Crash after second call of makeImageSnapshot() on canvasRef

[cmkf01]

Hi everyone,

Hoping to resolve a breaking problem. My thoughts up front are that the canvasRef becomes stale but unclear how to resolve this.

Situation:
The app renders an SkImage, zooms and pans with a gesture handler, then takes a snapshot based on user input bounding box coordinates. It then renders the snapshots on a new screen.
This works perfectly once only. However, when the state is cleared and new bounds are created, the app crashes on trying to take a new snapshot of the canvas.

Screenshot here:
https://github.com/Shopify/react-native-skia/assets/127895219/2ef1d7da-a15f-42b3-8046-045ef54889d6

Repo here:
https://github.com/cmkf01/skia_issue_example

Looking forward to resolving this, thank-you in advance.

[cmkf01]

Hey, I hope I have provided enough information to this problem. Perhaps someone on the react-native-skia team could take a look for me? It could be a really obvious mistake in with my code, but may be an bug with RNSkia for all I know... thanks again in advance!

[wcandillon]

Thanks for providing a repository for this. Unfortunately I was not able to reproduce it on Android. I assume that you use Android right?
May I ask if the code example could be made smaller? I found the example to be somewhat convoluted. Removing parts of it may also help to find what causes the issue.

[wcandillon]

Would it be possible to refactor your code to try to isolate the issue? I've noticed that you use SkiaView and also with a child which I think is undefined behaviour. I should also mention that the SkiaView API is deprecated.

[cmkf01]

Thanks @wcandillon again.

Can I clarify - I can remove the SkiaView easily but do you mean that the .makeImageSnapshot() call is also deprecated. If so, what is your suggestion for replacing it with .makeImageFromView() given that does not accept a Rect argument? Is there a workaround that allows capturing only a selection of a viewRef - perhaps making an offscreen canvas?

[cmkf01]

@wcandillon - I have significantly simplified the app (https://github.com/cmkf01/skia_issue_example) without resolution - same crash type in the logcat. Does anything jump out to you as a potential culprit?

[wcandillon]

Super nice, I'm not able to reproduce the issue based on your example app, can you provide instructions on how to reproduce the issue? Is it easy to reproduce?

[cmkf01]

The user draws a number of Paths around the area of an image to make a snapshot, then presses a button to call makeImageSnapshot() of the canvasRef passing the bounds of the Path as the Rect argument, this adds the SkImage snapshot to state.

My experience is that on Android 8.0 is breaks after ~50 snapshots in this simple example, on Android 9.0 is breaks after ~200 snapshots with the same segmentation fault (logcat output in previous reply). It happens 100% of the time in my attempts and happens much earlier, e.g. after the second snapshot when I start to add features back into the app.

Thanks for your patience.

[wcandillon]

Is the issue the number of times we call makeImageSnapshot or is the issue the number of images present in the snapshot you take?

…

On Thu, Nov 9, 2023 at 3:02 PM cmkf01 ***@***.***> wrote: The user draws a number of Paths around the area of an image to make a snapshot, then presses a button to call makeImageSnapshot() of the canvasRef passing the bounds of the Path as the Rect argument, this adds the SkImage snapshot to state. My experience is that on Android 8.0 is breaks after ~50 snapshots in this simple example, on Android 9.0 is breaks after ~200 snapshots with the same segmentation fault (logcat output in previous reply). It happens 100% of the time in my attempts and happens much earlier, e.g. after the second snapshot when I start to add features back into the app. Thanks for your patience. — Reply to this email directly, view it on GitHub <#1858 (reply in thread)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AACKXVVOF7CBFZNKCDYMRLTYDTPAVAVCNFSM6AAAAAA5AE2OGOVHI2DSMVQWIX3LMV43SRDJONRXK43TNFXW4Q3PNVWWK3TUHM3TKMRSHA3TG> . You are receiving this because you were mentioned.Message ID: ***@***.*** com>

[cmkf01]

Good question, I think it is the number of images rather than calling the function but, as you see in the screen capture in the original post, that was only two images