> why does the framebuffer need to be consulted when the background is a known, > solid color?
the underlying operation is just plain draw, and drawing text corresponds to drawing solid black through the font (as a mask) onto the destination image. if the mask has fractional alpha, that requires reading the destination image to do the mixing. the destination image might in this case be a known solid color, but in general it need not be. you could address this by adding a fourth argument to memdraw and then using it inside devdraw to specify a "read from this instead of the destination" image. it's not clear to me that this is worth the bother, and it makes the interface less clean. you'd also have to redo libframe to use stringbg everywhere. russ
