Bitwise Operators

From GiderosMobile
Revision as of 02:22, 13 February 2020 by MoKaLux (talk | contribs)


Supported platforms: Platform android.pngPlatform ios.pngPlatform mac.pngPlatform pc.png
Available since: Gideros 2017.10

Description


Bitwise operators to manipulate numbers.

a | b   Bitwise 'a OR b'.
a & b   Bitwise 'a AND b'.
a ~ b   Bitwise 'a XOR b'.
a << b   Bitwise shift 'a' by 'b' left.
a >> b   Bitwise shift 'a' by 'b' right.
~ a   Bitwise 'NOT a'.

Examples

Set joypad switches

 
if k==KeyCode.UP then joypad=joypad|0b001000
elseif k==KeyCode.DOWN then joypad=joypad|0b000100
elseif k==KeyCode.LEFT then joypad=joypad|0b000010
elseif k==KeyCode.RIGHT then joypad=joypad|0b000001
end

Clear joypad switches

 
if k==KeyCode.UP then joypad=joypad&0b0111
elseif k==KeyCode.DOWN then joypad=joypadRGUDLR&0b1011
elseif k==KeyCode.LEFT then joypad=joypadRGUDLR&0b1101
elseif k==KeyCode.RIGHT then joypad=joypadRGUDLR&0b1110
end

Move in a direction based on joystick switches (using above examples)

 
local deltaX={0,-1,1,0,0,-1,1,0,0,-1,1,0,0,-1,1,0}
local deltaY={0,0,0,0,1,1,1,1,-1,-1,-1,-1,0,0,0,0}
x=x+deltaX[joypad+1]
y=y+deltaY[joypad+1]

Debounce bits, eg joypad switches

 
joypad=(joypad~joypadOld)&joypad
joypadOld=joypad

Methods

Events

Constants