/*
 * Desafio: verificar o modelview
 */

#include <iostream>
#include <GL/freeglut.h>

static int year = 0, day = 0;

void init (void)
{
  /* selecionar cor de fundo (preto) */
  glClearColor(0.0, 0.0, 0.0, 0.0);
 //Definindo os limites da Porta de Visao (ViewPort)

}

//desenha as transformacoes
void display(void){
	glClear(GL_COLOR_BUFFER_BIT);
	glColor3f(1.0, 1.0, 1.0);

	glPushMatrix(); //Sun
		glRotatef(year, 1.0, 0.0, 0.0);
		glRotatef(day, 0.0, 0.0, 1.0);
		glutWireSphere(1.0, 20, 16);
	glPopMatrix();

	glPushMatrix();// Planet 1
		glRotatef(year, 0.0, 1.0, 0.0);
		glTranslatef(2.0, 0.0, 0.0);
		glRotatef(day, 0.0, 1.0, 0.0);
		glutWireSphere(0.2, 10, 8);
	glPopMatrix();

	glPushMatrix(); // Planet 2
		glRotatef(year, 0.0, 1.0, 0.0);
		glTranslatef(4.0, 0.0, 0.0);
		glRotatef(day, 0.0, 1.0, 0.0);
		glutWireSphere(0.2, 10, 8);
	glPopMatrix();

	glPushMatrix(); // Moon 1
		glRotatef(year, 0.0, 1.0, 0.0);
		glTranslatef(4.0, 0.0, 0.0);
		glRotatef(day*0.1, 0.0, 1.0, 0.0);
		glTranslatef(0.5, 0.0, 0.0);
		glutWireSphere(0.1, 10, 8);
	glPopMatrix();

	glPushMatrix(); // Moon 2
		glRotatef(year, 0.0, 1.0, 0.0);
		glTranslatef(4.0, 0.0, 0.0);
		glRotatef(day*0.1, 0.0, 0, 1.0);
		glTranslatef(0.5, 0.0, 0.0);
		glutWireSphere(0.1, 10, 8);
	glPopMatrix();


	glutSwapBuffers();
}

void keyboard(unsigned char key, int x, int y)	{
	switch (key) {
		case 'd':
			day = (day + 10) % 360;
			glutPostRedisplay();
			break;
		case 'D':
			day = (day - 10) % 360;
			glutPostRedisplay();
			break;
		case 'y':
			year = (year + 5) % 360;
			glutPostRedisplay();
			break;
		case 'Y':
			year = (year - 5) % 360;
			glutPostRedisplay();
			break;
		case 27:
			exit(0);
			break;
		default:
			break;

	}
}

void reshape(int w, int h){
	glViewport (0, 0, w,  h);
	glMatrixMode(GL_MODELVIEW);
	glLoadIdentity();
	gluPerspective(120.0, w/h, 1.0, 20.0);
	gluLookAt (0.0, 0.0, 5.0, 0.0, 0.0, 0.0, 0.0, 1.0, 0.0);
}

void update(int value){
	glutTimerFunc(10, update, 1);
	day += year++;
	glutPostRedisplay();
}


int main(int argc, char** argv) {

	/* inicializa o sitema GLUT */
	glutInit(&argc, argv);

	glutInitDisplayMode(GLUT_DOUBLE | GLUT_RGB);
	glutInitWindowSize(1000,1000);
	glutInitWindowPosition(100, 100);
	glutCreateWindow("Rotação de Planetas");

	//chama a funcao init e inicia as propriedades View Port
	init();
	glutDisplayFunc(display);
	glutTimerFunc(10, update, 1);
	glutReshapeFunc(reshape);
	glutKeyboardFunc(keyboard);
	glutMainLoop();

	return 0;
}