Bullet Collision Detection & Physics Library: btConvexHull.h Source File

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btConvexHull.h
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1
2/*
3Stan Melax Convex Hull Computation
4Copyright (c) 2008 Stan Melax http://www.melax.com/
5
6This software is provided 'as-is', without any express or implied warranty.
7In no event will the authors be held liable for any damages arising from the use of this software.
8Permission is granted to anyone to use this software for any purpose,
9including commercial applications, and to alter it and redistribute it freely,
10subject to the following restrictions:
11
121. 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.
132. Altered source versions must be plainly marked as such, and must not be misrepresented as being the original software.
143. This notice may not be removed or altered from any source distribution.
15*/
16
18
19#ifndef BT_CD_HULL_H
20#define BT_CD_HULL_H
21
22#include "btVector3.h"
23#include "btAlignedObjectArray.h"
24
25 typedef btAlignedObjectArray<unsigned int> TUIntArray;
26
27 class HullResult
28{
29public:
30 HullResult(void)
31 {
32 mPolygons = true;
33 mNumOutputVertices = 0;
34 mNumFaces = 0;
35 mNumIndices = 0;
36 }
37 bool mPolygons; // true if indices represents polygons, false indices are triangles
38 unsigned int mNumOutputVertices; // number of vertices in the output hull
39 btAlignedObjectArray<btVector3> m_OutputVertices; // array of vertices
40 unsigned int mNumFaces; // the number of faces produced
41 unsigned int mNumIndices; // the total number of indices
42 btAlignedObjectArray<unsigned int> m_Indices; // pointer to indices.
43
44 // If triangles, then indices are array indexes into the vertex list.
45 // If polygons, indices are in the form (number of points in face) (p1, p2, p3, ..) etc..
46};
47
48 enum HullFlag
49{
50 QF_TRIANGLES = (1 << 0), // report results as triangles, not polygons.
51 QF_REVERSE_ORDER = (1 << 1), // reverse order of the triangle indices.
52 QF_DEFAULT = QF_TRIANGLES
53};
54
55 class HullDesc
56{
57public:
58 HullDesc(void)
59 {
60 mFlags = QF_DEFAULT;
61 mVcount = 0;
62 mVertices = 0;
63 mVertexStride = sizeof(btVector3);
64 mNormalEpsilon = 0.001f;
65 mMaxVertices = 4096; // maximum number of points to be considered for a convex hull.
66 mMaxFaces = 4096;
67 };
68
69 HullDesc(HullFlag flag,
70 unsigned int vcount,
71 const btVector3* vertices,
72 unsigned int stride = sizeof(btVector3))
73 {
74 mFlags = flag;
75 mVcount = vcount;
76 mVertices = vertices;
77 mVertexStride = stride;
78 mNormalEpsilon = btScalar(0.001);
79 mMaxVertices = 4096;
80 }
81
82 bool HasHullFlag(HullFlag flag) const
83 {
84 if (mFlags & flag) return true;
85 return false;
86 }
87
88 void SetHullFlag(HullFlag flag)
89 {
90 mFlags |= flag;
91 }
92
93 void ClearHullFlag(HullFlag flag)
94 {
95 mFlags &= ~flag;
96 }
97
98 unsigned int mFlags; // flags to use when generating the convex hull.
99 unsigned int mVcount; // number of vertices in the input point cloud
100 const btVector3* mVertices; // the array of vertices.
101 unsigned int mVertexStride; // the stride of each vertex, in bytes.
102 btScalar mNormalEpsilon; // the epsilon for removing duplicates. This is a normalized value, if normalized bit is on.
103 unsigned int mMaxVertices; // maximum number of vertices to be considered for the hull!
104 unsigned int mMaxFaces;
105};
106
107 enum HullError
108{
109 QE_OK, // success!
110 QE_FAIL // failed.
111};
112
113 class btPlane
114{
115public:
116 btVector3 normal;
117 btScalar dist; // distance below origin - the D from plane equasion Ax+By+Cz+D=0
118 btPlane(const btVector3& n, btScalar d) : normal(n), dist(d) {}
119 btPlane() : normal(), dist(0) {}
120};
121
122 class ConvexH
123{
124public:
125 class HalfEdge
126 {
127 public:
128 short ea; // the other half of the edge (index into edges list)
129 unsigned char v; // the vertex at the start of this edge (index into vertices list)
130 unsigned char p; // the facet on which this edge lies (index into facets list)
131 HalfEdge() {}
132 HalfEdge(short _ea, unsigned char _v, unsigned char _p) : ea(_ea), v(_v), p(_p) {}
133 };
134 ConvexH()
135 {
136 }
137 ~ConvexH()
138 {
139 }
140 btAlignedObjectArray<btVector3> vertices;
141 btAlignedObjectArray<HalfEdge> edges;
142 btAlignedObjectArray<btPlane> facets;
143 ConvexH(int vertices_size, int edges_size, int facets_size);
144};
145
146 class int4
147{
148public:
149 int x, y, z, w;
150 int4(){};
151 int4(int _x, int _y, int _z, int _w)
152 {
153 x = _x;
154 y = _y;
155 z = _z;
156 w = _w;
157 }
158 const int& operator[](int i) const { return (&x)[i]; }
159 int& operator[](int i) { return (&x)[i]; }
160};
161
162 class PHullResult
163{
164public:
165 PHullResult(void)
166 {
167 mVcount = 0;
168 mIndexCount = 0;
169 mFaceCount = 0;
170 mVertices = 0;
171 }
172
173 unsigned int mVcount;
174 unsigned int mIndexCount;
175 unsigned int mFaceCount;
176 btVector3* mVertices;
177 TUIntArray m_Indices;
178};
179
182 class HullLibrary
183{
184 btAlignedObjectArray<class btHullTriangle*> m_tris;
185
186public:
187 btAlignedObjectArray<int> m_vertexIndexMapping;
188
189 HullError CreateConvexHull(const HullDesc& desc, // describes the input request
190 HullResult& result); // contains the resulst
191 HullError ReleaseResult(HullResult& result); // release memory allocated for this result, we are done with it.
192
193private:
194 bool ComputeHull(unsigned int vcount, const btVector3* vertices, PHullResult& result, unsigned int vlimit);
195
196 class btHullTriangle* allocateTriangle(int a, int b, int c);
197 void deAllocateTriangle(btHullTriangle*);
198 void b2bfix(btHullTriangle* s, btHullTriangle* t);
199
200 void removeb2b(btHullTriangle* s, btHullTriangle* t);
201
202 void checkit(btHullTriangle* t);
203
204 btHullTriangle* extrudable(btScalar epsilon);
205
206 int calchull(btVector3* verts, int verts_count, TUIntArray& tris_out, int& tris_count, int vlimit);
207
208 int calchullgen(btVector3* verts, int verts_count, int vlimit);
209
210 int4 FindSimplex(btVector3* verts, int verts_count, btAlignedObjectArray<int>& allow);
211
212 class ConvexH* ConvexHCrop(ConvexH& convex, const btPlane& slice);
213
214 void extrude(class btHullTriangle* t0, int v);
215
216 ConvexH* test_cube();
217
218 //BringOutYourDead (John Ratcliff): When you create a convex hull you hand it a large input set of vertices forming a 'point cloud'.
219 //After the hull is generated it give you back a set of polygon faces which index the *original* point cloud.
220 //The thing is, often times, there are many 'dead vertices' in the point cloud that are on longer referenced by the hull.
221 //The routine 'BringOutYourDead' find only the referenced vertices, copies them to an new buffer, and re-indexes the hull so that it is a minimal representation.
222 void BringOutYourDead(const btVector3* verts, unsigned int vcount, btVector3* overts, unsigned int& ocount, unsigned int* indices, unsigned indexcount);
223
224 bool CleanupVertices(unsigned int svcount,
225 const btVector3* svertices,
226 unsigned int stride,
227 unsigned int& vcount, // output number of vertices
228 btVector3* vertices, // location to store the results.
229 btScalar normalepsilon,
230 btVector3& scale);
231};
232
233#endif //BT_CD_HULL_H
btAlignedObjectArray.h
HullError
HullError
Definition btConvexHull.h:108
QE_OK
@ QE_OK
Definition btConvexHull.h:109
QE_FAIL
@ QE_FAIL
Definition btConvexHull.h:110
TUIntArray
btAlignedObjectArray< unsigned int > TUIntArray
includes modifications/improvements by John Ratcliff, see BringOutYourDead below.
Definition btConvexHull.h:25
HullFlag
HullFlag
Definition btConvexHull.h:49
QF_TRIANGLES
@ QF_TRIANGLES
Definition btConvexHull.h:50
QF_REVERSE_ORDER
@ QF_REVERSE_ORDER
Definition btConvexHull.h:51
QF_DEFAULT
@ QF_DEFAULT
Definition btConvexHull.h:52
btScalar
float btScalar
The btScalar type abstracts floating point numbers, to easily switch between double and single floati...
Definition btScalar.h:314
btVector3.h
ConvexH::HalfEdge
Definition btConvexHull.h:126
ConvexH::HalfEdge::HalfEdge
HalfEdge()
Definition btConvexHull.h:131
ConvexH::HalfEdge::p
unsigned char p
Definition btConvexHull.h:130
ConvexH::HalfEdge::ea
short ea
Definition btConvexHull.h:128
ConvexH::HalfEdge::v
unsigned char v
Definition btConvexHull.h:129
ConvexH::HalfEdge::HalfEdge
HalfEdge(short _ea, unsigned char _v, unsigned char _p)
Definition btConvexHull.h:132
ConvexH
Definition btConvexHull.h:123
ConvexH::edges
btAlignedObjectArray< HalfEdge > edges
Definition btConvexHull.h:141
ConvexH::~ConvexH
~ConvexH()
Definition btConvexHull.h:137
ConvexH::facets
btAlignedObjectArray< btPlane > facets
Definition btConvexHull.h:142
ConvexH::vertices
btAlignedObjectArray< btVector3 > vertices
Definition btConvexHull.h:140
ConvexH::ConvexH
ConvexH()
Definition btConvexHull.h:134
HullDesc
Definition btConvexHull.h:56
HullDesc::HullDesc
HullDesc(HullFlag flag, unsigned int vcount, const btVector3 *vertices, unsigned int stride=sizeof(btVector3))
Definition btConvexHull.h:69
HullDesc::HasHullFlag
bool HasHullFlag(HullFlag flag) const
Definition btConvexHull.h:82
HullDesc::mVcount
unsigned int mVcount
Definition btConvexHull.h:99
HullDesc::mFlags
unsigned int mFlags
Definition btConvexHull.h:98
HullDesc::mNormalEpsilon
btScalar mNormalEpsilon
Definition btConvexHull.h:102
HullDesc::mMaxFaces
unsigned int mMaxFaces
Definition btConvexHull.h:104
HullDesc::HullDesc
HullDesc(void)
Definition btConvexHull.h:58
HullDesc::ClearHullFlag
void ClearHullFlag(HullFlag flag)
Definition btConvexHull.h:93
HullDesc::mMaxVertices
unsigned int mMaxVertices
Definition btConvexHull.h:103
HullDesc::mVertices
const btVector3 * mVertices
Definition btConvexHull.h:100
HullDesc::mVertexStride
unsigned int mVertexStride
Definition btConvexHull.h:101
HullDesc::SetHullFlag
void SetHullFlag(HullFlag flag)
Definition btConvexHull.h:88
HullLibrary
The HullLibrary class can create a convex hull from a collection of vertices, using the ComputeHull m...
Definition btConvexHull.h:183
HullLibrary::extrudable
btHullTriangle * extrudable(btScalar epsilon)
Definition btConvexHull.cpp:443
HullLibrary::allocateTriangle
class btHullTriangle * allocateTriangle(int a, int b, int c)
Definition btConvexHull.cpp:403
HullLibrary::ComputeHull
bool ComputeHull(unsigned int vcount, const btVector3 *vertices, PHullResult &result, unsigned int vlimit)
Definition btConvexHull.cpp:633
HullLibrary::ReleaseResult
HullError ReleaseResult(HullResult &result)
Definition btConvexHull.cpp:789
HullLibrary::BringOutYourDead
void BringOutYourDead(const btVector3 *verts, unsigned int vcount, btVector3 *overts, unsigned int &ocount, unsigned int *indices, unsigned indexcount)
Definition btConvexHull.cpp:1074
HullLibrary::CreateConvexHull
HullError CreateConvexHull(const HullDesc &desc, HullResult &result)
Definition btConvexHull.cpp:670
HullLibrary::deAllocateTriangle
void deAllocateTriangle(btHullTriangle *)
Definition btConvexHull.cpp:413
HullLibrary::calchull
int calchull(btVector3 *verts, int verts_count, TUIntArray &tris_out, int &tris_count, int vlimit)
Definition btConvexHull.cpp:605
HullLibrary::m_vertexIndexMapping
btAlignedObjectArray< int > m_vertexIndexMapping
Definition btConvexHull.h:187
HullLibrary::b2bfix
void b2bfix(btHullTriangle *s, btHullTriangle *t)
Definition btConvexHull.cpp:355
HullLibrary::removeb2b
void removeb2b(btHullTriangle *s, btHullTriangle *t)
Definition btConvexHull.cpp:371
HullLibrary::m_tris
btAlignedObjectArray< class btHullTriangle * > m_tris
Definition btConvexHull.h:184
HullLibrary::ConvexHCrop
class ConvexH * ConvexHCrop(ConvexH &convex, const btPlane &slice)
HullLibrary::checkit
void checkit(btHullTriangle *t)
Definition btConvexHull.cpp:379
HullLibrary::test_cube
ConvexH * test_cube()
HullLibrary::extrude
void extrude(class btHullTriangle *t0, int v)
Definition btConvexHull.cpp:421
HullLibrary::calchullgen
int calchullgen(btVector3 *verts, int verts_count, int vlimit)
Definition btConvexHull.cpp:498
HullLibrary::FindSimplex
int4 FindSimplex(btVector3 *verts, int verts_count, btAlignedObjectArray< int > &allow)
Definition btConvexHull.cpp:457
HullLibrary::CleanupVertices
bool CleanupVertices(unsigned int svcount, const btVector3 *svertices, unsigned int stride, unsigned int &vcount, btVector3 *vertices, btScalar normalepsilon, btVector3 &scale)
Definition btConvexHull.cpp:824
HullResult
Definition btConvexHull.h:28
HullResult::m_OutputVertices
btAlignedObjectArray< btVector3 > m_OutputVertices
Definition btConvexHull.h:39
HullResult::m_Indices
btAlignedObjectArray< unsigned int > m_Indices
Definition btConvexHull.h:42
HullResult::HullResult
HullResult(void)
Definition btConvexHull.h:30
HullResult::mNumOutputVertices
unsigned int mNumOutputVertices
Definition btConvexHull.h:38
HullResult::mNumFaces
unsigned int mNumFaces
Definition btConvexHull.h:40
HullResult::mPolygons
bool mPolygons
Definition btConvexHull.h:37
HullResult::mNumIndices
unsigned int mNumIndices
Definition btConvexHull.h:41
PHullResult
Definition btConvexHull.h:163
PHullResult::mFaceCount
unsigned int mFaceCount
Definition btConvexHull.h:175
PHullResult::PHullResult
PHullResult(void)
Definition btConvexHull.h:165
PHullResult::mVcount
unsigned int mVcount
Definition btConvexHull.h:173
PHullResult::mIndexCount
unsigned int mIndexCount
Definition btConvexHull.h:174
PHullResult::mVertices
btVector3 * mVertices
Definition btConvexHull.h:176
PHullResult::m_Indices
TUIntArray m_Indices
Definition btConvexHull.h:177
btAlignedObjectArray
The btAlignedObjectArray template class uses a subset of the stl::vector interface for its methods It...
Definition btAlignedObjectArray.h:46
btHullTriangle
Definition btConvexHull.cpp:324
btPlane
Definition btConvexHull.h:114
btPlane::btPlane
btPlane()
Definition btConvexHull.h:119
btPlane::btPlane
btPlane(const btVector3 &n, btScalar d)
Definition btConvexHull.h:118
btPlane::normal
btVector3 normal
Definition btConvexHull.h:116
btPlane::dist
btScalar dist
Definition btConvexHull.h:117
btVector3
btVector3 can be used to represent 3D points and vectors.
Definition btVector3.h:82
int4
Definition btConvexHull.h:147
int4::x
int x
Definition btConvexHull.h:149
int4::w
int w
Definition btConvexHull.h:149
int4::int4
int4()
Definition btConvexHull.h:150
int4::int4
int4(int _x, int _y, int _z, int _w)
Definition btConvexHull.h:151
int4::y
int y
Definition btConvexHull.h:149
int4::operator[]
int & operator[](int i)
Definition btConvexHull.h:159
int4::z
int z
Definition btConvexHull.h:149
int4::operator[]
const int & operator[](int i) const
Definition btConvexHull.h:158