brainleak
Well-known member
My application draws a rectangle filled with a black brush with a certain degree of transparency on top of a background image. The rectangle is clearly visible except if the background consists of a large gray area, in which case it becomes difficult to distingish.
The way to manually overcome this would be easy enough allowing the user to select on the fly a different (lighter) fill colour, but I was wondering if this could be somehow automated by means of some sort of (bitwise?) operation combining the rectangle and the image below.
The way to manually overcome this would be easy enough allowing the user to select on the fly a different (lighter) fill colour, but I was wondering if this could be somehow automated by means of some sort of (bitwise?) operation combining the rectangle and the image below.