_DEVICEINPUT - QB64Official/qb64 GitHub Wiki

The _DEVICEINPUT function returns the device number when a controller device button, wheel or axis event occurs.

Syntax

device% = _DEVICEINPUT device_active% = _DEVICEINPUT(device_number%)

Parameter(s)

Use the _DEVICEINPUT device% INTEGER returned to find the number of the controller device being used.
A literal specific device_number% parameter can be used to return -1 if active or 0 if inactive. EX: WHILE _DEVICEINPUT(2)

Description

Use _DEVICES to find the number of controller devices available BEFORE using this function.
_DEVICE$ can be used to list the device names and control types using valid _DEVICES numbers.
When a device button is pressed or a scroll wheel or axis is moved, the device number will be returned.
Devices are numbered as 1 for keyboard and 2 for mouse. Other controller devices will be numbered 3 or higher if installed.
_LASTBUTTON, _LASTAXIS, or _LASTWHEEL will indicate the number of functions available with the specified device number.
User input events can be monitored reading valid numbered _AXIS, _BUTTON, _BUTTONCHANGE or _WHEEL functions.
Note: ON...GOSUB keyboard, mouse, gamecontrol can be used to control the devices 1,2 and 3, etc.

Example(s)

Checking device controller interfaces and finding out what devices are being used.


FOR i = 1 TO _DEVICES
  PRINT STR$(i) + ") " + _DEVICE$(i)
  PRINT "Button:"; _LASTBUTTON(i); ",Axis:"; _LASTAXIS(i); ",Wheel:"; _LASTWHEEL(i)
NEXT

PRINT
DO
  x = _DEVICEINPUT
  IF x THEN PRINT "Device ="; x;
LOOP UNTIL INKEY$ = CHR$(27) 'escape key exit

END


[KEYBOARD][BUTTON]
Buttons: 512 Axis: 0 Wheels: 0
[MOUSE][BUTTON][AXIS][WHEEL]
Buttons: 3 Axis: 2 Wheels: 3
[CONTROLLER][NAME][Microsoft Sidewinder Precision Pro (USB)](NAME][Microsoft Sidewinder Precision Pro (USB))[BUTTON][AXIS]
Buttons: 9 Axis: 6 Wheels: 0

Device = 2 Device = 2

Note: Mouse events must be within the program screen area. Keyboard presses are registered only when program is in focus.

Why does a mouse have 3 wheels? Relative x and y movements can be read using the first 2 _WHEEL reads.


ignore = _MOUSEMOVEMENTX 'dummy call to put mouse into relative movement mode

PRINT "Move your mouse and/or your mouse wheel (ESC to exit)"

d = _DEVICES '  always read number of devices to enable device input
DO: _LIMIT 30  'main loop
  DO WHILE _DEVICEINPUT(2) 'loop only runs during a device 2 mouse event
        PRINT _WHEEL(1), _WHEEL(2), _WHEEL(3)
  LOOP 
LOOP UNTIL INKEY$ = CHR$(27)

Explanation: Referencing the _MOUSEMOVEMENTX function hides the mouse and sets the mouse to a relative movement mode which can be read by _WHEEL. _DEVICEINPUT(2) returns -1 (true) only when the mouse is moved, scrolled or clicked.

Using ON...GOSUB with the _DEVICEINPUT number to add keyboard, mouse and game controller event procedures.


n = _DEVICES 'required when reading devices
PRINT "Number of devices found ="; n
FOR i = 1 TO n
    PRINT i; _DEVICE$(i) ' 1 = keyboard, 2 = mouse, 3 = other controller, etc.
NEXT
PRINT

DO: device = _DEVICEINPUT
    ON device GOSUB keyboard, mouse, controller  'must be inside program loop
LOOP UNTIL INKEY$ = CHR$(27)
END

keyboard:
PRINT device; "Keyboard";
RETURN

mouse:
PRINT device; "Mouse ";
RETURN

controller:
PRINT device; "Game control ";
RETURN

Note: ON...GOSUB and ON...GOTO events require numerical values to match the order of line labels listed in the event used inside loops.