al_set_new_bitmap_samples - Allegro 5 API

       Sets  the  multi-sampling  samples used by newly created bitmaps (on the current thread) if they are used
       with al_set_target_bitmap(3alleg5).  0 means multi-sampling will  not  be  used  when  drawing  into  the
       bitmap,  which  is  the  default.  1 means multi-sampling will be used but only using a single sample per
       pixel (so usually there will be no visual difference to not using multi-sampling at all).

              Note: Some platforms have restrictions on when the multi-sampling buffer for a bitmap is realized,
              i.e. down-scaled back to the actual bitmap dimensions.  This may  only  happen  after  a  call  to
              al_set_target_bitmap(3alleg5).  So for example:

              al_set_target_bitmap(multisample);
              al_clear_to_color(blue);
              al_draw_line(0, 0, 100, 100, red, 1);
              al_lock_bitmap(multisample, ...)
              // ERROR: the contents of the bitmap will be undefined

              al_set_target_bitmap(backbuffer);
              al_lock_bitmap(multisample, ...)
              // CORRECT: at this point, the bitmap contents are updated and
              // there will be an anti-aliased line in it.

       al_set_new_bitmap_samples - Allegro 5 API

       5.2.1

              [UnstableAPI]: This is an experimental feature and currently only works for the OpenGL backend.

Allegro reference manual                                                      al_set_new_bitmap_samples(3alleg5)

              #include <allegro5/allegro.h>

              void al_set_new_bitmap_samples(int samples)
              SETTER(new_bitmap_samples, samples)