# OpenGL.GL.EXT.blend_subtract

OpenGL extension EXT.blend_subtract

This module customises the behaviour of the
OpenGL.raw.GL.EXT.blend_subtract to provide a more
Python-friendly API

Overview (from the spec)

Two additional blending equations are specified using the interface
defined by EXT_blend_minmax. These equations are similar to the
default blending equation, but produce the difference of its left
and right hand sides, rather than the sum. Image differences are
useful in many image processing applications.

The official definition of this extension is available here:
http://www.opengl.org/registry/specs/EXT/blend_subtract.txt

## Functions

## Constants

GL_FUNC_REVERSE_SUBTRACT_EXT (32779)

GL_FUNC_SUBTRACT_EXT (32778)