Provided by: allegro5-doc_5.0.11-2_all 

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