Question

how could I do the same as GluPerspective without Glu? Thanks

ex: gluPerspective(45.0, (float)w / (float)h, 1.0, 200.0);

Answer 1

void gluPerspective( GLdouble fovy, GLdouble aspect, GLdouble zNear, GLdouble zFar )
{
    GLdouble xmin, xmax, ymin, ymax;

    ymax = zNear * tan( fovy * M_PI / 360.0 );
    ymin = -ymax;
    xmin = ymin * aspect;
    xmax = ymax * aspect;

    glFrustum( xmin, xmax, ymin, ymax, zNear, zFar );
}