Provided by: allegro5-doc_5.0.10-2_all bug


       al_iphone_override_screen_scale - Allegro 5 API


              #include <allegro5/allegro_iphone.h>

              void al_iphone_override_screen_scale(float scale)


       Original  iPhones  and iPod Touches had a screen resolution of 320x480 (in Portrait mode).
       When the iPhone 4 and iPod Touch 4th generation devices  came  out,  they  were  backwards
       compatible  with  all  old  iPhone  apps.   This  means  that they assume a 320x480 screen
       resolution by default, while they actually have a 640x960 pixel screen (exactly 2x on each
       dimension).  An API was added to allow access to the full (or in fact any fraction of the)
       resolution of the new devices.  This function is normally not needed, as in the case  when
       you want a scale of 2.0 for "retina display" resolution (640x960).  In that case you would
       just call al_create_display with the larger  width  and  height  parameters.   It  is  not
       limited  to  2.0  scaling  factors  however.   You  can  use 1.5 or 0.5 or other values in
       between, however if it's not an exact multiple of the original iPhone  resolution,  linear
       filtering will be applied to the final image.

       This function should be called BEFORE calling al_create_display.