OpenGL Programming Guide: The Official Guide to Learning OpenGL, Version 4.3, Eighth Edition

Appendix C. Built-in GLSL Variables and Functions

The OpenGL Shading Language has a small number of built-in variables, a set of constants, and a large collection of built-in functions. This appendix describes each of these, in the following major sections:

• “Built-in Variables” lists the variables, first showing the declarations for all stages, followed by the description of each.

• “Built-in Constants” lists all the built-in constants.

• “Built-in Functions” describes all GLSL built-in functions. You’ll need to refer to the table at the beginning of the section to decode the types.