/*
* Copyright (c) 2006-2007 Erin Catto http:
*
* 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, and must not be
* misrepresented the original software.
* 3. This notice may not be removed or altered from any source distribution.
*/
/**
* Point-to-point constraint
*
* C = p2 - p1
* Cdot = v2 - v1
* = v2 + cross(w2, r2) - v1 - cross(w1, r1)
* J = [-I -r1_skew I r2_skew ]
* Identity used:
* w k % (rx i + ry j) = w * (-ry i + rx j)
*
* Motor constraint
* Cdot = w2 - w1
* J = [0 0 -1 0 0 1]
* K = invI1 + invI2
*
* @class b2RevoluteJoint
* @constructor
*/
var b2RevoluteJoint = function (def) {
// The constructor for b2Joint
// initialize instance variables for references
this.m_node1 = new b2JointNode();
this.m_node2 = new b2JointNode();
//
this.m_type = def.type;
this.m_prev = null;
this.m_next = null;
this.m_body1 = def.body1;
this.m_body2 = def.body2;
this.m_collideConnected = def.collideConnected;
this.m_islandFlag = false;
this.m_userData = def.userData;
//
// initialize instance variables for references
this.K = new b2Mat22();
this.K1 = new b2Mat22();
this.K2 = new b2Mat22();
this.K3 = new b2Mat22();
this.m_localAnchor1 = new b2Vec2();
this.m_localAnchor2 = new b2Vec2();
this.m_ptpImpulse = new b2Vec2();
this.m_ptpMass = new b2Mat22();
//
//super(def);
var tMat;
var tX;
var tY;
//this.m_localAnchor1 = b2Math.b2MulTMV(this.m_body1.m_R, b2Math.SubtractVV( def.anchorPoint, this.m_body1.m_position));
tMat = this.m_body1.m_R;
tX = def.anchorPoint.x - this.m_body1.m_position.x;
tY = def.anchorPoint.y - this.m_body1.m_position.y;
this.m_localAnchor1.x = tX * tMat.col1.x + tY * tMat.col1.y;
this.m_localAnchor1.y = tX * tMat.col2.x + tY * tMat.col2.y;
//this.m_localAnchor2 = b2Math.b2MulTMV(this.m_body2.m_R, b2Math.SubtractVV( def.anchorPoint, this.m_body2.m_position));
tMat = this.m_body2.m_R;
tX = def.anchorPoint.x - this.m_body2.m_position.x;
tY = def.anchorPoint.y - this.m_body2.m_position.y;
this.m_localAnchor2.x = tX * tMat.col1.x + tY * tMat.col1.y;
this.m_localAnchor2.y = tX * tMat.col2.x + tY * tMat.col2.y;
this.m_intialAngle = this.m_body2.m_rotation - this.m_body1.m_rotation;
this.m_ptpImpulse.Set(0.0, 0.0);
this.m_motorImpulse = 0.0;
this.m_limitImpulse = 0.0;
this.m_limitPositionImpulse = 0.0;
this.m_lowerAngle = def.lowerAngle;
this.m_upperAngle = def.upperAngle;
this.m_maxMotorTorque = def.motorTorque;
this.m_motorSpeed = def.motorSpeed;
this.m_enableLimit = def.enableLimit;
this.m_enableMotor = def.enableMotor;
};
Object.extend(b2RevoluteJoint.prototype, b2Joint.prototype);
Object.extend(b2RevoluteJoint.prototype,
{
GetAnchor1: function(){
var tMat = this.m_body1.m_R;
return new b2Vec2( this.m_body1.m_position.x + (tMat.col1.x * this.m_localAnchor1.x + tMat.col2.x * this.m_localAnchor1.y),
this.m_body1.m_position.y + (tMat.col1.y * this.m_localAnchor1.x + tMat.col2.y * this.m_localAnchor1.y));
},
GetAnchor2: function(){
var tMat = this.m_body2.m_R;
return new b2Vec2( this.m_body2.m_position.x + (tMat.col1.x * this.m_localAnchor2.x + tMat.col2.x * this.m_localAnchor2.y),
this.m_body2.m_position.y + (tMat.col1.y * this.m_localAnchor2.x + tMat.col2.y * this.m_localAnchor2.y));
},
GetJointAngle: function(){
return this.m_body2.m_rotation - this.m_body1.m_rotation;
},
GetJointSpeed: function(){
return this.m_body2.m_angularVelocity - this.m_body1.m_angularVelocity;
},
GetMotorTorque: function(invTimeStep){
return invTimeStep * this.m_motorImpulse;
},
SetMotorSpeed: function(speed)
{
this.m_motorSpeed = speed;
},
SetMotorTorque: function(torque)
{
this.m_maxMotorTorque = torque;
},
GetReactionForce: function(invTimeStep)
{
var tVec = this.m_ptpImpulse.Copy();
tVec.Multiply(invTimeStep);
//return invTimeStep * this.m_ptpImpulse;
return tVec;
},
GetReactionTorque: function(invTimeStep)
{
return invTimeStep * this.m_limitImpulse;
},
//--------------- Internals Below -------------------
// internal vars
K: new b2Mat22(),
K1: new b2Mat22(),
K2: new b2Mat22(),
K3: new b2Mat22(),
PrepareVelocitySolver: function(){
var b1 = this.m_body1;
var b2 = this.m_body2;
var tMat;
// Compute the effective mass matrix.
//b2Vec2 r1 = b2Mul(b1->m_R, this.m_localAnchor1);
tMat = b1.m_R;
var r1X = tMat.col1.x * this.m_localAnchor1.x + tMat.col2.x * this.m_localAnchor1.y;
var r1Y = tMat.col1.y * this.m_localAnchor1.x + tMat.col2.y * this.m_localAnchor1.y;
//b2Vec2 r2 = b2Mul(b2->m_R, this.m_localAnchor2);
tMat = b2.m_R;
var r2X = tMat.col1.x * this.m_localAnchor2.x + tMat.col2.x * this.m_localAnchor2.y;
var r2Y = tMat.col1.y * this.m_localAnchor2.x + tMat.col2.y * this.m_localAnchor2.y;
// this.K = [(1/m1 + 1/m2) * eye(2) - skew(r1) * invI1 * skew(r1) - skew(r2) * invI2 * skew(r2)]
// = [1/m1+1/m2 0 ] + invI1 * [r1.y*r1.y -r1.x*r1.y] + invI2 * [r1.y*r1.y -r1.x*r1.y]
// [ 0 1/m1+1/m2] [-r1.x*r1.y r1.x*r1.x] [-r1.x*r1.y r1.x*r1.x]
var invMass1 = b1.m_invMass;
var invMass2 = b2.m_invMass;
var invI1 = b1.m_invI;
var invI2 = b2.m_invI;
//var this.K1 = new b2Mat22();
this.K1.col1.x = invMass1 + invMass2; this.K1.col2.x = 0.0;
this.K1.col1.y = 0.0; this.K1.col2.y = invMass1 + invMass2;
//var this.K2 = new b2Mat22();
this.K2.col1.x = invI1 * r1Y * r1Y; this.K2.col2.x = -invI1 * r1X * r1Y;
this.K2.col1.y = -invI1 * r1X * r1Y; this.K2.col2.y = invI1 * r1X * r1X;
//var this.K3 = new b2Mat22();
this.K3.col1.x = invI2 * r2Y * r2Y; this.K3.col2.x = -invI2 * r2X * r2Y;
this.K3.col1.y = -invI2 * r2X * r2Y; this.K3.col2.y = invI2 * r2X * r2X;
//var this.K = b2Math.AddMM(b2Math.AddMM(this.K1, this.K2), this.K3);
this.K.SetM(this.K1);
this.K.AddM(this.K2);
this.K.AddM(this.K3);
//this.m_ptpMass = this.K.Invert();
this.K.Invert(this.m_ptpMass);
this.m_motorMass = 1.0 / (invI1 + invI2);
if (this.m_enableMotor == false)
{
this.m_motorImpulse = 0.0;
}
if (this.m_enableLimit)
{
var jointAngle = b2.m_rotation - b1.m_rotation - this.m_intialAngle;
if (b2Math.b2Abs(this.m_upperAngle - this.m_lowerAngle) < 2.0 * b2Settings.b2_angularSlop)
{
this.m_limitState = b2Joint.e_equalLimits;
}
else if (jointAngle <= this.m_lowerAngle)
{
if (this.m_limitState != b2Joint.e_atLowerLimit)
{
this.m_limitImpulse = 0.0;
}
this.m_limitState = b2Joint.e_atLowerLimit;
}
else if (jointAngle >= this.m_upperAngle)
{
if (this.m_limitState != b2Joint.e_atUpperLimit)
{
this.m_limitImpulse = 0.0;
}
this.m_limitState = b2Joint.e_atUpperLimit;
}
else
{
this.m_limitState = b2Joint.e_inactiveLimit;
this.m_limitImpulse = 0.0;
}
}
else
{
this.m_limitImpulse = 0.0;
}
// Warm starting.
if (b2World.s_enableWarmStarting)
{
//b1.m_linearVelocity.Subtract( b2Math.MulFV( invMass1, this.m_ptpImpulse) );
b1.m_linearVelocity.x -= invMass1 * this.m_ptpImpulse.x;
b1.m_linearVelocity.y -= invMass1 * this.m_ptpImpulse.y;
//b1.m_angularVelocity -= invI1 * (b2Math.b2CrossVV(r1, this.m_ptpImpulse) + this.m_motorImpulse + this.m_limitImpulse);
b1.m_angularVelocity -= invI1 * ((r1X * this.m_ptpImpulse.y - r1Y * this.m_ptpImpulse.x) + this.m_motorImpulse + this.m_limitImpulse);
//b2.m_linearVelocity.Add( b2Math.MulFV( invMass2 , this.m_ptpImpulse ));
b2.m_linearVelocity.x += invMass2 * this.m_ptpImpulse.x;
b2.m_linearVelocity.y += invMass2 * this.m_ptpImpulse.y;
//b2.m_angularVelocity += invI2 * (b2Math.b2CrossVV(r2, this.m_ptpImpulse) + this.m_motorImpulse + this.m_limitImpulse);
b2.m_angularVelocity += invI2 * ((r2X * this.m_ptpImpulse.y - r2Y * this.m_ptpImpulse.x) + this.m_motorImpulse + this.m_limitImpulse);
}
else{
this.m_ptpImpulse.SetZero();
this.m_motorImpulse = 0.0;
this.m_limitImpulse = 0.0;
}
this.m_limitPositionImpulse = 0.0;
},
SolveVelocityConstraints: function(step){
var b1 = this.m_body1;
var b2 = this.m_body2;
var tMat;
//var r1 = b2Math.b2MulMV(b1.m_R, this.m_localAnchor1);
tMat = b1.m_R;
var r1X = tMat.col1.x * this.m_localAnchor1.x + tMat.col2.x * this.m_localAnchor1.y;
var r1Y = tMat.col1.y * this.m_localAnchor1.x + tMat.col2.y * this.m_localAnchor1.y;
//var r2 = b2Math.b2MulMV(b2.m_R, this.m_localAnchor2);
tMat = b2.m_R;
var r2X = tMat.col1.x * this.m_localAnchor2.x + tMat.col2.x * this.m_localAnchor2.y;
var r2Y = tMat.col1.y * this.m_localAnchor2.x + tMat.col2.y * this.m_localAnchor2.y;
var oldLimitImpulse;
// Solve point-to-point constraint
//b2Vec2 ptpCdot = b2.m_linearVelocity + b2Cross(b2.m_angularVelocity, r2) - b1.m_linearVelocity - b2Cross(b1.m_angularVelocity, r1);
var ptpCdotX = b2.m_linearVelocity.x + (-b2.m_angularVelocity * r2Y) - b1.m_linearVelocity.x - (-b1.m_angularVelocity * r1Y);
var ptpCdotY = b2.m_linearVelocity.y + (b2.m_angularVelocity * r2X) - b1.m_linearVelocity.y - (b1.m_angularVelocity * r1X);
//b2Vec2 ptpImpulse = -b2Mul(this.m_ptpMass, ptpCdot);
var ptpImpulseX = -(this.m_ptpMass.col1.x * ptpCdotX + this.m_ptpMass.col2.x * ptpCdotY);
var ptpImpulseY = -(this.m_ptpMass.col1.y * ptpCdotX + this.m_ptpMass.col2.y * ptpCdotY);
this.m_ptpImpulse.x += ptpImpulseX;
this.m_ptpImpulse.y += ptpImpulseY;
//b1->m_linearVelocity -= b1->m_invMass * ptpImpulse;
b1.m_linearVelocity.x -= b1.m_invMass * ptpImpulseX;
b1.m_linearVelocity.y -= b1.m_invMass * ptpImpulseY;
//b1->m_angularVelocity -= b1->m_invI * b2Cross(r1, ptpImpulse);
b1.m_angularVelocity -= b1.m_invI * (r1X * ptpImpulseY - r1Y * ptpImpulseX);
//b2->m_linearVelocity += b2->m_invMass * ptpImpulse;
b2.m_linearVelocity.x += b2.m_invMass * ptpImpulseX;
b2.m_linearVelocity.y += b2.m_invMass * ptpImpulseY;
//b2->m_angularVelocity += b2->m_invI * b2Cross(r2, ptpImpulse);
b2.m_angularVelocity += b2.m_invI * (r2X * ptpImpulseY - r2Y * ptpImpulseX);
if (this.m_enableMotor && this.m_limitState != b2Joint.e_equalLimits)
{
var motorCdot = b2.m_angularVelocity - b1.m_angularVelocity - this.m_motorSpeed;
var motorImpulse = -this.m_motorMass * motorCdot;
var oldMotorImpulse = this.m_motorImpulse;
this.m_motorImpulse = b2Math.b2Clamp(this.m_motorImpulse + motorImpulse, -step.dt * this.m_maxMotorTorque, step.dt * this.m_maxMotorTorque);
motorImpulse = this.m_motorImpulse - oldMotorImpulse;
b1.m_angularVelocity -= b1.m_invI * motorImpulse;
b2.m_angularVelocity += b2.m_invI * motorImpulse;
}
if (this.m_enableLimit && this.m_limitState != b2Joint.e_inactiveLimit)
{
var limitCdot = b2.m_angularVelocity - b1.m_angularVelocity;
var limitImpulse = -this.m_motorMass * limitCdot;
if (this.m_limitState == b2Joint.e_equalLimits)
{
this.m_limitImpulse += limitImpulse;
}
else if (this.m_limitState == b2Joint.e_atLowerLimit)
{
oldLimitImpulse = this.m_limitImpulse;
this.m_limitImpulse = b2Math.b2Max(this.m_limitImpulse + limitImpulse, 0.0);
limitImpulse = this.m_limitImpulse - oldLimitImpulse;
}
else if (this.m_limitState == b2Joint.e_atUpperLimit)
{
oldLimitImpulse = this.m_limitImpulse;
this.m_limitImpulse = b2Math.b2Min(this.m_limitImpulse + limitImpulse, 0.0);
limitImpulse = this.m_limitImpulse - oldLimitImpulse;
}
b1.m_angularVelocity -= b1.m_invI * limitImpulse;
b2.m_angularVelocity += b2.m_invI * limitImpulse;
}
},
SolvePositionConstraints: function(){
var oldLimitImpulse;
var limitC;
var b1 = this.m_body1;
var b2 = this.m_body2;
var positionError = 0.0;
var tMat;
// Solve point-to-point position error.
//var r1 = b2Math.b2MulMV(b1.m_R, this.m_localAnchor1);
tMat = b1.m_R;
var r1X = tMat.col1.x * this.m_localAnchor1.x + tMat.col2.x * this.m_localAnchor1.y;
var r1Y = tMat.col1.y * this.m_localAnchor1.x + tMat.col2.y * this.m_localAnchor1.y;
//var r2 = b2Math.b2MulMV(b2.m_R, this.m_localAnchor2);
tMat = b2.m_R;
var r2X = tMat.col1.x * this.m_localAnchor2.x + tMat.col2.x * this.m_localAnchor2.y;
var r2Y = tMat.col1.y * this.m_localAnchor2.x + tMat.col2.y * this.m_localAnchor2.y;
//b2Vec2 p1 = b1->m_position + r1;
var p1X = b1.m_position.x + r1X;
var p1Y = b1.m_position.y + r1Y;
//b2Vec2 p2 = b2->m_position + r2;
var p2X = b2.m_position.x + r2X;
var p2Y = b2.m_position.y + r2Y;
//b2Vec2 ptpC = p2 - p1;
var ptpCX = p2X - p1X;
var ptpCY = p2Y - p1Y;
//float32 positionError = ptpC.Length();
positionError = Math.sqrt(ptpCX*ptpCX + ptpCY*ptpCY);
// Prevent overly large corrections.
//b2Vec2 dpMax(b2_maxLinearCorrection, b2_maxLinearCorrection);
//ptpC = b2Clamp(ptpC, -dpMax, dpMax);
//float32 invMass1 = b1->m_invMass, invMass2 = b2->m_invMass;
var invMass1 = b1.m_invMass;
var invMass2 = b2.m_invMass;
//float32 invI1 = b1->m_invI, invI2 = b2->m_invI;
var invI1 = b1.m_invI;
var invI2 = b2.m_invI;
//b2Mat22 this.K1;
this.K1.col1.x = invMass1 + invMass2; this.K1.col2.x = 0.0;
this.K1.col1.y = 0.0; this.K1.col2.y = invMass1 + invMass2;
//b2Mat22 this.K2;
this.K2.col1.x = invI1 * r1Y * r1Y; this.K2.col2.x = -invI1 * r1X * r1Y;
this.K2.col1.y = -invI1 * r1X * r1Y; this.K2.col2.y = invI1 * r1X * r1X;
//b2Mat22 this.K3;
this.K3.col1.x = invI2 * r2Y * r2Y; this.K3.col2.x = -invI2 * r2X * r2Y;
this.K3.col1.y = -invI2 * r2X * r2Y; this.K3.col2.y = invI2 * r2X * r2X;
//b2Mat22 this.K = this.K1 + this.K2 + this.K3;
this.K.SetM(this.K1);
this.K.AddM(this.K2);
this.K.AddM(this.K3);
//b2Vec2 impulse = this.K.Solve(-ptpC);
this.K.Solve(b2RevoluteJoint.tImpulse, -ptpCX, -ptpCY);
var impulseX = b2RevoluteJoint.tImpulse.x;
var impulseY = b2RevoluteJoint.tImpulse.y;
//b1.m_position -= b1.m_invMass * impulse;
b1.m_position.x -= b1.m_invMass * impulseX;
b1.m_position.y -= b1.m_invMass * impulseY;
//b1.m_rotation -= b1.m_invI * b2Cross(r1, impulse);
b1.m_rotation -= b1.m_invI * (r1X * impulseY - r1Y * impulseX);
b1.m_R.Set(b1.m_rotation);
//b2.m_position += b2.m_invMass * impulse;
b2.m_position.x += b2.m_invMass * impulseX;
b2.m_position.y += b2.m_invMass * impulseY;
//b2.m_rotation += b2.m_invI * b2Cross(r2, impulse);
b2.m_rotation += b2.m_invI * (r2X * impulseY - r2Y * impulseX);
b2.m_R.Set(b2.m_rotation);
// Handle limits.
var angularError = 0.0;
if (this.m_enableLimit && this.m_limitState != b2Joint.e_inactiveLimit)
{
var angle = b2.m_rotation - b1.m_rotation - this.m_intialAngle;
var limitImpulse = 0.0;
if (this.m_limitState == b2Joint.e_equalLimits)
{
// Prevent large angular corrections
limitC = b2Math.b2Clamp(angle, -b2Settings.b2_maxAngularCorrection, b2Settings.b2_maxAngularCorrection);
limitImpulse = -this.m_motorMass * limitC;
angularError = b2Math.b2Abs(limitC);
}
else if (this.m_limitState == b2Joint.e_atLowerLimit)
{
limitC = angle - this.m_lowerAngle;
angularError = b2Math.b2Max(0.0, -limitC);
// Prevent large angular corrections and allow some slop.
limitC = b2Math.b2Clamp(limitC + b2Settings.b2_angularSlop, -b2Settings.b2_maxAngularCorrection, 0.0);
limitImpulse = -this.m_motorMass * limitC;
oldLimitImpulse = this.m_limitPositionImpulse;
this.m_limitPositionImpulse = b2Math.b2Max(this.m_limitPositionImpulse + limitImpulse, 0.0);
limitImpulse = this.m_limitPositionImpulse - oldLimitImpulse;
}
else if (this.m_limitState == b2Joint.e_atUpperLimit)
{
limitC = angle - this.m_upperAngle;
angularError = b2Math.b2Max(0.0, limitC);
// Prevent large angular corrections and allow some slop.
limitC = b2Math.b2Clamp(limitC - b2Settings.b2_angularSlop, 0.0, b2Settings.b2_maxAngularCorrection);
limitImpulse = -this.m_motorMass * limitC;
oldLimitImpulse = this.m_limitPositionImpulse;
this.m_limitPositionImpulse = b2Math.b2Min(this.m_limitPositionImpulse + limitImpulse, 0.0);
limitImpulse = this.m_limitPositionImpulse - oldLimitImpulse;
}
b1.m_rotation -= b1.m_invI * limitImpulse;
b1.m_R.Set(b1.m_rotation);
b2.m_rotation += b2.m_invI * limitImpulse;
b2.m_R.Set(b2.m_rotation);
}
return positionError <= b2Settings.b2_linearSlop && angularError <= b2Settings.b2_angularSlop;
},
m_localAnchor1: new b2Vec2(),
m_localAnchor2: new b2Vec2(),
m_ptpImpulse: new b2Vec2(),
m_motorImpulse: null,
m_limitImpulse: null,
m_limitPositionImpulse: null,
m_ptpMass: new b2Mat22(),
m_motorMass: null,
m_intialAngle: null,
m_lowerAngle: null,
m_upperAngle: null,
m_maxMotorTorque: null,
m_motorSpeed: null,
m_enableLimit: null,
m_enableMotor: null,
m_limitState: 0});
b2RevoluteJoint.tImpulse = new b2Vec2();
