Shader compilation error

[gerkol]

Hi, I'm trying to run my app using flutter pi on yocto linux (rbpi3). I created the build as follows using flutter 2.10.2

1. flutter build bundle

~/snap/flutter/common/flutter/bin/cache/dart-sdk/bin/dart \
            --verbose \
            --disable-analytics \
            --disable-dart-dev ~/snap/flutter/common/flutter/bin/cache/artifacts/engine/linux-x64/frontend_server.dart.snapshot \
            --sdk-root ~/snap/flutter/common/flutter/bin/cache/artifacts/engine/common/flutter_patched_sdk_product/ \
            --target=flutter \
            --no-print-incremental-dependencies \
            -Ddart.vm.profile=false \
            -Ddart.vm.product=true \
            --aot --tfa \
            --packages .dart_tool/package_config.json \
            --output-dill .dart_tool/flutter_build/*/app.dill \
            --depfile .dart_tool/flutter_build/*/kernel_snapshot.d \
            file:./lib/main.dart

 ./gen_snapshot_linux_x64_release \
            --snapshot_kind=app-aot-elf \
            --elf=libapp.so \
            --strip \
            .dart_tool/flutter_build/*/app.dill

The app is executing using flutter-pi --release ./flutter-assets. However, I get the following error

Shader compilation error
------------------------
   1    uniform half3 u_0_edgeArray_S1[4];in half4 vcolor_S0;half4 ConvexPoly_S1(half4 _input) {
   2    half _1_alpha = 1.0;half _2_edge;(_2_edge = dot(u_0_edgeArray_S1[0], half3(float3(sk_FragCoord.xy, 1.0))));(_2_edge = half(((_2_edge >= 0.5) ? 1.0 : 0.0)));(_1_alpha *= _2_edge);(_2_edge = dot(u_0_edgeArray_S1[1], half3(float3(sk_FragCoord.xy, 1.0))));(_2_edge = half(((_2_edge >= 0.5) ? 1.0 : 0.0)));(_1_alpha *= _2_edge);(_2_edge = dot(u_0_edgeArray_S1[2], half3(float3(sk_FragCoord.xy, 1.0))));(_2_edge = half(((_2_edge >= 0.5) ? 1.0 : 0.0)));(_1_alpha *= _2_edge);(_2_edge = dot(u_0_edgeArray_S1[3], half3(float3(sk_FragCoord.xy, 1.0))));(_2_edge = half(((_2_edge >= 0.5) ? 1.0 : 0.0)));(_1_alpha *= _2_edge);return (_input * _1_alpha);}
   3    
   4    void main() {// Stage 0, QuadPerEdgeAAGeometryProcessor
   5    half4 outputColor_S0;outputColor_S0 = vcolor_S0;const half4 outputCoverage_S0 = half4(1);half4 output_S1;output_S1 = ConvexPoly_S1(outputCoverage_S0);{ // Xfer Processor: Porter Duff Shader
   6    sk_FragColor = blend_src(outputColor_S0, _dstColor);sk_FragColor = output_S1 * sk_FragColor + (half4(1.0) - output_S1) * _dstColor;}}
Errors:
error: 6: unknown identifier '_dstColor'
error: 6: unknown identifier '_dstColor'
2 errors

What could be a possible cause for that?

[ardera]

I think that's most likely a flutter bug, it's best you open an issue on the flutter repo

[gerkol]

Yes probably. I'll do that.

Is there any way to get access to the logs produced by the flutter app when executing it with flutter-pi?

[ardera]

All logs should be dumped to stdout directly. Maybe there's flags to enable/disable specific logging, but I guess the flutter engineers will tell you that when you report the issue

[gerkol]

Is there a way to pass the flag --enable-software-rendering when executing with flutter-pi?

[ardera]

yeah flutter-pi /path/to/assetbundle --enable-software-rendering