File indexing completed on 2024-04-21 14:43:24

 /*
  * box2ddistancejoint.cpp
  * Copyright (c) 2011 Joonas Erkinheimo <joonas.erkinheimo@nokia.com>
  *
  * This file is part of the Box2D QML plugin.
  *
  * 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 "box2ddistancejoint.h"
 
 #include "box2dworld.h"
 #include "box2dbody.h"
 
 Box2DDistanceJoint::Box2DDistanceJoint(QObject *parent)
     : Box2DJoint(DistanceJoint, parent)
     , m_length(1.0f)
     , m_frequencyHz(0.0f)
     , m_dampingRatio(0.0f)
     , m_defaultLocalAnchorA(true)
     , m_defaultLocalAnchorB(true)
     , m_defaultLength(true)
 {
 }
 
 void Box2DDistanceJoint::setLocalAnchorA(const QPointF &localAnchorA)
 {
     m_defaultLocalAnchorA = false;
 
     if (m_localAnchorA == localAnchorA)
         return;
 
     m_localAnchorA = localAnchorA;
     emit localAnchorAChanged();
 }
 
 void Box2DDistanceJoint::setLocalAnchorB(const QPointF &localAnchorB)
 {
     m_defaultLocalAnchorB = false;
 
     if (m_localAnchorB == localAnchorB)
         return;
 
     m_localAnchorB = localAnchorB;
     emit localAnchorBChanged();
 }
 
 void Box2DDistanceJoint::setLength(float length)
 {
     if (m_length == length)
         return;
 
     m_length = length;
     m_defaultLength = false;
     if (distanceJoint())
         distanceJoint()->SetLength(world()->toMeters(length));
     emit lengthChanged();
 }
 
 void Box2DDistanceJoint::setFrequencyHz(float frequencyHz)
 {
     if (m_frequencyHz == frequencyHz)
         return;
 
     m_frequencyHz = frequencyHz;
     if (distanceJoint())
         distanceJoint()->SetFrequency(frequencyHz);
     emit frequencyHzChanged();
 }
 
 void Box2DDistanceJoint::setDampingRatio(float dampingRatio)
 {
     if (m_dampingRatio == dampingRatio)
         return;
 
     m_dampingRatio = dampingRatio;
     if (distanceJoint())
         distanceJoint()->SetDampingRatio(dampingRatio);
     emit dampingRatioChanged();
 }
 
 b2Joint *Box2DDistanceJoint::createJoint()
 {
     b2DistanceJointDef jointDef;
     initializeJointDef(jointDef);
 
     // Default to bodyA center
     if (m_defaultLocalAnchorA)
         jointDef.localAnchorA = jointDef.bodyA->GetLocalCenter();
     else
         jointDef.localAnchorA = world()->toMeters(m_localAnchorA);
 
     // Default to bodyB center
     if (m_defaultLocalAnchorB)
         jointDef.localAnchorB = jointDef.bodyB->GetLocalCenter();
     else
         jointDef.localAnchorB = world()->toMeters(m_localAnchorB);
 
     // Default to length between anchors
     if (m_defaultLength) {
         b2Vec2 a = jointDef.bodyA->GetWorldPoint(jointDef.localAnchorA);
         b2Vec2 b = jointDef.bodyB->GetWorldPoint(jointDef.localAnchorB);
         jointDef.length = (b - a).Length();
     } else {
         jointDef.length = world()->toMeters(m_length);
     }
 
     jointDef.frequencyHz = m_frequencyHz;
     jointDef.dampingRatio = m_dampingRatio;
 
     return world()->world().CreateJoint(&jointDef);
 }
 
 QPointF Box2DDistanceJoint::getReactionForce(float32 inv_dt) const
 {
     if (distanceJoint())
         return invertY(distanceJoint()->GetReactionForce(inv_dt));
     return QPointF();
 }
 
 float Box2DDistanceJoint::getReactionTorque(float32 inv_dt) const
 {
     if (distanceJoint())
         return distanceJoint()->GetReactionTorque(inv_dt);
     return 0.0f;
 }