Bug 234321 – [GPU Process] Can't getImageData on canvas larger than 4096x4096

• Status: RESOLVED
• Resolution: FIXED
• Component: New Bugs

[Myles C. Maxfield]

[GPU Process] Can't getImageData on canvas larger than 4096x4096

[Myles C. Maxfield]

Created attachment 447170 [details]
Patch

[Myles C. Maxfield]

<rdar://problem/83575501>

[Myles C. Maxfield]

Looks like iOS needs a different policy than macOS.

[Myles C. Maxfield]

static inline size_t maxCanvasArea()
{
    if (maxCanvasAreaForTesting)
        return *maxCanvasAreaForTesting;

    // Firefox limits width/height to 32767 pixels, but slows down dramatically before it
    // reaches that limit. We limit by area instead, giving us larger maximum dimensions,
    // in exchange for a smaller maximum canvas size. The maximum canvas size is in device pixels.
#if PLATFORM(IOS_FAMILY)
    return 4096 * 4096;
#else
    return 16384 * 16384;
#endif
}

[Myles C. Maxfield]

Created attachment 447408 [details]
Patch

[Tim Horton]

Comment on attachment 447408 [details]
Patch

View in context: https://bugs.webkit.org/attachment.cgi?id=447408&action=review

> Source/WebCore/ChangeLog:9
> +        We already have a policy about how big canvases can be. Simply export tat policy

“tat”

[Myles C. Maxfield]

Looks like window.internals.setMaxCanvasPixelMemory() doesn’t make it to the GPU Process 🤔

[Myles C. Maxfield]

Created attachment 448651 [details]
Patch for committing

[Myles C. Maxfield]

Created attachment 448652 [details]
Patch for committing

[Myles C. Maxfield]

Committed r287805 (245857@trunk): <https://commits.webkit.org/245857@trunk>