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source: code/trunk/src/external/bullet/BulletCollision/CollisionShapes/btHeightfieldTerrainShape.h @ 11566

Last change on this file since 11566 was 8393, checked in by rgrieder, 14 years ago

Updated Bullet from v2.77 to v2.78.
(I'm not going to make a branch for that since the update from 2.74 to 2.77 hasn't been tested that much either).

You will HAVE to do a complete RECOMPILE! I tested with MSVC and MinGW and they both threw linker errors at me.

  • Property svn:eol-style set to native
File size: 6.2 KB
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1/*
2Bullet Continuous Collision Detection and Physics Library
3Copyright (c) 2003-2009 Erwin Coumans  http://bulletphysics.org
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 BT_HEIGHTFIELD_TERRAIN_SHAPE_H
17#define BT_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  \b NOTE: be careful with coordinates.  If you have a heightfield with a local
34  min height of -100m, and a max height of +500m, you may be tempted to place it
35  at the origin (0,0) and expect the heights in world coordinates to be
36  -100 to +500 meters.
37  Actually, the heights will be -300 to +300m, because bullet will re-center
38  the heightfield based on its AABB (which is determined by the min/max
39  heights).  So keep in mind that once you create a btHeightfieldTerrainShape
40  object, the heights will be adjusted relative to the center of the AABB.  This
41  is different to the behavior of many rendering engines, but is useful for
42  physics engines.
43
44  Most (but not all) rendering and heightfield libraries assume upAxis = 1
45  (that is, the y-axis is "up").  This class allows any of the 3 coordinates
46  to be "up".  Make sure your choice of axis is consistent with your rendering
47  system.
48
49  The heightfield heights are determined from the data type used for the
50  heightfieldData array. 
51
52   - PHY_UCHAR: height at a point is the uchar value at the
53       grid point, multipled by heightScale.  uchar isn't recommended
54       because of its inability to deal with negative values, and
55       low resolution (8-bit).
56
57   - PHY_SHORT: height at a point is the short int value at that grid
58       point, multipled by heightScale.
59
60   - PHY_FLOAT: height at a point is the float value at that grid
61       point.  heightScale is ignored when using the float heightfield
62       data type.
63
64  Whatever the caller specifies as minHeight and maxHeight will be honored.
65  The class will not inspect the heightfield to discover the actual minimum
66  or maximum heights.  These values are used to determine the heightfield's
67  axis-aligned bounding box, multiplied by localScaling.
68
69  For usage and testing see the TerrainDemo.
70 */
71class btHeightfieldTerrainShape : public btConcaveShape
72{
73protected:
74        btVector3       m_localAabbMin;
75        btVector3       m_localAabbMax;
76        btVector3       m_localOrigin;
77
78        ///terrain data
79        int     m_heightStickWidth;
80        int m_heightStickLength;
81        btScalar        m_minHeight;
82        btScalar        m_maxHeight;
83        btScalar m_width;
84        btScalar m_length;
85        btScalar m_heightScale;
86        union
87        {
88                unsigned char*  m_heightfieldDataUnsignedChar;
89                short*          m_heightfieldDataShort;
90                btScalar*                       m_heightfieldDataFloat;
91                void*                   m_heightfieldDataUnknown;
92        };
93
94        PHY_ScalarType  m_heightDataType;       
95        bool    m_flipQuadEdges;
96  bool  m_useDiamondSubdivision;
97
98        int     m_upAxis;
99       
100        btVector3       m_localScaling;
101
102        virtual btScalar        getRawHeightFieldValue(int x,int y) const;
103        void            quantizeWithClamp(int* out, const btVector3& point,int isMax) const;
104        void            getVertex(int x,int y,btVector3& vertex) const;
105
106
107
108        /// protected initialization
109        /**
110          Handles the work of constructors so that public constructors can be
111          backwards-compatible without a lot of copy/paste.
112         */
113        void initialize(int heightStickWidth, int heightStickLength,
114                        void* heightfieldData, btScalar heightScale,
115                        btScalar minHeight, btScalar maxHeight, int upAxis,
116                        PHY_ScalarType heightDataType, bool flipQuadEdges);
117
118public:
119        /// preferred constructor
120        /**
121          This constructor supports a range of heightfield
122          data types, and allows for a non-zero minimum height value.
123          heightScale is needed for any integer-based heightfield data types.
124         */
125        btHeightfieldTerrainShape(int heightStickWidth,int heightStickLength,
126                                  void* heightfieldData, btScalar heightScale,
127                                  btScalar minHeight, btScalar maxHeight,
128                                  int upAxis, PHY_ScalarType heightDataType,
129                                  bool flipQuadEdges);
130
131        /// legacy constructor
132        /**
133          The legacy constructor assumes the heightfield has a minimum height
134          of zero.  Only unsigned char or floats are supported.  For legacy
135          compatibility reasons, heightScale is calculated as maxHeight / 65535
136          (and is only used when useFloatData = false).
137         */
138        btHeightfieldTerrainShape(int heightStickWidth,int heightStickLength,void* heightfieldData, btScalar maxHeight,int upAxis,bool useFloatData,bool flipQuadEdges);
139
140        virtual ~btHeightfieldTerrainShape();
141
142
143        void setUseDiamondSubdivision(bool useDiamondSubdivision=true) { m_useDiamondSubdivision = useDiamondSubdivision;}
144
145
146        virtual void getAabb(const btTransform& t,btVector3& aabbMin,btVector3& aabbMax) const;
147
148        virtual void    processAllTriangles(btTriangleCallback* callback,const btVector3& aabbMin,const btVector3& aabbMax) const;
149
150        virtual void    calculateLocalInertia(btScalar mass,btVector3& inertia) const;
151
152        virtual void    setLocalScaling(const btVector3& scaling);
153       
154        virtual const btVector3& getLocalScaling() const;
155       
156        //debugging
157        virtual const char*     getName()const {return "HEIGHTFIELD";}
158
159};
160
161#endif //BT_HEIGHTFIELD_TERRAIN_SHAPE_H
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