Ubuntu Manpage: al_set_new_display_option

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
with a setting as close as possible to the requested one. You can query the actual
value used in that case by calling al_get_display_option(3alleg5) after the display has
been created.

• 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.

ALLEGRO_AUTO_CONVERT_BITMAPS
This is on by default. It causes any existing memory bitmaps with the
ALLEGRO_CONVERT_BITMAP flag to be converted to a display bitmap of the newly
created display with the option set.

Since: 5.1.0

ALLEGRO_SUPPORTED_ORIENTATIONS
This is a bit-combination of the orientations supported by the application. The
orientations are the same as for al_get_display_orientation(3alleg5) with the
additional possibilities:

• ALLEGRO_DISPLAY_ORIENTATION_PORTRAIT

• ALLEGRO_DISPLAY_ORIENTATION_LANDSCAPE

• ALLEGRO_DISPLAY_ORIENTATION_ALL

PORTRAIT means only the two portrait orientations are supported, LANDSCAPE means
only the two landscape orientations and ALL allows all four orientations. When the
orientation changes between a portrait and a landscape orientation the display
needs to be resized. This is done by sending an
ALLEGRO_EVENT_DISPLAY_RESIZE(3alleg5) message which should be handled by calling
al_acknowledge_resize(3alleg5).

Since: 5.1.0

ALLEGRO_OPENGL_MAJOR_VERSION
Request a specific OpenGL major version.

Since: 5.1.13

ALLEGRO_OPENGL_MINOR_VERSION
Request a specific OpenGL minor version.

Since: 5.1.13

NAME

SYNOPSIS

DESCRIPTION

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