al_get_default_shader_source - Man Page

#include <allegro5/allegro.h>

char const *al_get_default_shader_source(ALLEGRO_SHADER_PLATFORM platform,
   ALLEGRO_SHADER_TYPE type)

Returns a string containing the source code to Allegro’s default vertex or pixel shader appropriate for the passed platform. The ALLEGRO_SHADER_AUTO value means GLSL is used if OpenGL is being used otherwise HLSL. ALLEGRO_SHADER_AUTO requires that there is a current display set on the calling thread. This function can return NULL if Allegro was built without support for shaders of the selected platform.

5.1.6

al_attach_shader_source(3)

al_attach_shader_source(3).