/* Auteur: Nicolas JANEY */
/* nicolas.janey@univ-fcomte.fr */
/* Mars 2002 */
/* Rasterisation d'un segment de droite */
/* sur un ecran bitmap */
#include <stdio.h>
#include <stdlib.h>
#include <math.h>
#include <GL/glut.h>
#include <GL/gl.h>
#include <GL/glu.h>
#include "ModuleCouleurs.h"
#include "ModuleMenus.h"
#include "ModuleReshape.h"
struct coord2D {
double x;
double y; } ;
struct segment {
coord2D pi;
coord2D pf; } ;
int aff = 0;
static segment seg = { { 5,3 },{ 35,16 } };
void pixel(int x, int y) {
glBegin(GL_QUADS) ;
glVertex2i(x,y) ;
glVertex2i(x+1,y) ;
glVertex2i(x+1,y+1) ;
glVertex2i(x,y+1) ;
glEnd() ;
}
void lignePixels(int xi,int yi,int xf,int yf) {
int i,cumul ;
int x = xi ;
int y = yi ;
int dx = xf - xi ;
int dy = yf - yi ;
int xinc = ( dx > 0 ) ? 1 : -1 ;
int yinc = ( dy > 0 ) ? 1 : -1 ;
dx = abs(dx) ;
dy = abs(dy) ;
pixel(x,y) ;
if ( dx > dy ) {
cumul = dx / 2 ;
for ( i = 1 ; i <= dx ; i++ ) {
x += xinc ;
cumul += dy ;
if (cumul >= dx) {
cumul -= dx ;
y += yinc ; }
pixel(x,y) ; } }
else {
cumul = dy / 2 ;
for ( i = 1 ; i <= dy ; i++ ) {
y += yinc ;
cumul += dx ;
if ( cumul >= dy ) {
cumul -= dy ;
x += xinc ; }
pixel(x,y) ; } }
}
void dessineSegment(float *c,segment *s) {
glColor4fv(c) ;
glLineWidth(3.0) ;
glBegin(GL_LINES) ;
glVertex2d(s->pi.x+0.5,s->pi.y+0.5);
glVertex2d(s->pf.x+0.5,s->pf.y+0.5);
glEnd() ;
glLineWidth(1.0) ;
}
void dessineQuadrillage(float *c) {
int i;
glColor4fv(c) ;
glBegin(GL_LINES);
for ( i = 1 ; i < 20 ; i++ ) {
glVertex2d(1.0,i);
glVertex2d(39.0,i); }
for ( i = 1 ; i < 40 ; i++ ) {
glVertex2d(i,1.0);
glVertex2d(i,19.0); }
glEnd() ;
}
void display() {
glClear(GL_COLOR_BUFFER_BIT|GL_DEPTH_BUFFER_BIT);
glPushMatrix();
switch (aff) {
case 0 : dessineSegment(couleurRouge(),&seg) ;
break ;
case 1 : dessineQuadrillage(couleurBleu()) ;
dessineSegment(couleurRouge(),&seg) ;
break ; }
glPopMatrix();
glFlush();
glutSwapBuffers() ;
}
void key(unsigned char key,int x,int y) {
switch ( key ) {
case 0x1B : exit(0);
break;
case 0x0D : aff = (aff+1)%2;
glutPostRedisplay();
break; }
}
void myinit() {
glClearColor(0.8F,0.8F,0.8F,1.0F);
}
int main(int argc,char **argv) {
glutInit(&argc,argv);
glutInitDisplayMode(GLUT_RGBA|GLUT_DEPTH|GLUT_DOUBLE);
glutInitWindowSize(320,160);
glutInitWindowPosition(50,50);
glutCreateWindow("Rasterisation d'un segment");
myinit();
creationMenuBasique();
setParametresOrthoBasique(0.0,20.0,0.0,20.0,-50.0,50.0);
glutReshapeFunc(reshapeOrthoBasique);
glutKeyboardFunc(key);
glutDisplayFunc(display);
glutMainLoop();
return(0);
}
RETOUR