How to constrain area redrawing to clip region?

[AndyObtiva]

Hi,

I built this game, Glimmer Tetris

It runs fast with a basic 2D look (each block is a path).

When I attempt to add a simulated bevel-block 3D look via 4 extra polygons per block where each polygon is a figure of multiple line calls done under a single path (similar to the Glimmer Tetris built with SWT)...

Area redrawing slows down to a crawl!

I ensured that only a single redraw is happening per movement of the Tetris tetromino blocks.

My question is: I could probably optimize performance by asking the area to redraw only the blocks that changed instead of the entire playfield.

How do I do that with libui? Is that option available? The only thing I saw is queueRedrawAll, which redraws everything.

Is that what save and restore are all about? Initial saving... restoring the whole area, making a small change, and then saving again? Does that improve performance?

If clipped redrawing is not available, this would be a great performance optimization feature to have I think.

[AndyObtiva]

BTW, I solved the slowdown problem by dividing the area into many tiny little areas layed out with a vertical box of horizontal boxes (grid did not work as it did not show multiple areas when nested underneath it, so that is another issue). That way, on every change, only changed Tetris blocks got redrawn, making area redraws happen much faster.