Performing Floating-point Operations in Direct3D

The DirectX runtime saves and restores floating-point state when it calls many of a display driver's Direct3D callback functions. However, as described in Performing Floating-point Operations in DirectDraw, some of the driver's Direct3D callback functions must save floating-point state prior to performing floating-point operations and must restore floating-point state when the operations complete.

The DirectX runtime saves and restores floating-point state as required for the following Direct3D callback functions:

• D3dContextCreate

• D3dContextDestroy

• D3dDrawPrimitives2

• D3dGetDriverState

• D3dValidateTextureStageState

For the following callback functions, a Direct3D-supported display driver must save floating-point state before performing floating-point operations, and restore it when the operations are complete:

• D3dCreateSurfaceEx

• D3dDestroyDDLocal

• D3DBuffer Callbacks

For more information about floating-point operations, see Floating-Point Operations in Graphics Driver Functions.