When converting from RGB to greyscale, it's common to use the formula (R, G, B) -> (Y, Y, Y) where Y = 0.30 * R + 0.59 * G + 0.11 * B
R, G, and B range from 0 to 255, and Y will as well since 0.30 + 0.59 + 0.11 == 1.0. So using the value of 127.5 (halfway between black and white) as the threshold might be reasonable. Of course, you'll need to pull out R, G, and B from the uint that represents the color. Its in the form 0x00rrggbb... the low 8 bits are B, the next higher 8 bits are G, and the next higher 8 bits are R. - Gordon ________________________________ From: [email protected] [mailto:[EMAIL PROTECTED] On Behalf Of barry.beattie Sent: Tuesday, September 11, 2007 7:36 PM To: [email protected] Subject: [flexcoders] colour values: fill "threshold" colour to change black to white labels? I'm having custom fill colours on a chart and placing label text on top of them. since the colours are just unsigned Int's is there a simple thrashold of fill values I can use to switch the label text from black to white? fill.. | .label black ... white dk blu .. white lt blu .. black yellow .. black red ..... white some simple number for the fill colour I can use as a comparson/"if" statement? this comparison will be done within an itemRenderer but the fill colour value set outside (in the chart MXML) thanx barry.b
