Difference between revisions of "Bitwise Operators"

From GiderosMobile
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a<b> &gt;&gt; </b>b &emsp; Bitwise shift 'a' by 'b' right.<br />
 
a<b> &gt;&gt; </b>b &emsp; Bitwise shift 'a' by 'b' right.<br />
 
<b> ~ </b>a &emsp; Bitwise 'NOT a'.<br />
 
<b> ~ </b>a &emsp; Bitwise 'NOT a'.<br />
 +
=== Examples ===
 +
'''Set joypad switches'''<br/>
 +
<source lang="lua"><br />
 +
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'''<br/>
 +
<source lang="lua"><br />
 +
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)'''<br/>
 +
<source lang="lua"><br />
 +
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'''<br/>
 +
<source lang="lua"><br />
 +
joypad=(joypad~joypadOld)&joypad
 +
joypadOld=joypad</source>
 
{|-
 
{|-
 
| style="width: 50%;"|
 
| style="width: 50%;"|

Revision as of 11:45, 23 August 2018

Supported platforms: android, ios, mac, pc
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

<br /> 
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

<br /> 
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)

<br /> 
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

<br /> 
joypad=(joypad~joypadOld)&joypad
joypadOld=joypad

Methods

Events

Constants