DirectComposition glossary

This topic defines Microsoft DirectComposition terms.

animation function: A construct that specifies how the value of a single object property changes over a period of time.
animation object: An object that represents a function for animating the properties of another object.
animation segment: The fundamental timing definitions of an animation function; they are the primitives from which more complex and higher level animation functions are built.
back buffer: A rectangle of memory that an application can directly write to. The back buffer is never directly displayed on the monitor.
batch: A group of DirectComposition method calls that are processed atomically.
bitmap: A color buffer, either with or without an alpha channel, that resides in system or video memory.
border mode: A property of a Microsoft DirectComposition visual that affects how the edges of a bitmap are composed when the bitmap is transformed such that the edges are not axis-aligned with integer coordinates. It also affects how content is clipped at the corners of a clip that has rounded corners, and at the edge of a clip that is transformed such that the edges are not axis-aligned with integer coordinates.
clip object: A object that represents a clip rectangle.
clip rectangle: A set of coordinates that define the area of visual's bitmap content that is drawn on the screen when the bitmap is rendered.
cloak: To temporarily prevent Desktop Window Manager (DWM) from drawing a window to the display. Applications typically cloak a window while DirectComposition uses the window's bitmap in a composition.
commit: To submit a batch of commands to DirectCompositionDirectComposition for processing.
composite mode: One of several ways of blending two bitmaps (a source and a destination) to achieve a particular effect.
composition: A collection of bitmaps that are combined and manipulated by applying various transforms, effects, and animations to produce an intended visual result in an application UI.
composition target window: The window to which a visual tree is bound, and in which the resulting composition is drawn.
effect: An operation that modifies how the bitmaps of a visual tree are rasterized, typically by applying a pixel shader.
effect group: A group of bitmap effects that are applied together to modify the rasterization of a visual’s sub-tree.
frame: An iteration of the composition engine that produces a rasterization of the visual tree.
front buffer: A rectangle of memory that is translated by the graphics adapter and displayed on the monitor.
interpolation mode: A property that determines how a bitmap is composed when it is transformed such that there is no one-to-one correspondence between pixels in the bitmap and pixels on the screen.
root visual: The visual from which all other visuals in a visual tree are descended.
swap chain: A collection of one or more back buffers that can be serially presented to the front buffer
surface: A representation of a linear area of display memory that usually resides in the display memory of the display card, although surfaces can exist in system memory.
transform: A matrix that represents a coordinate transformation in either two-dimensional or three-dimensional space.
transform group: A collection of transforms whose matrices are multiplied together in the order in which they are specified in the collection before they are applied to a visual.
visual: An object that contains an optional reference to a bitmap object, and a set of properties that determine where and how the bitmap is rendered to the screen.
visual object: See visual.
visual subtree: A portion of a visual tree consisting of a particular visual and all of its child and descendent visuals.
visual tree: A hierarchical collection of visuals used to create a composition.
windowless swap chain: A swap chain that is associated with a DirectComposition visual object instead of a window.