b2Island.h

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/*
* Copyright (c) 2006-2009 Erin Catto http://www.box2d.org
*
* This software is provided 'as-is', without any express or implied
* warranty.  In no event will the authors be held liable for any damages
* arising from the use of this software.
* Permission is granted to anyone to use this software for any purpose,
* including commercial applications, and to alter it and redistribute it
* freely, subject to the following restrictions:
* 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.
* 2. Altered source versions must be plainly marked as such, and must not be
* misrepresented as being the original software.
* 3. This notice may not be removed or altered from any source distribution.
*/

#ifndef B2_ISLAND_H
#define B2_ISLAND_H

#include <Box2D/Common/b2Math.h>
#include <Box2D/Dynamics/b2Body.h>
#include <Box2D/Dynamics/b2TimeStep.h>

class b2Contact;
class b2Joint;
class b2StackAllocator;
class b2ContactListener;
struct b2ContactVelocityConstraint;
struct b2Profile;

class b2Island
{
public:
        b2Island(int32 bodyCapacity, int32 contactCapacity, int32 jointCapacity,
                        b2StackAllocator* allocator, b2ContactListener* listener);
        ~b2Island();

        void Clear()
        {
                m_bodyCount = 0;
                m_contactCount = 0;
                m_jointCount = 0;
        }

        void Solve(b2Profile* profile, const b2TimeStep& step, const b2Vec2& gravity, bool allowSleep);

        void SolveTOI(const b2TimeStep& subStep, int32 toiIndexA, int32 toiIndexB);

        void Add(b2Body* body)
        {
                b2Assert(m_bodyCount < m_bodyCapacity);
                body->m_islandIndex = m_bodyCount;
                m_bodies[m_bodyCount] = body;
                ++m_bodyCount;
        }

        void Add(b2Contact* contact)
        {
                b2Assert(m_contactCount < m_contactCapacity);
                m_contacts[m_contactCount++] = contact;
        }

        void Add(b2Joint* joint)
        {
                b2Assert(m_jointCount < m_jointCapacity);
                m_joints[m_jointCount++] = joint;
        }

        void Report(const b2ContactVelocityConstraint* constraints);

        b2StackAllocator* m_allocator;
        b2ContactListener* m_listener;

        b2Body** m_bodies;
        b2Contact** m_contacts;
        b2Joint** m_joints;

        b2Position* m_positions;
        b2Velocity* m_velocities;

        int32 m_bodyCount;
        int32 m_jointCount;
        int32 m_contactCount;

        int32 m_bodyCapacity;
        int32 m_contactCapacity;
        int32 m_jointCapacity;
};

#endif