Extents Adjustment

Some hardware uses an anti-aliasing kernel that influences pixels outside the extents rectangle defined by the screen-space vertices. Applications that use the extents rectangle in the D3DCLIPSTATUS structure (defined in d3dtypes.h) for dirty rectangle processing might experience rendering artifacts because the extents rectangle does not cover the pixels modified by the hardware.

Direct3D addresses this problem by enabling hardware drivers to request that the extents rectangle be adjusted outward by a specified number of pixels in the dvExtentsAdjust member of the D3DHAL_D3DEXTENDEDCAPS structure. This member is filled in response to the GUID_D3DExtendedCaps GUID in DdGetDriverInfo. The extents rectangle is clipped to the extents of the render target surface for the device. The default is zero.