OffscreenCanvas is not defined

[gqgs]

• I'm submitting a ... [x] bug report [ ] feature request [ ] question about the decisions made in the repository [ ] question about how to use this project

https://github.com/HighCWu/waifu2x-tfjs/blob/2a31b376d5d2f43c9890d335251cce9259bd6828/src/lib/predictor.ts#L7

This call breaks in browsers without OffscreenCanvas support. https://caniuse.com/offscreencanvas

It seems the script still works fine without the call to tf_webgl.setWebGLContext.

[HighCWu]

• I'm submitting a ... [x] bug report [ ] feature request [ ] question about the decisions made in the repository [ ] question about how to use this project

https://github.com/HighCWu/waifu2x-tfjs/blob/2a31b376d5d2f43c9890d335251cce9259bd6828/src/lib/predictor.ts#L7

This call breaks in browsers without OffscreenCanvas support. https://caniuse.com/offscreencanvas

It seems the script still works fine without the call to tf_webgl.setWebGLContext.

OffscreenCanvas can be used for Web worker background processing to avoid UI freezes. This is a new feature of newer browsers. I recommend upgrading the browser. Maybe I will try to add a compatibility check in a future version .

[gqgs]

@HighCWu Thanks for the reply. A possible hotfix would be just checking if the browser has support in that section.

if (typeof OffscreenCanvas !== "undefined") {
    const canvas = new OffscreenCanvas(320, 200);
    let context = canvas.getContext('webgl2');
    if (!context) {
        context = canvas.getContext('webgl');
        if (context)
            tf_webgl.setWebGLContext(1, context);
    }
    else {
        tf_webgl.setWebGLContext(2, context);
    }
}

The UI will freeze if it is undetected but for now it might be better than the script not working at all. Unfortunately upgrading the browser it's not a option for a lot of people as you can see in the caniuse link above. Firefox, Safari and IE still don't support OffscreenCanvas in their latest versions.

[HighCWu]

@HighCWu Thanks for the reply. A possible hotfix would be just checking if the browser has support in that section.

if (typeof OffscreenCanvas !== "undefined") {
    const canvas = new OffscreenCanvas(320, 200);
    let context = canvas.getContext('webgl2');
    if (!context) {
        context = canvas.getContext('webgl');
        if (context)
            tf_webgl.setWebGLContext(1, context);
    }
    else {
        tf_webgl.setWebGLContext(2, context);
    }
}

The UI will freeze if it is undetected but for now it might be better than the script not working at all.
Unfortunately upgrading the browser it's not a option for a lot of people as you can see in the caniuse link above.
Firefox, Safari and IE still don't support OffscreenCanvas in their latest versions.

Thanks. I'll try it later.

[gqgs]

cdbe616fadcc2a16c454c517d0fb961e8239bc74