#ifndef IFORCE2D_GHOST_VERTICES_H
#define IFORCE2D_GHOST_VERTICES_H

#ifndef DEGTORAD
#define DEGTORAD 0.0174532925199432957f
#define RADTODEG 57.295779513082320876f
#endif

//demonstrates the use of ghost vertices of edge shapes

class iforce2d_ghost_vertices : public Test
{
public:
    //for keeping track of input state
    enum moveState {
        MS_STOP,
        MS_LEFT,
        MS_RIGHT,
    };

    float getHeight(float x) {
        return 0;//1 - cosf( x * 0.1f );
    }

    iforce2d_ghost_vertices() {

        //body def
        b2BodyDef myBodyDef;
        myBodyDef.type = b2_dynamicBody;

        //fixture def
        b2FixtureDef myFixtureDef;
        myFixtureDef.density = 1;
        myFixtureDef.friction = 0;
        b2PolygonShape polygonShape;
        myFixtureDef.shape = &polygonShape;
        polygonShape.SetAsBox(1, 1);

        //a dynamic body to act as the main body of a player character
        myBodyDef.position.Set(0, 5);
        m_playerBody = m_world->CreateBody(&myBodyDef);
        m_playerBody->CreateFixture(&myFixtureDef);

        //another dynamic body to weigh down the main body and make the problem occur more regularly
        myBodyDef.fixedRotation = true;
        myBodyDef.position.Set(0, 6);
        myFixtureDef.density = 50;
        m_weightBody = m_world->CreateBody(&myBodyDef);
        m_weightBody->CreateFixture(&myFixtureDef);

        //joint the two bodies together
        b2RevoluteJointDef jointDef;
        jointDef.bodyA = m_playerBody;
        jointDef.bodyB = m_weightBody;
        jointDef.localAnchorA.Set(0,0);
        jointDef.localAnchorB.Set(0,-1);
        m_world->CreateJoint(&jointDef);

        //body to support the 'ground' fixtures
        myBodyDef.position.Set(0, 0);
        b2Body* fakeGroundBody = m_world->CreateBody(&myBodyDef);

        //ground made of boxes
        for (int i = 0; i < 21; i++) {
            polygonShape.SetAsBox( 1, 2, b2Vec2(-20+i*2,2), 0);
            fakeGroundBody->CreateFixture(&myFixtureDef);
        }

        //ground made of edges
        b2EdgeShape edgeShape;
        myFixtureDef.shape = &edgeShape;
        for (int i = 0; i < 21; i++) {
            float left = -20+i*2 - 1;
            float right = -20+i*2 + 1;
            edgeShape.Set( b2Vec2(left,10+getHeight(left)), b2Vec2(right,10+getHeight(right)) );
            fakeGroundBody->CreateFixture(&myFixtureDef);
        }

        //ground made of edges with ghost vertices set
        myFixtureDef.shape = &edgeShape;
        for (int i = 0; i < 21; i++) {
            float left = -20+i*2 - 1;
            float right = -20+i*2 + 1;
            edgeShape.Set( b2Vec2(left,20+getHeight(left)), b2Vec2(right,20+getHeight(right)) );
            edgeShape.m_vertex0.Set( left-1,20+getHeight(left) );
            edgeShape.m_vertex3.Set( right+1,20+getHeight(right) );
            edgeShape.m_hasVertex0 = true;
            edgeShape.m_hasVertex3 = true;
            fakeGroundBody->CreateFixture(&myFixtureDef);
        }

        //ground body
        b2BodyDef groundBodyDef;
        b2Body* groundBody = m_world->CreateBody(&groundBodyDef);

        edgeShape.Set( b2Vec2(-20,0), b2Vec2(20,0) );
        groundBody->CreateFixture(&myFixtureDef);
        edgeShape.Set( b2Vec2(-21.1,0), b2Vec2(-21.1,2) );
        groundBody->CreateFixture(&myFixtureDef);
        edgeShape.Set( b2Vec2( 21.1, 0), b2Vec2(21.1, 2) );
        groundBody->CreateFixture(&myFixtureDef);

        m_moveState = MS_STOP;
    }

    void Keyboard(unsigned char key)
    {
        switch (key)
        {
        case 'q': //move left
            m_moveState = MS_LEFT;
            break;
        case 'w': //stop
            m_moveState = MS_STOP;
            break;
        case 'e': //move right
            m_moveState = MS_RIGHT;
            break;

        default:
            Test::Keyboard(key);
        }
    }

    void Step(Settings* settings)
    {
        b2Vec2 vel = m_weightBody->GetLinearVelocity();
        float force = 0;
        switch ( m_moveState )
        {
        case MS_LEFT:  if ( vel.x > -5 ) force = -1000;  break;
        case MS_STOP:  force = vel.x * -100; break;
        case MS_RIGHT: if ( vel.x <  5 ) force =  1000; break;
        }
        m_weightBody->ApplyForce( b2Vec2(force,-10), m_weightBody->GetWorldCenter() );

        //tap the lower body downwards just as it nears a tile boundary
        b2Vec2 pos = m_playerBody->GetPosition();
        if ( fabsf( pos.x - (int)pos.x ) < 0.02f )
            m_playerBody->ApplyLinearImpulse( b2Vec2(0,-20), m_weightBody->GetWorldCenter() );

        //run the default physics and rendering
        Test::Step(settings);

        m_debugDraw.DrawString(5, m_textLine, "Press q/w/e to move the player");
        m_textLine += 15;
    }

    static Test* Create()
    {
        return new iforce2d_ghost_vertices;
    }

    b2Body* m_playerBody;
    b2Body* m_weightBody;
    moveState m_moveState;

};

#endif