,
104                        btScalar minHeight, btScalar maxHeight, int upAxis,
105                        PHY_ScalarType heightDataType, bool flipQuadEdges);
106
107public:
108        /// preferred constructor
109        /**
110          This constructor supports a range of heightfield
111          data types, and allows for a non-zero minimum height value.
112          heightScale is needed for any integer-based heightfield data types.
113         */
114        btHeightfieldTerrainShape(int heightStickWidth,int heightStickLength,
115                                  void* heightfieldData, btScalar heightScale,
116                                  btScalar minHeight, btScalar maxHeight,
117                                  int upAxis, PHY_ScalarType heightDataType,
118                                  bool flipQuadEdges);
119
120        /// legacy constructor
121        /**
122          The legacy constructor assumes the heightfield has a minimum height
123          of zero.  Only unsigned char or floats are supported.  For legacy
124          compatibility reasons, heightScale is calculated as maxHeight / 65535
125          (and is only used when useFloatData = false).
126         */
127        btHeightfieldTerrainShape(int heightStickWidth,int heightStickLength,void* heightfieldData, btScalar maxHeight,int upAxis,bool useFloatData,bool flipQuadEdges);
128
129        virtual ~btHeightfieldTerrainShape();
130
131
132        void setUseDiamondSubdivision(bool useDiamondSubdivision=true) { m_useDiamondSubdivision = useDiamondSubdivision;}
133
134
135        virtual void getAabb(const btTransform& t,btVector3& aabbMin,btVector3& aabbMax) const;
136
137        virtual void    processAllTriangles(btTriangleCallback* callback,const btVector3& aabbMin,const btVector3& aabbMax) const;
138
139        virtual void    calculateLocalInertia(btScalar mass,btVector3& inertia) const;
140
141        virtual void    setLocalScaling(const btVector3& scaling);
142       
143        virtual const btVector3& getLocalScaling() const;
144       
145        //debugging
146        virtual const char*     getName()const {return "HEIGHTFIELD";}
147
148};
149
150#endif //HEIGHTFIELD_TERRAIN_SHAPE_H
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