OpenGL Programming Guide

Glossary

pixel

Picture element. The bits at location (x, y) of all the bitplanes in the framebuffer constitute the single pixel (x, y). In an image in client memory, a pixel is one group of elements. In OpenGL window coordinates, each pixel corresponds to a 1.0 × 1.0 screen area. The coordinates of the lower left corner of the pixel named x,y are (x, y), and of the upper right corner are (x+1, y+1).

OpenGL Programming Guide