1372 lines
45 KiB
C#
1372 lines
45 KiB
C#
/*
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* Farseer Physics Engine:
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* Copyright (c) 2012 Ian Qvist
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*
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* Original source Box2D:
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* Copyright (c) 2006-2011 Erin Catto http://www.box2d.org
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*
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* This software is provided 'as-is', without any express or implied
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* warranty. In no event will the authors be held liable for any damages
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* arising from the use of this software.
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* Permission is granted to anyone to use this software for any purpose,
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* including commercial applications, and to alter it and redistribute it
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* freely, subject to the following restrictions:
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* 1. The origin of this software must not be misrepresented; you must not
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* claim that you wrote the original software. If you use this software
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* in a product, an acknowledgment in the product documentation would be
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* appreciated but is not required.
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* 2. Altered source versions must be plainly marked as such, and must not be
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* misrepresented as being the original software.
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* 3. This notice may not be removed or altered from any source distribution.
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*/
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//#define USE_AWAKE_BODY_SET
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using System;
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using System.Collections.Generic;
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using System.Diagnostics;
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using FarseerPhysics.Collision;
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using FarseerPhysics.Collision.Shapes;
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using FarseerPhysics.Common;
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using FarseerPhysics.Common.PhysicsLogic;
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using FarseerPhysics.Controllers;
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using FarseerPhysics.Dynamics.Contacts;
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using FarseerPhysics.Dynamics.Joints;
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using Microsoft.Xna.Framework;
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namespace FarseerPhysics.Dynamics
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{
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/// <summary>
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/// The body type.
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/// </summary>
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public enum BodyType
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{
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/// <summary>
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/// Zero velocity, may be manually moved. Note: even static bodies have mass.
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/// </summary>
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Static,
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/// <summary>
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/// Zero mass, non-zero velocity set by user, moved by solver
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/// </summary>
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Kinematic,
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/// <summary>
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/// Positive mass, non-zero velocity determined by forces, moved by solver
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/// </summary>
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Dynamic,
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}
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public class Body : IDisposable
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{
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[ThreadStatic]
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private static int _bodyIdCounter;
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private float _angularDamping;
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private BodyType _bodyType;
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private float _inertia;
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private float _linearDamping;
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private float _mass;
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private bool _sleepingAllowed = true;
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private bool _awake = true;
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private bool _fixedRotation;
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internal bool _enabled = true;
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internal float _angularVelocity;
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internal Vector2 _linearVelocity;
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internal Vector2 _force;
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internal float _invI;
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internal float _invMass;
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internal float _sleepTime;
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internal Sweep _sweep; // the swept motion for CCD
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internal float _torque;
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internal World _world;
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internal Transform _xf; // the body origin transform
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internal bool _island;
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public PhysicsLogicFilter PhysicsLogicFilter;
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public ControllerFilter ControllerFilter;
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public Body(World world, Vector2? position = null, float rotation = 0, object userdata = null)
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{
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FixtureList = new List<Fixture>();
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BodyId = _bodyIdCounter++;
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_world = world;
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UserData = userdata;
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GravityScale = 1.0f;
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BodyType = BodyType.Static;
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Enabled = true; //FPE note: Also creates proxies in the broadphase
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_xf.q.Set(rotation);
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if (position.HasValue)
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{
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_xf.p = position.Value;
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_sweep.C0 = _xf.p;
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_sweep.C = _xf.p;
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_sweep.A0 = rotation;
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_sweep.A = rotation;
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}
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world.AddBody(this); //FPE note: bodies can't live without a World
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}
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/// <summary>
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/// A unique id for this body.
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/// </summary>
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public int BodyId { get; private set; }
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public int IslandIndex { get; set; }
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/// <summary>
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/// Scale the gravity applied to this body.
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/// Defaults to 1. A value of 2 means double the gravity is applied to this body.
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/// </summary>
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public float GravityScale { get; set; }
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/// <summary>
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/// Set the user data. Use this to store your application specific data.
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/// </summary>
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/// <value>The user data.</value>
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public object UserData { get; set; }
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/// <summary>
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/// Gets the total number revolutions the body has made.
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/// </summary>
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/// <value>The revolutions.</value>
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public float Revolutions
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{
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get { return Rotation / (float)Math.PI; }
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}
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/// <summary>
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/// Gets or sets the body type.
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/// Warning: Calling this mid-update might cause a crash.
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/// </summary>
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/// <value>The type of body.</value>
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public BodyType BodyType
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{
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get { return _bodyType; }
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set
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{
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if (_bodyType == value)
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return;
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_bodyType = value;
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ResetMassData();
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if (_bodyType == BodyType.Static)
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{
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_linearVelocity = Vector2.Zero;
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_angularVelocity = 0.0f;
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_sweep.A0 = _sweep.A;
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_sweep.C0 = _sweep.C;
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SynchronizeFixtures();
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}
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Awake = true;
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_force = Vector2.Zero;
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_torque = 0.0f;
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// Delete the attached contacts.
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ContactEdge ce = ContactList;
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while (ce != null)
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{
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ContactEdge ce0 = ce;
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ce = ce.Next;
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_world.ContactManager.Destroy(ce0.Contact);
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}
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ContactList = null;
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// Touch the proxies so that new contacts will be created (when appropriate)
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IBroadPhase broadPhase = _world.ContactManager.BroadPhase;
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foreach (Fixture fixture in FixtureList)
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{
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int proxyCount = fixture.ProxyCount;
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for (int j = 0; j < proxyCount; j++)
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{
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broadPhase.TouchProxy(fixture.Proxies[j].ProxyId);
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}
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}
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}
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}
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/// <summary>
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/// Get or sets the linear velocity of the center of mass.
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/// </summary>
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/// <value>The linear velocity.</value>
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public Vector2 LinearVelocity
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{
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set
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{
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Debug.Assert(!float.IsNaN(value.X) && !float.IsNaN(value.Y));
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if (_bodyType == BodyType.Static)
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return;
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if (Vector2.Dot(value, value) > 0.0f)
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Awake = true;
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_linearVelocity = value;
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}
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get { return _linearVelocity; }
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}
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/// <summary>
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/// Gets or sets the angular velocity. Radians/second.
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/// </summary>
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/// <value>The angular velocity.</value>
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public float AngularVelocity
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{
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set
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{
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Debug.Assert(!float.IsNaN(value));
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if (_bodyType == BodyType.Static)
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return;
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if (value * value > 0.0f)
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Awake = true;
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_angularVelocity = value;
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}
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get { return _angularVelocity; }
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}
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/// <summary>
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/// Gets or sets the linear damping.
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/// </summary>
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/// <value>The linear damping.</value>
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public float LinearDamping
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{
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get { return _linearDamping; }
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set
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{
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Debug.Assert(!float.IsNaN(value));
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_linearDamping = value;
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}
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}
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/// <summary>
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/// Gets or sets the angular damping.
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/// </summary>
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/// <value>The angular damping.</value>
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public float AngularDamping
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{
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get { return _angularDamping; }
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set
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{
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Debug.Assert(!float.IsNaN(value));
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_angularDamping = value;
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}
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}
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/// <summary>
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/// Gets or sets a value indicating whether this body should be included in the CCD solver.
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/// </summary>
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/// <value><c>true</c> if this instance is included in CCD; otherwise, <c>false</c>.</value>
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public bool IsBullet { get; set; }
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/// <summary>
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/// You can disable sleeping on this body. If you disable sleeping, the
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/// body will be woken.
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/// </summary>
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/// <value><c>true</c> if sleeping is allowed; otherwise, <c>false</c>.</value>
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public bool SleepingAllowed
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{
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set
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{
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if (!value)
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Awake = true;
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_sleepingAllowed = value;
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}
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get { return _sleepingAllowed; }
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}
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/// <summary>
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/// Set the sleep state of the body. A sleeping body has very
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/// low CPU cost.
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/// </summary>
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/// <value><c>true</c> if awake; otherwise, <c>false</c>.</value>
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public bool Awake
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{
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set
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{
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if (value)
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{
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if (!_awake)
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{
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_sleepTime = 0.0f;
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_world.ContactManager.UpdateContacts(ContactList, true);
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#if USE_AWAKE_BODY_SET
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if (InWorld && !World.AwakeBodySet.Contains(this))
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{
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World.AwakeBodySet.Add(this);
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}
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#endif
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}
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}
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else
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{
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#if USE_AWAKE_BODY_SET
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// Check even for BodyType.Static because if this body had just been changed to Static it will have
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// set Awake = false in the process.
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if (InWorld && World.AwakeBodySet.Contains(this))
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{
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World.AwakeBodySet.Remove(this);
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}
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#endif
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ResetDynamics();
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_sleepTime = 0.0f;
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_world.ContactManager.UpdateContacts(ContactList, false);
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}
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_awake = value;
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}
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get { return _awake; }
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}
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/// <summary>
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/// Set the active state of the body. An inactive body is not
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/// simulated and cannot be collided with or woken up.
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/// If you pass a flag of true, all fixtures will be added to the
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/// broad-phase.
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/// If you pass a flag of false, all fixtures will be removed from
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/// the broad-phase and all contacts will be destroyed.
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/// Fixtures and joints are otherwise unaffected. You may continue
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/// to create/destroy fixtures and joints on inactive bodies.
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/// Fixtures on an inactive body are implicitly inactive and will
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/// not participate in collisions, ray-casts, or queries.
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/// Joints connected to an inactive body are implicitly inactive.
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/// An inactive body is still owned by a b2World object and remains
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/// in the body list.
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/// </summary>
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/// <value><c>true</c> if active; otherwise, <c>false</c>.</value>
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public bool Enabled
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{
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set
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{
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if (value == _enabled)
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return;
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if (value)
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{
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// Create all proxies.
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IBroadPhase broadPhase = _world.ContactManager.BroadPhase;
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for (int i = 0; i < FixtureList.Count; i++)
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{
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FixtureList[i].CreateProxies(broadPhase, ref _xf);
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}
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// Contacts are created the next time step.
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}
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else
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{
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// Destroy all proxies.
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IBroadPhase broadPhase = _world.ContactManager.BroadPhase;
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for (int i = 0; i < FixtureList.Count; i++)
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{
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FixtureList[i].DestroyProxies(broadPhase);
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}
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// Destroy the attached contacts.
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ContactEdge ce = ContactList;
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while (ce != null)
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{
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ContactEdge ce0 = ce;
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ce = ce.Next;
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_world.ContactManager.Destroy(ce0.Contact);
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}
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ContactList = null;
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}
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_enabled = value;
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}
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get { return _enabled; }
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}
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/// <summary>
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/// Set this body to have fixed rotation. This causes the mass
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/// to be reset.
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/// </summary>
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/// <value><c>true</c> if it has fixed rotation; otherwise, <c>false</c>.</value>
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public bool FixedRotation
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{
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set
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{
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if (_fixedRotation == value)
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return;
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_fixedRotation = value;
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_angularVelocity = 0f;
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ResetMassData();
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}
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get { return _fixedRotation; }
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}
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/// <summary>
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/// Gets all the fixtures attached to this body.
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/// </summary>
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/// <value>The fixture list.</value>
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public List<Fixture> FixtureList { get; internal set; }
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/// <summary>
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/// Get the list of all joints attached to this body.
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/// </summary>
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/// <value>The joint list.</value>
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public JointEdge JointList { get; internal set; }
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/// <summary>
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/// Get the list of all contacts attached to this body.
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/// Warning: this list changes during the time step and you may
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/// miss some collisions if you don't use ContactListener.
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/// </summary>
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/// <value>The contact list.</value>
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public ContactEdge ContactList { get; internal set; }
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/// <summary>
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/// Get the world body origin position.
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/// </summary>
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/// <returns>Return the world position of the body's origin.</returns>
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public Vector2 Position
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{
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get { return _xf.p; }
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set
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{
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Debug.Assert(!float.IsNaN(value.X) && !float.IsNaN(value.Y));
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SetTransform(ref value, Rotation);
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}
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}
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/// <summary>
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/// Get the angle in radians.
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/// </summary>
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/// <returns>Return the current world rotation angle in radians.</returns>
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public float Rotation
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{
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get { return _sweep.A; }
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set
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{
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Debug.Assert(!float.IsNaN(value));
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SetTransform(ref _xf.p, value);
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}
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}
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/// <summary>
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/// Gets or sets a value indicating whether this body is static.
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/// </summary>
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/// <value><c>true</c> if this instance is static; otherwise, <c>false</c>.</value>
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public bool IsStatic
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{
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get { return _bodyType == BodyType.Static; }
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set { BodyType = value ? BodyType.Static : BodyType.Dynamic; }
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}
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/// <summary>
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/// Gets or sets a value indicating whether this body is kinematic.
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/// </summary>
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/// <value><c>true</c> if this instance is kinematic; otherwise, <c>false</c>.</value>
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public bool IsKinematic
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{
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get { return _bodyType == BodyType.Kinematic; }
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set { BodyType = value ? BodyType.Kinematic : BodyType.Dynamic; }
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}
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/// <summary>
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/// Gets or sets a value indicating whether this body ignores gravity.
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/// </summary>
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/// <value><c>true</c> if it ignores gravity; otherwise, <c>false</c>.</value>
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public bool IgnoreGravity { get; set; }
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/// <summary>
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/// Get the world position of the center of mass.
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/// </summary>
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/// <value>The world position.</value>
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public Vector2 WorldCenter
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{
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get { return _sweep.C; }
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}
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/// <summary>
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/// Get the local position of the center of mass.
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/// </summary>
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/// <value>The local position.</value>
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public Vector2 LocalCenter
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{
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get { return _sweep.LocalCenter; }
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set
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{
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if (_bodyType != BodyType.Dynamic)
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return;
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// Move center of mass.
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Vector2 oldCenter = _sweep.C;
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_sweep.LocalCenter = value;
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_sweep.C0 = _sweep.C = MathUtils.Mul(ref _xf, ref _sweep.LocalCenter);
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// Update center of mass velocity.
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Vector2 a = _sweep.C - oldCenter;
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_linearVelocity += new Vector2(-_angularVelocity * a.Y, _angularVelocity * a.X);
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}
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}
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/// <summary>
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/// Gets or sets the mass. Usually in kilograms (kg).
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/// </summary>
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/// <value>The mass.</value>
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public float Mass
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{
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get { return _mass; }
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set
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{
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Debug.Assert(!float.IsNaN(value));
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if (_bodyType != BodyType.Dynamic) //Make an assert
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return;
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_mass = value;
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if (_mass <= 0.0f)
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_mass = 1.0f;
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_invMass = 1.0f / _mass;
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}
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}
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/// <summary>
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/// Get or set the rotational inertia of the body about the local origin. usually in kg-m^2.
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/// </summary>
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/// <value>The inertia.</value>
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public float Inertia
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{
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get { return _inertia + Mass * Vector2.Dot(_sweep.LocalCenter, _sweep.LocalCenter); }
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set
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{
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Debug.Assert(!float.IsNaN(value));
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if (_bodyType != BodyType.Dynamic) //Make an assert
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return;
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if (value > 0.0f && !_fixedRotation) //Make an assert
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{
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_inertia = value - Mass * Vector2.Dot(LocalCenter, LocalCenter);
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Debug.Assert(_inertia > 0.0f);
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_invI = 1.0f / _inertia;
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}
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}
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}
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public float Restitution
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{
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get
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{
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float res = 0;
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for (int i = 0; i < FixtureList.Count; i++)
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{
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Fixture f = FixtureList[i];
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res += f.Restitution;
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}
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return FixtureList.Count > 0 ? res / FixtureList.Count : 0;
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}
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set
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{
|
|
for (int i = 0; i < FixtureList.Count; i++)
|
|
{
|
|
Fixture f = FixtureList[i];
|
|
f.Restitution = value;
|
|
}
|
|
}
|
|
}
|
|
|
|
public float Friction
|
|
{
|
|
get
|
|
{
|
|
float res = 0;
|
|
|
|
for (int i = 0; i < FixtureList.Count; i++)
|
|
{
|
|
Fixture f = FixtureList[i];
|
|
res += f.Friction;
|
|
}
|
|
|
|
return FixtureList.Count > 0 ? res / FixtureList.Count : 0;
|
|
}
|
|
set
|
|
{
|
|
for (int i = 0; i < FixtureList.Count; i++)
|
|
{
|
|
Fixture f = FixtureList[i];
|
|
f.Friction = value;
|
|
}
|
|
}
|
|
}
|
|
|
|
public Category CollisionCategories
|
|
{
|
|
set
|
|
{
|
|
for (int i = 0; i < FixtureList.Count; i++)
|
|
{
|
|
Fixture f = FixtureList[i];
|
|
f.CollisionCategories = value;
|
|
}
|
|
}
|
|
}
|
|
|
|
public Category CollidesWith
|
|
{
|
|
set
|
|
{
|
|
for (int i = 0; i < FixtureList.Count; i++)
|
|
{
|
|
Fixture f = FixtureList[i];
|
|
f.CollidesWith = value;
|
|
}
|
|
}
|
|
}
|
|
|
|
/// <summary>
|
|
/// Body objects can define which categories of bodies they wish to ignore CCD with.
|
|
/// This allows certain bodies to be configured to ignore CCD with objects that
|
|
/// aren't a penetration problem due to the way content has been prepared.
|
|
/// This is compared against the other Body's fixture CollisionCategories within World.SolveTOI().
|
|
/// </summary>
|
|
public Category IgnoreCCDWith
|
|
{
|
|
set
|
|
{
|
|
for (int i = 0; i < FixtureList.Count; i++)
|
|
{
|
|
Fixture f = FixtureList[i];
|
|
f.IgnoreCCDWith = value;
|
|
}
|
|
}
|
|
}
|
|
|
|
public short CollisionGroup
|
|
{
|
|
set
|
|
{
|
|
for (int i = 0; i < FixtureList.Count; i++)
|
|
{
|
|
Fixture f = FixtureList[i];
|
|
f.CollisionGroup = value;
|
|
}
|
|
}
|
|
}
|
|
|
|
public bool IsSensor
|
|
{
|
|
set
|
|
{
|
|
for (int i = 0; i < FixtureList.Count; i++)
|
|
{
|
|
Fixture f = FixtureList[i];
|
|
f.IsSensor = value;
|
|
}
|
|
}
|
|
}
|
|
|
|
public bool IgnoreCCD { get; set; }
|
|
|
|
/// <summary>
|
|
/// Resets the dynamics of this body.
|
|
/// Sets torque, force and linear/angular velocity to 0
|
|
/// </summary>
|
|
public void ResetDynamics()
|
|
{
|
|
_torque = 0;
|
|
_angularVelocity = 0;
|
|
_force = Vector2.Zero;
|
|
_linearVelocity = Vector2.Zero;
|
|
}
|
|
|
|
/// <summary>
|
|
/// Creates a fixture and attach it to this body.
|
|
/// If the density is non-zero, this function automatically updates the mass of the body.
|
|
/// Contacts are not created until the next time step.
|
|
/// Warning: This function is locked during callbacks.
|
|
/// </summary>
|
|
/// <param name="shape">The shape.</param>
|
|
/// <param name="userData">Application specific data</param>
|
|
/// <returns></returns>
|
|
public Fixture CreateFixture(Shape shape, object userData = null)
|
|
{
|
|
return new Fixture(this, shape, userData);
|
|
}
|
|
|
|
/// <summary>
|
|
/// Destroy a fixture. This removes the fixture from the broad-phase and
|
|
/// destroys all contacts associated with this fixture. This will
|
|
/// automatically adjust the mass of the body if the body is dynamic and the
|
|
/// fixture has positive density.
|
|
/// All fixtures attached to a body are implicitly destroyed when the body is destroyed.
|
|
/// Warning: This function is locked during callbacks.
|
|
/// </summary>
|
|
/// <param name="fixture">The fixture to be removed.</param>
|
|
public void DestroyFixture(Fixture fixture)
|
|
{
|
|
Debug.Assert(fixture.Body == this);
|
|
|
|
// Remove the fixture from this body's singly linked list.
|
|
Debug.Assert(FixtureList.Count > 0);
|
|
|
|
// You tried to remove a fixture that not present in the fixturelist.
|
|
Debug.Assert(FixtureList.Contains(fixture));
|
|
|
|
// Destroy any contacts associated with the fixture.
|
|
ContactEdge edge = ContactList;
|
|
while (edge != null)
|
|
{
|
|
Contact c = edge.Contact;
|
|
edge = edge.Next;
|
|
|
|
Fixture fixtureA = c.FixtureA;
|
|
Fixture fixtureB = c.FixtureB;
|
|
|
|
if (fixture == fixtureA || fixture == fixtureB)
|
|
{
|
|
// This destroys the contact and removes it from
|
|
// this body's contact list.
|
|
_world.ContactManager.Destroy(c);
|
|
}
|
|
}
|
|
|
|
if (_enabled)
|
|
{
|
|
IBroadPhase broadPhase = _world.ContactManager.BroadPhase;
|
|
fixture.DestroyProxies(broadPhase);
|
|
}
|
|
|
|
FixtureList.Remove(fixture);
|
|
fixture.Destroy();
|
|
fixture.Body = null;
|
|
|
|
ResetMassData();
|
|
}
|
|
|
|
/// <summary>
|
|
/// Set the position of the body's origin and rotation.
|
|
/// This breaks any contacts and wakes the other bodies.
|
|
/// Manipulating a body's transform may cause non-physical behavior.
|
|
/// </summary>
|
|
/// <param name="position">The world position of the body's local origin.</param>
|
|
/// <param name="rotation">The world rotation in radians.</param>
|
|
public void SetTransform(ref Vector2 position, float rotation)
|
|
{
|
|
SetTransformIgnoreContacts(ref position, rotation);
|
|
|
|
_world.ContactManager.FindNewContacts();
|
|
}
|
|
|
|
/// <summary>
|
|
/// Set the position of the body's origin and rotation.
|
|
/// This breaks any contacts and wakes the other bodies.
|
|
/// Manipulating a body's transform may cause non-physical behavior.
|
|
/// </summary>
|
|
/// <param name="position">The world position of the body's local origin.</param>
|
|
/// <param name="rotation">The world rotation in radians.</param>
|
|
public void SetTransform(Vector2 position, float rotation)
|
|
{
|
|
Debug.Assert(position.IsValid());
|
|
|
|
SetTransform(ref position, rotation);
|
|
}
|
|
|
|
/// <summary>
|
|
/// For teleporting a body without considering new contacts immediately.
|
|
/// </summary>
|
|
/// <param name="position">The position.</param>
|
|
/// <param name="angle">The angle.</param>
|
|
public void SetTransformIgnoreContacts(ref Vector2 position, float angle)
|
|
{
|
|
_xf.q.Set(angle);
|
|
_xf.p = position;
|
|
|
|
_sweep.C = MathUtils.Mul(ref _xf, _sweep.LocalCenter);
|
|
_sweep.A = angle;
|
|
|
|
_sweep.C0 = _sweep.C;
|
|
_sweep.A0 = angle;
|
|
|
|
IBroadPhase broadPhase = _world.ContactManager.BroadPhase;
|
|
for (int i = 0; i < FixtureList.Count; i++)
|
|
{
|
|
FixtureList[i].Synchronize(broadPhase, ref _xf, ref _xf);
|
|
}
|
|
}
|
|
|
|
/// <summary>
|
|
/// Get the body transform for the body's origin.
|
|
/// </summary>
|
|
/// <param name="transform">The transform of the body's origin.</param>
|
|
public void GetTransform(out Transform transform)
|
|
{
|
|
transform = _xf;
|
|
}
|
|
|
|
/// <summary>
|
|
/// Apply a force at a world point. If the force is not
|
|
/// applied at the center of mass, it will generate a torque and
|
|
/// affect the angular velocity. This wakes up the body.
|
|
/// </summary>
|
|
/// <param name="force">The world force vector, usually in Newtons (N).</param>
|
|
/// <param name="point">The world position of the point of application.</param>
|
|
public void ApplyForce(Vector2 force, Vector2 point)
|
|
{
|
|
Debug.Assert(force.IsValid());
|
|
|
|
ApplyForce(ref force, ref point);
|
|
}
|
|
|
|
/// <summary>
|
|
/// Applies a force at the center of mass.
|
|
/// </summary>
|
|
/// <param name="force">The force.</param>
|
|
public void ApplyForce(ref Vector2 force)
|
|
{
|
|
ApplyForce(ref force, ref _xf.p);
|
|
}
|
|
|
|
/// <summary>
|
|
/// Applies a force at the center of mass.
|
|
/// </summary>
|
|
/// <param name="force">The force.</param>
|
|
public void ApplyForce(Vector2 force)
|
|
{
|
|
Debug.Assert(force.IsValid());
|
|
|
|
ApplyForce(ref force, ref _xf.p);
|
|
}
|
|
|
|
/// <summary>
|
|
/// Apply a force at a world point. If the force is not
|
|
/// applied at the center of mass, it will generate a torque and
|
|
/// affect the angular velocity. This wakes up the body.
|
|
/// </summary>
|
|
/// <param name="force">The world force vector, usually in Newtons (N).</param>
|
|
/// <param name="point">The world position of the point of application.</param>
|
|
public void ApplyForce(ref Vector2 force, ref Vector2 point)
|
|
{
|
|
Debug.Assert(!float.IsNaN(force.X));
|
|
Debug.Assert(!float.IsNaN(force.Y));
|
|
Debug.Assert(!float.IsNaN(point.X));
|
|
Debug.Assert(!float.IsNaN(point.Y));
|
|
|
|
if (_bodyType == BodyType.Dynamic)
|
|
{
|
|
if (Awake == false)
|
|
{
|
|
Awake = true;
|
|
}
|
|
|
|
_force += force;
|
|
_torque += (point.X - _sweep.C.X) * force.Y - (point.Y - _sweep.C.Y) * force.X;
|
|
}
|
|
}
|
|
|
|
/// <summary>
|
|
/// Apply a torque. This affects the angular velocity
|
|
/// without affecting the linear velocity of the center of mass.
|
|
/// This wakes up the body.
|
|
/// </summary>
|
|
/// <param name="torque">The torque about the z-axis (out of the screen), usually in N-m.</param>
|
|
public void ApplyTorque(float torque)
|
|
{
|
|
Debug.Assert(!float.IsNaN(torque));
|
|
|
|
if (_bodyType == BodyType.Dynamic)
|
|
{
|
|
if (Awake == false)
|
|
{
|
|
Awake = true;
|
|
}
|
|
|
|
_torque += torque;
|
|
}
|
|
}
|
|
|
|
/// <summary>
|
|
/// Apply an impulse at a point. This immediately modifies the velocity.
|
|
/// This wakes up the body.
|
|
/// </summary>
|
|
/// <param name="impulse">The world impulse vector, usually in N-seconds or kg-m/s.</param>
|
|
public void ApplyLinearImpulse(Vector2 impulse)
|
|
{
|
|
Debug.Assert(impulse.IsValid());
|
|
|
|
ApplyLinearImpulse(ref impulse);
|
|
}
|
|
|
|
/// <summary>
|
|
/// Apply an impulse at a point. This immediately modifies the velocity.
|
|
/// It also modifies the angular velocity if the point of application
|
|
/// is not at the center of mass.
|
|
/// This wakes up the body.
|
|
/// </summary>
|
|
/// <param name="impulse">The world impulse vector, usually in N-seconds or kg-m/s.</param>
|
|
/// <param name="point">The world position of the point of application.</param>
|
|
public void ApplyLinearImpulse(Vector2 impulse, Vector2 point)
|
|
{
|
|
Debug.Assert(impulse.IsValid());
|
|
|
|
ApplyLinearImpulse(ref impulse, ref point);
|
|
}
|
|
|
|
/// <summary>
|
|
/// Apply an impulse at a point. This immediately modifies the velocity.
|
|
/// This wakes up the body.
|
|
/// </summary>
|
|
/// <param name="impulse">The world impulse vector, usually in N-seconds or kg-m/s.</param>
|
|
public void ApplyLinearImpulse(ref Vector2 impulse)
|
|
{
|
|
if (_bodyType != BodyType.Dynamic)
|
|
{
|
|
return;
|
|
}
|
|
if (Awake == false)
|
|
{
|
|
Awake = true;
|
|
}
|
|
_linearVelocity += _invMass * impulse;
|
|
}
|
|
|
|
/// <summary>
|
|
/// Apply an impulse at a point. This immediately modifies the velocity.
|
|
/// It also modifies the angular velocity if the point of application
|
|
/// is not at the center of mass.
|
|
/// This wakes up the body.
|
|
/// </summary>
|
|
/// <param name="impulse">The world impulse vector, usually in N-seconds or kg-m/s.</param>
|
|
/// <param name="point">The world position of the point of application.</param>
|
|
public void ApplyLinearImpulse(ref Vector2 impulse, ref Vector2 point)
|
|
{
|
|
if (_bodyType != BodyType.Dynamic)
|
|
return;
|
|
|
|
if (Awake == false)
|
|
Awake = true;
|
|
|
|
_linearVelocity += _invMass * impulse;
|
|
_angularVelocity += _invI * ((point.X - _sweep.C.X) * impulse.Y - (point.Y - _sweep.C.Y) * impulse.X);
|
|
}
|
|
|
|
/// <summary>
|
|
/// Apply an angular impulse.
|
|
/// </summary>
|
|
/// <param name="impulse">The angular impulse in units of kg*m*m/s.</param>
|
|
public void ApplyAngularImpulse(float impulse)
|
|
{
|
|
if (_bodyType != BodyType.Dynamic)
|
|
{
|
|
return;
|
|
}
|
|
|
|
if (Awake == false)
|
|
{
|
|
Awake = true;
|
|
}
|
|
|
|
_angularVelocity += _invI * impulse;
|
|
}
|
|
|
|
/// <summary>
|
|
/// This resets the mass properties to the sum of the mass properties of the fixtures.
|
|
/// This normally does not need to be called unless you called SetMassData to override
|
|
/// the mass and you later want to reset the mass.
|
|
/// </summary>
|
|
public void ResetMassData()
|
|
{
|
|
// Compute mass data from shapes. Each shape has its own density.
|
|
_mass = 0.0f;
|
|
_invMass = 0.0f;
|
|
_inertia = 0.0f;
|
|
_invI = 0.0f;
|
|
_sweep.LocalCenter = Vector2.Zero;
|
|
|
|
// Kinematic bodies have zero mass.
|
|
if (BodyType == BodyType.Kinematic)
|
|
{
|
|
_sweep.C0 = _xf.p;
|
|
_sweep.C = _xf.p;
|
|
_sweep.A0 = _sweep.A;
|
|
return;
|
|
}
|
|
|
|
Debug.Assert(BodyType == BodyType.Dynamic || BodyType == BodyType.Static);
|
|
|
|
// Accumulate mass over all fixtures.
|
|
Vector2 localCenter = Vector2.Zero;
|
|
foreach (Fixture f in FixtureList)
|
|
{
|
|
if (f.Shape._density == 0)
|
|
{
|
|
continue;
|
|
}
|
|
|
|
MassData massData = f.Shape.MassData;
|
|
_mass += massData.Mass;
|
|
localCenter += massData.Mass * massData.Centroid;
|
|
_inertia += massData.Inertia;
|
|
}
|
|
|
|
//Static bodies only have mass, they don't have other properties. A little hacky tho...
|
|
if (BodyType == BodyType.Static)
|
|
{
|
|
_sweep.C0 = _sweep.C = _xf.p;
|
|
return;
|
|
}
|
|
|
|
// Compute center of mass.
|
|
if (_mass > 0.0f)
|
|
{
|
|
_invMass = 1.0f / _mass;
|
|
localCenter *= _invMass;
|
|
}
|
|
else
|
|
{
|
|
// Force all dynamic bodies to have a positive mass.
|
|
_mass = 1.0f;
|
|
_invMass = 1.0f;
|
|
}
|
|
|
|
if (_inertia > 0.0f && !_fixedRotation)
|
|
{
|
|
// Center the inertia about the center of mass.
|
|
_inertia -= _mass * Vector2.Dot(localCenter, localCenter);
|
|
|
|
Debug.Assert(_inertia > 0.0f);
|
|
_invI = 1.0f / _inertia;
|
|
}
|
|
else
|
|
{
|
|
_inertia = 0.0f;
|
|
_invI = 0.0f;
|
|
}
|
|
|
|
// Move center of mass.
|
|
Vector2 oldCenter = _sweep.C;
|
|
_sweep.LocalCenter = localCenter;
|
|
_sweep.C0 = _sweep.C = MathUtils.Mul(ref _xf, ref _sweep.LocalCenter);
|
|
|
|
// Update center of mass velocity.
|
|
Vector2 a = _sweep.C - oldCenter;
|
|
_linearVelocity += new Vector2(-_angularVelocity * a.Y, _angularVelocity * a.X);
|
|
}
|
|
|
|
/// <summary>
|
|
/// Get the world coordinates of a point given the local coordinates.
|
|
/// </summary>
|
|
/// <param name="localPoint">A point on the body measured relative the the body's origin.</param>
|
|
/// <returns>The same point expressed in world coordinates.</returns>
|
|
public Vector2 GetWorldPoint(ref Vector2 localPoint)
|
|
{
|
|
return MathUtils.Mul(ref _xf, ref localPoint);
|
|
}
|
|
|
|
/// <summary>
|
|
/// Get the world coordinates of a point given the local coordinates.
|
|
/// </summary>
|
|
/// <param name="localPoint">A point on the body measured relative the the body's origin.</param>
|
|
/// <returns>The same point expressed in world coordinates.</returns>
|
|
public Vector2 GetWorldPoint(Vector2 localPoint)
|
|
{
|
|
return GetWorldPoint(ref localPoint);
|
|
}
|
|
|
|
/// <summary>
|
|
/// Get the world coordinates of a vector given the local coordinates.
|
|
/// Note that the vector only takes the rotation into account, not the position.
|
|
/// </summary>
|
|
/// <param name="localVector">A vector fixed in the body.</param>
|
|
/// <returns>The same vector expressed in world coordinates.</returns>
|
|
public Vector2 GetWorldVector(ref Vector2 localVector)
|
|
{
|
|
return MathUtils.Mul(_xf.q, localVector);
|
|
}
|
|
|
|
/// <summary>
|
|
/// Get the world coordinates of a vector given the local coordinates.
|
|
/// </summary>
|
|
/// <param name="localVector">A vector fixed in the body.</param>
|
|
/// <returns>The same vector expressed in world coordinates.</returns>
|
|
public Vector2 GetWorldVector(Vector2 localVector)
|
|
{
|
|
return GetWorldVector(ref localVector);
|
|
}
|
|
|
|
/// <summary>
|
|
/// Gets a local point relative to the body's origin given a world point.
|
|
/// Note that the vector only takes the rotation into account, not the position.
|
|
/// </summary>
|
|
/// <param name="worldPoint">A point in world coordinates.</param>
|
|
/// <returns>The corresponding local point relative to the body's origin.</returns>
|
|
public Vector2 GetLocalPoint(ref Vector2 worldPoint)
|
|
{
|
|
return MathUtils.MulT(ref _xf, worldPoint);
|
|
}
|
|
|
|
/// <summary>
|
|
/// Gets a local point relative to the body's origin given a world point.
|
|
/// </summary>
|
|
/// <param name="worldPoint">A point in world coordinates.</param>
|
|
/// <returns>The corresponding local point relative to the body's origin.</returns>
|
|
public Vector2 GetLocalPoint(Vector2 worldPoint)
|
|
{
|
|
return GetLocalPoint(ref worldPoint);
|
|
}
|
|
|
|
/// <summary>
|
|
/// Gets a local vector given a world vector.
|
|
/// Note that the vector only takes the rotation into account, not the position.
|
|
/// </summary>
|
|
/// <param name="worldVector">A vector in world coordinates.</param>
|
|
/// <returns>The corresponding local vector.</returns>
|
|
public Vector2 GetLocalVector(ref Vector2 worldVector)
|
|
{
|
|
return MathUtils.MulT(_xf.q, worldVector);
|
|
}
|
|
|
|
/// <summary>
|
|
/// Gets a local vector given a world vector.
|
|
/// Note that the vector only takes the rotation into account, not the position.
|
|
/// </summary>
|
|
/// <param name="worldVector">A vector in world coordinates.</param>
|
|
/// <returns>The corresponding local vector.</returns>
|
|
public Vector2 GetLocalVector(Vector2 worldVector)
|
|
{
|
|
return GetLocalVector(ref worldVector);
|
|
}
|
|
|
|
/// <summary>
|
|
/// Get the world linear velocity of a world point attached to this body.
|
|
/// </summary>
|
|
/// <param name="worldPoint">A point in world coordinates.</param>
|
|
/// <returns>The world velocity of a point.</returns>
|
|
public Vector2 GetLinearVelocityFromWorldPoint(Vector2 worldPoint)
|
|
{
|
|
return GetLinearVelocityFromWorldPoint(ref worldPoint);
|
|
}
|
|
|
|
/// <summary>
|
|
/// Get the world linear velocity of a world point attached to this body.
|
|
/// </summary>
|
|
/// <param name="worldPoint">A point in world coordinates.</param>
|
|
/// <returns>The world velocity of a point.</returns>
|
|
public Vector2 GetLinearVelocityFromWorldPoint(ref Vector2 worldPoint)
|
|
{
|
|
return _linearVelocity +
|
|
new Vector2(-_angularVelocity * (worldPoint.Y - _sweep.C.Y),
|
|
_angularVelocity * (worldPoint.X - _sweep.C.X));
|
|
}
|
|
|
|
/// <summary>
|
|
/// Get the world velocity of a local point.
|
|
/// </summary>
|
|
/// <param name="localPoint">A point in local coordinates.</param>
|
|
/// <returns>The world velocity of a point.</returns>
|
|
public Vector2 GetLinearVelocityFromLocalPoint(Vector2 localPoint)
|
|
{
|
|
return GetLinearVelocityFromLocalPoint(ref localPoint);
|
|
}
|
|
|
|
/// <summary>
|
|
/// Get the world velocity of a local point.
|
|
/// </summary>
|
|
/// <param name="localPoint">A point in local coordinates.</param>
|
|
/// <returns>The world velocity of a point.</returns>
|
|
public Vector2 GetLinearVelocityFromLocalPoint(ref Vector2 localPoint)
|
|
{
|
|
return GetLinearVelocityFromWorldPoint(GetWorldPoint(ref localPoint));
|
|
}
|
|
|
|
internal void SynchronizeFixtures()
|
|
{
|
|
Transform xf1 = new Transform();
|
|
xf1.q.Set(_sweep.A0);
|
|
xf1.p = _sweep.C0 - MathUtils.Mul(xf1.q, _sweep.LocalCenter);
|
|
|
|
IBroadPhase broadPhase = _world.ContactManager.BroadPhase;
|
|
for (int i = 0; i < FixtureList.Count; i++)
|
|
{
|
|
FixtureList[i].Synchronize(broadPhase, ref xf1, ref _xf);
|
|
}
|
|
}
|
|
|
|
internal void SynchronizeTransform()
|
|
{
|
|
_xf.q.Set(_sweep.A);
|
|
_xf.p = _sweep.C - MathUtils.Mul(_xf.q, _sweep.LocalCenter);
|
|
}
|
|
|
|
/// <summary>
|
|
/// This is used to prevent connected bodies from colliding.
|
|
/// It may lie, depending on the collideConnected flag.
|
|
/// </summary>
|
|
/// <param name="other">The other body.</param>
|
|
/// <returns></returns>
|
|
internal bool ShouldCollide(Body other)
|
|
{
|
|
// At least one body should be dynamic.
|
|
if (_bodyType != BodyType.Dynamic && other._bodyType != BodyType.Dynamic)
|
|
{
|
|
return false;
|
|
}
|
|
|
|
// Does a joint prevent collision?
|
|
for (JointEdge jn = JointList; jn != null; jn = jn.Next)
|
|
{
|
|
if (jn.Other == other)
|
|
{
|
|
if (jn.Joint.CollideConnected == false)
|
|
{
|
|
return false;
|
|
}
|
|
}
|
|
}
|
|
|
|
return true;
|
|
}
|
|
|
|
internal void Advance(float alpha)
|
|
{
|
|
// Advance to the new safe time. This doesn't sync the broad-phase.
|
|
_sweep.Advance(alpha);
|
|
_sweep.C = _sweep.C0;
|
|
_sweep.A = _sweep.A0;
|
|
_xf.q.Set(_sweep.A);
|
|
_xf.p = _sweep.C - MathUtils.Mul(_xf.q, _sweep.LocalCenter);
|
|
}
|
|
|
|
public event OnCollisionEventHandler OnCollision
|
|
{
|
|
add
|
|
{
|
|
for (int i = 0; i < FixtureList.Count; i++)
|
|
{
|
|
FixtureList[i].OnCollision += value;
|
|
}
|
|
}
|
|
remove
|
|
{
|
|
for (int i = 0; i < FixtureList.Count; i++)
|
|
{
|
|
FixtureList[i].OnCollision -= value;
|
|
}
|
|
}
|
|
}
|
|
|
|
public event OnSeparationEventHandler OnSeparation
|
|
{
|
|
add
|
|
{
|
|
for (int i = 0; i < FixtureList.Count; i++)
|
|
{
|
|
FixtureList[i].OnSeparation += value;
|
|
}
|
|
}
|
|
remove
|
|
{
|
|
for (int i = 0; i < FixtureList.Count; i++)
|
|
{
|
|
FixtureList[i].OnSeparation -= value;
|
|
}
|
|
}
|
|
}
|
|
|
|
public void IgnoreCollisionWith(Body other)
|
|
{
|
|
for (int i = 0; i < FixtureList.Count; i++)
|
|
{
|
|
for (int j = 0; j < other.FixtureList.Count; j++)
|
|
{
|
|
FixtureList[i].IgnoreCollisionWith(other.FixtureList[j]);
|
|
}
|
|
}
|
|
}
|
|
|
|
public void RestoreCollisionWith(Body other)
|
|
{
|
|
for (int i = 0; i < FixtureList.Count; i++)
|
|
{
|
|
for (int j = 0; j < other.FixtureList.Count; j++)
|
|
{
|
|
FixtureList[i].RestoreCollisionWith(other.FixtureList[j]);
|
|
}
|
|
}
|
|
}
|
|
|
|
#region IDisposable Members
|
|
|
|
public bool IsDisposed { get; set; }
|
|
|
|
public void Dispose()
|
|
{
|
|
if (!IsDisposed)
|
|
{
|
|
_world.RemoveBody(this);
|
|
IsDisposed = true;
|
|
GC.SuppressFinalize(this);
|
|
}
|
|
}
|
|
|
|
#endregion
|
|
|
|
/// <summary>
|
|
/// Makes a clone of the body. Fixtures and therefore shapes are not included.
|
|
/// Use DeepClone() to clone the body, as well as fixtures and shapes.
|
|
/// </summary>
|
|
/// <param name="world"></param>
|
|
/// <returns></returns>
|
|
public Body Clone(World world = null)
|
|
{
|
|
Body body = new Body(world ?? _world, Position, Rotation, UserData);
|
|
body._bodyType = _bodyType;
|
|
body._linearVelocity = _linearVelocity;
|
|
body._angularVelocity = _angularVelocity;
|
|
body.GravityScale = GravityScale;
|
|
body.UserData = UserData;
|
|
body._enabled = _enabled;
|
|
body._fixedRotation = _fixedRotation;
|
|
body._sleepingAllowed = _sleepingAllowed;
|
|
body._linearDamping = _linearDamping;
|
|
body._angularDamping = _angularDamping;
|
|
body._awake = _awake;
|
|
body.IsBullet = IsBullet;
|
|
body.IgnoreCCD = IgnoreCCD;
|
|
body.IgnoreGravity = IgnoreGravity;
|
|
body._torque = _torque;
|
|
|
|
return body;
|
|
}
|
|
|
|
/// <summary>
|
|
/// Clones the body and all attached fixtures and shapes. Simply said, it makes a complete copy of the body.
|
|
/// </summary>
|
|
/// <param name="world"></param>
|
|
/// <returns></returns>
|
|
public Body DeepClone(World world = null)
|
|
{
|
|
Body body = Clone(world ?? _world);
|
|
|
|
int count = FixtureList.Count; //Make a copy of the count. Otherwise it causes an infinite loop.
|
|
for (int i = 0; i < count; i++)
|
|
{
|
|
FixtureList[i].CloneOnto(body);
|
|
}
|
|
|
|
return body;
|
|
}
|
|
}
|
|
} |