b2Joint.cpp

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/*
* Copyright (c) 2006-2007 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.
*/

#include <Box2D/Dynamics/Joints/b2Joint.h>
#include <Box2D/Dynamics/Joints/b2DistanceJoint.h>
#include <Box2D/Dynamics/Joints/b2WheelJoint.h>
#include <Box2D/Dynamics/Joints/b2MouseJoint.h>
#include <Box2D/Dynamics/Joints/b2RevoluteJoint.h>
#include <Box2D/Dynamics/Joints/b2PrismaticJoint.h>
#include <Box2D/Dynamics/Joints/b2PulleyJoint.h>
#include <Box2D/Dynamics/Joints/b2GearJoint.h>
#include <Box2D/Dynamics/Joints/b2WeldJoint.h>
#include <Box2D/Dynamics/Joints/b2FrictionJoint.h>
#include <Box2D/Dynamics/Joints/b2RopeJoint.h>
#include <Box2D/Dynamics/Joints/b2MotorJoint.h>
#include <Box2D/Dynamics/b2Body.h>
#include <Box2D/Dynamics/b2World.h>
#include <Box2D/Common/b2BlockAllocator.h>

#include <new>

b2Joint* b2Joint::Create(const b2JointDef* def, b2BlockAllocator* allocator)
{
        b2Joint* joint = NULL;

        switch (def->type)
        {
        case e_distanceJoint:
                {
                        void* mem = allocator->Allocate(sizeof(b2DistanceJoint));
                        joint = new (mem) b2DistanceJoint(static_cast<const b2DistanceJointDef*>(def));
                }
                break;

        case e_mouseJoint:
                {
                        void* mem = allocator->Allocate(sizeof(b2MouseJoint));
                        joint = new (mem) b2MouseJoint(static_cast<const b2MouseJointDef*>(def));
                }
                break;

        case e_prismaticJoint:
                {
                        void* mem = allocator->Allocate(sizeof(b2PrismaticJoint));
                        joint = new (mem) b2PrismaticJoint(static_cast<const b2PrismaticJointDef*>(def));
                }
                break;

        case e_revoluteJoint:
                {
                        void* mem = allocator->Allocate(sizeof(b2RevoluteJoint));
                        joint = new (mem) b2RevoluteJoint(static_cast<const b2RevoluteJointDef*>(def));
                }
                break;

        case e_pulleyJoint:
                {
                        void* mem = allocator->Allocate(sizeof(b2PulleyJoint));
                        joint = new (mem) b2PulleyJoint(static_cast<const b2PulleyJointDef*>(def));
                }
                break;

        case e_gearJoint:
                {
                        void* mem = allocator->Allocate(sizeof(b2GearJoint));
                        joint = new (mem) b2GearJoint(static_cast<const b2GearJointDef*>(def));
                }
                break;

        case e_wheelJoint:
                {
                        void* mem = allocator->Allocate(sizeof(b2WheelJoint));
                        joint = new (mem) b2WheelJoint(static_cast<const b2WheelJointDef*>(def));
                }
                break;

        case e_weldJoint:
                {
                        void* mem = allocator->Allocate(sizeof(b2WeldJoint));
                        joint = new (mem) b2WeldJoint(static_cast<const b2WeldJointDef*>(def));
                }
                break;
        
        case e_frictionJoint:
                {
                        void* mem = allocator->Allocate(sizeof(b2FrictionJoint));
                        joint = new (mem) b2FrictionJoint(static_cast<const b2FrictionJointDef*>(def));
                }
                break;

        case e_ropeJoint:
                {
                        void* mem = allocator->Allocate(sizeof(b2RopeJoint));
                        joint = new (mem) b2RopeJoint(static_cast<const b2RopeJointDef*>(def));
                }
                break;

        case e_motorJoint:
                {
                        void* mem = allocator->Allocate(sizeof(b2MotorJoint));
                        joint = new (mem) b2MotorJoint(static_cast<const b2MotorJointDef*>(def));
                }
                break;

        default:
                b2Assert(false);
                break;
        }

        return joint;
}

void b2Joint::Destroy(b2Joint* joint, b2BlockAllocator* allocator)
{
        joint->~b2Joint();
        switch (joint->m_type)
        {
        case e_distanceJoint:
                allocator->Free(joint, sizeof(b2DistanceJoint));
                break;

        case e_mouseJoint:
                allocator->Free(joint, sizeof(b2MouseJoint));
                break;

        case e_prismaticJoint:
                allocator->Free(joint, sizeof(b2PrismaticJoint));
                break;

        case e_revoluteJoint:
                allocator->Free(joint, sizeof(b2RevoluteJoint));
                break;

        case e_pulleyJoint:
                allocator->Free(joint, sizeof(b2PulleyJoint));
                break;

        case e_gearJoint:
                allocator->Free(joint, sizeof(b2GearJoint));
                break;

        case e_wheelJoint:
                allocator->Free(joint, sizeof(b2WheelJoint));
                break;
    
        case e_weldJoint:
                allocator->Free(joint, sizeof(b2WeldJoint));
                break;

        case e_frictionJoint:
                allocator->Free(joint, sizeof(b2FrictionJoint));
                break;

        case e_ropeJoint:
                allocator->Free(joint, sizeof(b2RopeJoint));
                break;

        case e_motorJoint:
                allocator->Free(joint, sizeof(b2MotorJoint));
                break;

        default:
                b2Assert(false);
                break;
        }
}

b2Joint::b2Joint(const b2JointDef* def)
{
        b2Assert(def->bodyA != def->bodyB);

        m_type = def->type;
        m_prev = NULL;
        m_next = NULL;
        m_bodyA = def->bodyA;
        m_bodyB = def->bodyB;
        m_index = 0;
        m_collideConnected = def->collideConnected;
        m_islandFlag = false;
        m_userData = def->userData;

        m_edgeA.joint = NULL;
        m_edgeA.other = NULL;
        m_edgeA.prev = NULL;
        m_edgeA.next = NULL;

        m_edgeB.joint = NULL;
        m_edgeB.other = NULL;
        m_edgeB.prev = NULL;
        m_edgeB.next = NULL;
}

bool b2Joint::IsActive() const
{
        return m_bodyA->IsActive() && m_bodyB->IsActive();
}