Opposite color

[RomanK]

Hi guys,

just a quick question...

Let's say I have the hex color 0xFFC90F which is something between yellow and orange.

I have a gui with that background color and a label on top of it.

The label needs to clearly readable. So you might suggest to make its font black.

Well, but the background color can be changed. The font will be invisible or hardly to read when the background is black or grey.

How can I let autoit calculate a good font color depending on the GUI background?

Roman

EDIT: Sorry for posting in the wrong section. Please move it, thanks!

Edited January 23, 2009 by RomanK

[KaFu]

Can't remember where I found this piece of code, kudos to the author ...

#Include <Color.au3>

MsgBox(0,'',_ColorInverse('0xFFC90F'))

Func _ColorInverse($nColor)
    Local $nRed = _ColorGetRed($nColor)
    Local $nGreen = _ColorGetGreen($nColor)
    Local $nBlue = _ColorGetBlue($nColor)
    Return "0x" & Hex(255 - $nRed, 2) & Hex(255 - $nGreen, 2) & Hex(255 - $nBlue, 2)
EndFunc   ;==>_ColorInverse

[ProgAndy]

This should get better readable colors:

Func _CalcContrastColor ($crBg)
    ; http://www.codeproject.com/KB/tips/JbColorContrast.aspx
    Local Const $TOLERANCE = 30

    if ( _
        abs(BitAND($crBg  , 0xFF) - 0x80) <= $TOLERANCE And _
        abs(BitAND(BitShift($crBg , 8) , 0xFF) - 0x80) <= $TOLERANCE And _
        abs(BitAND(BitShift($crBg , 16) & 0xFF) - 0x80) <= $TOLERANCE _
    ) Then return BitAND((0x7F7F7F + $crBg) , 0xFFFFFF);

    return BitXOR($crBg ,0xFFFFFF);
EndFunc

(opposite color is not a good choice for our eyes)

[KaFu]

(opposite color is not a good choice for our eyes)

Nice , yeah, I found it commented out in one of my scripts ...

[RomanK]

Thanks to both of you.

@ProgAndy: This gives nice colors, may I use it for Caravelle³ ?