Time redraw of an image

slow-redraw.red

Red [needs: view]               ;) run as `red --cli ...` to eliminate GUI console influence!

img: make image! 2000x1000      ;) need a big enough image
system/view/auto-sync?: no      ;) disable auto-update so we can profile it
view [
    panel [
        base font-color black "CHASE THE MOUSE AROUND" 1000x500 img
        all-over on-over [
            t0: now/precise
            face/image/(10x10): random white      ;) update the image
            show face/parent                      ;) then force redraw
            ; show face                             ;) this one reports false time 0-1 ms while being just as slow!
            print [to float! 1000.0 * difference now/precise t0 "ms to redraw"]
        ]
    ]
]