Quote Originally Posted by czar
In my case I just used

Unit Maths

if GetPrecisionMode = pmsingle then SetPrecisionMode(pmDouble);
Well, this is not good as it can break Direct3D. You better save current FP control word, do SetPrecisionMode(pmDouble); before your code and restore control word before starting to call DirectX functions. This way you will be sure what everything will work correct and performance will be at top.