IDirect3DVolumeTexture9::AddDirtyBox Method

Adds a dirty region to a volume texture resource.

Syntax

HRESULT AddDirtyBox(      

    CONST D3DBOX *pDirtyBox
);

Parameters

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.

Return Value

If the method succeeds, the return value is D3D_OK.

If the method fails, the return value can be D3DERR_INVALIDCALL.

Remarks

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.