L'exécutable

• z et Z pour régler le zoom
• o et O pour régler l'ouverture en perspective
• p et P pour passer de la perspective à la projection orthographique
• up, down, left et right pour les contrôles d'orientation

Projections orthographique et en perspective

Projection en perspective avec rapprochement de la scène

Projection en perspective : très grosses déformations

Le source: Projections.cpp

#include <windows.h>

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

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

static int proj = 0 ;
static int ww ;
static int hh ;
static float anglex = 0.0F ;
static float angley = 0.0F ;
static float zoomPersp = 1.0F ;
static float zoomParal = 1.0F ;
static float ouverture = 1.0F ;

void projection(void) {
  if ( proj ) {
    glMatrixMode(GL_PROJECTION);
    glLoadIdentity();
    gluPerspective(60.0*ouverture,(double) ww/hh,0.5,200.0);
    glMatrixMode(GL_MODELVIEW);
    glTranslatef(0.0F,0.0F,-5.0F*zoomPersp); }
    else {
    glMatrixMode(GL_PROJECTION);
    glLoadIdentity();
    glOrtho(-2.5*zoomParal,2.5*zoomParal,-2.5*zoomParal*(double) hh/ww,2.5*zoomParal*(double) hh/ww,-25,25);
    glMatrixMode(GL_MODELVIEW);
    glTranslatef(0.0F,0.0F,-5.0F); }
}

void CALLBACK display(void) {   
  glClear(GL_COLOR_BUFFER_BIT|GL_DEPTH_BUFFER_BIT);
  glPushMatrix();
  glColor3f(1.0F,1.0F,1.0F);
  projection();
  glPushMatrix();
  glRotatef(anglex,1.0F,0.0F,0.0F);
  glRotatef(angley,0.0F,1.0F,0.0F);
  glTranslatef(-1.0F,0.0F,0.0F) ;
  float jaune[] = { 1.0F,1.0F,0.0F };
  glMaterialfv(GL_FRONT,GL_DIFFUSE,jaune);
  auxSolidCube(2.0);
  glTranslatef(2.0F,0.0F,0.0F) ;
  float bleu[] = { 0.0F,0.0F,1.0F };
  glMaterialfv(GL_FRONT,GL_DIFFUSE,bleu);
  auxSolidSphere(1.3);
  glPopMatrix();
  glPopMatrix();
  glFlush();
  auxSwapBuffers() ;
}

void CALLBACK myinit(void) {
  glShadeModel(GL_SMOOTH);
  glDepthFunc(GL_LESS) ;
  glEnable(GL_DEPTH_TEST);
  glEnable(GL_LIGHTING);
  glEnable(GL_LIGHT0);
}

void CALLBACK myReshape(int w, int h) { 
  glViewport(0,0,w,h);
  ww = w ;
  hh = h ;
}

void CALLBACK keyo(void) { 
  ouverture *= 1.01F ;
  ouverture *= 1.01F ;
}

void CALLBACK keyO(void) {
  ouverture /= 1.01F ;
  ouverture /= 1.01F ;
}

void CALLBACK keyz(void) { 
  zoomPersp *= 1.01F ;
  zoomParal *= 1.01F ;
}

void CALLBACK keyZ(void) {
  zoomPersp /= 1.01F ;
  zoomParal /= 1.01F ;
}

void CALLBACK keyP(void) {  
  proj++;
  proj %= 2;
}

void CALLBACK keyp(void) { 
  proj++;
  proj %= 2;
}

void CALLBACK up(void) {
  anglex++ ;
}

void CALLBACK down(void) {
  anglex-- ;
}

void CALLBACK left(void) {
  angley++ ;
}

void CALLBACK right(void) {
  angley-- ;
}

void main(void) {
  auxInitDisplayMode(AUX_DOUBLE|AUX_RGBA|AUX_DEPTH);
  auxInitPosition(0,0,200,200);
  auxInitWindow("Visualisations");
  myinit();
  auxKeyFunc(AUX_O,keyO);
  auxKeyFunc(AUX_o,keyo);
  auxKeyFunc(AUX_P,keyP);
  auxKeyFunc(AUX_p,keyp);
  auxKeyFunc(AUX_Z,keyZ);
  auxKeyFunc(AUX_z,keyz);
  auxKeyFunc(AUX_UP,up) ;
  auxKeyFunc(AUX_DOWN,down) ;
  auxKeyFunc(AUX_LEFT,left) ;
  auxKeyFunc(AUX_RIGHT,right) ;
  auxReshapeFunc(myReshape);
  auxMainLoop(display);
}

 RETOUR