procedure Perspective(const aFOVAngle, aAspectRatio, aNear, aFar: Single);
procedure Ortho(const aLeft, aRight, aBottom, aTop, aNear, aFar: Single);
procedure Activate;
procedure Perspective(const aFOVAngle, aAspectRatio, aNear, aFar: Single);
procedure Ortho(const aLeft, aRight, aBottom, aTop, aNear, aFar: Single);
procedure Activate;