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

Bullet Collision Detection & Physics Library

btConvexHull.h
Go to the documentation of this file.
1
2 /*
3 Stan Melax Convex Hull Computation
4 Copyright (c) 2008 Stan Melax http://www.melax.com/
5
6 This software is provided 'as-is', without any express or implied warranty.
7 In no event will the authors be held liable for any damages arising from the use of this software.
8 Permission is granted to anyone to use this software for any purpose,
9 including commercial applications, and to alter it and redistribute it freely,
10 subject to the following restrictions:
11
12 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.
13 2. Altered source versions must be plainly marked as such, and must not be misrepresented as being the original software.
14 3. 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 {
29 public:
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 {
57 public:
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 {
115 public:
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 {
124 public:
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 {
148 public:
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 {
164 public:
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
186 public:
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
193 private:
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
HullError
HullError
Definition: btConvexHull.h:108
HullResult::mNumFaces
unsigned int mNumFaces
Definition: btConvexHull.h:40
HullLibrary::ReleaseResult
HullError ReleaseResult(HullResult &result)
Definition: btConvexHull.cpp:787
ConvexH::~ConvexH
~ConvexH()
Definition: btConvexHull.h:137
HullDesc::mMaxVertices
unsigned int mMaxVertices
Definition: btConvexHull.h:103
ConvexH
Definition: btConvexHull.h:123
btPlane::normal
btVector3 normal
Definition: btConvexHull.h:116
int4::y
int y
Definition: btConvexHull.h:149
QE_OK
@ QE_OK
Definition: btConvexHull.h:109
btScalar
float btScalar
The btScalar type abstracts floating point numbers, to easily switch between double and single floati...
Definition: btScalar.h:314
ConvexH::ConvexH
ConvexH()
Definition: btConvexHull.h:134
HullResult::HullResult
HullResult(void)
Definition: btConvexHull.h:30
QF_DEFAULT
@ QF_DEFAULT
Definition: btConvexHull.h:52
ConvexH::vertices
btAlignedObjectArray< btVector3 > vertices
Definition: btConvexHull.h:140
ConvexH::HalfEdge::v
unsigned char v
Definition: btConvexHull.h:129
btHullTriangle
Definition: btConvexHull.cpp:324
HullResult::m_OutputVertices
btAlignedObjectArray< btVector3 > m_OutputVertices
Definition: btConvexHull.h:39
HullLibrary::extrude
void extrude(class btHullTriangle *t0, int v)
Definition: btConvexHull.cpp:421
HullLibrary::ComputeHull
bool ComputeHull(unsigned int vcount, const btVector3 *vertices, PHullResult &result, unsigned int vlimit)
Definition: btConvexHull.cpp:633
QF_REVERSE_ORDER
@ QF_REVERSE_ORDER
Definition: btConvexHull.h:51
int4::int4
int4(int _x, int _y, int _z, int _w)
Definition: btConvexHull.h:151
HullLibrary::deAllocateTriangle
void deAllocateTriangle(btHullTriangle *)
Definition: btConvexHull.cpp:413
btPlane::dist
btScalar dist
Definition: btConvexHull.h:117
HullDesc::mFlags
unsigned int mFlags
Definition: btConvexHull.h:98
QF_TRIANGLES
@ QF_TRIANGLES
Definition: btConvexHull.h:50
HullFlag
HullFlag
Definition: btConvexHull.h:49
HullLibrary
The HullLibrary class can create a convex hull from a collection of vertices, using the ComputeHull m...
Definition: btConvexHull.h:183
HullDesc::HullDesc
HullDesc(void)
Definition: btConvexHull.h:58
PHullResult::mFaceCount
unsigned int mFaceCount
Definition: btConvexHull.h:175
HullResult::mNumOutputVertices
unsigned int mNumOutputVertices
Definition: btConvexHull.h:38
HullDesc::mVcount
unsigned int mVcount
Definition: btConvexHull.h:99
HullDesc::mVertices
const btVector3 * mVertices
Definition: btConvexHull.h:100
btPlane::btPlane
btPlane()
Definition: btConvexHull.h:119
btVector3.h
HullDesc::HullDesc
HullDesc(HullFlag flag, unsigned int vcount, const btVector3 *vertices, unsigned int stride=sizeof(btVector3))
Definition: btConvexHull.h:69
int4::z
int z
Definition: btConvexHull.h:149
btPlane
Definition: btConvexHull.h:114
HullLibrary::CreateConvexHull
HullError CreateConvexHull(const HullDesc &desc, HullResult &result)
Definition: btConvexHull.cpp:670
QE_FAIL
@ QE_FAIL
Definition: btConvexHull.h:110
PHullResult::mVertices
btVector3 * mVertices
Definition: btConvexHull.h:176
HullDesc::HasHullFlag
bool HasHullFlag(HullFlag flag) const
Definition: btConvexHull.h:82
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:822
btPlane::btPlane
btPlane(const btVector3 &n, btScalar d)
Definition: btConvexHull.h:118
int4::operator[]
const int & operator[](int i) const
Definition: btConvexHull.h:158
HullLibrary::m_tris
btAlignedObjectArray< class btHullTriangle * > m_tris
Definition: btConvexHull.h:184
HullLibrary::BringOutYourDead
void BringOutYourDead(const btVector3 *verts, unsigned int vcount, btVector3 *overts, unsigned int &ocount, unsigned int *indices, unsigned indexcount)
Definition: btConvexHull.cpp:1072
PHullResult
Definition: btConvexHull.h:163
HullDesc
Definition: btConvexHull.h:56
PHullResult::PHullResult
PHullResult(void)
Definition: btConvexHull.h:165
TUIntArray
btAlignedObjectArray< unsigned int > TUIntArray
includes modifications/improvements by John Ratcliff, see BringOutYourDead below.
Definition: btConvexHull.h:25
btVector3
btVector3 can be used to represent 3D points and vectors.
Definition: btVector3.h:82
int4::operator[]
int & operator[](int i)
Definition: btConvexHull.h:159
HullLibrary::extrudable
btHullTriangle * extrudable(btScalar epsilon)
Definition: btConvexHull.cpp:443
HullResult::mPolygons
bool mPolygons
Definition: btConvexHull.h:37
HullDesc::ClearHullFlag
void ClearHullFlag(HullFlag flag)
Definition: btConvexHull.h:93
HullDesc::mMaxFaces
unsigned int mMaxFaces
Definition: btConvexHull.h:104
ConvexH::facets
btAlignedObjectArray< btPlane > facets
Definition: btConvexHull.h:142
HullLibrary::m_vertexIndexMapping
btAlignedObjectArray< int > m_vertexIndexMapping
Definition: btConvexHull.h:187
HullLibrary::calchullgen
int calchullgen(btVector3 *verts, int verts_count, int vlimit)
Definition: btConvexHull.cpp:498
HullDesc::mNormalEpsilon
btScalar mNormalEpsilon
Definition: btConvexHull.h:102
HullLibrary::allocateTriangle
class btHullTriangle * allocateTriangle(int a, int b, int c)
Definition: btConvexHull.cpp:403
HullLibrary::b2bfix
void b2bfix(btHullTriangle *s, btHullTriangle *t)
Definition: btConvexHull.cpp:355
int4::w
int w
Definition: btConvexHull.h:149
btAlignedObjectArray< unsigned int >
ConvexH::HalfEdge::p
unsigned char p
Definition: btConvexHull.h:130
int4
Definition: btConvexHull.h:147
HullDesc::mVertexStride
unsigned int mVertexStride
Definition: btConvexHull.h:101
PHullResult::m_Indices
TUIntArray m_Indices
Definition: btConvexHull.h:177
PHullResult::mVcount
unsigned int mVcount
Definition: btConvexHull.h:173
ConvexH::HalfEdge
Definition: btConvexHull.h:126
HullResult
Definition: btConvexHull.h:28
HullLibrary::ConvexHCrop
class ConvexH * ConvexHCrop(ConvexH &convex, const btPlane &slice)
HullDesc::SetHullFlag
void SetHullFlag(HullFlag flag)
Definition: btConvexHull.h:88
ConvexH::edges
btAlignedObjectArray< HalfEdge > edges
Definition: btConvexHull.h:141
btAlignedObjectArray.h
HullResult::mNumIndices
unsigned int mNumIndices
Definition: btConvexHull.h:41
ConvexH::HalfEdge::HalfEdge
HalfEdge(short _ea, unsigned char _v, unsigned char _p)
Definition: btConvexHull.h:132
HullLibrary::checkit
void checkit(btHullTriangle *t)
Definition: btConvexHull.cpp:379
HullResult::m_Indices
btAlignedObjectArray< unsigned int > m_Indices
Definition: btConvexHull.h:42
HullLibrary::test_cube
ConvexH * test_cube()
int4::int4
int4()
Definition: btConvexHull.h:150
int4::x
int x
Definition: btConvexHull.h:149
PHullResult::mIndexCount
unsigned int mIndexCount
Definition: btConvexHull.h:174
ConvexH::HalfEdge::HalfEdge
HalfEdge()
Definition: btConvexHull.h:131
HullLibrary::calchull
int calchull(btVector3 *verts, int verts_count, TUIntArray &tris_out, int &tris_count, int vlimit)
Definition: btConvexHull.cpp:605
ConvexH::HalfEdge::ea
short ea
Definition: btConvexHull.h:128
HullLibrary::removeb2b
void removeb2b(btHullTriangle *s, btHullTriangle *t)
Definition: btConvexHull.cpp:371
HullLibrary::FindSimplex
int4 FindSimplex(btVector3 *verts, int verts_count, btAlignedObjectArray< int > &allow)
Definition: btConvexHull.cpp:457