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/*
* A lit, rotating torus via vertex program
*/
#include <assert.h>
#include <string.h>
#include <stdio.h>
#include <stdlib.h>
#include <math.h>
#define GL_GLEXT_PROTOTYPES
#include <GL/glut.h>
static float Xrot = 0.0, Yrot = 0.0, Zrot = 0.0;
static GLboolean Anim = GL_TRUE;
static void Idle( void )
{
Xrot += .3;
Yrot += .4;
Zrot += .2;
glutPostRedisplay();
}
static void Display( void )
{
glClear( GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT );
glPushMatrix();
glRotatef(Xrot, 1, 0, 0);
glRotatef(Yrot, 0, 1, 0);
glRotatef(Zrot, 0, 0, 1);
glutSolidTorus(0.75, 2.0, 10, 20);
glPopMatrix();
glutSwapBuffers();
}
static void Reshape( int width, int height )
{
glViewport( 0, 0, width, height );
glMatrixMode( GL_PROJECTION );
glLoadIdentity();
glFrustum( -2.0, 2.0, -2.0, 2.0, 5.0, 25.0 );
glMatrixMode( GL_MODELVIEW );
glLoadIdentity();
glTranslatef( 0.0, 0.0, -12.0 );
}
static void Key( unsigned char key, int x, int y )
{
(void) x;
(void) y;
switch (key) {
case ' ':
Xrot = Yrot = Zrot = 0;
break;
case 'a':
Anim = !Anim;
if (Anim)
glutIdleFunc(Idle);
else
glutIdleFunc(NULL);
break;
case 'z':
Zrot -= 5.0;
break;
case 'Z':
Zrot += 5.0;
break;
case 27:
exit(0);
break;
}
glutPostRedisplay();
}
static void SpecialKey( int key, int x, int y )
{
const GLfloat step = 3.0;
(void) x;
(void) y;
switch (key) {
case GLUT_KEY_UP:
Xrot -= step;
break;
case GLUT_KEY_DOWN:
Xrot += step;
break;
case GLUT_KEY_LEFT:
Yrot -= step;
break;
case GLUT_KEY_RIGHT:
Yrot += step;
break;
}
glutPostRedisplay();
}
static void Init( void )
{
/* borrowed from an nvidia demo:
* c[0..3] = modelview matrix
* c[4..7] = inverse modelview matrix
* c[32] = light pos
* c[35] = diffuse color
*/
static const char prog[] =
"!!VP1.0\n"
"#Simple transform and diffuse lighting\n"
"\n"
"DP4 o[HPOS].x, c[0], v[OPOS] ; # object x MVP -> clip\n"
"DP4 o[HPOS].y, c[1], v[OPOS] ;\n"
"DP4 o[HPOS].z, c[2], v[OPOS] ;\n"
"DP4 o[HPOS].w, c[3], v[OPOS] ;\n"
"DP3 R1.x, c[4], v[NRML] ; # normal x MV-1T -> lighting normal\n"
"DP3 R1.y, c[5], v[NRML] ;\n"
"DP3 R1.z, c[6], v[NRML] ;\n"
"DP3 R0, c[32], R1 ; # L.N\n"
"MUL o[COL0].xyz, R0, c[35] ; # col = L.N * diffuse\n"
"MOV o[TEX0], v[TEX0];\n"
"END";
if (!glutExtensionSupported("GL_NV_vertex_program")) {
printf("Sorry, this program requires GL_NV_vertex_program");
exit(1);
}
glLoadProgramNV(GL_VERTEX_PROGRAM_NV, 1,
strlen(prog), (const GLubyte *) prog);
assert(glIsProgramNV(1));
glBindProgramNV(GL_VERTEX_PROGRAM_NV, 1);
/* Load the program registers */
glTrackMatrixNV(GL_VERTEX_PROGRAM_NV, 0, GL_MODELVIEW_PROJECTION_NV, GL_IDENTITY_NV);
glTrackMatrixNV(GL_VERTEX_PROGRAM_NV, 4, GL_MODELVIEW, GL_INVERSE_TRANSPOSE_NV);
/* Light position */
glProgramParameter4fNV(GL_VERTEX_PROGRAM_NV, 32, 2, 2, 4, 1);
/* Diffuse material color */
glProgramParameter4fNV(GL_VERTEX_PROGRAM_NV, 35, 0.25, 0, 0.25, 1);
glEnable(GL_VERTEX_PROGRAM_NV);
glEnable(GL_DEPTH_TEST);
glClearColor(0.3, 0.3, 0.3, 1);
printf("glGetError = %d\n", (int) glGetError());
}
int main( int argc, char *argv[] )
{
glutInit( &argc, argv );
glutInitWindowPosition( 0, 0 );
glutInitWindowSize( 250, 250 );
glutInitDisplayMode( GLUT_RGB | GLUT_DOUBLE | GLUT_DEPTH );
glutCreateWindow(argv[0]);
glutReshapeFunc( Reshape );
glutKeyboardFunc( Key );
glutSpecialFunc( SpecialKey );
glutDisplayFunc( Display );
if (Anim)
glutIdleFunc(Idle);
Init();
glutMainLoop();
return 0;
}
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