/* Auteur: Nicolas JANEY         */
/* nicolas.janey@univ-fcomte.fr  */
/* Avril 2004                    */
/* Illustration du trace de      */
/* cercle par l'algorithme       */
/* de Bresenham (Midpoint)       */

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

#include <stdio.h>
#include <stdlib.h>
#include <math.h>

#include "ModuleCouleurs.h"
#include "ModuleMenus.h"
#include "ModuleReshape.h"
#include "ModuleManipulateur.h"

static int aff = 0;
static int r = 1;
static int cpt;

void circle(int xi,int yi,float r) {
  glColor4fv(couleurBleu());
  glBegin(GL_LINE_LOOP);
  for ( int i = 0 ; i < 360 ; i++ ) {
    float angle = i * 3.14159F / 180;
    float x = (float) (xi + r*cos(angle));
    float y = (float) (yi + r*sin(angle));
    glVertex2f(x,y); }
  glEnd();
}

void pixel(int x,int y,float *c) {
  cpt++;
  glColor4fv(c);
  glPushMatrix();
  glTranslatef((float) x,(float) y,0.0F);
  glutWireCube(1.0);
  glPopMatrix();
}

void pixelsSymetriques8(int x,int y,float *c) {
  pixel(x,y,c);
  pixel(-x,y,c);
  pixel(x,-y,c);
  pixel(-x,-y,c);
  pixel(y,x,c);
  pixel(-y,x,c);
  pixel(y,-x,c);
  pixel(-y,-x,c);
}

void pixelsSymetriques4(int x,int y,float *c) {
  pixel(x,y,c);
  pixel(x,-y,c);
  pixel(y,x,c);
  pixel(-y,x,c);
}

void pixelsDiagonale(int x,float *c) {
  pixel(x,x,c);
  pixel(x,-x,c);
  pixel(-x,x,c);
  pixel(-x,-x,c);
}

void cercle(float *c,int r) {
  int x,y,d;
  x = 0;
  y = r;
  d = 1 - r;
  pixelsSymetriques4(x,y,c);
  while ( y > x ) {
    if ( d < 0 )
      d += 2 * x + 3;
      else {
      d += 2 * (x - y) + 5;
      y--; }
    x++;
    if ( x == y )
      pixelsDiagonale(x,c);
    if ( y > x )
      pixelsSymetriques8(x,y,c); }
}

void trame(int xi,int y,float *c) {
  for ( int x = -xi ; x <= xi ; x++ )
    pixel(x,y,c);
}

void disque1(float *c,int r) {
  int x,y,d;
  x = 0;
  y = r;
  d = 1 - r;
  trame(y,x,c);
  while ( y > x ) {
    if ( d < 0 )
      d += 2 * x + 3;
      else {
      d += 2 * (x - y) + 5;
      trame(x,y,c);
      trame(x,-y,c);
      y--; }
    x++;
    trame(y,x,c);
    trame(y,-x,c); }
}

void disque2(float *c,int r) {
  int *xt =(int *) calloc((r+1),sizeof(int));
  int x,y,d;
  x = 0;
  y = r;
  d = 1 - r;
  xt[y] = x;
  xt[x] = y;
  while ( y > x ) {
    if ( d < 0 )
      d += 2 * x + 3;
      else {
      d += 2 * (x - y) + 5;
      y--; }
    x++;
    if ( x > xt[y] )
      xt[y] = x;
    if ( y > xt[x] )
      xt[x] = y; }
  for ( x = -xt[0] ; x <= xt[0] ; x++ )
    pixel(x,0,c);
  for ( y = 1 ; y <= r ; y++ )
    for ( x = -xt[y] ; x <= xt[y] ; x++ ) {
      pixel(x,y,c);
      pixel(x,-y,c); }
  free(xt);
}

void display() {
  glClear(GL_COLOR_BUFFER_BIT|GL_DEPTH_BUFFER_BIT);
  glPushMatrix();
  manipulateurSouris();
  manipulateurClavier();
  switch (aff) {
    case 0 : circle(0,0,r);
             cpt = 0;
             cercle(couleurRouge(),r);
             printf("%d\n",cpt);
             break;
    case 1 : circle(0,0,r);
             cpt = 0;
             disque1(couleurRouge(),r);
             printf("%d\n",cpt);
             break;
    case 2 : circle(0,0,r);
             cpt = 0;
             disque2(couleurRouge(),r);
             printf("%d\n",cpt);
             break; }
  glPopMatrix();
  glFlush();
  glutSwapBuffers();
}

void myinit() {
  glShadeModel(GL_SMOOTH);
  glClearColor(0.8F,0.8F,0.8F,1.0F);
}

void key(unsigned char key,int x,int y) {
  if ( keyManipulateur(key,x,y) )
    glutPostRedisplay();
    else
    switch ( key ) {
      case 45   : r--;
                  if ( r < 1 )
                    r = 1;
                  glutPostRedisplay();
                  break;
      case 43   : r++;
                  glutPostRedisplay();
                  break;
      case 0x0D : aff = (aff+1)%3;
                  glutPostRedisplay();
                  break;
      case 0x1B : exit(0);
                  break; }
}

int main(int argc,char **argv) {
  glutInit(&argc,argv);
  glutInitDisplayMode(GLUT_RGBA|GLUT_DEPTH|GLUT_DOUBLE);
  glutInitWindowSize(350,350); 
  glutInitWindowPosition(50,50); 
  glutCreateWindow("Cercles par l'algorithme du midpoint"); 
  myinit(); 
  creationMenuBasique();
  setParametresOrthoBasique(-20.0,20.0,-20.0,20.0,-300.0,300.0);
  glutReshapeFunc(reshapeOrthoBasique);
  glutMotionFunc(motionBasique);
  glutMouseFunc(sourisBasique);
  setManipulateurDistance(1.0F);
  glutKeyboardFunc(key);
  glutDisplayFunc(display);
  glutMainLoop();
  return(0);
}