// ************************************************
// IntersectTest.cpp
//	Intersection test sample
//
//  Author: Marcio Serolli Pinho
//	Email: pinho@inf.pucrs.br		 
//	Homepages:
//		http://www.smallvr.org
//		http://grv.inf.pucrs.br
//		http://www.inf.pucrs.br/~pinho
//
//	Porto Alegre, Brazil, 2002.
// ************************************************

#ifdef WIN32
#include <windows.h>
#endif

#include <GL\gl.h>

// SmallVR header file
#include "SmVR.h"

float WindowRatio;

SmVR_CPoint	User(0,0,10);

// Root Object to represent the entire scene
SmVR_CGeometricObject *RootObject;

// Object data struct
SmVR_CPoint Tri[3] =
					{ 
						SmVR_CPoint(0,0,0), 
						SmVR_CPoint(10,0,0), 
						SmVR_CPoint(10,10,0)
					};

// **********************************************************************
// int DrawTest(void *p)
//
// **********************************************************************
int DrawTest(void *p) 
{ 
	int i;
	// Draw a triangle
	glBegin (GL_TRIANGLES);
		glColor3f(1,0,0);
		for (i=0;i<3;i++)
		{
			glVertex3f(Tri[i].X, Tri[i].Y, Tri[i].Z); 
		}
	glEnd();
	return 1;
} 
// **********************************************************************
//  void PosicUser()
//
//
// **********************************************************************
void PosicUser()
{
	// Set the clipping volume
	glMatrixMode(GL_PROJECTION);
	glLoadIdentity();
	gluPerspective(90,WindowRatio,0.01,200);

	// Set the user Position
	glMatrixMode(GL_MODELVIEW);
	glLoadIdentity();
	gluLookAt(User.X,User.Y, User.Z,
		      User.X,User.Y, User.Z-3,
			  0.0f,1.0f,0.0f);
}
// **********************************************************************
//  void reshape( int w, int h )
//		trata o redimensionamento da janela OpenGL
//
// **********************************************************************
void reshape( int w, int h )
{
	// Prevent a divide by zero, when window is too short
	// (you cant make a window of zero width).
	if(h == 0)
		h = 1;

	WindowRatio = 1.0f * w / h;
	// Reset the coordinate system before modifying
	glMatrixMode(GL_PROJECTION);
	glLoadIdentity();
	// Set the viewport to be the entire window
    glViewport(0, 0, w, h);

	PosicUser();

}
// **********************************************************************
//  void display( void )
//
//
// **********************************************************************
void display( void )
{

	glClear( GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT );

	PosicUser();

	glMatrixMode(GL_MODELVIEW);

	RootObject->Render();
	
	glutSwapBuffers();
}
// **********************************************************************
//  void keyboard ( unsigned char key, int x, int y )   
//
// **********************************************************************
void keyboard ( unsigned char key, int x, int y )  
{
	switch ( key ) 
	{
	    case 27:   
			exit(0);   
			break;  
	}
}
// **********************************************************************
//  void init(void)
//		Inicializa os parāmetros globais de OpenGL
//
// **********************************************************************
void init(void)
{
	glClearColor(0.0f, 0.0f, 0.0f, 1.0f); // Fundo de tela preto
	glColorMaterial ( GL_FRONT, GL_AMBIENT_AND_DIFFUSE );

	glShadeModel(GL_SMOOTH);						
	glColorMaterial ( GL_FRONT, GL_AMBIENT_AND_DIFFUSE );
	glEnable(GL_DEPTH_TEST);
	glEnable ( GL_CULL_FACE );

}

// **********************************************************************
//  void main ( int argc, char** argv )
//
//
// **********************************************************************
void main ( int argc, char** argv )   
{
	SmVR_CGeometricObject *TestObject;
	
	SmVR_CPoint aux;

	// GLUT initialization
	glutInit            ( &argc, argv ); 
	glutInitDisplayMode (GLUT_DOUBLE | GLUT_RGB | GLUT_DEPTH);// | GLUT_DOUBLE | GLUT_RGBA ); 
	glutInitWindowPosition (0,0);
	glutInitWindowSize  ( 700, 500 ); 
	glutCreateWindow    ( "SmallVR Test" ); 
		

	// initialize OpenGL parameters
	init ();

	// initialize the library
	RootObject = SmVR_Init(NULL);

	// Create a new object
	TestObject = new SmVR_CGeometricObject("Test Object", DrawTest);

	// Add the object to the scene
	RootObject->AddChild(TestObject);


	TestObject->TranslateBy(-5,0,0);

	TestObject->GetPointInOCS(Tri[0],&aux,RootObject);
	printf("Ponto : (%6.3f, %6.3f, %6.3f)\n", aux.X, aux.Y, aux.Z);
	TestObject->GetPointInOCS(Tri[1],&aux,RootObject);
	printf("Ponto : (%6.3f, %6.3f, %6.3f)\n", aux.X, aux.Y, aux.Z);
	TestObject->GetPointInOCS(Tri[2],&aux,RootObject);
	printf("Ponto : (%6.3f, %6.3f, %6.3f)\n", aux.X, aux.Y, aux.Z);

	
	// GLUT stuff
	glutDisplayFunc ( display );  
	glutReshapeFunc ( reshape );
	glutKeyboardFunc ( keyboard );
	glutIdleFunc ( display );

	glutMainLoop ( );          

}