progs/demos/renormal.c

   1
   2 /*
   3  * Test GL_EXT_rescale_normal extension
   4  * Brian Paul  January 1998   This program is in the public domain.
   5  */
   6
   7 #include <stdio.h>
   8 #include <stdlib.h>
   9 #include <math.h>
  10 #include <GL/glut.h>
  11
  12
  13 static GLfloat Phi = 0.0;
  14
  15
  16 static void Idle( void )
  17 {
  18    static double t0 = -1.;
  19    double dt, t = glutGet(GLUT_ELAPSED_TIME) / 1000.0;
  20    if (t0 < 0.0)
  21       t0 = t;
  22    dt = t - t0;
  23    t0 = t;
  24    Phi += 3.0 * dt;
  25    glutPostRedisplay();
  26 }
  27
  28
  29 static void Display( void )
  30 {
  31    GLfloat scale = 0.6 + 0.5 * sin(Phi);
  32    glClear( GL_COLOR_BUFFER_BIT );
  33    glPushMatrix();
  34    glScalef(scale, scale, scale);
  35    glutSolidSphere(2.0, 20, 20);
  36    glPopMatrix();
  37    glutSwapBuffers();
  38 }
  39
  40
  41 static void Reshape( int width, int height )
  42 {
  43    glViewport( 0, 0, width, height );
  44    glMatrixMode( GL_PROJECTION );
  45    glLoadIdentity();
  46    glFrustum( -1.0, 1.0, -1.0, 1.0, 5.0, 25.0 );
  47    glMatrixMode( GL_MODELVIEW );
  48    glLoadIdentity();
  49    glTranslatef( 0.0, 0.0, -15.0 );
  50 }
  51
  52
  53
  54 static void Init( void )
  55 {
  56    static GLfloat mat[4] = { 0.8, 0.8, 0.0, 1.0 };
  57    static GLfloat pos[4] = { -1.0, 1.0, 1.0, 0.0 };
  58
  59    /* setup lighting, etc */
  60    glEnable(GL_LIGHTING);
  61    glEnable(GL_LIGHT0);
  62    glMaterialfv(GL_FRONT, GL_AMBIENT_AND_DIFFUSE, mat);
  63    glLightfv(GL_LIGHT0, GL_POSITION, pos);
  64
  65    glEnable(GL_CULL_FACE);
  66
  67    glDisable(GL_RESCALE_NORMAL_EXT);
  68    glDisable(GL_NORMALIZE);
  69 }
  70
  71
  72 #define UNSCALED  1
  73 #define NORMALIZE 2
  74 #define RESCALE   3
  75 #define QUIT      4
  76
  77
  78 static void ModeMenu(int entry)
  79 {
  80    if (entry==UNSCALED) {
  81       glDisable(GL_RESCALE_NORMAL_EXT);
  82       glDisable(GL_NORMALIZE);
  83    }
  84    else if (entry==NORMALIZE) {
  85       glEnable(GL_NORMALIZE);
  86       glDisable(GL_RESCALE_NORMAL_EXT);
  87    }
  88    else if (entry==RESCALE) {
  89       glDisable(GL_NORMALIZE);
  90       glEnable(GL_RESCALE_NORMAL_EXT);
  91    }
  92    else if (entry==QUIT) {
  93       exit(0);
  94    }
  95    glutPostRedisplay();
  96 }
  97
  98 static void
  99 key(unsigned char k, int x, int y)
 100 {
 101   (void) x;
 102   (void) y;
 103   switch (k) {
 104   case 27:  /* Escape */
 105     exit(0);
 106     break;
 107   default:
 108     return;
 109   }
 110   glutPostRedisplay();
 111 }
 112
 113 int main( int argc, char *argv[] )
 114 {
 115    glutInit( &argc, argv );
 116    glutInitWindowPosition(0, 0);
 117    glutInitWindowSize( 400, 400 );
 118
 119    glutInitDisplayMode( GLUT_RGB | GLUT_DOUBLE );
 120
 121    glutCreateWindow(argv[0]);
 122
 123    Init();
 124
 125    glutIdleFunc( Idle );
 126    glutReshapeFunc( Reshape );
 127    glutDisplayFunc( Display );
 128    glutKeyboardFunc(key);
 129
 130    glutCreateMenu(ModeMenu);
 131    glutAddMenuEntry("Unscaled", UNSCALED);
 132    glutAddMenuEntry("Normalize", NORMALIZE);
 133    glutAddMenuEntry("Rescale EXT", RESCALE);
 134    glutAddMenuEntry("Quit", QUIT);
 135    glutAttachMenu(GLUT_RIGHT_BUTTON);
 136
 137    glutMainLoop();
 138    return 0;
 139 }