/* Auteur: Nicolas JANEY         */
/* nicolas.janey@univ-fcomte.fr  */
/* Avril 2001                    */
/* Programmation du calcul       */
/* d'une courbe de Bezier        */
/* pour dessiner un cercle!      */

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

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

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

static int n = 100 ;

float p = 0.55F ;
float pts1[4][3] = { {1.0F,0.0F,0.0F},
                     {1.0F,p,0.0F},
                     {p,1.0F,0.0F},
                     {0.0F,1.0F,0.0F} } ;

void traceCercle(float r) {
  glPushMatrix() ;
  glScalef(r,r,r) ;
  glColor4fv(couleurMagenta());
  glBegin(GL_LINE_LOOP) ;
  for ( int i = 0 ; i < 360 ; i++ ) {
    float x =(float) cos(i*3.1459/180) ;
    float y =(float) sin(i*3.1459/180) ;
    glVertex2f(x,y) ; }
  glEnd() ;
  glPopMatrix() ;
}

void traceQuartCercleBezierGL(float r) {
  glPushMatrix() ;
  glScalef(r,r,r) ;
  glMap1f(GL_MAP1_VERTEX_3,
          0.0,1.0,3,4,&pts1[0][0]); 
  glEnable(GL_MAP1_VERTEX_3); 
  glColor4fv(couleurCyan());
  glBegin(GL_POINTS); 
  for ( int i = 0 ; i <= n ; i++ ) 
    glEvalCoord1f((GLfloat) i/100.0F); 
  glEnd(); 
  glPopMatrix() ;
}

void traceCercleBezierGL(float r) {
  glPushMatrix() ;
  traceQuartCercleBezierGL(r) ;
  glRotatef(90.0F,0.0F,0.0F,1.0F) ;
  traceQuartCercleBezierGL(r) ;
  glRotatef(90.0F,0.0F,0.0F,1.0F) ;
  traceQuartCercleBezierGL(r) ;
  glRotatef(90.0F,0.0F,0.0F,1.0F) ;
  traceQuartCercleBezierGL(r) ;
  glPopMatrix() ;
}

void display(void) { 
  glClear(GL_COLOR_BUFFER_BIT|
          GL_DEPTH_BUFFER_BIT); 
  glPushMatrix();
  glEnable(GL_DEPTH_TEST);
  manipulateurSouris();
  manipulateurClavier();
  traceCercle(6.0F) ;
  traceCercleBezierGL(6.0F) ;
  glPopMatrix();
  glPushMatrix();
  glDisable(GL_DEPTH_TEST);
  glColor4fv(couleurJaune()); 
  placeFontCursor(-6.5F,-6.5F,0.0F);
  simpleBitmapOutput("p = %5.2f",p);
  glPopMatrix();
  glFlush();
  glutSwapBuffers();
} 

void myinit(void) { 
  glClearColor(0.0,0.0,0.0,1.0); 
  glShadeModel(GL_FLAT); 
  glDepthFunc(GL_LESS);
} 
  
void key(unsigned char key,int x,int y) {
  if ( keyManipulateur(key,x,y) )
    glutPostRedisplay();
    else
    switch ( key ) {
      case 43   : p += 0.01F ;
                  pts1[1][1] = p ;
                  pts1[2][0] = p ;
                  glutPostRedisplay();
                  break;
      case 45   : p -= 0.01F ;
                  pts1[1][1] = p ;
                  pts1[2][0] = p ;
                  glutPostRedisplay();
                  break; }
}

int main(int argc,char **argv) {
  glutInit(&argc,argv);
  glutInitDisplayMode(GLUT_RGBA|GLUT_DEPTH|GLUT_DOUBLE);
  glutInitWindowSize(300,300); 
  glutInitWindowPosition(50,50); 
  glutCreateWindow("Courbe de Bezier"); 
  myinit(); 
  creationMenuBasique();
  setParametresOrthoBasique(-7.0,7.0,-7.0,7.0,-500.0,500.0);
  setManipulateurDistance(1.0F);
  glutReshapeFunc(reshapeOrthoBasique);
  glutKeyboardFunc(key);
  glutSpecialFunc(specialBasique);
  glutMotionFunc(motionBasique);
  glutMouseFunc(sourisBasique);
  glutDisplayFunc(display);
  glutMainLoop();
  return(0);
}