Direct2D Glossary

A8 target

A render target that uses a pixel format representing an alpha channel with eight bits. A8 targets are useful for drawing geometries as masks.

aliasing

In computer graphics, the jagged appearance of curves or diagonal lines. Aliasing is most visible at lower resolutions.

antialiasing

A technique for smoothing the jagged appearance of curved or diagonal lines. Methods of antialiasing include surrounding pixels with intermediate shades and manipulating the size and horizontal alignment of the pixels.

batch

A set of requests or transactions that have been grouped together.

bitmap

A representation of characters or graphics by individual pixels. The pixels can be arranged horizontally, in rows, or vertically, in columns. Each pixel can be represented by one or more bits.

bits per pixel (bpp)

The number of bits that are used to store and display the color data for a single pixel. This is the standard unit of measurement for bit depth (also called color depth). Common bit depths include 8, 16, and 32.

brush

A Direct2D resource that paints an infinite plane with a solid color, a gradient, or a bitmap. A brush is typically used to stroke and fill a geometry.

ClearType

A font display technology that dramatically improves font display resolution, such that letters on the computer screen appear smooth, not jagged. ClearType improves text appearance on LCD monitors that have a digital interface, such as laptop monitors and high-quality flat-panel desktop monitors.

DC

See definition for: device context.

device context (DC)

A GDI device context. See also: Graphics Device Interface.

Direct2D

A hardware-accelerated, immediate-mode 2-D rendering API.

Direct3D

The hardware acceleration platform and runtime for 3-D graphics in Windows.

DirectWrite

A text API that provides text rendering, font management, and text layout support that is independent of any specific rendering system.

DirectX Graphics Infrastructure (DXGI)

The infrastructure that manages the low-level graphics-related tasks that are independent of the DirectX graphics runtime. DXGI provides a common framework for graphics components.

DXGI

See definition for: DirectX Graphics Infrastructure (DXGI).

figure

An open or closed shape defined by a start point and a collection of segments.

flatten

To generate a polygonal approximation of a (potentially curved) geometry.

GDI

See definition for: Graphics Device Interface (GDI).

geometric mask

A clip or a cutout, defined by an ID2D1Geometry object, that masks a layer when it is drawn by a render target. A geometric mask can be either aliased or have sub-pixel edges.

geometry transform

A transform that is applied to a geometry before it is stroked or filled.

glyph

A graphical representation of a character, part of a character, or sequence of characters.

glyph run

A continuous run of glyphs that share a common format.

gradient brush

A brush that paints an area in a gradual progression from one color to another or from one shade to another shade of the same color.

gradient stop

A specific color that is defined for a location within the gradient region. Gradient stops are used to define the color at specific locations along the gradient path.

graphics primitive

In computer graphics, a shape such as a line, circle, curve, or polygon that a graphics adapter can draw, store, and manipulate as a discrete entity.

Graphics Device Interface (GDI)

A graphics API that enables applications to send graphics commands to a display or printing device, generally without consideration for its specifications or capabilities. A Microsoft Win32 GDI receives rendering requests from applications and passes those requests to the kernel-mode GDI.

handle to a device context (HDC)

A reference to a GDI device context.

HDC

See definition for: handle to a device context.

mesh

A collection of vertices that define a set of triangles that constitute a shape.

Multi-Sample Anti-Aliasing (MSAA)

An antialiasing technique that processes an entire scene.

opacity mask

A mask, described by a brush or bitmap, that is applied to another object to make that object partially or completely transparent. An opacity mask uses alpha channel information to specify how the source pixels of the object are blended into the final destination target. The transparent portions of the mask indicate the areas where the underlying image is hidden, whereas the opaque portions of the mask indicate where the masked object is allowed.

Per Primitive Anti-Aliasing (PPAA)

An antialiasing technique that is applied to each individual graphics primitive rather than an entire scene.

radial gradient brush

A gradient where the start point is defined by a focal point and the end point is defined by a gradient.

render target

A Direct2D resource that issues drawing commands. There are different types of render targets, each rendering to a different destination. For example, an ID2D1HwndRenderTarget renders to a window, and an ID2D1BitmapRenderTarget renders to a bitmap.

segment

A portion of a geometric path, defined by the start and end points.

tessellate

To break a shape into a collection of triangles.

transform

A matrix that represents a linear mapping in a number of dimensions. Direct2D uses a 2-by-3 matrix, which limits the API to those deformations that are affine.

translation

The process of using a transformation matrix to move an object.

vertex

The highest point of a curve, the point where a curve ends, or the point where two segments meet in a polygon or a freeform path.

vertex shader

A type of programmable shader that contains a set of assembly instructions that are run on the GPU per vertex and per pixel for the current draw call. A vertex shader offloads intensive calculations from CPU to GPU.

Windows Imaging Component (WIC)

An API that enables applications to (1) display and edit any image format for which a WIC-compliant CODEC is installed, and to (2) read and write metadata or image files.

XML Paper Specification (XPS)

A document format, described by the XML Paper Specification, that can be used to store documents, to process them for printing, and to print them.

XPS

See definition for: XML Paper Specification (XPS).