1
2 /*
3 This source file is part of GIMPACT Library.
4
5 For the latest info, see http://gimpact.sourceforge.net/
6
7 Copyright (c) 2007 Francisco Leon Najera. C.C. 80087371.
8 email: projectileman@yahoo.com
9
10
11 This software is provided 'as-is', without any express or implied warranty.
12 In no event will the authors be held liable for any damages arising from the use of this software.
13 Permission is granted to anyone to use this software for any purpose,
14 including commercial applications, and to alter it and redistribute it freely,
15 subject to the following restrictions:
16
17 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.
18 2. Altered source versions must be plainly marked as such, and must not be misrepresented as being the original software.
19 3. This notice may not be removed or altered from any source distribution.
20 */
21 #include "btContactProcessing.h"
22
23 #define MAX_COINCIDENT 8
24
25 struct CONTACT_KEY_TOKEN
26 {
27 unsigned int m_key;
28 int m_value;
CONTACT_KEY_TOKENCONTACT_KEY_TOKEN29 CONTACT_KEY_TOKEN()
30 {
31 }
32
CONTACT_KEY_TOKENCONTACT_KEY_TOKEN33 CONTACT_KEY_TOKEN(unsigned int key, int token)
34 {
35 m_key = key;
36 m_value = token;
37 }
38
CONTACT_KEY_TOKENCONTACT_KEY_TOKEN39 CONTACT_KEY_TOKEN(const CONTACT_KEY_TOKEN& rtoken)
40 {
41 m_key = rtoken.m_key;
42 m_value = rtoken.m_value;
43 }
44
operator <CONTACT_KEY_TOKEN45 inline bool operator<(const CONTACT_KEY_TOKEN& other) const
46 {
47 return (m_key < other.m_key);
48 }
49
operator >CONTACT_KEY_TOKEN50 inline bool operator>(const CONTACT_KEY_TOKEN& other) const
51 {
52 return (m_key > other.m_key);
53 }
54 };
55
56 class CONTACT_KEY_TOKEN_COMP
57 {
58 public:
operator ()(const CONTACT_KEY_TOKEN & a,const CONTACT_KEY_TOKEN & b) const59 bool operator()(const CONTACT_KEY_TOKEN& a, const CONTACT_KEY_TOKEN& b) const
60 {
61 return (a < b);
62 }
63 };
64
merge_contacts(const btContactArray & contacts,bool normal_contact_average)65 void btContactArray::merge_contacts(
66 const btContactArray& contacts, bool normal_contact_average)
67 {
68 clear();
69
70 int i;
71 if (contacts.size() == 0) return;
72
73 if (contacts.size() == 1)
74 {
75 push_back(contacts[0]);
76 return;
77 }
78
79 btAlignedObjectArray<CONTACT_KEY_TOKEN> keycontacts;
80
81 keycontacts.reserve(contacts.size());
82
83 //fill key contacts
84
85 for (i = 0; i < contacts.size(); i++)
86 {
87 keycontacts.push_back(CONTACT_KEY_TOKEN(contacts[i].calc_key_contact(), i));
88 }
89
90 //sort keys
91 keycontacts.quickSort(CONTACT_KEY_TOKEN_COMP());
92
93 // Merge contacts
94 int coincident_count = 0;
95 btVector3 coincident_normals[MAX_COINCIDENT];
96
97 unsigned int last_key = keycontacts[0].m_key;
98 unsigned int key = 0;
99
100 push_back(contacts[keycontacts[0].m_value]);
101
102 GIM_CONTACT* pcontact = &(*this)[0];
103
104 for (i = 1; i < keycontacts.size(); i++)
105 {
106 key = keycontacts[i].m_key;
107 const GIM_CONTACT* scontact = &contacts[keycontacts[i].m_value];
108
109 if (last_key == key) //same points
110 {
111 //merge contact
112 if (pcontact->m_depth - CONTACT_DIFF_EPSILON > scontact->m_depth) //)
113 {
114 *pcontact = *scontact;
115 coincident_count = 0;
116 }
117 else if (normal_contact_average)
118 {
119 if (btFabs(pcontact->m_depth - scontact->m_depth) < CONTACT_DIFF_EPSILON)
120 {
121 if (coincident_count < MAX_COINCIDENT)
122 {
123 coincident_normals[coincident_count] = scontact->m_normal;
124 coincident_count++;
125 }
126 }
127 }
128 }
129 else
130 { //add new contact
131
132 if (normal_contact_average && coincident_count > 0)
133 {
134 pcontact->interpolate_normals(coincident_normals, coincident_count);
135 coincident_count = 0;
136 }
137
138 push_back(*scontact);
139 pcontact = &(*this)[this->size() - 1];
140 }
141 last_key = key;
142 }
143 }
144
merge_contacts_unique(const btContactArray & contacts)145 void btContactArray::merge_contacts_unique(const btContactArray& contacts)
146 {
147 clear();
148
149 if (contacts.size() == 0) return;
150
151 if (contacts.size() == 1)
152 {
153 push_back(contacts[0]);
154 return;
155 }
156
157 GIM_CONTACT average_contact = contacts[0];
158
159 for (int i = 1; i < contacts.size(); i++)
160 {
161 average_contact.m_point += contacts[i].m_point;
162 average_contact.m_normal += contacts[i].m_normal * contacts[i].m_depth;
163 }
164
165 //divide
166 btScalar divide_average = 1.0f / ((btScalar)contacts.size());
167
168 average_contact.m_point *= divide_average;
169
170 average_contact.m_normal *= divide_average;
171
172 average_contact.m_depth = average_contact.m_normal.length();
173
174 average_contact.m_normal /= average_contact.m_depth;
175 }
176