btn - nesbox/TIC-80 GitHub Wiki

• btn(id) -> is_pressed
• btn() -> GAMEPADS data (see RAM)

Parameters

• id : id (0..31) of the key we want to interrogate (see the key map for reference or type help buttons in console).

Returns

• is_pressed : button is pressed (true/false)
• GAMEPADS data : 32-bit value that represents current state of all GAMEPAD button inputs

Description

This function allows you to read the status of TIC's controller buttons. It returns true if the button with the supplied id is currently in the pressed state and remains true for as long as the button is held down. To see if a button was just pressed, use btnp instead.

Input Tag

Set the metadata input tag to gamepad to display only the on-screen gamepad on Android devices and hide the keyboard.

Example

The following example displays the state of all buttons during each frame:

--Key Test Project
--By Rain_Effect,pixelbath
local ox=70
local oy=15
local btnLabel={"Up","Down","Left","Right","Btn A","Btn B","Btn X","Btn Y"}

function printBtnLabels(x, y, headingText)
  print(headingText,x,y,8)
  for i=1,8 do
    print(btnLabel[i],x,y+i*10,12)
  end
end

function printInputState(x, y, headingText, startIdx)
  print(headingText,x,y,8)
  for i=1,8 do
    if btn(i-1+startIdx) then
      print("On",x,y+i*10,6)
    else
      print("Off",x-3,y+i*10,1)
    end
  end
end

function TIC()
  cls(0)

  print("Key Test Project",ox,oy,12)

  printBtnLabels(ox-30, oy+15, "Btn")
  printInputState(ox+20, oy+15, "1P", 0)
  printInputState(ox+50, oy+15, "2P", 8)
  printInputState(ox+80, oy+15, "3P", 16)
  printInputState(ox+110, oy+15, "4P", 24)
end