mirror of https://github.com/axmolengine/axmol.git
83 lines
2.5 KiB
C
83 lines
2.5 KiB
C
|
/*
|
||
|
|
* Copyright (c) 2006-2009 Erin Catto http://www.gphysics.com
|
||
|
|
*
|
||
|
|
* 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_WELD_JOINT_H
|
||
|
|
#define B2_WELD_JOINT_H
|
||
|
|
|
||
|
|
#include <Box2D/Dynamics/Joints/b2Joint.h>
|
||
|
|
|
||
|
|
/// Weld joint definition. You need to specify local anchor points
|
||
|
|
/// where they are attached and the relative body angle. The position
|
||
|
|
/// of the anchor points is important for computing the reaction torque.
|
||
|
|
struct b2WeldJointDef : public b2JointDef
|
||
|
|
{
|
||
|
|
b2WeldJointDef()
|
||
|
|
{
|
||
|
|
type = e_weldJoint;
|
||
|
|
localAnchorA.Set(0.0f, 0.0f);
|
||
|
|
localAnchorB.Set(0.0f, 0.0f);
|
||
|
|
referenceAngle = 0.0f;
|
||
|
|
}
|
||
|
|
|
||
|
|
/// Initialize the bodies, anchors, and reference angle using a world
|
||
|
|
/// anchor point.
|
||
|
|
void Initialize(b2Body* body1, b2Body* body2, const b2Vec2& anchor);
|
||
|
|
|
||
|
|
/// The local anchor point relative to body1's origin.
|
||
|
|
b2Vec2 localAnchorA;
|
||
|
|
|
||
|
|
/// The local anchor point relative to body2's origin.
|
||
|
|
b2Vec2 localAnchorB;
|
||
|
|
|
||
|
|
/// The body2 angle minus body1 angle in the reference state (radians).
|
||
|
|
float32 referenceAngle;
|
||
|
|
};
|
||
|
|
|
||
|
|
/// A weld joint essentially glues two bodies together. A weld joint may
|
||
|
|
/// distort somewhat because the island constraint solver is approximate.
|
||
|
|
class b2WeldJoint : public b2Joint
|
||
|
|
{
|
||
|
|
public:
|
||
|
|
b2Vec2 GetAnchorA() const;
|
||
|
|
b2Vec2 GetAnchorB() const;
|
||
|
|
|
||
|
|
b2Vec2 GetReactionForce(float32 inv_dt) const;
|
||
|
|
float32 GetReactionTorque(float32 inv_dt) const;
|
||
|
|
|
||
|
|
protected:
|
||
|
|
|
||
|
|
friend class b2Joint;
|
||
|
|
|
||
|
|
b2WeldJoint(const b2WeldJointDef* def);
|
||
|
|
|
||
|
|
void InitVelocityConstraints(const b2TimeStep& step);
|
||
|
|
void SolveVelocityConstraints(const b2TimeStep& step);
|
||
|
|
|
||
|
|
bool SolvePositionConstraints(float32 baumgarte);
|
||
|
|
|
||
|
|
b2Vec2 m_localAnchorA;
|
||
|
|
b2Vec2 m_localAnchorB;
|
||
|
|
float32 m_referenceAngle;
|
||
|
|
|
||
|
|
b2Vec3 m_impulse;
|
||
|
|
|
||
|
|
b2Mat33 m_mass;
|
||
|
|
};
|
||
|
|
|
||
|
|
#endif
|