API Docs for: 0.6.1
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File: src/constraints/ConeTwistConstraint.js

module.exports = ConeTwistConstraint;

var Constraint = require('./Constraint');
var PointToPointConstraint = require('./PointToPointConstraint');
var ConeEquation = require('../equations/ConeEquation');
var RotationalEquation = require('../equations/RotationalEquation');
var ContactEquation = require('../equations/ContactEquation');
var Vec3 = require('../math/Vec3');

/**
 * @class ConeTwistConstraint
 * @constructor
 * @author schteppe
 * @param {Body} bodyA
 * @param {Body} bodyB
 * @param {object} [options]
 * @param {Vec3} [options.pivotA]
 * @param {Vec3} [options.pivotB]
 * @param {Vec3} [options.axisA]
 * @param {Vec3} [options.axisB]
 * @param {Number} [options.maxForce=1e6]
 * @extends PointToPointConstraint
 */
function ConeTwistConstraint(bodyA, bodyB, options){
    options = options || {};
    var maxForce = typeof(options.maxForce) !== 'undefined' ? options.maxForce : 1e6;

    // Set pivot point in between
    var pivotA = options.pivotA ? options.pivotA.clone() : new Vec3();
    var pivotB = options.pivotB ? options.pivotB.clone() : new Vec3();
    this.axisA = options.axisA ? options.axisA.clone() : new Vec3();
    this.axisB = options.axisB ? options.axisB.clone() : new Vec3();

    PointToPointConstraint.call(this, bodyA, pivotA, bodyB, pivotB, maxForce);

    this.collideConnected = !!options.collideConnected;

    this.angle = typeof(options.angle) !== 'undefined' ? options.angle : 0;

    /**
     * @property {ConeEquation} coneEquation
     */
    var c = this.coneEquation = new ConeEquation(bodyA,bodyB,options);

    /**
     * @property {RotationalEquation} twistEquation
     */
    var t = this.twistEquation = new RotationalEquation(bodyA,bodyB,options);
    this.twistAngle = typeof(options.twistAngle) !== 'undefined' ? options.twistAngle : 0;

    // Make the cone equation push the bodies toward the cone axis, not outward
    c.maxForce = 0;
    c.minForce = -maxForce;

    // Make the twist equation add torque toward the initial position
    t.maxForce = 0;
    t.minForce = -maxForce;

    this.equations.push(c, t);
}
ConeTwistConstraint.prototype = new PointToPointConstraint();
ConeTwistConstraint.constructor = ConeTwistConstraint;

var ConeTwistConstraint_update_tmpVec1 = new Vec3();
var ConeTwistConstraint_update_tmpVec2 = new Vec3();

ConeTwistConstraint.prototype.update = function(){
    var bodyA = this.bodyA,
        bodyB = this.bodyB,
        cone = this.coneEquation,
        twist = this.twistEquation;

    PointToPointConstraint.prototype.update.call(this);

    // Update the axes to the cone constraint
    bodyA.vectorToWorldFrame(this.axisA, cone.axisA);
    bodyB.vectorToWorldFrame(this.axisB, cone.axisB);

    // Update the world axes in the twist constraint
    this.axisA.tangents(twist.axisA, twist.axisA);
    bodyA.vectorToWorldFrame(twist.axisA, twist.axisA);

    this.axisB.tangents(twist.axisB, twist.axisB);
    bodyB.vectorToWorldFrame(twist.axisB, twist.axisB);

    cone.angle = this.angle;
    twist.maxAngle = this.twistAngle;
};