# Monitors

These functions are declared in the main Allegro header file:

~~~~c
 #include <allegro5/allegro.h>
~~~~

## API: ALLEGRO_MONITOR_INFO

Describes a monitors size and position relative to other
monitors. x1, y1 will be 0, 0 on the primary display.
Other monitors can have negative values if they are to the
left or above the primary display.

~~~~c
typedef struct ALLEGRO_MONITOR_INFO
{
   int x1;
   int y1;
   int x2;
   int y2;
} ALLEGRO_MONITOR_INFO;
~~~~

See also: [al_get_monitor_info]

## API: al_get_new_display_adapter

Gets the video adapter index where new displays
will be created by the calling thread, if previously set with
[al_set_new_display_adapter].
Otherwise returns `ALLEGRO_DEFAULT_DISPLAY_ADAPTER`.

See also: [al_set_new_display_adapter]

## API: al_set_new_display_adapter

Sets the adapter to use for new displays created by the calling thread.
The adapter has a monitor attached to it. Information
about the monitor can be gotten using [al_get_num_video_adapters]
and [al_get_monitor_info].

To return to the default behaviour, pass `ALLEGRO_DEFAULT_DISPLAY_ADAPTER`.

See also: [al_get_num_video_adapters], [al_get_monitor_info]

## API: al_get_monitor_info

Get information about a monitor's position on the desktop.
adapter is a number from 0 to al_get_num_video_adapters()-1.

Returns true on success, false on failure.

See also: [ALLEGRO_MONITOR_INFO], [al_get_num_video_adapters]

## API: al_get_num_video_adapters

Get the number of video "adapters" attached to the computer. Each
video card attached to the computer counts as one or more adapters.
An adapter is thus really a video port that can have a monitor connected
to it.

See also: [al_get_monitor_info]
