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/*
* Test GL_EXT_rescale_normal extension
* Brian Paul January 1998 This program is in the public domain.
*/
#include <stdio.h>
#include <stdlib.h>
#include <math.h>
#include <GL/glut.h>
static GLfloat Phi = 0.0;
static void Idle(void)
{
Phi += 0.1;
glutPostRedisplay();
}
static void Display( void )
{
GLfloat scale = 0.6 + 0.5 * sin(Phi);
glClear( GL_COLOR_BUFFER_BIT );
glPushMatrix();
glScalef(scale, scale, scale);
glutSolidSphere(2.0, 20, 20);
glPopMatrix();
glutSwapBuffers();
}
static void Reshape( int width, int height )
{
glViewport( 0, 0, width, height );
glMatrixMode( GL_PROJECTION );
glLoadIdentity();
glFrustum( -1.0, 1.0, -1.0, 1.0, 5.0, 25.0 );
glMatrixMode( GL_MODELVIEW );
glLoadIdentity();
glTranslatef( 0.0, 0.0, -15.0 );
}
static void Init( void )
{
static GLfloat mat[4] = { 0.8, 0.8, 0.0, 1.0 };
static GLfloat pos[4] = { -1.0, 1.0, 1.0, 0.0 };
/* setup lighting, etc */
glEnable(GL_LIGHTING);
glEnable(GL_LIGHT0);
glMaterialfv(GL_FRONT, GL_AMBIENT_AND_DIFFUSE, mat);
glLightfv(GL_LIGHT0, GL_POSITION, pos);
glEnable(GL_CULL_FACE);
glDisable(GL_RESCALE_NORMAL_EXT);
glDisable(GL_NORMALIZE);
}
#define UNSCALED 1
#define NORMALIZE 2
#define RESCALE 3
#define QUIT 4
static void ModeMenu(int entry)
{
if (entry==UNSCALED) {
glDisable(GL_RESCALE_NORMAL_EXT);
glDisable(GL_NORMALIZE);
}
else if (entry==NORMALIZE) {
glEnable(GL_NORMALIZE);
glDisable(GL_RESCALE_NORMAL_EXT);
}
else if (entry==RESCALE) {
glDisable(GL_NORMALIZE);
glEnable(GL_RESCALE_NORMAL_EXT);
}
else if (entry==QUIT) {
exit(0);
}
glutPostRedisplay();
}
static void
key(unsigned char k, int x, int y)
{
(void) x;
(void) y;
switch (k) {
case 27: /* Escape */
exit(0);
break;
default:
return;
}
glutPostRedisplay();
}
int main( int argc, char *argv[] )
{
glutInit( &argc, argv );
glutInitWindowPosition(0, 0);
glutInitWindowSize( 400, 400 );
glutInitDisplayMode( GLUT_RGB | GLUT_DOUBLE );
glutCreateWindow(argv[0]);
Init();
glutIdleFunc( Idle );
glutReshapeFunc( Reshape );
glutDisplayFunc( Display );
glutKeyboardFunc(key);
glutCreateMenu(ModeMenu);
glutAddMenuEntry("Unscaled", UNSCALED);
glutAddMenuEntry("Normalize", NORMALIZE);
glutAddMenuEntry("Rescale EXT", RESCALE);
glutAddMenuEntry("Quit", QUIT);
glutAttachMenu(GLUT_RIGHT_BUTTON);
glutMainLoop();
return 0;
}
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