Provided by: allegro5-doc_5.2.10.1+dfsg-1build1_all 

NAME
al_have_opengl_extension - Allegro 5 API
SYNOPSIS
#include <allegro5/allegro_opengl.h>
bool al_have_opengl_extension(const char *extension)
DESCRIPTION
This function is a helper to determine whether an OpenGL extension is available on the given display or
not.
Example:
bool packedpixels = al_have_opengl_extension("GL_EXT_packed_pixels");
If packedpixels is true then you can safely use the constants related to the packed pixels extension.
Returns true if the extension is available; false otherwise.
Allegro reference manual al_have_opengl_extension(3alleg5)