Difference between revisions of "Bitwise Operators"
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=== Examples === | === Examples === | ||
'''Set joypad switches''' | '''Set joypad switches''' | ||
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if k==KeyCode.UP then joypad=joypad|0b001000 | if k==KeyCode.UP then joypad=joypad|0b001000 | ||
elseif k==KeyCode.DOWN then joypad=joypad|0b000100 | elseif k==KeyCode.DOWN then joypad=joypad|0b000100 | ||
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'''Clear joypad switches''' | '''Clear joypad switches''' | ||
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if k==KeyCode.UP then joypad=joypad&0b0111 | if k==KeyCode.UP then joypad=joypad&0b0111 | ||
elseif k==KeyCode.DOWN then joypad=joypadRGUDLR&0b1011 | elseif k==KeyCode.DOWN then joypad=joypadRGUDLR&0b1011 | ||
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'''Move in a direction based on joystick switches (using above examples)''' | '''Move in a direction based on joystick switches (using above examples)''' | ||
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local deltaX={0,-1,1,0,0,-1,1,0,0,-1,1,0,0,-1,1,0} | 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} | local deltaY={0,0,0,0,1,1,1,1,-1,-1,-1,-1,0,0,0,0} | ||
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'''Debounce bits, eg joypad switches''' | '''Debounce bits, eg joypad switches''' | ||
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debouncedJoypad=(joypad~joypadOld)&joypad | debouncedJoypad=(joypad~joypadOld)&joypad | ||
joypadOld=joypad | joypadOld=joypad | ||
Revision as of 14:26, 13 July 2023
Supported platforms: 
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 <syntaxhighlight lang="lua"> 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 </source>
Clear joypad switches <syntaxhighlight lang="lua"> 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 </source>
Move in a direction based on joystick switches (using above examples) <syntaxhighlight lang="lua"> 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] </source>
Debounce bits, eg joypad switches <syntaxhighlight lang="lua"> debouncedJoypad=(joypad~joypadOld)&joypad joypadOld=joypad </source>
See also
https://www.lua.org/pil/3.3.html
