How to make a partial screen redraw in html5 target?


Now html5 redrawing much CPU time, even if the screen has not changed or has changed quite a small area. This is not good.
How to redraw only a small area of the screen? Or several areas. Suppose even that we know what areas need to be redrawn.

Did no one cares about the performance?

Do you have any performance issues? I’ve made several games using OpenFl, and never got performance issues.
Also you can try use -Ddom renderer, which will render to DOM elements instead of one big canvas.

I use webgl. -Ddom renderer slower webgl.
While I run on a powerful computer with no performance issues.
But old computers and phones insufficient performance.
8 fps and full CPU load when the screen does not change it’s probably not what the user expects to see. Full CPU load on the phones is critical for its battery.

It is classic game loop for Open GL / Web GL to clear screen than redraw everything.

Maybe you have too much display objects? Can you show some example or even show screenshot?

You can cache them as bitmap for cases when screen not changing.

Another thing - maybe you doing some computations, and low fps issue is not related to renderer at all?