1507076 - Add mIgnoreTransform handling for SurfaceTextureHost with WebRender

Status: RESOLVED WORKSFORME

(Core :: Graphics: WebRender, enhancement, P3)

Description

[Sotaro Ikeda [:sotaro]]

This bug is created by Bug 1499255 Comment 8.

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.

In 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 WebRender, the getTransformMatrix() is not handled yet. Then it worked as mIgnoreTransform == true.

Comment 3

[Sotaro Ikeda [:sotaro]]

On android, SurfaceTextureImage is created as gl::OriginPos::BottomLeft, though it is not handled by WebRender yet.
https://searchfox.org/mozilla-central/source/dom/media/platforms/android/RemoteDataDecoder.cpp#283

Comment 4

[Sotaro Ikeda [:sotaro]]

On android, SurfaceTexture is used only for video decoding and WebGL, if android frameworks as expected, it seems not necessary to handle getTransformMatrix().

But if we use SurfaceTexture for camera frame rendering, it might cause the problem. Further, there might be a device that change rotation at ANativeWindow side.

Comment 5

[Kris Taeleman (:ktaeleman)]

@sotaro: What issues is this currently causing? Or is this a performance issue?

Comment 6

[Sotaro Ikeda [:sotaro]]

For now, we do not have a issue by it. Then we could close this bug for now. When the problem happens, this bug could be re-opened.

This is not a performance issue. When transform is set by android platform, image is just rendered as rotated.