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    Phi += 0.1;
  19    glutPostRedisplay();
  20 }
  21
  22
  23 static void Display( void )
  24 {
  25    GLfloat scale = 0.6 + 0.5 * sin(Phi);
  26    glClear( GL_COLOR_BUFFER_BIT );
  27    glPushMatrix();
  28    glScalef(scale, scale, scale);
  29    glutSolidSphere(2.0, 20, 20);
  30    glPopMatrix();
  31    glutSwapBuffers();
  32 }
  33
  34
  35 static void Reshape( int width, int height )
  36 {
  37    glViewport( 0, 0, width, height );
  38    glMatrixMode( GL_PROJECTION );
  39    glLoadIdentity();
  40    glFrustum( -1.0, 1.0, -1.0, 1.0, 5.0, 25.0 );
  41    glMatrixMode( GL_MODELVIEW );
  42    glLoadIdentity();
  43    glTranslatef( 0.0, 0.0, -15.0 );
  44 }
  45
  46
  47
  48 static void Init( void )
  49 {
  50    static GLfloat mat[4] = { 0.8, 0.8, 0.0, 1.0 };
  51    static GLfloat pos[4] = { -1.0, 1.0, 1.0, 0.0 };
  52
  53    /* setup lighting, etc */
  54    glEnable(GL_LIGHTING);
  55    glEnable(GL_LIGHT0);
  56    glMaterialfv(GL_FRONT, GL_AMBIENT_AND_DIFFUSE, mat);
  57    glLightfv(GL_LIGHT0, GL_POSITION, pos);
  58
  59    glEnable(GL_CULL_FACE);
  60
  61    glDisable(GL_RESCALE_NORMAL_EXT);
  62    glDisable(GL_NORMALIZE);
  63 }
  64
  65
  66 #define UNSCALED  1
  67 #define NORMALIZE 2
  68 #define RESCALE   3
  69 #define QUIT      4
  70
  71
  72 static void ModeMenu(int entry)
  73 {
  74    if (entry==UNSCALED) {
  75       glDisable(GL_RESCALE_NORMAL_EXT);
  76       glDisable(GL_NORMALIZE);
  77    }
  78    else if (entry==NORMALIZE) {
  79       glEnable(GL_NORMALIZE);
  80       glDisable(GL_RESCALE_NORMAL_EXT);
  81    }
  82    else if (entry==RESCALE) {
  83       glDisable(GL_NORMALIZE);
  84       glEnable(GL_RESCALE_NORMAL_EXT);
  85    }
  86    else if (entry==QUIT) {
  87       exit(0);
  88    }
  89    glutPostRedisplay();
  90 }
  91
  92 static void
  93 key(unsigned char k, int x, int y)
  94 {
  95   (void) x;
  96   (void) y;
  97   switch (k) {
  98   case 27:  /* Escape */
  99     exit(0);
 100     break;
 101   default:
 102     return;
 103   }
 104   glutPostRedisplay();
 105 }
 106
 107 int main( int argc, char *argv[] )
 108 {
 109    glutInit( &argc, argv );
 110    glutInitWindowSize( 400, 400 );
 111
 112    glutInitDisplayMode( GLUT_RGB | GLUT_DOUBLE );
 113
 114    glutCreateWindow(argv[0]);
 115
 116    Init();
 117
 118    glutIdleFunc( Idle );
 119    glutReshapeFunc( Reshape );
 120    glutDisplayFunc( Display );
 121    glutKeyboardFunc(key);
 122
 123    glutCreateMenu(ModeMenu);
 124    glutAddMenuEntry("Unscaled", UNSCALED);
 125    glutAddMenuEntry("Normalize", NORMALIZE);
 126    glutAddMenuEntry("Rescale EXT", RESCALE);
 127    glutAddMenuEntry("Quit", QUIT);
 128    glutAttachMenu(GLUT_RIGHT_BUTTON);
 129
 130    glutMainLoop();
 131    return 0;
 132 }