1 /*
2 Bullet Continuous Collision Detection and Physics Library
3 Copyright (c) 2003-2009 Erwin Coumans  http://bulletphysics.org
4 
5 This software is provided 'as-is', without any express or implied warranty.
6 In no event will the authors be held liable for any damages arising from the use of this software.
7 Permission is granted to anyone to use this software for any purpose,
8 including commercial applications, and to alter it and redistribute it freely,
9 subject to the following restrictions:
10 
11 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.
12 2. Altered source versions must be plainly marked as such, and must not be misrepresented as being the original software.
13 3. This notice may not be removed or altered from any source distribution.
14 */
15 
16 
17 #include "btTriangleMesh.h"
18 
19 
20 
btTriangleMesh(bool use32bitIndices,bool use4componentVertices)21 btTriangleMesh::btTriangleMesh (bool use32bitIndices,bool use4componentVertices)
22 :m_use32bitIndices(use32bitIndices),
23 m_use4componentVertices(use4componentVertices),
24 m_weldingThreshold(0.0)
25 {
26 	btIndexedMesh meshIndex;
27 	meshIndex.m_numTriangles = 0;
28 	meshIndex.m_numVertices = 0;
29 	meshIndex.m_indexType = PHY_INTEGER;
30 	meshIndex.m_triangleIndexBase = 0;
31 	meshIndex.m_triangleIndexStride = 3*sizeof(int);
32 	meshIndex.m_vertexBase = 0;
33 	meshIndex.m_vertexStride = sizeof(btVector3);
34 	m_indexedMeshes.push_back(meshIndex);
35 
36 	if (m_use32bitIndices)
37 	{
38 		m_indexedMeshes[0].m_numTriangles = m_32bitIndices.size()/3;
39 		m_indexedMeshes[0].m_triangleIndexBase = 0;
40 		m_indexedMeshes[0].m_indexType = PHY_INTEGER;
41 		m_indexedMeshes[0].m_triangleIndexStride = 3*sizeof(int);
42 	} else
43 	{
44 		m_indexedMeshes[0].m_numTriangles = m_16bitIndices.size()/3;
45 		m_indexedMeshes[0].m_triangleIndexBase = 0;
46 		m_indexedMeshes[0].m_indexType = PHY_SHORT;
47 		m_indexedMeshes[0].m_triangleIndexStride = 3*sizeof(short int);
48 	}
49 
50 	if (m_use4componentVertices)
51 	{
52 		m_indexedMeshes[0].m_numVertices = m_4componentVertices.size();
53 		m_indexedMeshes[0].m_vertexBase = 0;
54 		m_indexedMeshes[0].m_vertexStride = sizeof(btVector3);
55 	} else
56 	{
57 		m_indexedMeshes[0].m_numVertices = m_3componentVertices.size()/3;
58 		m_indexedMeshes[0].m_vertexBase = 0;
59 		m_indexedMeshes[0].m_vertexStride = 3*sizeof(btScalar);
60 	}
61 
62 
63 }
64 
addIndex(int index)65 void	btTriangleMesh::addIndex(int index)
66 {
67 	if (m_use32bitIndices)
68 	{
69 		m_32bitIndices.push_back(index);
70 		m_indexedMeshes[0].m_triangleIndexBase = (unsigned char*) &m_32bitIndices[0];
71 	} else
72 	{
73 		m_16bitIndices.push_back(index);
74 		m_indexedMeshes[0].m_triangleIndexBase = (unsigned char*) &m_16bitIndices[0];
75 	}
76 }
77 
78 
findOrAddVertex(const btVector3 & vertex,bool removeDuplicateVertices)79 int	btTriangleMesh::findOrAddVertex(const btVector3& vertex, bool removeDuplicateVertices)
80 {
81 	//return index of new/existing vertex
82 	///@todo: could use acceleration structure for this
83 	if (m_use4componentVertices)
84 	{
85 		if (removeDuplicateVertices)
86 			{
87 			for (int i=0;i< m_4componentVertices.size();i++)
88 			{
89 				if ((m_4componentVertices[i]-vertex).length2() <= m_weldingThreshold)
90 				{
91 					return i;
92 				}
93 			}
94 		}
95 		m_indexedMeshes[0].m_numVertices++;
96 		m_4componentVertices.push_back(vertex);
97 		m_indexedMeshes[0].m_vertexBase = (unsigned char*)&m_4componentVertices[0];
98 
99 		return m_4componentVertices.size()-1;
100 
101 	} else
102 	{
103 
104 		if (removeDuplicateVertices)
105 		{
106 			for (int i=0;i< m_3componentVertices.size();i+=3)
107 			{
108 				btVector3 vtx(m_3componentVertices[i],m_3componentVertices[i+1],m_3componentVertices[i+2]);
109 				if ((vtx-vertex).length2() <= m_weldingThreshold)
110 				{
111 					return i/3;
112 				}
113 			}
114 	}
115 		m_3componentVertices.push_back((float)vertex.getX());
116 		m_3componentVertices.push_back((float)vertex.getY());
117 		m_3componentVertices.push_back((float)vertex.getZ());
118 		m_indexedMeshes[0].m_numVertices++;
119 		m_indexedMeshes[0].m_vertexBase = (unsigned char*)&m_3componentVertices[0];
120 		return (m_3componentVertices.size()/3)-1;
121 	}
122 
123 }
124 
addTriangle(const btVector3 & vertex0,const btVector3 & vertex1,const btVector3 & vertex2,bool removeDuplicateVertices)125 void	btTriangleMesh::addTriangle(const btVector3& vertex0,const btVector3& vertex1,const btVector3& vertex2,bool removeDuplicateVertices)
126 {
127 	m_indexedMeshes[0].m_numTriangles++;
128 	addIndex(findOrAddVertex(vertex0,removeDuplicateVertices));
129 	addIndex(findOrAddVertex(vertex1,removeDuplicateVertices));
130 	addIndex(findOrAddVertex(vertex2,removeDuplicateVertices));
131 }
132 
getNumTriangles() const133 int btTriangleMesh::getNumTriangles() const
134 {
135 	if (m_use32bitIndices)
136 	{
137 		return m_32bitIndices.size() / 3;
138 	}
139 	return m_16bitIndices.size() / 3;
140 }
141