1543621 - WebGL is rendered as upside down on android

Status: RESOLVED FIXED

(Core :: Graphics: WebRender, defect)

Description

[Sotaro Ikeda [:sotaro]]

On WebGL, a rotation info is delivered by GeckoSurfaceTexture. It is not handled yet with WebRender.

Bug 1507076 is related.

Comment 1

[Sotaro Ikeda [:sotaro]]

SurfaceTexture is expected to be used with SurfaceTexture.getTransformMatrix(). With the matrix, SurfaceTexture's gl texture worked as bottom left origin. But current WebRender does not use the getTransformMatrix(). Then the gl texture worked as top left origin. Then WebGL rendering was flipped. Then Bug 1507076 is related.

On android, GLConsumer::computeTransformMatrix() calculate a matrix for the getTransformMatrix(). If there is no transform, it jut multiply y-flip.
http://androidxref.com/9.0.0_r3/xref/frameworks/native/libs/gui/GLConsumer.cpp#866
https://developer.android.com/reference/android/graphics/SurfaceTexture

Comment 2

[Sotaro Ikeda [:sotaro]]

On android, SurfaceTextureImage is created as gl::OriginPos::BottomLeft. The origin is not handled by WebRender. But it does not cause rendering problem, since getTransformMatrix() is also not handled and texture origin effectively worked as gl::OriginPos::TopLeft.

https://searchfox.org/mozilla-central/source/dom/media/platforms/android/RemoteDataDecoder.cpp#283

Comment 3

[Sotaro Ikeda [:sotaro]]

On android WebGL, y-flip is handled by nsDisplayCanvas::CreateWebRenderCommands(). But with WebRender, the getTransformMatrix() is not handled yet. Gl texture of SurfaceTexture is rendered as top left origin, then texture rendering result became y-flipped.
https://searchfox.org/mozilla-central/source/layout/generic/nsHTMLCanvasFrame.cpp#178

Comment 4

[Sotaro Ikeda [:sotaro]]

If SurfaceTexture usage is only Video decoding and WebGL, it is not necessary to handle getTransformMatrix() for now.

Long term solution is going to be handled by Bug 1507076.

Comment 5

[Sotaro Ikeda [:sotaro]]

Attachment: Bug 1543621 - Move Y flip handling to AsyncImagePipelineManager::ApplyAsyncImageForPipeline()

Comment 6

[Sotaro Ikeda [:sotaro]]

https://treeherder.mozilla.org/#/jobs?repo=try&revision=65d78f55d2ee2705eae80a3fc7e32556ccac3fff

Comment 7

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/b2a8685b55e1
Move Y flip handling to AsyncImagePipelineManager::ApplyAsyncImageForPipeline() r=nical

Comment 8

[Andrei Ciure[:aciure]]

https://hg.mozilla.org/mozilla-central/rev/b2a8685b55e1