Fragment Shader

A Fragment Shader is a user-supplied program that, when executed, will process a Fragment from the rasterization process into a set of colors and a single depth value.

Overview

The fragment shader is the OpenGL pipeline stage after a primitive is rasterized. For each sample of the pixels covered by a primitive, a "fragment" is generated. Each fragment has a Window Space position, a few other values, and it contains all of the interpolated per-vertex output values from the last Vertex Processing stage.

The output of a fragment shader is a depth value, a possible stencil value (unmodified by the fragment shader), and zero or more color values to be potentially written to the buffers in the current framebuffers.

See also

• The previous pipeline stages:
  • Vertex Post-Processing
  • Rasterization
• The next pipeline stage:
  • Per-Sample Processing