Bullet Collision Detection & Physics Library: btTriangleShapeEx.cpp Source File

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btTriangleShapeEx.cpp
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1
4 /*
5 This source file is part of GIMPACT Library.
6
7 For the latest info, see http://gimpact.sourceforge.net/
8
9 Copyright (c) 2007 Francisco Leon Najera. C.C. 80087371.
10 email: projectileman@yahoo.com
11
12
13 This software is provided 'as-is', without any express or implied warranty.
14 In no event will the authors be held liable for any damages arising from the use of this software.
15 Permission is granted to anyone to use this software for any purpose,
16 including commercial applications, and to alter it and redistribute it freely,
17 subject to the following restrictions:
18
19 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.
20 2. Altered source versions must be plainly marked as such, and must not be misrepresented as being the original software.
21 3. This notice may not be removed or altered from any source distribution.
22 */
23
24 #include "btTriangleShapeEx.h"
25
26
27
28 void GIM_TRIANGLE_CONTACT::merge_points(const btVector4 & plane,
29 btScalar margin, const btVector3 * points, int point_count)
30 {
31 m_point_count = 0;
32 m_penetration_depth= -1000.0f;
33
34 int point_indices[MAX_TRI_CLIPPING];
35
36 int _k;
37
38 for ( _k=0;_k<point_count;_k++)
39 {
40 btScalar _dist = - bt_distance_point_plane(plane,points[_k]) + margin;
41
42 if (_dist>=0.0f)
43 {
44 if (_dist>m_penetration_depth)
45 {
46 m_penetration_depth = _dist;
47 point_indices[0] = _k;
48 m_point_count=1;
49 }
50 else if ((_dist+SIMD_EPSILON)>=m_penetration_depth)
51 {
52 point_indices[m_point_count] = _k;
53 m_point_count++;
54 }
55 }
56 }
57
58 for ( _k=0;_k<m_point_count;_k++)
59 {
60 m_points[_k] = points[point_indices[_k]];
61 }
62 }
63
65 bool btPrimitiveTriangle::overlap_test_conservative(const btPrimitiveTriangle& other)
66 {
67 btScalar total_margin = m_margin + other.m_margin;
68 // classify points on other triangle
69 btScalar dis0 = bt_distance_point_plane(m_plane,other.m_vertices[0]) - total_margin;
70
71 btScalar dis1 = bt_distance_point_plane(m_plane,other.m_vertices[1]) - total_margin;
72
73 btScalar dis2 = bt_distance_point_plane(m_plane,other.m_vertices[2]) - total_margin;
74
75 if (dis0>0.0f&&dis1>0.0f&&dis2>0.0f) return false;
76
77 // classify points on this triangle
78 dis0 = bt_distance_point_plane(other.m_plane,m_vertices[0]) - total_margin;
79
80 dis1 = bt_distance_point_plane(other.m_plane,m_vertices[1]) - total_margin;
81
82 dis2 = bt_distance_point_plane(other.m_plane,m_vertices[2]) - total_margin;
83
84 if (dis0>0.0f&&dis1>0.0f&&dis2>0.0f) return false;
85
86 return true;
87 }
88
89 int btPrimitiveTriangle::clip_triangle(btPrimitiveTriangle & other, btVector3 * clipped_points )
90 {
91 // edge 0
92
93 btVector3 temp_points[MAX_TRI_CLIPPING];
94
95
96 btVector4 edgeplane;
97
98 get_edge_plane(0,edgeplane);
99
100
101 int clipped_count = bt_plane_clip_triangle(
102 edgeplane,other.m_vertices[0],other.m_vertices[1],other.m_vertices[2],temp_points);
103
104 if (clipped_count == 0) return 0;
105
106 btVector3 temp_points1[MAX_TRI_CLIPPING];
107
108
109 // edge 1
110 get_edge_plane(1,edgeplane);
111
112
113 clipped_count = bt_plane_clip_polygon(edgeplane,temp_points,clipped_count,temp_points1);
114
115 if (clipped_count == 0) return 0;
116
117 // edge 2
118 get_edge_plane(2,edgeplane);
119
120 clipped_count = bt_plane_clip_polygon(
121 edgeplane,temp_points1,clipped_count,clipped_points);
122
123 return clipped_count;
124 }
125
126 bool btPrimitiveTriangle::find_triangle_collision_clip_method(btPrimitiveTriangle & other, GIM_TRIANGLE_CONTACT & contacts)
127 {
128 btScalar margin = m_margin + other.m_margin;
129
130 btVector3 clipped_points[MAX_TRI_CLIPPING];
131 int clipped_count;
132 //create planes
133 // plane v vs U points
134
135 GIM_TRIANGLE_CONTACT contacts1;
136
137 contacts1.m_separating_normal = m_plane;
138
139
140 clipped_count = clip_triangle(other,clipped_points);
141
142 if (clipped_count == 0 )
143 {
144 return false;//Reject
145 }
146
147 //find most deep interval face1
148 contacts1.merge_points(contacts1.m_separating_normal,margin,clipped_points,clipped_count);
149 if (contacts1.m_point_count == 0) return false; // too far
150 //Normal pointing to this triangle
151 contacts1.m_separating_normal *= -1.f;
152
153
154 //Clip tri1 by tri2 edges
155 GIM_TRIANGLE_CONTACT contacts2;
156 contacts2.m_separating_normal = other.m_plane;
157
158 clipped_count = other.clip_triangle(*this,clipped_points);
159
160 if (clipped_count == 0 )
161 {
162 return false;//Reject
163 }
164
165 //find most deep interval face1
166 contacts2.merge_points(contacts2.m_separating_normal,margin,clipped_points,clipped_count);
167 if (contacts2.m_point_count == 0) return false; // too far
168
169
170
171
173 if (contacts2.m_penetration_depth<contacts1.m_penetration_depth)
174 {
175 contacts.copy_from(contacts2);
176 }
177 else
178 {
179 contacts.copy_from(contacts1);
180 }
181 return true;
182 }
183
184
185
187
188 bool btTriangleShapeEx::overlap_test_conservative(const btTriangleShapeEx& other)
189 {
190 btScalar total_margin = getMargin() + other.getMargin();
191
192 btVector4 plane0;
193 buildTriPlane(plane0);
194 btVector4 plane1;
195 other.buildTriPlane(plane1);
196
197 // classify points on other triangle
198 btScalar dis0 = bt_distance_point_plane(plane0,other.m_vertices1[0]) - total_margin;
199
200 btScalar dis1 = bt_distance_point_plane(plane0,other.m_vertices1[1]) - total_margin;
201
202 btScalar dis2 = bt_distance_point_plane(plane0,other.m_vertices1[2]) - total_margin;
203
204 if (dis0>0.0f&&dis1>0.0f&&dis2>0.0f) return false;
205
206 // classify points on this triangle
207 dis0 = bt_distance_point_plane(plane1,m_vertices1[0]) - total_margin;
208
209 dis1 = bt_distance_point_plane(plane1,m_vertices1[1]) - total_margin;
210
211 dis2 = bt_distance_point_plane(plane1,m_vertices1[2]) - total_margin;
212
213 if (dis0>0.0f&&dis1>0.0f&&dis2>0.0f) return false;
214
215 return true;
216 }
217
218
btTriangleShapeEx::overlap_test_conservative
bool overlap_test_conservative(const btTriangleShapeEx &other)
class btTriangleShapeEx: public btTriangleShape
Definition: btTriangleShapeEx.cpp:188
SIMD_EPSILON
#define SIMD_EPSILON
Definition: btScalar.h:494
btPrimitiveTriangle::overlap_test_conservative
bool overlap_test_conservative(const btPrimitiveTriangle &other)
Test if triangles could collide.
Definition: btTriangleShapeEx.cpp:65
GIM_TRIANGLE_CONTACT::m_point_count
int m_point_count
Definition: btTriangleShapeEx.h:41
GIM_TRIANGLE_CONTACT::copy_from
void copy_from(const GIM_TRIANGLE_CONTACT &other)
Definition: btTriangleShapeEx.h:45
btPrimitiveTriangle
Definition: btTriangleShapeEx.h:74
btTriangleShapeEx
Helper class for colliding Bullet Triangle Shapes.
Definition: btTriangleShapeEx.h:135
btTriangleShapeEx.h
btPrimitiveTriangle::m_plane
btVector4 m_plane
Definition: btTriangleShapeEx.h:78
btTriangleShapeEx::buildTriPlane
void buildTriPlane(btVector4 &plane) const
Definition: btTriangleShapeEx.h:169
GIM_TRIANGLE_CONTACT::m_points
btVector3 m_points[MAX_TRI_CLIPPING]
Definition: btTriangleShapeEx.h:43
bt_plane_clip_triangle
int bt_plane_clip_triangle(const btVector4 &plane, const btVector3 &point0, const btVector3 &point1, const btVector3 &point2, btVector3 *clipped)
Clips a polygon by a plane.
Definition: btClipPolygon.h:122
btConvexInternalShape::getMargin
virtual btScalar getMargin() const
Definition: btConvexInternalShape.h:113
btVector4
Definition: btVector3.h:1077
bt_distance_point_plane
btScalar bt_distance_point_plane(const btVector4 &plane, const btVector3 &point)
Definition: btClipPolygon.h:31
MAX_TRI_CLIPPING
#define MAX_TRI_CLIPPING
Definition: btTriangleShapeEx.h:35
bt_plane_clip_polygon
int bt_plane_clip_polygon(const btVector4 &plane, const btVector3 *polygon_points, int polygon_point_count, btVector3 *clipped)
Clips a polygon by a plane.
Definition: btClipPolygon.h:72
GIM_TRIANGLE_CONTACT::merge_points
void merge_points(const btVector4 &plane, btScalar margin, const btVector3 *points, int point_count)
classify points that are closer
Definition: btTriangleShapeEx.cpp:28
btPrimitiveTriangle::clip_triangle
int clip_triangle(btPrimitiveTriangle &other, btVector3 *clipped_points)
Clips the triangle against this.
Definition: btTriangleShapeEx.cpp:89
btVector3
btVector3 can be used to represent 3D points and vectors.
Definition: btVector3.h:83
btPrimitiveTriangle::find_triangle_collision_clip_method
bool find_triangle_collision_clip_method(btPrimitiveTriangle &other, GIM_TRIANGLE_CONTACT &contacts)
Find collision using the clipping method.
Definition: btTriangleShapeEx.cpp:126
btPrimitiveTriangle::m_margin
btScalar m_margin
Definition: btTriangleShapeEx.h:79
GIM_TRIANGLE_CONTACT
Structure for collision.
Definition: btTriangleShapeEx.h:38
btPrimitiveTriangle::m_vertices
btVector3 m_vertices[3]
Definition: btTriangleShapeEx.h:77
GIM_TRIANGLE_CONTACT::m_penetration_depth
btScalar m_penetration_depth
Definition: btTriangleShapeEx.h:40
GIM_TRIANGLE_CONTACT::m_separating_normal
btVector4 m_separating_normal
Definition: btTriangleShapeEx.h:42
btTriangleShape::m_vertices1
btVector3 m_vertices1[3]
Definition: btTriangleShape.h:30
btScalar
float btScalar
The btScalar type abstracts floating point numbers, to easily switch between double and single floati...
Definition: btScalar.h:278