No rendering on Android

[carrott2]

No rendering on Android (tested on Snapdragon 8 sGen3), AdrenoVK gives some warnings about unknown struct types

I/FlutterAnglePlugin(26021): Android version is greater than or equal to 28. 
I/angle_android_graphic_jni(26021): OpenGL initialized: Vendor=Google Inc. (Qualcomm), Renderer=ANGLE (Qualcomm, Vulkan 1.3.128 (Adreno (TM) 735 (0x43030B00)), Qualcomm Technologies Inc. Adreno Vulkan Driver-512.762.1), Version=OpenGL ES 3.1.0 (ANGLE 2.1.24882 git hash: 51d2561b5a6b) 
I/FlutterAnglePlugin(26021): Using Android Virtual Device. 
I/FlutterAnglePlugin(26021): Android version is greater than or equal to 28. 
I/FlutterAnglePlugin(26021): ANGLE OpenGL initialized successfully 
I/FlutterAnglePlugin(26021): Using Android Virtual Device. 
I/FlutterAnglePlugin(26021): Android version is greater than or equal to 28. 
I/angle_android_graphic_jni(26021): Created window surface from Surface: 0x422 
I/FlutterAnglePlugin(26021): Created ANGLE texture using SurfaceProducer API 
I/FlutterAnglePlugin(26021): Created ANGLE texture 1218x2709 
I/AdrenoVK-0(26021): Unknown struct with type 0x3b9bb469 provided to vkBindImageMemory2 
W/qdgralloc(26021): getInterlacedFlag: getMetaData returned 3, defaulting to interlaced_flag = 0 
I/AdrenoVK-0(26021): Unknown tessellation state create type: 0 
I/AdrenoVK-0(26021): Unknown struct with type 0x3b9bb469 provided to vkBindImageMemory2 
W/qdgralloc(26021): getInterlacedFlag: getMetaData returned 3, defaulting to interlaced_flag = 0 
I/AdrenoVK-0(26021): Unknown struct with type 0x3b9bb469 provided to vkBindImageMemory2 
W/qdgralloc(26021): getInterlacedFlag: getMetaData returned 3, defaulting to interlaced_flag = 0 
I/AdrenoVK-0(26021): Unknown struct with type 0x3b9bb469 provided to vkBindImageMemory2 
W/qdgralloc(26021): getInterlacedFlag: getMetaData returned 3, defaulting to interlaced_flag = 0 
I/AdrenoVK-0(26021): Unknown struct with type 0x3b9bb469 provided to vkBindImageMemory2 
W/qdgralloc(26021): getInterlacedFlag: getMetaData returned 3, defaulting to interlaced_flag = 0

blacklisting for angle ( https://github.com/Knightro63/flutter_angle/blob/main/flutter_angle/android/src/main/java/org/fluttergl/flutter_angle/FlutterAnglePlugin.java "isBlacklistedForAngle" ) for my device fixed the issue.
Same issue also occurs on other devices like on the Mediatek Dimensity 7025.

[carrott2]

Also, is there a specific version of angle this plugin relies on? was trying to add prebuilt binaries for arm64 but using prebuilt binaries for example from chrome don't seem to work (eg. libGLESv2.dll, libEGL.dll)

[Knightro63]

Hi @carrott2,

The .dll files should only be for Windows and it uses ANGLE from probably 2024. Android uses ANGLE or OpenGL depending on what device you are trying to use. The black listed devices are not all on there because another user was trying to use a huawei and received the error.

For Android it should automatically create the binaries in the .cxx folder from the CMake file and the .so files in debug and release.

If you want to try without ANGLE you can do angle.init(false,false);. This will run on OpenGL for Android.

[carrott2]

Thanks for the response, for "arm64" I meant windows arm64 binaries.

[Knightro63]

Hi @carrott2,

It should work on Windows with arm devices. I am currently using it with my Lenovo X-Elite Snapdragon chip.

[carrott2]

I see, then I must have done something wrong when compiling it (with github actions)

"\windows\flutter\ephemeral.plugin_symlinks\flutter_angle\windows\bin\lib\libGLESv2.dll.lib : warning LNK4272: library machine type 'x64' conflicts with target machine type 'ARM64'"

[Knightro63]

Hi @carrott2,

I see. I will need to make them again. I think my computer is running it through an emulator. you can try this flutter build windows --target-platform=windows-x64
I wont be able to fix it until this weekend. Sorry for the issue.

[rkasza-github]

Adding a precise root-cause analysis, in case it helps — I hit the identical symptom (scene fully initializes, render loop runs, isSceneReady, model + textures load, no GL/shader errors, but the Texture widget stays blank) on a Mali-G76 device (Xiaomi Redmi Note 10, Android 13), i.e. a different GPU than the Adreno report above — so this is not GPU-specific, it's the Android ANGLE present path in 0.4.0 (worked on 0.3.9).

The frame is rendered but never presented on Android. Using three_js on top of flutter_angle 0.4.0, I added on-device logging inside the render loop (getIntegerv(GL_FRAMEBUFFER_BINDING)):

• After activateTexture(texture) the bound FBO is 0 (the surface).
• After renderer.render() the content is drawn, but nothing ever swaps/signals the frame, so the surface is never composited.

Tracing lib/desktop/angle.dart:

• createTexture() on Android does _useSurface = true and texture.surfaceId = Pointer.fromAddress(result['surface'] as int? ?? 0).
• But the native FlutterGLTexture ANGLE constructors (both the SurfaceProducer and SurfaceTextureEntry paths in createTextureAngleImplementation) set surfaceHandle = 0, and the response returns "surface" = surfaceHandle → surfaceId ends up nullptr.
• So in updateTexture(): if (_useSurface && texture.surfaceId != nullptr) eglSwapBuffers(...) is never true (surfaceId is nullptr), the else branch just binds FBO 0 with no swap, and if (!Platform.isAndroid) textureFrameAvailable(...) skips the frame signal on Android.
• The native plugin (FlutterAnglePlugin.java / OpenGLManager.java) has no textureFrameAvailable method case and no eglSwapBuffers/present anywhere.

Net effect: on the Android ANGLE path, nothing ever calls eglSwapBuffers or signals a new frame, so the producer/surface is never updated → blank. iOS presents fine because _useSurface + a valid IOSurface surfaceId makes the eglSwapBuffers branch run.

This lines up with #53 (the 0.4.0 changes around NativeArray / the Android present path). A fix presumably needs the native side to return the real EGL surface handle (so the Dart eglSwapBuffers branch runs) or to present/signal the frame on Android. Happy to test a fix against three_js if useful.