Bullet Collision Detection & Physics Library
gim_contact.cpp
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1
2/*
3-----------------------------------------------------------------------------
4This source file is part of GIMPACT Library.
5
6For the latest info, see http://gimpact.sourceforge.net/
7
8Copyright (c) 2006 Francisco Leon Najera. C.C. 80087371.
9email: projectileman@yahoo.com
10
11 This library is free software; you can redistribute it and/or
12 modify it under the terms of EITHER:
13 (1) The GNU Lesser General Public License as published by the Free
14 Software Foundation; either version 2.1 of the License, or (at
15 your option) any later version. The text of the GNU Lesser
16 General Public License is included with this library in the
17 file GIMPACT-LICENSE-LGPL.TXT.
18 (2) The BSD-style license that is included with this library in
19 the file GIMPACT-LICENSE-BSD.TXT.
20 (3) The zlib/libpng license that is included with this library in
21 the file GIMPACT-LICENSE-ZLIB.TXT.
22
23 This library is distributed in the hope that it will be useful,
24 but WITHOUT ANY WARRANTY; without even the implied warranty of
25 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the files
26 GIMPACT-LICENSE-LGPL.TXT, GIMPACT-LICENSE-ZLIB.TXT and GIMPACT-LICENSE-BSD.TXT for more details.
27
28-----------------------------------------------------------------------------
29*/
30
31#include "gim_contact.h"
32
33#define MAX_COINCIDENT 8
34
36 const gim_contact_array & contacts, bool normal_contact_average)
37{
38 clear();
39
40 if(contacts.size()==1)
41 {
42 push_back(contacts.back());
43 return;
44 }
45
46 gim_array<GIM_RSORT_TOKEN> keycontacts(contacts.size());
47 keycontacts.resize(contacts.size(),false);
48
49 //fill key contacts
50
51 GUINT i;
52
53 for (i = 0;i<contacts.size() ;i++ )
54 {
55 keycontacts[i].m_key = contacts[i].calc_key_contact();
56 keycontacts[i].m_value = i;
57 }
58
59 //sort keys
60 gim_heap_sort(keycontacts.pointer(),keycontacts.size(),GIM_RSORT_TOKEN_COMPARATOR());
61
62 // Merge contacts
63
64 GUINT coincident_count=0;
65 btVector3 coincident_normals[MAX_COINCIDENT];
66
67 GUINT last_key = keycontacts[0].m_key;
68 GUINT key = 0;
69
70 push_back(contacts[keycontacts[0].m_value]);
71 GIM_CONTACT * pcontact = &back();
72
73
74
75 for( i=1;i<keycontacts.size();i++)
76 {
77 key = keycontacts[i].m_key;
78 const GIM_CONTACT * scontact = &contacts[keycontacts[i].m_value];
79
80 if(last_key == key)//same points
81 {
82 //merge contact
83 if(pcontact->m_depth - CONTACT_DIFF_EPSILON > scontact->m_depth)//)
84 {
85 *pcontact = *scontact;
86 coincident_count = 0;
87 }
88 else if(normal_contact_average)
89 {
90 if(btFabs(pcontact->m_depth - scontact->m_depth)<CONTACT_DIFF_EPSILON)
91 {
92 if(coincident_count<MAX_COINCIDENT)
93 {
94 coincident_normals[coincident_count] = scontact->m_normal;
95 coincident_count++;
96 }
97 }
98 }
99 }
100 else
101 {//add new contact
102
103 if(normal_contact_average && coincident_count>0)
104 {
105 pcontact->interpolate_normals(coincident_normals,coincident_count);
106 coincident_count = 0;
107 }
108
109 push_back(*scontact);
110 pcontact = &back();
111 }
112 last_key = key;
113 }
114}
115
117{
118 clear();
119
120 if(contacts.size()==1)
121 {
122 push_back(contacts.back());
123 return;
124 }
125
126 GIM_CONTACT average_contact = contacts.back();
127
128 for (GUINT i=1;i<contacts.size() ;i++ )
129 {
130 average_contact.m_point += contacts[i].m_point;
131 average_contact.m_normal += contacts[i].m_normal * contacts[i].m_depth;
132 }
133
134 //divide
135 GREAL divide_average = 1.0f/((GREAL)contacts.size());
136
137 average_contact.m_point *= divide_average;
138
139 average_contact.m_normal *= divide_average;
140
141 average_contact.m_depth = average_contact.m_normal.length();
142
143 average_contact.m_normal /= average_contact.m_depth;
144
145}
146
#define CONTACT_DIFF_EPSILON
btScalar btFabs(btScalar x)
Definition: btScalar.h:475
The GIM_CONTACT is an internal GIMPACT structure, similar to btManifoldPoint.
void interpolate_normals(btVector3 *normals, int normal_count)
Prototype for comparators.
btVector3 can be used to represent 3D points and vectors.
Definition: btVector3.h:84
btScalar length() const
Return the length of the vector.
Definition: btVector3.h:263
Very simple array container with fast access and simd memory.
Definition: gim_array.h:44
T & back()
Definition: gim_array.h:198
void push_back(const GIM_CONTACT &obj)
Definition: gim_array.h:214
GUINT size() const
Definition: gim_array.h:144
void resize(GUINT size, bool call_constructor=true, const T &fillData=T())
Definition: gim_array.h:288
T * pointer()
Definition: gim_array.h:163
void merge_contacts(const gim_contact_array &contacts, bool normal_contact_average=true)
Definition: gim_contact.cpp:35
void merge_contacts_unique(const gim_contact_array &contacts)
#define MAX_COINCIDENT
Definition: gim_contact.cpp:33
#define GREAL
Definition: gim_math.h:39
#define GUINT
Definition: gim_math.h:42
void gim_heap_sort(T *pArr, GUINT element_count, COMP_CLASS CompareFunc)