@awayfl/awayfl-player/lib/Box2Dold/Dynamics/Contacts/b2PolygonContact.ts

Flash Player emulator for executing SWF files (published for FP versions 6 and up) in javascript

/*
* Copyright (c) 2006-2007 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.
*/

import { b2Shape } from '../../Collision/Shapes/b2Shape';
import { b2Contact } from './b2Contact';
import { b2Manifold } from '../../Collision/b2Manifold';
import { b2ContactListener } from '../b2ContactListener';
import { b2Vec2 } from '../../Common/Math';
import { b2ManifoldPoint } from '../../Collision/b2ManifoldPoint';
import { b2PolygonShape } from '../../Collision/Shapes/b2PolygonShape';
import { b2Collision } from '../../Collision/b2Collision';
import { b2Body } from '../b2Body';
import { b2ContactPoint } from '../../Collision/b2ContactPoint';

export class b2PolygonContact extends b2Contact {
	public static Create(shape1: b2Shape, shape2: b2Shape, allocator: any): b2Contact {
		//void* mem = allocator->Allocate(sizeof(b2PolyContact));
		return new b2PolygonContact(shape1, shape2);
	}

	public static Destroy(contact: b2Contact, allocator: any): void {
		//((b2PolyContact*)contact)->~b2PolyContact();
		//allocator->Free(contact, sizeof(b2PolyContact));
	}

	constructor(shape1: b2Shape, shape2: b2Shape) {
		super(shape1, shape2);
		this.m_manifold = this.m_manifolds[0];
		//b2Settings.b2Assert(m_shape1.m_type == b2Shape.e_polygonShape);
		//b2Settings.b2Assert(m_shape2.m_type == b2Shape.e_polygonShape);
		this.m_manifold.pointCount = 0;
	}
	//~b2PolyContact() {}

	// store temp manifold to reduce calls to new
	public m0: b2Manifold = new b2Manifold();
	public static readonly s_evalCP: b2ContactPoint = new b2ContactPoint();

	public Evaluate(listener: b2ContactListener): void {
		let v1: b2Vec2;
		let v2: b2Vec2;
		let mp0: b2ManifoldPoint;

		const b1: b2Body = this.m_shape1.m_body;
		const b2: b2Body = this.m_shape2.m_body;

		let cp: b2ContactPoint;
		let i: number /** int */;

		//b2Manifold m0;
		//memcpy(&m0, &m_manifold, sizeof(b2Manifold));
		// TODO: make sure this is completely necessary
		this.m0.Set(this.m_manifold);

		b2Collision.b2CollidePolygons(this.m_manifold, this.m_shape1 as b2PolygonShape, b1.m_xf, this.m_shape2 as b2PolygonShape, b2.m_xf);
		const persisted: boolean[] = [false, false];

		cp = b2PolygonContact.s_evalCP;
		cp.shape1 = this.m_shape1;
		cp.shape2 = this.m_shape2;
		cp.friction = this.m_friction;
		cp.restitution = this.m_restitution;

		// Match contact ids to facilitate warm starting.
		if (this.m_manifold.pointCount > 0) {

			// Match old contact ids to new contact ids and copy the
			// stored impulses to warm start the solver.
			for (i = 0; i < this.m_manifold.pointCount; ++i) {
				const mp: b2ManifoldPoint = this.m_manifold.points[ i ];
				mp.normalImpulse = 0.0;
				mp.tangentImpulse = 0.0;
				let found: boolean = false;
				const idKey: number /** uint */ = mp.id._key;

				for (let j: number /** int */ = 0; j < this.m0.pointCount; ++j) {
					if (persisted[j] == true) {
						continue;
					}

					mp0 = this.m0.points[ j ];

					if (mp0.id._key == idKey) {
						persisted[j] = true;
						mp.normalImpulse = mp0.normalImpulse;
						mp.tangentImpulse = mp0.tangentImpulse;

						// A persistent point.
						found = true;

						// Report persistent point.
						if (listener != null) {
							cp.position = b1.GetWorldPoint(mp.localPoint1);
							v1 = b1.GetLinearVelocityFromLocalPoint(mp.localPoint1);
							v2 = b2.GetLinearVelocityFromLocalPoint(mp.localPoint2);
							cp.velocity.Set(v2.x - v1.x, v2.y - v1.y);
							cp.normal.SetV(this.m_manifold.normal);
							cp.separation = mp.separation;
							cp.id.key = idKey;
							listener.Persist(cp);
						}
						break;
					}
				}

				// Report added point.
				if (found == false && listener != null) {
					cp.position = b1.GetWorldPoint(mp.localPoint1);
					v1 = b1.GetLinearVelocityFromLocalPoint(mp.localPoint1);
					v2 = b2.GetLinearVelocityFromLocalPoint(mp.localPoint2);
					cp.velocity.Set(v2.x - v1.x, v2.y - v1.y);
					cp.normal.SetV(this.m_manifold.normal);
					cp.separation = mp.separation;
					cp.id.key = idKey;
					listener.Add(cp);
				}
			}

			this.m_manifoldCount = 1;
		} else {
			this.m_manifoldCount = 0;
		}

		if (listener == null) {
			return;
		}

		// Report removed points.
		for (i = 0; i < this.m0.pointCount; ++i) {
			if (persisted[i]) {
				continue;
			}

			mp0 = this.m0.points[ i ];
			cp.position = b1.GetWorldPoint(mp0.localPoint1);
			v1 = b1.GetLinearVelocityFromLocalPoint(mp0.localPoint1);
			v2 = b2.GetLinearVelocityFromLocalPoint(mp0.localPoint2);
			cp.velocity.Set(v2.x - v1.x, v2.y - v1.y);
			cp.normal.SetV(this.m0.normal);
			cp.separation = mp0.separation;
			cp.id.key = mp0.id._key;
			listener.Remove(cp);
		}
	}

	public GetManifolds(): b2Manifold[] {
		return this.m_manifolds;
	}

	public m_manifolds: b2Manifold[] = [new b2Manifold()];
	public m_manifold: b2Manifold;
}