﻿/*
* Box2D.XNA port of Box2D:
* Copyright (c) 2009 Brandon Furtwangler, Nathan Furtwangler
*
* Original source Box2D:
* Copyright (c) 2006-2009 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. 
*/

using Box2D.XNA.TestBed.Framework;
using Microsoft.Xna.Framework;

namespace Box2D.XNA.TestBed.Tests
{
    public class Pulleys : Test
    {
        Pulleys()
	    {
		    Body ground = null;
		    {
			    BodyDef bd = new BodyDef();
			    ground = _world.CreateBody(bd);

			    PolygonShape shape = new PolygonShape();
			    shape.SetAsEdge(new Vector2(-40.0f, 0.0f), new Vector2(40.0f, 0.0f));
			    ground.CreateFixture(shape, 0.0f);
		    }

		    {
			    float a = 2.0f;
			    float b = 4.0f;
			    float y = 16.0f;
			    float L = 12.0f;

			    PolygonShape shape = new PolygonShape();
			    shape.SetAsBox(a, b);

			    BodyDef bd = new BodyDef();
                bd.type = BodyType.Dynamic;

			    bd.position = new Vector2(-10.0f, y);
			    Body body1 = _world.CreateBody(bd);
			    body1.CreateFixture(shape, 5.0f);

			    bd.position = new Vector2(10.0f, y);
			    Body body2 = _world.CreateBody(bd);
			    body2.CreateFixture(shape, 5.0f);

			    PulleyJointDef pulleyDef = new PulleyJointDef();
			    Vector2 anchor1 = new Vector2(-10.0f, y + b);
			    Vector2 anchor2 = new Vector2(10.0f, y + b);
			    Vector2 groundAnchor1 = new Vector2(-10.0f, y + b + L);
                Vector2 groundAnchor2 = new Vector2(10.0f, y + b + L);
			    pulleyDef.Initialize(body1, body2, groundAnchor1, groundAnchor2, anchor1, anchor2, 2.0f);

			    _joint1 = (PulleyJoint)_world.CreateJoint(pulleyDef);
		    }
	    }

	    public override void Step(Framework.Settings settings)
	    {
		    base.Step(settings);

		    float ratio = _joint1.GetRatio();
		    float L = _joint1.GetLength1() + ratio * _joint1.GetLength2();
            _debugDraw.DrawString(50, _textLine, "L1 + {0:n} * L2 = {1:n}", (float)ratio, (float)L);
		    _textLine += 15;
	    }

	    internal static Test Create()
	    {
		    return new Pulleys();
	    }

	    PulleyJoint _joint1;
    }
}
