Related to: gluPerspective. The viewing volume is frustum-shaped amd defined
by the four parameters. The fovy and aspect ratio are used to compute the
positions of the left, right, top, and bottom sides of the viewing volume in
the zNear plane. The fovy is the y field-of-view, the angle made by the top
and bottom sides of frustum if they were to intersect. The aspect ratio is
the width of the frustum divided by its height. Note that the resulting
volume is both vertically and horizontally symmetrical around the center of
the near plane.
Creates a perspective projection matrix.
Related to: gluPerspective. The viewing volume is frustum-shaped amd defined by the four parameters. The fovy and aspect ratio are used to compute the positions of the left, right, top, and bottom sides of the viewing volume in the zNear plane. The fovy is the y field-of-view, the angle made by the top and bottom sides of frustum if they were to intersect. The aspect ratio is the width of the frustum divided by its height. Note that the resulting volume is both vertically and horizontally symmetrical around the center of the near plane.