NAME

SYNOPSIS

#include <allegro5/allegro.h>
void al_set_new_display_option(int option, int value, int importance)

    

DESCRIPTION

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(3) 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(3) is equivalent to al_flip_display(3).

ALLEGRO_VSYNC

Set to 1 to tell the driver to wait for vsync in al_flip_display(3), 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(3) or al_load_bitmap(3) 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(3) 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(3) 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.

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(3) with the additional possibilities:

ALLEGRO_OPENGL_MAJOR_VERSION

Request a specific OpenGL major version.

ALLEGRO_OPENGL_MINOR_VERSION

Request a specific OpenGL minor version.

SEE ALSO