#include <stdlib.h>
#include <stdio.h>
#include <math.h>
#include <GL/glut.h>

// Definir cores
#define RED		 1.0, 0.0, 0.0, 1.0
#define GREEN    0.0, 1.0, 0.0, 1.0
#define BLUE     0.0, 0.0, 1.0, 1.0
#define YELLOW	 1.0, 1.0, 0.0, 1.0
#define WHITE    1.0, 1.0, 1.0, 1.0
#define BLACK    0.0, 0.0, 0.0, 1.0
#define PI 		 3.14159

// Sistema Coordenadas + objectos
GLint		wScreen=800, hScreen=600;		// janela (pixeis)
GLfloat		xC=1000.0, yC=1000.0, zC=1000.0;		// Mundo (unidades mundo)

//------------------------------------------------------------ Observador
GLfloat  rVisao=10, aVisao=0.5*PI, incVisao=0.05;
GLfloat  obsP[] ={rVisao*cos(aVisao), 3.0, rVisao*sin(aVisao)};
GLfloat  angZoom=90;
GLfloat  incZoom=3;

GLfloat mov=0;
GLfloat alpha=0;
GLfloat tam=2.0;
GLfloat xx=0;
GLfloat yy=0;
GLfloat zz=0;

GLboolean   frenteVisivel=1;

void inicializa(void){
	glClearColor(BLACK);		// Apagar
	glEnable(GL_DEPTH_TEST);	// Profundidade
	glShadeModel(GL_SMOOTH);	// Interpolacao de cores

	glEnable(GL_CULL_FACE);		// Faces visiveis
	glCullFace(GL_BACK);		// Mostrar so as da frente

	glEnableClientState(GL_VERTEX_ARRAY);
    glEnableClientState(GL_NORMAL_ARRAY);
    glEnableClientState(GL_COLOR_ARRAY);
}

void drawParedes(){
	// Plano XoY
	glColor4f(RED);
	glPushMatrix();
		//glTranslatef(-10,0,-10);
		glBegin(GL_QUADS);
			glVertex3f(0,0,0);
			glVertex3f(100,0,0);
			glVertex3f(100,300,0);
			glVertex3f(0,300,0);
		glEnd();

		glBegin(GL_QUADS);
			glVertex3f(0,0,100);
			glVertex3f(0,300,100);
			glVertex3f(100,300,100);
			glVertex3f(100,0,100);
		glEnd();

		// Plano YoZ
		glColor4f(GREEN);
		glBegin(GL_QUADS);
			glVertex3f(0,0,0);
			glVertex3f(0,300,0);
			glVertex3f(0,300,100);
			glVertex3f(0,0,100);
		glEnd();

		glBegin(GL_QUADS);
			glVertex3f(100,0,0);
			glVertex3f(100,0,100);
			glVertex3f(100,300,100);
			glVertex3f(100,300,0);
		glEnd();

		// Plano XoZ - chao
		glColor4f(YELLOW);
		glBegin(GL_QUADS);
			glVertex3f(0,0,0);
			glVertex3f(0,0,100);
			glVertex3f(100,0,100);
			glVertex3f(100,0,0);
		glEnd();
	glPopMatrix();
}

void display(void){

	//================================================================= APaga ecran/profundidade
	 glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT );


	//================================================================= Não modificar
	glViewport (0, 0, wScreen, hScreen);
	glMatrixMode(GL_PROJECTION);
	glLoadIdentity();
	//gluPerspective(angZoom, (float)wScreen/hScreen, 0.1, 3*zC);
	glMatrixMode(GL_MODELVIEW);
	glLoadIdentity();
	gluLookAt(obsP[0], obsP[1], obsP[2], xx, yy, zz, 0, 1, 0);
	//================================================================= Não modificar

	//…………………………………………………………………………………………………………………………………………………………Objectos
	drawParedes();

	//~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~Actualizacao
	glutSwapBuffers();
}


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

	glutInit(&argc, argv);
	glutInitDisplayMode (GLUT_DOUBLE | GLUT_RGB | GLUT_DEPTH );
	glutInitWindowSize (wScreen, hScreen);
	glutInitWindowPosition (300, 100);

	inicializa();

	//glutSpecialFunc(teclasNotAscii);
	glutDisplayFunc(display);
	//glutKeyboardFunc(keyboard);

	glutMainLoop();

	return 0;
}