Bitwise masking

BlitzMax Forums/BlitzMax Beginners Area/Bitwise masking

EOF	(Posted 2010) [#1]

How do you mask out (or toggle OFF) values using bitwise operations?

For example, I am using the pixmaps ReadPixel() and want to WritePixel() back but excluding the alpha channel

The value read is 32 bit in the form of $AARRGGBB
I want to write back the equivalent of $00RRGGBB

Zeke	(Posted 2010) [#2]

Local Color:Int = $AA112233
Print Hex(Color)
Color:& $00FFFFFF 'Color=Color & $00FFFFFF
Print Hex(Color)

EOF	(Posted 2010) [#3]

Ahh thanks Zeke

For reference I also have this code for "argb" related manipulation:

' get separate alpha, red, green, and blue from 32bit ARGB value
Local argb%=ReadPixel(pixmap,x,y)
Local a% = (argb & $ff000000) Shr 24
Local r% = (argb & $ff0000) Shr 16
Local g% = (argb & $ff00)  Shr 8
Local b% = (argb & $ff)

' return the 32bit argb value from separate alpha, red, green, and blue values
Function GetARGB%(a%,r%,g%,b%)
	Return (a Shl 24) + (r Shl 16) + (g Shl 8) + b
EndFunction