src/tests/vptorus.c

   1 /*
   2  * A lit, rotating torus via vertex program
   3  */
   4
   5 #include <assert.h>
   6 #include <string.h>
   7 #include <stdio.h>
   8 #include <stdlib.h>
   9 #include <math.h>
  10 #include <GL/glew.h>
  11 #include "glut_wrap.h"
  12
  13 static float Xrot = 0.0, Yrot = 0.0, Zrot = 0.0;
  14 static GLboolean Anim = GL_TRUE;
  15
  16
  17 static void Idle( void )
  18 {
  19    Xrot += .3;
  20    Yrot += .4;
  21    Zrot += .2;
  22    glutPostRedisplay();
  23 }
  24
  25
  26 static void Display( void )
  27 {
  28    glClear( GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT );
  29
  30    glPushMatrix();
  31       glRotatef(Xrot, 1, 0, 0);
  32       glRotatef(Yrot, 0, 1, 0);
  33       glRotatef(Zrot, 0, 0, 1);
  34       glutSolidTorus(0.75, 2.0, 10, 20);
  35    glPopMatrix();
  36
  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( -2.0, 2.0, -2.0, 2.0, 5.0, 25.0 );
  47    glMatrixMode( GL_MODELVIEW );
  48    glLoadIdentity();
  49    glTranslatef( 0.0, 0.0, -12.0 );
  50 }
  51
  52
  53 static void Key( unsigned char key, int x, int y )
  54 {
  55    (void) x;
  56    (void) y;
  57    switch (key) {
  58       case ' ':
  59          Xrot = Yrot = Zrot = 0;
  60          break;
  61       case 'a':
  62          Anim = !Anim;
  63          if (Anim)
  64             glutIdleFunc(Idle);
  65          else
  66             glutIdleFunc(NULL);
  67          break;
  68       case 'z':
  69          Zrot -= 5.0;
  70          break;
  71       case 'Z':
  72          Zrot += 5.0;
  73          break;
  74       case 27:
  75          exit(0);
  76          break;
  77    }
  78    glutPostRedisplay();
  79 }
  80
  81
  82 static void SpecialKey( int key, int x, int y )
  83 {
  84    const GLfloat step = 3.0;
  85    (void) x;
  86    (void) y;
  87    switch (key) {
  88       case GLUT_KEY_UP:
  89          Xrot -= step;
  90          break;
  91       case GLUT_KEY_DOWN:
  92          Xrot += step;
  93          break;
  94       case GLUT_KEY_LEFT:
  95          Yrot -= step;
  96          break;
  97       case GLUT_KEY_RIGHT:
  98          Yrot += step;
  99          break;
 100    }
 101    glutPostRedisplay();
 102 }
 103
 104
 105 static void Init( void )
 106 {
 107    /* borrowed from an nvidia demo:
 108     * c[0..3] = modelview matrix
 109     * c[4..7] = inverse modelview matrix
 110     * c[32] = light pos
 111     * c[35] = diffuse color
 112     */
 113    static const char prog[] =
 114       "!!VP1.0\n"
 115       "#Simple transform and diffuse lighting\n"
 116       "\n"
 117       "DP4   o[HPOS].x, c[0], v[OPOS] ; # object x MVP -> clip\n"
 118       "DP4   o[HPOS].y, c[1], v[OPOS] ;\n"
 119       "DP4   o[HPOS].z, c[2], v[OPOS] ;\n"
 120       "DP4   o[HPOS].w, c[3], v[OPOS] ;\n"
 121
 122       "DP3   R1.x, c[4], v[NRML] ;      # normal x MV-1T -> lighting normal\n"
 123       "DP3   R1.y, c[5], v[NRML] ;\n"
 124       "DP3   R1.z, c[6], v[NRML] ;\n"
 125
 126       "DP3   R0, c[32], R1 ;            # L.N\n"
 127       "MUL   o[COL0].xyz, R0, c[35] ;   # col = L.N * diffuse\n"
 128       "MOV   o[TEX0], v[TEX0];\n"
 129       "END";
 130
 131    if (!glutExtensionSupported("GL_NV_vertex_program")) {
 132       printf("Sorry, this program requires GL_NV_vertex_program");
 133       exit(1);
 134    }
 135
 136    glLoadProgramNV(GL_VERTEX_PROGRAM_NV, 1,
 137                    strlen(prog), (const GLubyte *) prog);
 138    assert(glIsProgramNV(1));
 139    glBindProgramNV(GL_VERTEX_PROGRAM_NV, 1);
 140
 141    /* Load the program registers */
 142    glTrackMatrixNV(GL_VERTEX_PROGRAM_NV, 0, GL_MODELVIEW_PROJECTION_NV, GL_IDENTITY_NV);
 143    glTrackMatrixNV(GL_VERTEX_PROGRAM_NV, 4, GL_MODELVIEW, GL_INVERSE_TRANSPOSE_NV);
 144
 145    /* Light position */
 146    glProgramParameter4fNV(GL_VERTEX_PROGRAM_NV, 32, 2, 2, 4, 1);
 147    /* Diffuse material color */
 148    glProgramParameter4fNV(GL_VERTEX_PROGRAM_NV, 35, 0.25, 0, 0.25, 1);
 149
 150    glEnable(GL_VERTEX_PROGRAM_NV);
 151    glEnable(GL_DEPTH_TEST);
 152    glClearColor(0.3, 0.3, 0.3, 1);
 153
 154    printf("glGetError = %d\n", (int) glGetError());
 155 }
 156
 157
 158 int main( int argc, char *argv[] )
 159 {
 160    glutInit( &argc, argv );
 161    glutInitWindowPosition( 0, 0 );
 162    glutInitWindowSize( 250, 250 );
 163    glutInitDisplayMode( GLUT_RGB | GLUT_DOUBLE | GLUT_DEPTH );
 164    glutCreateWindow(argv[0]);
 165    glewInit();
 166    glutReshapeFunc( Reshape );
 167    glutKeyboardFunc( Key );
 168    glutSpecialFunc( SpecialKey );
 169    glutDisplayFunc( Display );
 170    if (Anim)
 171       glutIdleFunc(Idle);
 172    Init();
 173    glutMainLoop();
 174    return 0;
 175 }