/* Dessin d'un segment de droite par Bresenham  */
/* Remplissage 2D d'un triangle                 */
/*                                              */
/* Auteur: Nicolas JANEY                        */
/* nicolas.janey@univ-fcomte.fr                 */
/* Novembre 2010                                */

#if defined(WIN32) || defined(WIN64)
  #define _CRTDBG_MAP_ALLOC
  #if defined(_DEBUG)
    #define _AFXDLL
    #include <afx.h>
  #endif
#endif
#include <stdlib.h>
#if defined(WIN32) || defined(WIN64)
  #include <crtdbg.h>
#endif
#include <stdio.h>
#include <math.h>

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

#include "Position2D.h"
#include "Segment2D.h"
#include "Triangle2D.h"
#include "Trace.h"

/* Variables globales                           */

static int sc = 0;

/* Fonction executee lors d'un changement       */
/* de la taille de la fenetre OpenGL            */
/* Configuration d'une camera de visualisation  */
/* en projection en parallele orthographique    */

void reshape(int tx,int ty) {
  glViewport(0,0,tx,ty);
  glMatrixMode(GL_PROJECTION);
  glLoadIdentity();
  glOrtho((-tx/2)/10.0,(-tx/2+tx)/10.0,
          (-ty/2)/10.0,(-ty/2+ty)/10.0,
          -1.0,1.0);
  glMatrixMode(GL_MODELVIEW);
  glLoadIdentity();
}

/* Fonction executee lors d'un rafraichissement */
/* de la fenetre de dessin                      */

void display(void) {
  glClearColor(0.6F,0.6F,0.6F,1.0F) ;
  glClear(GL_COLOR_BUFFER_BIT|GL_DEPTH_BUFFER_BIT) ;
  Position2D *ps11 = new Position2D(-15.0,9.0);
  Position2D *ps12 = new Position2D(10.0,-10.0);
  Segment2D *s1 = new Segment2D(ps11,ps12);
  Position2D *ps21 = new Position2D(3.0,2.0);
  Position2D *ps22 = new Position2D(15.0,6.0);
  Segment2D *s2 = new Segment2D(ps21,ps22);
  Position2D *ps32 = new Position2D(-7.0,-13.0);
  Position2D *ps31 = new Position2D(-17.0,5.0);
  Segment2D *s3 = new Segment2D(ps31,ps32);
  Position2D *pt1 = new Position2D(-13.0,9.0);
  Position2D *pt2 = new Position2D(11.0,13.0);
  Position2D *pt3 = new Position2D(2.0,-10.0);
  Triangle2D *t = new Triangle2D(pt1,pt2,pt3);
  glPushMatrix();
  if ( sc == 0 ) {
    glColor3f(0.0F,1.0F,0.0F);
    s1->trace();
    s2->trace();
    s3->trace(); }
  if ( ( sc == 2 ) || ( sc == 3 ) ) {
    glColor3f(0.0F,0.0F,1.0F);
    t->remplit(); }
  if ( ( sc == 1 ) || ( sc == 3 ) ) {
    glColor3f(1.0F,0.0F,0.0F);
    t->trace(); }
  glPopMatrix();
  delete(s1);
  delete(ps11);
  delete(ps12);
  delete(s2);
  delete(ps21);
  delete(ps22);
  delete(s3);
  delete(ps31);
  delete(ps32);
  delete(pt1);
  delete(pt2);
  delete(pt3);
  delete(t);
  glFlush();
  glutSwapBuffers();
  int error = glGetError();
  if ( error != GL_NO_ERROR )
    printf("Attention, erreur OpenGL %d\n",error);
}

/* Fonction executee lors de la frappe          */
/* d'une touche alphanumerique du clavier       */

void keyboard(unsigned char key,int x,int y) {
  switch ( key ) {
    case 0x0D : sc = (sc+1)%4;
                glutPostRedisplay();
                break;
    case 0x1B : exit(0); }
}

/* Fonction d'initialisation d'OpenGL           */
void init(void) {
  glPointSize(10.0F);
}

/* Fonction principale                          */

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

#if defined(WIN32) || defined(WIN64)
  _CrtSetDbgFlag ( _CRTDBG_ALLOC_MEM_DF | _CRTDBG_LEAK_CHECK_DF );
  //_crtBreakAlloc = 109;
#endif

  glutInit(&argc,argv);
  glutInitDisplayMode(GLUT_RGBA|GLUT_DOUBLE|GLUT_DEPTH);
  glutInitWindowSize(400,300); 
  glutInitWindowPosition(50,50); 
  glutCreateWindow("Bresenham & remplissage triangle");
  init();
  glutReshapeFunc(reshape);
  glutKeyboardFunc(keyboard);
  glutDisplayFunc(display);
  glutMainLoop();
  return(0);
}