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

NAME

       al_set_new_display_option - Allegro 5 API

SYNOPSIS

              #include <allegro5/allegro.h>

              void al_set_new_display_option(int option, int value, int importance)

DESCRIPTION

       Set  an extra display option, to be used when creating new displays on the calling thread.
       Display options differ from display flags, and specify some details of the context  to  be
       created  within the window itself.  These mainly have no effect on Allegro itself, but you
       may want to specify them, for example if you want to use multisampling.

       The 'importance' parameter can be either:

       • ALLEGRO_REQUIRE - The display will not be created if the setting can not be met.

       • ALLEGRO_SUGGEST - If the setting is not available, the display will be  created  anyway.
         FIXME: We need a way to query the settings back from a created display.

       • ALLEGRO_DONTCARE  -  If  you  added  a display option with one of the above two settings
         before, it will be removed again.  Else this does nothing.

       The supported options are:

       ALLEGRO_COLOR_SIZE
              This can be used to ask for a specific bit depth.  For example to  force  a  16-bit
              framebuffer set this to 16.

       ALLEGRO_RED_SIZE, ALLEGRO_GREEN_SIZE, ALLEGRO_BLUE_SIZE,
              ALLEGRO_ALPHA_SIZE Individual color component size in bits.

       ALLEGRO_RED_SHIFT, ALLEGRO_GREEN_SHIFT, ALLEGRO_BLUE_SHIFT,
              ALLEGRO_ALPHA_SHIFT  Together  with  the  previous  settings  these  can be used to
              specify the exact pixel layout the display should use.  Normally there is no reason
              to use these.

       ALLEGRO_ACC_RED_SIZE, ALLEGRO_ACC_GREEN_SIZE, ALLEGRO_ACC_BLUE_SIZE,
              ALLEGRO_ACC_ALPHA_SIZE  This can be used to define the required accumulation buffer
              size.

       ALLEGRO_STEREO
              Whether the display is a stereo display.

       ALLEGRO_AUX_BUFFERS
              Number of auxiliary buffers the display should have.

       ALLEGRO_DEPTH_SIZE
              How many depth buffer (z-buffer) bits to use.

       ALLEGRO_STENCIL_SIZE
              How many bits to use for the stencil buffer.

       ALLEGRO_SAMPLE_BUFFERS
              Whether to use multisampling (1) or not (0).

       ALLEGRO_SAMPLES
              If the above is 1, the number of samples to use per pixel.  Else 0.

       ALLEGRO_RENDER_METHOD:
              0 if hardware acceleration is not used with this display.

       ALLEGRO_FLOAT_COLOR
              Whether to use floating point color components.

       ALLEGRO_FLOAT_DEPTH
              Whether to use a floating point depth buffer.

       ALLEGRO_SINGLE_BUFFER
              Whether the display uses a single buffer (1) or another update method (0).

       ALLEGRO_SWAP_METHOD
              If the above is 0, this is set to 1 to indicate the  display  is  using  a  copying
              method  to  make the next buffer in the flip chain available, or to 2 to indicate a
              flipping or other method.

       ALLEGRO_COMPATIBLE_DISPLAY
              Indicates if Allegro's graphics functions can use this display.  If you  request  a
              display  not  useable  by  Allegro,  you  can  still use for example OpenGL to draw
              graphics.

       ALLEGRO_UPDATE_DISPLAY_REGION
              Set to 1 if the display is capable of updating just a  region,  and  0  if  calling
              al_update_display_region(3alleg5) is equivalent to al_flip_display(3alleg5).

       ALLEGRO_VSYNC
              Set  to 1 to tell the driver to wait for vsync in al_flip_display(3alleg5), or to 2
              to force vsync off.  The default of 0 means that Allegro does not try to modify the
              vsync  behavior so it may be on or off.  Note that even in the case of 1 or 2 it is
              possible to override the vsync behavior in the graphics driver so  you  should  not
              rely on it.

       ALLEGRO_MAX_BITMAP_SIZE
              When  queried  this returns the maximum size (width as well as height) a bitmap can
              have    for    this    display.     Calls    to    al_create_bitmap(3alleg5)     or
              al_load_bitmap(3alleg5)  for  bitmaps larger than this size will fail.  It does not
              apply to memory bitmaps which always can have arbitrary  size  (but  are  slow  for
              drawing).

       ALLEGRO_SUPPORT_NPOT_BITMAP
              Set  to 1 if textures used for bitmaps on this display can have a size which is not
              a power of two.  This is mostly useful if you  use  Allegro  to  load  textures  as
              otherwise only power-of-two textures will be used internally as bitmap storage.

       ALLEGRO_CAN_DRAW_INTO_BITMAP
              Set to 1 if you can use al_set_target_bitmap(3alleg5) on bitmaps of this display to
              draw into them.  If this is not the case  software  emulation  will  be  used  when
              drawing into display bitmaps (which can be very slow).

       ALLEGRO_SUPPORT_SEPARATE_ALPHA
              This  is  set  to  1 if the al_set_separate_blender(3alleg5) function is supported.
              Otherwise the alpha parameters will be ignored.

SEE ALSO

       al_set_new_display_flags(3alleg5)