OpenGL in 2 Slides (cont.)

void drawPoly() {

glColor3f( 0, 1, 1 );

glBegin( GL_POLYGON );

glVertex3f( 0, 0, 0 );

glVertex3f( 1, 0, 0 );

glVertex3f( 0.5, 0, 1 );

glEnd();

}

void display() {

glClear( GL_COLOR_BUFFER_BIT );

glLoadIdentity();

gluLookAt( 0, -5, 0, 0, 0, 0, 0, 0, 1 );

drawPoly();

glutSwapBuffers();

}

glutInit( &argc, argv );

glutInitDisplayMode( GLUT_DOUBLE | GLUT_RGB );

glutCreateWindow( "Simple Viewer" );

glClearColor( 0, 0, 0, 0 );

glShadeModel( GL_FLAT );

glutDisplayFunc( display );

glutReshapeFunc( reshape ); // not shown here

glutMainLoop();

void reshape(int w, int h) {

if (!w || !h) return;

glViewport(0, 0, (GLsizei) w, (GLsizei) h);

glMatrixMode(GL_PROJECTION);

glLoadIdentity();

gluPerspective(45, (float)w/h, 1, 5000);

glMatrixMode(GL_MODELVIEW);

}

Displaying the same triangle polygon we showed before using OpenGL: