Leaving the FPU in double precision mode should be harmless, but will be slower than single precision.
All the values used by the 3D engine are single precision. So having the FPU calculate in higher precision is a waste of time.
As far as I know this is the only reason Direct3D uses single precision mode.
All the values used by the 3D engine are single precision. So having the FPU calculate in higher precision is a waste of time.
As far as I know this is the only reason Direct3D uses single precision mode.