The ability to accurately compute the color of any point given the material properties for the surface. Pixel operations . Storing, transforming, mapping, zooming. Polynomial evaluators . A point, line, polygon, bitmap, or image.
Raster primitives .
Bitmaps and pixel rectangles. RGBA mode . Color buffers store red, green, blue, and alpha color components, rather than indices. Selection and picking . A mode in which OpenGL determines whether certain user-identified graphics primitives are rendered into a region of interest in the frame buffer.