1 /*
2 * Copyright (c) 2006-2009 Erin Catto http://www.gphysics.com
3 *
4 * This software is provided 'as-is', without any express or implied
5 * warranty. In no event will the authors be held liable for any damages
6 * 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
9 * freely, subject to the following restrictions:
10 * 1. The origin of this software must not be misrepresented; you must not
11 * claim that you wrote the original software. If you use this software
12 * in a product, an acknowledgment in the product documentation would be
13 * appreciated but is not required.
14 * 2. Altered source versions must be plainly marked as such, and must not be
15 * misrepresented as being the original software.
16 * 3. This notice may not be removed or altered from any source distribution.
17 */
18
19 #include <Box2D/Collision/b2BroadPhase.h>
20 #include <cstring>
21 using namespace std;
22
b2BroadPhase()23 b2BroadPhase::b2BroadPhase()
24 {
25 m_proxyCount = 0;
26
27 m_pairCapacity = 16;
28 m_pairCount = 0;
29 m_pairBuffer = (b2Pair*)b2Alloc(m_pairCapacity * sizeof(b2Pair));
30
31 m_moveCapacity = 16;
32 m_moveCount = 0;
33 m_moveBuffer = (int32*)b2Alloc(m_moveCapacity * sizeof(int32));
34 }
35
~b2BroadPhase()36 b2BroadPhase::~b2BroadPhase()
37 {
38 b2Free(m_moveBuffer);
39 b2Free(m_pairBuffer);
40 }
41
CreateProxy(const b2AABB & aabb,void * userData)42 int32 b2BroadPhase::CreateProxy(const b2AABB& aabb, void* userData)
43 {
44 int32 proxyId = m_tree.CreateProxy(aabb, userData);
45 ++m_proxyCount;
46 BufferMove(proxyId);
47 return proxyId;
48 }
49
DestroyProxy(int32 proxyId)50 void b2BroadPhase::DestroyProxy(int32 proxyId)
51 {
52 UnBufferMove(proxyId);
53 --m_proxyCount;
54 m_tree.DestroyProxy(proxyId);
55 }
56
MoveProxy(int32 proxyId,const b2AABB & aabb,const b2Vec2 & displacement)57 void b2BroadPhase::MoveProxy(int32 proxyId, const b2AABB& aabb, const b2Vec2& displacement)
58 {
59 bool buffer = m_tree.MoveProxy(proxyId, aabb, displacement);
60 if (buffer)
61 {
62 BufferMove(proxyId);
63 }
64 }
65
BufferMove(int32 proxyId)66 void b2BroadPhase::BufferMove(int32 proxyId)
67 {
68 if (m_moveCount == m_moveCapacity)
69 {
70 int32* oldBuffer = m_moveBuffer;
71 m_moveCapacity *= 2;
72 m_moveBuffer = (int32*)b2Alloc(m_moveCapacity * sizeof(int32));
73 memcpy(m_moveBuffer, oldBuffer, m_moveCount * sizeof(int32));
74 b2Free(oldBuffer);
75 }
76
77 m_moveBuffer[m_moveCount] = proxyId;
78 ++m_moveCount;
79 }
80
UnBufferMove(int32 proxyId)81 void b2BroadPhase::UnBufferMove(int32 proxyId)
82 {
83 for (int32 i = 0; i < m_moveCount; ++i)
84 {
85 if (m_moveBuffer[i] == proxyId)
86 {
87 m_moveBuffer[i] = e_nullProxy;
88 return;
89 }
90 }
91 }
92
93 // This is called from b2DynamicTree::Query when we are gathering pairs.
QueryCallback(int32 proxyId)94 bool b2BroadPhase::QueryCallback(int32 proxyId)
95 {
96 // A proxy cannot form a pair with itself.
97 if (proxyId == m_queryProxyId)
98 {
99 return true;
100 }
101
102 // Grow the pair buffer as needed.
103 if (m_pairCount == m_pairCapacity)
104 {
105 b2Pair* oldBuffer = m_pairBuffer;
106 m_pairCapacity *= 2;
107 m_pairBuffer = (b2Pair*)b2Alloc(m_pairCapacity * sizeof(b2Pair));
108 memcpy(m_pairBuffer, oldBuffer, m_pairCount * sizeof(b2Pair));
109 b2Free(oldBuffer);
110 }
111
112 m_pairBuffer[m_pairCount].proxyIdA = b2Min(proxyId, m_queryProxyId);
113 m_pairBuffer[m_pairCount].proxyIdB = b2Max(proxyId, m_queryProxyId);
114 ++m_pairCount;
115
116 return true;
117 }
118