|Microsoft DirectX 9.0|
Adds a dirty region to a volume texture resource.
CONST D3DBOX *pDirtyBox );
- [in] Pointer to a D3DBOX structure, specifying the dirty region to add. Specifying NULL expands the dirty region to cover the entire volume texture.
If the method succeeds, the return value is D3D_OK.
If the method fails, the return value can be D3DERR_INVALIDCALL.
For performance reasons, dirty regions are only recorded for level zero of a texture. For sublevels, it is assumed that the corresponding (scaled) rectangle or box is also dirty. Dirty regions are automatically recorded when LockRect or IDirect3DVolumeTexture9::LockBox is called without D3DLOCK_NO_DIRTY_UPDATE or D3DLOCK_READONLY. Also, the destination surface of IDirect3DDevice9::UpdateSurface is marked dirty.
Applications can optimize what subset of a resource is copied by specifying boxes on the resource. However, the dirty regions may be expanded to optimize alignment.