On Fri, 16 Sep 2016 06:04:09 -0500, Robby Findler <[email protected]> wrote:
>You could draw into a bitmap and then have on-paint draw that bitmap, too. > >Robby Yes. "Double buffering" with an off-screen bitmap is the best way to minimize redrawing. However, it also should be pointed out that the DC has a clipping region. When a region is set, drawing will occur only within the region's boundaries - any pixels outside the region will be preserved. https://docs.racket-lang.org/draw/region_.html?q=region https://docs.racket-lang.org/draw/dc___.html?q=region#%28meth._%28%28%28lib._racket%2Fdraw..rkt%29._dc~3c~25~3e%29._set-clipping-region%29%29 https://docs.racket-lang.org/gui/canvas___.html?q=canvas#%28meth._%28%28%28lib._mred%2Fmain..rkt%29._canvas~3c~25~3e%29._get-dc%29%29 George -- You received this message because you are subscribed to the Google Groups "Racket Users" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. For more options, visit https://groups.google.com/d/optout.
