#include <GL/glut.h>
#include <GL/glu.h>
#include <GL/gl.h>
#include <stdio.h>

bool fullscreen = false;
bool mouseDown = false;

float xrot = 0.0f;
float yrot = 0.0f;

float xdiff = 0.0f;
float ydiff = 0.0f;

void drawBox()
{   
	glBegin(GL_QUADS);

	glColor3f(1.0f, 0.0f, 0.0f);
	// FRONT
	glVertex3f(-0.5f, -0.5f,  0.5f);
	glVertex3f( 0.5f, -0.5f,  0.5f);
	glVertex3f( 0.5f,  0.5f,  0.5f);
	glVertex3f(-0.5f,  0.5f,  0.5f);
	// BACK
	glVertex3f(-0.5f, -0.5f, -0.5f);
	glVertex3f(-0.5f,  0.5f, -0.5f);
	glVertex3f( 0.5f,  0.5f, -0.5f);
	glVertex3f( 0.5f, -0.5f, -0.5f);

	glColor3f(0.0f, 1.0f, 0.0f);
	// LEFT
	glVertex3f(-0.5f, -0.5f,  0.5f);
	glVertex3f(-0.5f,  0.5f,  0.5f);
	glVertex3f(-0.5f,  0.5f, -0.5f);
	glVertex3f(-0.5f, -0.5f, -0.5f);
	// RIGHT
	glVertex3f( 0.5f, -0.5f, -0.5f);
	glVertex3f( 0.5f,  0.5f, -0.5f);
	glVertex3f( 0.5f,  0.5f,  0.5f);
	glVertex3f( 0.5f, -0.5f,  0.5f);

	glColor3f(0.0f, 0.0f, 1.0f);
	// TOP
	glVertex3f(-0.5f,  0.5f,  0.5f);
	glVertex3f( 0.5f,  0.5f,  0.5f);
	glVertex3f( 0.5f,  0.5f, -0.5f);
	glVertex3f(-0.5f,  0.5f, -0.5f);
	// BOTTOM
	glVertex3f(-0.5f, -0.5f,  0.5f);
	glVertex3f(-0.5f, -0.5f, -0.5f);
	glVertex3f( 0.5f, -0.5f, -0.5f);
	glVertex3f( 0.5f, -0.5f,  0.5f);
	glEnd();
}

bool init()
{
	glClearColor(0.93f, 0.93f, 0.93f, 0.0f);
        glEnable(GL_CULL_FACE);
        glEnable(GL_DEPTH_TEST);
        

	return true;
}


void display()
{
	glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
        glMatrixMode(GL_MODELVIEW);
	glLoadIdentity();
        
	glTranslatef(0,0,-3.0f);

	glRotatef(xrot, 1.0f, 0.0f, 0.0f);
	glRotatef(yrot, 0.0f, 1.0f, 0.0f);
        
	drawBox();

	glutSwapBuffers();
}

void resize(int w, int h)
{
	glMatrixMode(GL_PROJECTION);
	glLoadIdentity();

	glViewport(0, 0, w, h);

	gluPerspective(45.0f, 1.0f * w / h, 1.0f, 100.0f); 
}

void mouse(int button, int state, int x, int y)
{
	if (button == GLUT_LEFT_BUTTON && state == GLUT_DOWN)
	{
		mouseDown = true;

		xdiff = x - yrot;
		ydiff = y - xrot ;
	}
	else
		mouseDown = false;
}

void mouseMotion(int x, int y)
{
	if (mouseDown)
	{
		yrot = x - xdiff;
		xrot = y - ydiff;

		glutPostRedisplay();
	}
}

int main(int argc, char *argv[])
{
	glutInit(&argc, argv);

	glutInitWindowPosition(50, 50);
	glutInitWindowSize(500, 500);

	glutInitDisplayMode(GLUT_RGB | GLUT_DOUBLE | GLUT_DEPTH);
	
	glutCreateWindow("cubo");

	glutDisplayFunc(display);
	glutMouseFunc(mouse);
	glutMotionFunc(mouseMotion);
	glutReshapeFunc(resize);

	if (!init())
		return 1;

	glutMainLoop();

	return 0;
}