/* Auteur: Nicolas JANEY          */
/* Avril 2001                     */
/* Programmation du calcul        */
/* d'une courbe de Bezier OpenGL  */

#include <windows.h>

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

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

#include "modulefont.h"

static GLfloat view_rotx=0.0F ;
static GLfloat view_roty=0.0F ;
static GLfloat view_rotz=0.0F ;

static GLfloat pts[7][3] = { 
  {3,2,-1},{-4,5,-4}, 
  {-5,4,3},{-1,-3,-2}, 
  {4,-1,0}}; 

void traceBezierGL(void) {
  glMap1f(GL_MAP1_VERTEX_3,
          0.0,1.0,3,5,&pts[0][0]); 
  glEnable(GL_MAP1_VERTEX_3); 
  glColor3f(0.0,1.0,1.0); 
  glBegin(GL_POINTS); 
  for ( int i = 0 ; i <= 100 ; i++ ) 
    glEvalCoord1f((GLfloat) i/100.0F); 
  glEnd(); 
}
  
void CALLBACK display(void) { 
  int i; 
  glClear(GL_COLOR_BUFFER_BIT|
          GL_DEPTH_BUFFER_BIT); 
  glPushMatrix();
  glEnable(GL_DEPTH_TEST);
  glRotatef(view_rotx,1.0,0.0,0.0);
  glRotatef(view_roty,0.0,1.0,0.0);
  glRotatef(view_rotz,0.0,0.0,1.0);
  traceBezierGL() ;
  glPointSize(5.0); 
  glColor3f(1.0,1.0,0.0); 
  glBegin(GL_POINTS); 
  for ( i = 0 ; i < 5 ; i++ ) 
    glVertex3fv(&pts[i][0]); 
  glEnd(); 
  glPointSize(1.0); 
  glColor3f(1.0,0.0,1.0); 
  glBegin(GL_LINE_STRIP); 
  for ( i = 0 ; i < 5 ; i++ ) 
    glVertex3fv(&pts[i][0]); 
  glEnd(); 
  glDisable(GL_DEPTH_TEST);
  glColor3f(1.0,1.0,0.0); 
  for ( i = 0 ; i < 5 ; i++ )  {
    glRasterPos3f(pts[i][0]+0.3F,
                  pts[i][1]+0.3F,
                  pts[i][2]+0.3F);
    char st[50] ;
    sprintf(st,"%d",i);
    printString(st); }
  glPopMatrix();
  glFlush();
  auxSwapBuffers();
} 

void CALLBACK myReshape(int w,int h) { 
  glViewport(0,0,w,h); 
  glMatrixMode(GL_PROJECTION); 
  glLoadIdentity(); 
  if( w <= h ) {
    float y = 7.F*(float)h/(float)w ;
    glOrtho(-7.,7.,-y,y,-7.,7.); }
    else  {
    float x = 7.F*(float)w/(float)h ;
    glOrtho(-x,x,-7.,7.,-7.,7.); }
  glMatrixMode(GL_MODELVIEW); 
  glLoadIdentity(); 
} 
  
void myinit(void) { 
  makeRasterFont();
  glClearColor(0.0,0.0,0.0,1.0); 
  glShadeModel(GL_FLAT); 
  glDepthFunc(GL_LESS);
} 
  
void CALLBACK keyx(void) {
  view_rotx += 2 ;
}

void CALLBACK keyX(void) {
  view_rotx -= 2 ;
}

void CALLBACK keyy(void) {
  view_roty += 2 ;
}

void CALLBACK keyY(void) {
  view_roty -= 2 ;
}

void CALLBACK keyz(void) {
  view_rotz += 2 ;
}

void CALLBACK keyZ(void) {
  view_rotz -= 2 ;
}

void main(void) { 
  auxInitDisplayMode(AUX_DOUBLE|AUX_RGBA|AUX_DEPTH); 
  auxInitPosition(0,0,300,300); 
  auxInitWindow("Courbe de Bezier"); 
  myinit(); 
  auxKeyFunc(AUX_x,keyx) ;
  auxKeyFunc(AUX_X,keyX) ;
  auxKeyFunc(AUX_y,keyy) ;
  auxKeyFunc(AUX_Y,keyY) ;
  auxKeyFunc(AUX_z,keyz) ;
  auxKeyFunc(AUX_Z,keyZ) ;
  auxReshapeFunc(myReshape); 
  auxMainLoop(display); 
}