Allegro 5 api
#include <allegro5/allegro.h> void al_rotate_transform(ALLEGRO_TRANSFORM *trans, float theta)
Apply a rotation to a transformation.
Parameters:
trans - Transformation to alter
theta - Rotation angle in radians
al_translate_transform(3alleg5), al_scale_transform(3alleg5), al_build_transform(3alleg5)