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

/*
* Copyright (c) 2006-2009 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 REVOLUTE_H
#define REVOLUTE_H

class Revolute : public Test
{
public:
    Revolute()
    {
        b2Body* ground = NULL;
        {
            b2BodyDef bd;
            ground = m_world->CreateBody(&bd);

            b2EdgeShape shape;
            shape.Set(b2Vec2(-40.0f, 0.0f), b2Vec2(40.0f, 0.0f));

            b2FixtureDef fd;
            fd.shape = &shape;
            //fd.filter.categoryBits = 2;

            ground->CreateFixture(&fd);
        }

        {
            b2CircleShape shape;
            shape.m_radius = 0.5f;

            b2BodyDef bd;
            bd.type = b2_dynamicBody;

            b2RevoluteJointDef rjd;

            bd.position.Set(-10.0f, 20.0f);
            b2Body* body = m_world->CreateBody(&bd);
            body->CreateFixture(&shape, 5.0f);

            float32 w = 100.0f;
            body->SetAngularVelocity(w);
            body->SetLinearVelocity(b2Vec2(-8.0f * w, 0.0f));

            rjd.Initialize(ground, body, b2Vec2(-10.0f, 12.0f));
            rjd.motorSpeed = 1.0f * b2_pi;
            rjd.maxMotorTorque = 10000.0f;
            rjd.enableMotor = false;
            rjd.lowerAngle = -0.25f * b2_pi;
            rjd.upperAngle = 0.5f * b2_pi;
            rjd.enableLimit = true;
            rjd.collideConnected = true;

            m_joint = (b2RevoluteJoint*)m_world->CreateJoint(&rjd);
        }

        {
            b2CircleShape circle_shape;
            circle_shape.m_radius = 3.0f;

            b2BodyDef circle_bd;
            circle_bd.type = b2_dynamicBody;
            circle_bd.position.Set(5.0f, 30.0f);

            b2FixtureDef fd;
            fd.density = 5.0f;
            fd.filter.maskBits = 1;
            fd.shape = &circle_shape;

            m_ball = m_world->CreateBody(&circle_bd);
            m_ball->CreateFixture(&fd);

            b2PolygonShape polygon_shape;
            polygon_shape.SetAsBox(10.0f, 0.2f, b2Vec2 (-10.0f, 0.0f), 0.0f);

            b2BodyDef polygon_bd;
            polygon_bd.position.Set(20.0f, 10.0f);
            polygon_bd.type = b2_dynamicBody;
            polygon_bd.bullet = true;
            b2Body* polygon_body = m_world->CreateBody(&polygon_bd);
            polygon_body->CreateFixture(&polygon_shape, 2.0f);

            b2RevoluteJointDef rjd;
            rjd.Initialize(ground, polygon_body, b2Vec2(20.0f, 10.0f));
            rjd.lowerAngle = -0.25f * b2_pi;
            rjd.upperAngle = 0.0f * b2_pi;
            rjd.enableLimit = true;
            m_world->CreateJoint(&rjd);
        }

        // Tests mass computation of a small object far from the origin
        {
            b2BodyDef bodyDef;
            bodyDef.type = b2_dynamicBody;
            b2Body* body = m_world->CreateBody(&bodyDef);

            b2PolygonShape polyShape;
            b2Vec2 verts[3];
            verts[0].Set( 17.63f, 36.31f );
            verts[1].Set( 17.52f, 36.69f );
            verts[2].Set( 17.19f, 36.36f );
            polyShape.Set(verts, 3);

            b2FixtureDef polyFixtureDef;
            polyFixtureDef.shape = &polyShape;
            polyFixtureDef.density = 1;

            body->CreateFixture(&polyFixtureDef);   //assertion hits inside here
        }

    }

    void Keyboard(unsigned char key)
    {
        switch (key)
        {
        case 'l':
            m_joint->EnableLimit(!m_joint->IsLimitEnabled());
            break;

        case 'm':
            m_joint->EnableMotor(!m_joint->IsMotorEnabled());
            break;
        }
    }

    void Step(Settings* settings)
    {
        Test::Step(settings);
        m_debugDraw.DrawString(5, m_textLine, "Keys: (l) limits, (m) motor");
        m_textLine += 15;

        //if (m_stepCount == 360)
        //{
        //  m_ball->SetTransform(b2Vec2(0.0f, 0.5f), 0.0f);
        //}

        //float32 torque1 = m_joint1->GetMotorTorque();
        //m_debugDraw.DrawString(5, m_textLine, "Motor Torque = %4.0f, %4.0f : Motor Force = %4.0f", (float) torque1, (float) torque2, (float) force3);
        //m_textLine += 15;
    }

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

    b2Body* m_ball;
    b2RevoluteJoint* m_joint;
};

#endif