D

dark light

A light source that removes illumination from a scene, created by specifying negative values for the colors of the light.

dead zone

An area within the range of an axis where the axis is considered to be at the center.

decal

A texture that is rendered directly, as a visual. Decals are rendered into a viewport-aligned rectangle.

destination color key

The color that, in the case f blitting, will be replaced or, in the case of overlays, be covered up on the destination surface.

device window

A visible application window that DirectDraw uses for display. Applications can have a device window for each display device in a machine. See also, focus window.

directional

A light source that is attached to a frame but appears to illuminate all objects with equal intensity, as if it were at an infinite distance from the objects. Directional light has orientation but no position, and it is commonly used to simulate distant light sources, such as the sun.