1/*
2* Copyright (c) 2006-2009 Erin Catto http://www.box2d.org
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 <string.h>
21
22b2BroadPhase::b2BroadPhase()
23{
24 m_proxyCount = 0;
25
26 m_pairCapacity = 16;
27 m_pairCount = 0;
28 m_pairBuffer = (b2Pair*)b2Alloc(m_pairCapacity * sizeof(b2Pair));
29
30 m_moveCapacity = 16;
31 m_moveCount = 0;
32 m_moveBuffer = (int32*)b2Alloc(m_moveCapacity * sizeof(int32));
33}
34
35b2BroadPhase::~b2BroadPhase()
36{
37 b2Free(m_moveBuffer);
38 b2Free(m_pairBuffer);
39}
40
41int32 b2BroadPhase::CreateProxy(const b2AABB& aabb, void* userData)
42{
43 int32 proxyId = m_tree.CreateProxy(aabb, userData);
44 ++m_proxyCount;
45 BufferMove(proxyId);
46 return proxyId;
47}
48
49void b2BroadPhase::DestroyProxy(int32 proxyId)
50{
51 UnBufferMove(proxyId);
52 --m_proxyCount;
53 m_tree.DestroyProxy(proxyId);
54}
55
56void b2BroadPhase::MoveProxy(int32 proxyId, const b2AABB& aabb, const b2Vec2& displacement)
57{
58 bool buffer = m_tree.MoveProxy(proxyId, aabb, displacement);
59 if (buffer)
60 {
61 BufferMove(proxyId);
62 }
63}
64
65void b2BroadPhase::TouchProxy(int32 proxyId)
66{
67 BufferMove(proxyId);
68}
69
70void b2BroadPhase::BufferMove(int32 proxyId)
71{
72 if (m_moveCount == m_moveCapacity)
73 {
74 int32* oldBuffer = m_moveBuffer;
75 m_moveCapacity *= 2;
76 m_moveBuffer = (int32*)b2Alloc(m_moveCapacity * sizeof(int32));
77 memcpy(m_moveBuffer, oldBuffer, m_moveCount * sizeof(int32));
78 b2Free(oldBuffer);
79 }
80
81 m_moveBuffer[m_moveCount] = proxyId;
82 ++m_moveCount;
83}
84
85void b2BroadPhase::UnBufferMove(int32 proxyId)
86{
87 for (int32 i = 0; i < m_moveCount; ++i)
88 {
89 if (m_moveBuffer[i] == proxyId)
90 {
91 m_moveBuffer[i] = e_nullProxy;
92 }
93 }
94}
95
96// This is called from b2DynamicTree::Query when we are gathering pairs.
97bool b2BroadPhase::QueryCallback(int32 proxyId)
98{
99 // A proxy cannot form a pair with itself.
100 if (proxyId == m_queryProxyId)
101 {
102 return true;
103 }
104
105 // Grow the pair buffer as needed.
106 if (m_pairCount == m_pairCapacity)
107 {
108 b2Pair* oldBuffer = m_pairBuffer;
109 m_pairCapacity *= 2;
110 m_pairBuffer = (b2Pair*)b2Alloc(m_pairCapacity * sizeof(b2Pair));
111 memcpy(m_pairBuffer, oldBuffer, m_pairCount * sizeof(b2Pair));
112 b2Free(oldBuffer);
113 }
114
115 m_pairBuffer[m_pairCount].proxyIdA = b2Min(proxyId, m_queryProxyId);
116 m_pairBuffer[m_pairCount].proxyIdB = b2Max(proxyId, m_queryProxyId);
117 ++m_pairCount;
118
119 return true;
120}
121