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3.6 Pixel Rectangles

Rectangles of color, depth, and certain other values may be converted to fragments using the DrawPixels  command. Some of the parameters and operations governing the operation of DrawPixels  are shared by ReadPixels  (used to obtain pixel values from the framebuffer) and CopyPixels  (used to copy pixels from one framebuffer location to another); the discussion of ReadPixels  and CopyPixels , however, is deferred until Chapter 4 after the framebuffer has been discussed in detail. Nevertheless, we note in this section when parameters and state pertaining to DrawPixels  also pertain to ReadPixels  or CopyPixels .

A number of parameters control the encoding of pixels in client memory (for reading and writing) and how pixels are processed before being placed in or after being read from the framebuffer (for reading, writing, and copying). These parameters are set with three commands: PixelStore , PixelTransfer , and PixelMap .

David Blythe
Sat Mar 29 02:23:21 PST 1997