JUCE/examples/Demo/Source/Demos/Box2DTests/Pulleys.h

/*
* Copyright (c) 2007-2009 Erin Catto http://www.box2d.org
*
* 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.
*/

#ifndef PULLEYS_H
#define PULLEYS_H

class Pulleys : public Test
{
public:
    Pulleys()
    {
        float32 y = 16.0f;
        float32 L = 12.0f;
        float32 a = 1.0f;
        float32 b = 2.0f;

        b2Body* ground = NULL;
        {
            b2BodyDef bd;
            ground = m_world->CreateBody(&bd);

            b2EdgeShape edge;
            edge.Set(b2Vec2(-40.0f, 0.0f), b2Vec2(40.0f, 0.0f));
            //ground->CreateFixture(&shape, 0.0f);

            b2CircleShape circle;
            circle.m_radius = 2.0f;

            circle.m_p.Set(-10.0f, y + b + L);
            ground->CreateFixture(&circle, 0.0f);

            circle.m_p.Set(10.0f, y + b + L);
            ground->CreateFixture(&circle, 0.0f);
        }

        {

            b2PolygonShape shape;
            shape.SetAsBox(a, b);

            b2BodyDef bd;
            bd.type = b2_dynamicBody;

            //bd.fixedRotation = true;
            bd.position.Set(-10.0f, y);
            b2Body* body1 = m_world->CreateBody(&bd);
            body1->CreateFixture(&shape, 5.0f);

            bd.position.Set(10.0f, y);
            b2Body* body2 = m_world->CreateBody(&bd);
            body2->CreateFixture(&shape, 5.0f);

            b2PulleyJointDef pulleyDef;
            b2Vec2 anchor1(-10.0f, y + b);
            b2Vec2 anchor2(10.0f, y + b);
            b2Vec2 groundAnchor1(-10.0f, y + b + L);
            b2Vec2 groundAnchor2(10.0f, y + b + L);
            pulleyDef.Initialize(body1, body2, groundAnchor1, groundAnchor2, anchor1, anchor2, 1.5f);

            m_joint1 = (b2PulleyJoint*)m_world->CreateJoint(&pulleyDef);
        }
    }

    void Keyboard(unsigned char key)
    {
        switch (key)
        {
        case 0:
            break;
        }
    }

    void Step(Settings* settings)
    {
        Test::Step(settings);

        float32 ratio = m_joint1->GetRatio();
        float32 L = m_joint1->GetLengthA() + ratio * m_joint1->GetLengthB();
        m_debugDraw.DrawString(5, m_textLine, "L1 + %4.2f * L2 = %4.2f", (float) ratio, (float) L);
        m_textLine += 15;
    }

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

    b2PulleyJoint* m_joint1;
};

#endif