bilinearfiltering A technique for choosing the texel color to apply to a pixel during texture mapping. The weighted average of the four texels nearest the pixel center is used.
blending When two triangles overlap in screen space, a decision must be made about the color of the pixels in the overlapping area. Blending is a technique for reducing the two colors to one, usually as a linear interpolation of the two candidates.
chroma-key A technique for removing pixels of a specific color, used to implement a “blue screen”.
clamp Forcing a value to lie within a specified range of values.
clippingElimination of those portions of a scene that are outside the clipping rectangle defined by calling grClipWindow().
depthbiasA constant that is added to the calculated depth of a pixel.
depthbufferOne possible use of the auxiliary buffer. It stores a depth value for each pixel. Subsequent pixels can be accepted or discarded based on a depth test.
diffuselight One of the components of a lighting model. Diffuse light comes from a single source, but is scattered equally in all directions when it strikes a surface. See ambient, emitted, and specularlight.
ditheringA technique for increasing the perceived range of colors in an image by applying a pattern to surrounding pixels to modify their color values. When viewed from a distance, these colors appear to blend into an intermediate color that can’t be represented directly. Dithering is similar to the half-toning used in black and white publications to produce shades of gray.
doublebuffering Using two color buffers: a scene is rendered in one buffer while the previously rendered scene in the other buffer is displayed. When the rendering is complete, the two buffers are swapped and the rendering of the next scene can begin in the buffer that is no longer being displayed. See singlebuffering, triplebuffering, and framebuffer.