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

#define PI 3.1415

GLint WIDTH =320;
GLint HEIGHT=240;

GLint fatias=30;
GLint pilhas=30;
GLint raioEsfera=1.5;

GLfloat obs[3]={0.0,7.0,0.0};
GLfloat olho[3]={0.0,3.0,0.0};

GLfloat plano_difusa[]    = { 0.5, 0.5, 0.0, 1.0 };
GLfloat plano_especular[] = { 1.0, 1.0, 1.0, 1.0 };
GLfloat plano_brilho[]    = { 50.0 };

GLfloat mat_a_difusa[]    = { 1.0, 1.0, 1.0, 1.0 };
GLfloat mat_a_especular[] = { 1.0, 1.0, 1.0, 1.0 };
GLfloat mat_a_brilho[]    = { 50.0 };

GLfloat mat_b_difusa[]    = { 0.7, 0.7, 0.7, 0.5 };
GLfloat mat_b_especular[] = { 1.0, 1.0, 1.0, 0.5 };
GLfloat mat_b_brilho[]    = { 50.0 };

GLfloat posicao_luz0[]    = { 0.0, 10.0, 0.0, 1.0};
GLfloat cor_luz0[]        = { 1.0, 1.0, 1.0, 1.0};
GLfloat cor_luz0_amb[]    = { 0.3, 0.3, 0.3, 1.0};

GLfloat posicao_luz1[]    = { 0.0, 10.0, 5.0, 1.0};
GLfloat cor_luz1[]        = { 0.0, 0.0, 1.0, 1.0};
GLfloat direcao_luz1[]    = { 0.0, -10.0, -5.0, 1.0};
GLint   spot_luz1         = 30;

GLfloat sem_cor[]         = { 0.0, 0.0, 0.0, 1.0};
  
GLint gouraud=0;

GLfloat tetaxz=0;
GLfloat raioxz=6;

void reshape(int width, int height){
  WIDTH=width;
  HEIGHT=height;
  glViewport(0,0,(GLint)width,(GLint)height);
  glMatrixMode(GL_PROJECTION);
  glLoadIdentity();
  gluPerspective(70.0,width/(float)height,0.1,30.0);
  glMatrixMode(GL_MODELVIEW);
}

void display(void){
  glEnable(GL_DEPTH_TEST);
  glEnable(GL_LIGHTING);

  glDepthMask(GL_TRUE);
  glClearColor(1.0,1.0,1.0,1.0);
  glClear(GL_COLOR_BUFFER_BIT|GL_DEPTH_BUFFER_BIT);

  if(gouraud){
    glShadeModel(GL_SMOOTH);
  }
  else{
    glShadeModel(GL_FLAT);
  }    
  
  glPushMatrix();

  /* calcula a posicao do observador */
  obs[0]=raioxz*cos(2*PI*tetaxz/360);
  obs[2]=raioxz*sin(2*PI*tetaxz/360);
  gluLookAt(obs[0],obs[1],obs[2],olho[0],olho[1],olho[2],0.0,1.0,0.0);
  
  /* propriedades do material do plano */
  glMaterialfv(GL_FRONT_AND_BACK, GL_DIFFUSE, plano_difusa);
  glMaterialfv(GL_FRONT_AND_BACK, GL_SPECULAR, plano_especular);
  glMaterialfv(GL_FRONT_AND_BACK, GL_SHININESS, plano_brilho);
  
  /* desenha o plano */
  glNormal3f(0,1,0); 
  glBegin(GL_QUADS);
  glVertex3f(-10,0,10);
  glVertex3f(10,0,10);
  glVertex3f(10,0,-10);
  glVertex3f(-10,0,-10);
  glEnd();

  glPushMatrix();
  glTranslatef(posicao_luz0[0],posicao_luz0[1],posicao_luz0[2]);
  glColor3f(1,0,0);
  glMaterialfv(GL_FRONT, GL_EMISSION, cor_luz0);
  glutSolidSphere(0.3,5,5);
  glPopMatrix();

  glPushMatrix();
  glTranslatef(posicao_luz1[0],posicao_luz1[1],posicao_luz1[2]);
  glMaterialfv(GL_FRONT, GL_EMISSION, cor_luz1);
  glutSolidSphere(0.3,5,5);
  glPopMatrix();

  glMaterialfv(GL_FRONT, GL_EMISSION, sem_cor);

  glMaterialfv(GL_FRONT, GL_DIFFUSE, mat_a_difusa);
  glMaterialfv(GL_FRONT, GL_SPECULAR, mat_a_especular);
  glMaterialfv(GL_FRONT, GL_SHININESS, mat_a_brilho);

  glPushMatrix();
  glTranslatef(0.0,3.0,-3.0);
  glutSolidSphere(raioEsfera,fatias,pilhas);
  glPopMatrix();

  glMaterialfv(GL_FRONT, GL_DIFFUSE, mat_b_difusa);
  glMaterialfv(GL_FRONT, GL_SPECULAR, mat_b_especular);
  glMaterialfv(GL_FRONT, GL_SHININESS, mat_b_brilho);
  
  glTranslatef(0.0,+3.0,+3.0);

  glutSolidSphere(raioEsfera,fatias,pilhas);

  glPopMatrix();
  glutSwapBuffers();
}

void special(int key, int x, int y){
  switch (key) {
  case GLUT_KEY_UP:
    obs[1]=obs[1]+1;
    glutPostRedisplay();
    break;
  case GLUT_KEY_DOWN:
    obs[1] =obs[1]-1;
    glutPostRedisplay();
    break;
  case GLUT_KEY_LEFT:
    tetaxz=tetaxz+2;
    glutPostRedisplay();
    break;
  case GLUT_KEY_RIGHT:
    tetaxz=tetaxz-2;
    glutPostRedisplay();
    break;
  }
}

void keyboard(unsigned char key, int x, int y){
  switch (key) {
  case 27:
    exit(0);
    break;
  case 'g':
    gouraud = !gouraud;
    glutPostRedisplay();
    break;
  case 'r':
    raioxz=raioxz+1;
    glutPostRedisplay();
    break;
  case 'R':
    if(raioxz>1){
      raioxz=raioxz-1;
      glutPostRedisplay();
    }
    break;
  }
}


void init(){
  gouraud=1;
  glEnable(GL_DEPTH_TEST);
  glEnable(GL_BLEND);
  glBlendFunc(GL_SRC_ALPHA,GL_ONE_MINUS_SRC_ALPHA);

  glLightfv(GL_LIGHT0, GL_DIFFUSE, cor_luz0);
  glLightfv(GL_LIGHT0, GL_SPECULAR, cor_luz0);
  glLightfv(GL_LIGHT0, GL_AMBIENT, cor_luz0_amb);
  glLightfv(GL_LIGHT0, GL_POSITION, posicao_luz0);

  glLightfv(GL_LIGHT1, GL_DIFFUSE, cor_luz1);
  glLightfv(GL_LIGHT1, GL_SPECULAR, cor_luz1);
  glLightf (GL_LIGHT1, GL_SPOT_CUTOFF, spot_luz1);
  glLightfv(GL_LIGHT1, GL_POSITION, posicao_luz1);
  glLightfv(GL_LIGHT1, GL_SPOT_DIRECTION, direcao_luz1);

  glEnable(GL_LIGHTING);
  glEnable(GL_LIGHT0);
  glEnable(GL_LIGHT1);

  glEnable(GL_AUTO_NORMAL);
  glEnable(GL_NORMALIZE);
}

void menu(int value){
  switch (value) {
  case 0:
    mat_a_especular[0]=mat_a_especular[1]=mat_a_especular[2]=0.0;
    break;
  case 1: 
    mat_a_especular[0]=mat_a_especular[1]=mat_a_especular[2]=0.5;
    break;
  case 2:
    mat_a_especular[0]=mat_a_especular[1]=mat_a_especular[2]=1.0;
    break;
  case 3:
    mat_a_difusa[0]=mat_a_difusa[1]=mat_a_difusa[2]=0.0;
    break;
  case 4: 
    mat_a_difusa[0]=mat_a_difusa[1]=mat_a_difusa[2]=0.5;
    break;
  case 5:
    mat_a_difusa[0]=mat_a_difusa[1]=mat_a_difusa[2]=1.0;
    break;
  }
  glutPostRedisplay();
}


int main(int argc,char **argv){
  glutInitWindowPosition(0,0);
  glutInitWindowSize(WIDTH,HEIGHT);
  glutInit(&argc,argv);
  glutInitDisplayMode(GLUT_RGB|GLUT_DEPTH|GLUT_DOUBLE);

  if(!glutCreateWindow("Modelos de iluminacao")) {
    fprintf(stderr,"Error opening a window.\n");
    exit(-1);
  }

  init();
  
  glutKeyboardFunc(keyboard);
  glutSpecialFunc(special);
  glutDisplayFunc(display);
  glutReshapeFunc(reshape);

  glutCreateMenu(menu);
  glutAddMenuEntry("-sem spec", 0);
  glutAddMenuEntry("-spec média", 1);
  glutAddMenuEntry("-spec alta", 2);
  glutAddMenuEntry("-sem difusa", 3);
  glutAddMenuEntry("-difusa média", 4);
  glutAddMenuEntry("-difusa alta", 5);
  glutAttachMenu(GLUT_RIGHT_BUTTON);

  glutMainLoop();
  return(0);
}