when i resize the window,context be cleared?

[kkxlkkxllb]

when i resize the browser window, why the canvas context be cleared?

[soulwire]

Hi. Thanks for trying Sketch!

There's a flag called autoclear (which defaults to true), so if you construct the Sketch like below the canvas won't be cleared automatically (see the wiki for more info)

Sketch.create({
    autoclear: false,
    setup: ...
    draw: ...
});

[kkxlkkxllb]

i found the real reason, eventMap's resize was in conflict with window resize event, so when i resize the browser window, it trigger sketch.js resize always.

[soulwire]

Yep, that's the expected behavior when you have fullscreen set to true since it needs to always fit the window. Resizing a canvas will aways clear the pixels and reset the state. If you don't want this to happen, you'll need to set fullscreen to false, specify a width and height and resize yourself manually.

Sketch.create({
    autoclear: false,
    fullscreen: false,
    width: 800,
    height: 600,
    ...
});

[kkxlkkxllb]

I have set fullscreen to true and also height & width, but it just clear the canvas when i resize browser window.
I test it on your "drawing" example both chrome and safari. same behavior.

Sketch.create({
            fullscreen: false,
            height: 600,
            width: 600,
            container: document.getElementById( 'container' ),
            autoclear: false,
           ...
});

[soulwire]

You're right, I see what you mean now. The latest commit should have fixed it (here's an example.)

Thanks for spotting this!

[kkxlkkxllb]

Great work, thanks!