Re: potential bug in graphics:draw-image

[bouma@PURDUE.EDU]

       image at the same offsets. This leaves some ugly residue. Is there
       something that I don't understand or is this a bug. I was under the
       impression that graphics:draw-image simply did a bitblt. Am I wrong?
               Jeff

       (defun BUG ()
        (let ((c (graphics:with-output-to-bitmap (t)
                   (graphics:draw-circle 100 100 100))))
          (dw:with-own-coordinates (t :erase-window t :enable-output-recording 
      nil)
            (graphics:draw-image c 0 0 :alu :flip)
            (graphics:draw-image c 10 10 :alu :flip)
            (graphics:draw-image c 10 10 :alu :flip)
            (graphics:draw-image c 0 0 :alu :flip)))
        (read-char)
        t)

  Well, it is doing something other than just a bitblt, because if you
  replace the calls to draw-image with ones to bitblt, it works fine!
  Draw-image appears to be doing an AND before it does the XOR. I would
  consider this a bug.

Bill <bouma@cs.purdue.edu>