== SoC Bullet - Bullet Upgrade to 2.76 ==
[blender.git] / extern / bullet2 / BulletCollision / Gimpact / btContactProcessing.cpp
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;
29         CONTACT_KEY_TOKEN()
30     {
31     }
32
33     CONTACT_KEY_TOKEN(unsigned int key,int token)
34     {
35         m_key = key;
36         m_value =  token;
37     }
38
39     CONTACT_KEY_TOKEN(const CONTACT_KEY_TOKEN& rtoken)
40     {
41         m_key = rtoken.m_key;
42         m_value = rtoken.m_value;
43     }
44
45     inline bool operator <(const CONTACT_KEY_TOKEN& other) const
46         {
47                 return (m_key < other.m_key);
48         }
49
50         inline bool operator >(const CONTACT_KEY_TOKEN& other) const
51         {
52                 return (m_key > other.m_key);
53         }
54
55 };
56
57 class CONTACT_KEY_TOKEN_COMP
58 {
59         public:
60
61                 bool operator() ( const CONTACT_KEY_TOKEN& a, const CONTACT_KEY_TOKEN& b )
62                 {
63                         return ( a < b );
64                 }
65 };
66
67
68 void btContactArray::merge_contacts(
69         const btContactArray & contacts, bool normal_contact_average)
70 {
71         clear();
72
73         int i;
74         if(contacts.size()==0) return;
75
76
77         if(contacts.size()==1)
78         {
79                 push_back(contacts[0]);
80                 return;
81         }
82
83         btAlignedObjectArray<CONTACT_KEY_TOKEN> keycontacts;
84
85         keycontacts.reserve(contacts.size());
86
87         //fill key contacts
88
89         for ( i = 0;i<contacts.size() ;i++ )
90         {
91                 keycontacts.push_back(CONTACT_KEY_TOKEN(contacts[i].calc_key_contact(),i));
92         }
93
94         //sort keys
95         keycontacts.quickSort(CONTACT_KEY_TOKEN_COMP());
96
97         // Merge contacts
98         int coincident_count=0;
99         btVector3 coincident_normals[MAX_COINCIDENT];
100
101         unsigned int last_key = keycontacts[0].m_key;
102         unsigned int key = 0;
103
104         push_back(contacts[keycontacts[0].m_value]);
105
106         GIM_CONTACT * pcontact = &(*this)[0];
107
108         for( i=1;i<keycontacts.size();i++)
109         {
110             key = keycontacts[i].m_key;
111                 const GIM_CONTACT * scontact = &contacts[keycontacts[i].m_value];
112
113                 if(last_key ==  key)//same points
114                 {
115                         //merge contact
116                         if(pcontact->m_depth - CONTACT_DIFF_EPSILON > scontact->m_depth)//)
117                         {
118                                 *pcontact = *scontact;
119                 coincident_count = 0;
120                         }
121                         else if(normal_contact_average)
122                         {
123                                 if(btFabs(pcontact->m_depth - scontact->m_depth)<CONTACT_DIFF_EPSILON)
124                 {
125                     if(coincident_count<MAX_COINCIDENT)
126                     {
127                         coincident_normals[coincident_count] = scontact->m_normal;
128                         coincident_count++;
129                     }
130                 }
131                         }
132                 }
133                 else
134                 {//add new contact
135
136                     if(normal_contact_average && coincident_count>0)
137                     {
138                         pcontact->interpolate_normals(coincident_normals,coincident_count);
139                         coincident_count = 0;
140                     }
141
142                     push_back(*scontact);
143                     pcontact = &(*this)[this->size()-1];
144         }
145                 last_key = key;
146         }
147 }
148
149 void btContactArray::merge_contacts_unique(const btContactArray & contacts)
150 {
151         clear();
152
153         if(contacts.size()==0) return;
154
155         if(contacts.size()==1)
156         {
157                 push_back(contacts[0]);
158                 return;
159         }
160
161         GIM_CONTACT average_contact = contacts[0];
162
163         for (int i=1;i<contacts.size() ;i++ )
164         {
165                 average_contact.m_point += contacts[i].m_point;
166                 average_contact.m_normal += contacts[i].m_normal * contacts[i].m_depth;
167         }
168
169         //divide
170         btScalar divide_average = 1.0f/((btScalar)contacts.size());
171
172         average_contact.m_point *= divide_average;
173
174         average_contact.m_normal *= divide_average;
175
176         average_contact.m_depth = average_contact.m_normal.length();
177
178         average_contact.m_normal /= average_contact.m_depth;
179
180 }
181