bullet3/examples/RenderingExamples/CoordinateSystemDemo.cpp

#include "CoordinateSystemDemo.h"
#include "../CommonInterfaces/CommonGraphicsAppInterface.h"
#include "../CommonInterfaces/CommonRenderInterface.h"

#include "../CommonInterfaces/CommonExampleInterface.h"
#include "LinearMath/btTransform.h"
#include "../CommonInterfaces/CommonGUIHelperInterface.h"
///quick demo showing the right-handed coordinate system and positive rotations around each axis
class CoordinateSystemDemo : public CommonExampleInterface
{
    CommonGraphicsApp* m_app;
    float m_x;
    float m_y;
    float m_z;
    
public:
    
    CoordinateSystemDemo(CommonGraphicsApp* app)
    :m_app(app),
    m_x(0),
    m_y(0),
	m_z(0)
    {
		m_app->setUpAxis(2);

		 {
            int boxId = m_app->registerCubeShape(0.1,0.1,0.1);
            btVector3 pos(0,0,0);
            btQuaternion orn(0,0,0,1);
            btVector4 color(0.3,0.3,0.3,1);
            btVector3 scaling(1,1,1);
            m_app->m_renderer->registerGraphicsInstance(boxId,pos,orn,color,scaling);
        }

		 m_app->m_renderer->writeTransforms();
    }
    virtual ~CoordinateSystemDemo()
    {
    }
    
    
    virtual void    initPhysics()
    {
    }
    virtual void    exitPhysics()
    {
        
    }
    virtual void	stepSimulation(float deltaTime)
    {
        m_x+=0.01f;
        m_y+=0.01f;
		m_z+=0.01f;

    }
    virtual void	renderScene()
    {
		m_app->m_renderer->renderScene();
		m_app->drawText3D("X",1,0,0,1);
		m_app->drawText3D("Y",0,1,0,1);
		m_app->drawText3D("Z",0,0,1,1);
    }

	virtual void drawArc(const btVector3& center, const btVector3& normal, const btVector3& axis, btScalar radiusA, btScalar radiusB, btScalar minAngle, btScalar maxAngle, 
				const btVector3& color, bool drawSect, btScalar stepDegrees = btScalar(10.f))
	{
		btScalar lineWidth = 3;
		const btVector3& vx = axis;
		btVector3 vy = normal.cross(axis);
		btScalar step = stepDegrees * SIMD_RADS_PER_DEG;
		int nSteps = (int)btFabs((maxAngle - minAngle) / step);
		if(!nSteps) nSteps = 1;
		btVector3 prev = center + radiusA * vx * btCos(minAngle) + radiusB * vy * btSin(minAngle);
		if(drawSect)
		{
			m_app->m_renderer->drawLine(center, prev, color,lineWidth);
		}
		for(int i = 1; i <= nSteps; i++)
		{
			btScalar angle = minAngle + (maxAngle - minAngle) * btScalar(i) / btScalar(nSteps);
			btVector3 next = center + radiusA * vx * btCos(angle) + radiusB * vy * btSin(angle);
			m_app->m_renderer->drawLine(prev, next, color,lineWidth);
			prev = next;
		}
		if(drawSect)
		{
			m_app->m_renderer->drawLine(center, prev, color,lineWidth);
		}
	}

    virtual void	physicsDebugDraw(int debugDrawFlags)
    {
      
		btVector3 xUnit(1,0,0);
		btVector3 yUnit(0,1,0);
		btVector3 zUnit(0,0,1);

		btScalar lineWidth=3;

		btQuaternion rotAroundX(xUnit,m_x);
		btQuaternion rotAroundY(yUnit,m_y);
		btQuaternion rotAroundZ(zUnit,m_z);

		btScalar radius=0.5;
		btVector3 toX=radius*quatRotate(rotAroundX,yUnit);
		btVector3 toY=radius*quatRotate(rotAroundY,xUnit);
		btVector3 toZ=radius*quatRotate(rotAroundZ,xUnit);
		
		m_app->m_renderer->drawLine(xUnit+toX+quatRotate(rotAroundX,btVector3(0,0.1,-0.2)),xUnit+toX,xUnit,lineWidth);
		m_app->m_renderer->drawLine(xUnit+toX+quatRotate(rotAroundX,btVector3(0,-0.2,-0.2)),xUnit+toX,xUnit,lineWidth);
		//draw the letter 'x' on the x-axis
		//m_app->m_renderer->drawLine(xUnit-0.1*zUnit+0.1*yUnit,xUnit+0.1*zUnit-0.1*yUnit,xUnit,lineWidth);
		//m_app->m_renderer->drawLine(xUnit+0.1*zUnit+0.1*yUnit,xUnit-0.1*zUnit-0.1*yUnit,xUnit,lineWidth);

		m_app->m_renderer->drawLine(xUnit+toX+quatRotate(rotAroundX,btVector3(0,-0.2,-0.2)),xUnit+toX,xUnit,lineWidth);

		m_app->m_renderer->drawLine(yUnit+toY+quatRotate(rotAroundY,btVector3(-0.2,0,0.2)),yUnit+toY,yUnit,lineWidth);
		m_app->m_renderer->drawLine(yUnit+toY+quatRotate(rotAroundY,btVector3(0.1,0,0.2)),yUnit+toY,yUnit,lineWidth);
		m_app->m_renderer->drawLine(zUnit+toZ+quatRotate(rotAroundZ,btVector3(0.1,-0.2,0)),zUnit+toZ,zUnit,lineWidth);
		m_app->m_renderer->drawLine(zUnit+toZ+quatRotate(rotAroundZ,btVector3(-0.2,-0.2,0)),zUnit+toZ,zUnit,lineWidth);

        
		drawArc(xUnit,xUnit,toX.normalized(),radius,radius,0.4,SIMD_2_PI,xUnit,false);
		drawArc(yUnit,yUnit,toY.normalized(),radius,radius,0.4,SIMD_2_PI,yUnit,false);
		drawArc(zUnit,zUnit,toZ.normalized(),radius,radius,0.4,SIMD_2_PI,zUnit,false);
    }
    virtual bool	mouseMoveCallback(float x,float y)
    {
		return false;   
    }
    virtual bool	mouseButtonCallback(int button, int state, float x, float y)
    {
        return false;   
    }
    virtual bool	keyboardCallback(int key, int state)
    {
        return false;   
    }
  

	virtual void resetCamera()
	{
		float dist = 3.5;
		float pitch = -32;
		float yaw = 136;
		float targetPos[3]={0,0,0};
		if (m_app->m_renderer  && m_app->m_renderer->getActiveCamera())
		{
			m_app->m_renderer->getActiveCamera()->setCameraDistance(dist);
			m_app->m_renderer->getActiveCamera()->setCameraPitch(pitch);
			m_app->m_renderer->getActiveCamera()->setCameraYaw(yaw);
			m_app->m_renderer->getActiveCamera()->setCameraTargetPosition(targetPos[0],targetPos[1],targetPos[2]);
		}
	}
};

CommonExampleInterface*    CoordinateSystemCreateFunc(struct CommonExampleOptions& options)
{
	return new CoordinateSystemDemo(options.m_guiHelper->getAppInterface());
}