[Re-land] Add SPIR-V FragmentShader API to painting.dart (flutter#28208)

[Re-land] Add SPIR-V FragmentShader API to painting.dart

- Add a SPIR-V FragmentShader interface in painting.dart
- Create end to end pixel tests for ops supported by the SPIR-V to SkSL transpiler
- The end to end tests also test the c++ fragment shader implementation

Co-authored-by: Christopher Crawford <[email protected]>

BUILD.gn

@@ -132,6 +132,9 @@ group("flutter") {
       "//flutter/flow:flow_unittests",
       "//flutter/fml:fml_unittests",
       "//flutter/lib/spirv/test/exception_shaders:spirv_compile_exception_shaders",
+      "//flutter/lib/spirv/test/general_shaders:spirv_compile_general_shaders",
+      "//flutter/lib/spirv/test/supported_glsl_op_shaders:spirv_compile_supported_glsl_shaders",
+      "//flutter/lib/spirv/test/supported_op_shaders:spirv_compile_supported_op_shaders",
       "//flutter/lib/ui:ui_unittests",
       "//flutter/runtime:no_dart_plugin_registrant_unittests",
       "//flutter/runtime:runtime_unittests",

ci/analyze.sh

@@ -30,6 +30,7 @@ function follow_links() (
 SCRIPT_DIR=$(follow_links "$(dirname -- "${BASH_SOURCE[0]}")")
 SRC_DIR="$(cd "$SCRIPT_DIR/../.."; pwd -P)"
 FLUTTER_DIR="$SRC_DIR/flutter"
+SKY_ENGINE_DIR="$SRC_DIR/out/host_debug_unopt/gen/dart-pkg/sky_engine"
 DART_BIN="$SRC_DIR/out/host_debug_unopt/dart-sdk/bin"
 DART="$DART_BIN/dart"
 
@@ -46,7 +47,8 @@ echo "Using dart from $DART_BIN"
 "$DART" --version
 echo ""
 
-"$DART" analyze "$FLUTTER_DIR/lib/ui"
+(cd $SKY_ENGINE_DIR && "$DART" pub get --offline)
+"$DART" analyze "$SKY_ENGINE_DIR/lib/ui/ui.dart"
 
 "$DART" analyze "$FLUTTER_DIR/lib/spirv"
 

ci/licenses_golden/licenses_flutter

@@ -358,6 +358,8 @@ FILE: ../../../flutter/lib/ui/painting/color_filter.cc
 FILE: ../../../flutter/lib/ui/painting/color_filter.h
 FILE: ../../../flutter/lib/ui/painting/engine_layer.cc
 FILE: ../../../flutter/lib/ui/painting/engine_layer.h
+FILE: ../../../flutter/lib/ui/painting/fragment_shader.cc
+FILE: ../../../flutter/lib/ui/painting/fragment_shader.h
 FILE: ../../../flutter/lib/ui/painting/gradient.cc
 FILE: ../../../flutter/lib/ui/painting/gradient.h
 FILE: ../../../flutter/lib/ui/painting/image.cc

ci/licenses_golden/tool_signature

@@ -1,2 +1,2 @@
-Signature: 2b08c736bc3af2c5d770099c53112c83
+Signature: e892e715f8184778851c5efcb6a1323a
 

lib/snapshot/libraries.json

@@ -146,6 +146,9 @@
         "uri": "../../../third_party/dart/sdk/lib/typed_data/typed_data.dart",
         "patches": "../../../third_party/dart/sdk/lib/_internal/vm/lib/typed_data_patch.dart"
       },
+      "_spirv": {
+        "uri": "../../lib/spirv/lib/spirv.dart"
+      },
       "ui": {
         "uri": "../../lib/ui/ui.dart"
       },

lib/snapshot/libraries.yaml

@@ -146,6 +146,9 @@ flutter:
       uri: "../../../third_party/dart/sdk/lib/typed_data/typed_data.dart"
       patches: "../../../third_party/dart/sdk/lib/_internal/vm/lib/typed_data_patch.dart"
 
+    _spirv:
+      uri: "../../lib/spirv/lib/spirv.dart"
+
     ui:
       uri: "../../lib/ui/ui.dart"
 

lib/spirv/README.md

@@ -33,13 +33,40 @@ Support for textures, control flow, and structured types is planned, but not cur
 
 ## Testing
 
-## Exception Tests
+### Exception Tests
 
 These tests rely on the `.spvasm` (SPIR-V Assembly)  and `.glsl` files contained under `test/exception_shaders` in this directory. They are compiled to binary SPIR-V using `spirv-asm`, from the SwiftShader dependency. They are tested by testing/dart/spirv_exception_test.dart as part of the normal suite of dart tests. The purpose of these tests is to exercise every explicit failure path for shader transpilation. Each `glsl` or `spvasm` file should include a comment describing the failure that it is testing. The given files should be valid apart from the single failure case they are testing.
 
-## Pixel Tests
+To test the exception tests directly: `./testing/run_tests.py --type dart --dart-filter spirv_exception_test.dart`
 
-Pixel test are not yet checked in, and should run as part of unit-testing for each implementation of `dart:ui`. These tests aim to validate the correctness of transpilation to each target language. Each shader should render the color green #00FF00 for a correct transpilation, and any other color for failure. They will be a combination of `.spvasm` files and more-readable GLSL files that are compiled to SPIR-V via `glslang`, provided by the SwiftShader dependency. Information for pixel tests will be expanded in a follow-up PR.
+### Pixel Tests
 
-These tests will be able to be run alone by executing `./ui_unittests` in the build-output directory.
+Pixel tests should run as part of unit-testing for each implementation of `dart:ui`. Currently, FragmentShader is only supported in C++. These tests aim to validate the correctness of transpilation to each target language. Each shader should render the color green for a correct transpilation, and any other color for failure. They will be a GLSL files that are compiled to SPIR-V via `shaderc`. Therefor, the `fragColor` should resolve to `vec4(0.0, 1.0, 0.0, 1.0)`
+for all tests.
 
+In each test, the uniform `a` is initialized with the value of 1.0.
+This is important so that expressions are not simplified during GLSL to SPIR-V compilation, which may result in the removal of the op being tested.
+
+To test the pixel tests directly: `./testing/run_tests.py --type dart --dart-filter fragment_shader_test.dart`
+
+#### A Note on Test Isolation
+
+Even the simplest GLSL program tests several instructions, so no test us completely isolated
+to a single op. Also, some of the GLSL 450 op tests will use addition in subtraction, along with the
+actual op being tested. However, the GLSL program for each test file is kept as simple as possible,
+to satisfy these conditions: pass if the op works, and fail if the op does not work. In some tests,
+it is sufficient to only call the GLSL op once, while other may need more calls to more completelty
+test the op. Many ops support scalars, vectors, or a combination as parameters. Most tests default
+to using scalars as params, but vec2, vec3, and vec4 parameters are also tested.
+
+- vec2 is tested as a paramter in glsl_op_normalize.glsl
+- vec3 is tested as a parameter in glsl_op_cross.glsl
+- vec4 is tested as a parameter in glsl_op_length.glsl
+
+### Adding New Tests
+
+To add a new test, add a glsl (fragment shader tests) or spvasm (spirv exception tests) src file to a `lib/spirv/test/` subfolder, and add the file as a source to the corresponding `BUILD.gn`.
+
+- New files in `exception_shaders` are automatically tested in `testing/dart/spirv_exception_test`.
+- New files in `supported_op_shaders` and `supported_glsl_op_shaders` are automatically tested in `testing/dart/fragment_shader_test`.
+- New files in `general_shaders` are not automatically tested and must add a new manual test case in `testing/dart/fragment_shader_test`.

lib/spirv/lib/src/constants.dart

@@ -34,6 +34,14 @@ const int _decorationLocation = 30;
 // Explicitly supported builtin types
 const int _builtinFragCoord = 15;
 
+// Ops that have no semantic meaning in output and can be safely ignored
+const int _opSource = 3;
+const int _opSourceExtension = 4;
+const int _opName = 5;
+const int _opMemberName = 6;
+const int _opString = 7;
+const int _opLine = 8;
+
 // Supported instructions
 const int _opExtInstImport = 11;
 const int _opExtInst = 12;
@@ -43,17 +51,21 @@ const int _opExecutionMode = 16;
 const int _opCapability = 17;
 const int _opTypeVoid = 19;
 const int _opTypeBool = 20;
+const int _opTypeInt = 21;
 const int _opTypeFloat = 22;
 const int _opTypeVector = 23;
 const int _opTypeMatrix = 24;
 const int _opTypePointer = 32;
 const int _opTypeFunction = 33;
+const int _opConstantTrue = 41;
+const int _opConstantFalse = 42;
 const int _opConstant = 43;
 const int _opConstantComposite = 44;
 const int _opFunction = 54;
 const int _opFunctionParameter = 55;
 const int _opFunctionEnd = 56;
 const int _opFunctionCall = 57;
+const int _opFUnordNotEqual = 183;
 const int _opVariable = 59;
 const int _opLoad = 61;
 const int _opStore = 62;
@@ -62,6 +74,8 @@ const int _opDecorate = 71;
 const int _opVectorShuffle = 79;
 const int _opCompositeConstruct = 80;
 const int _opCompositeExtract = 81;
+const int _opConvertFToS = 110;
+const int _opConvertSToF = 111;
 const int _opFNegate = 127;
 const int _opFAdd = 129;
 const int _opFSub = 131;
@@ -74,6 +88,7 @@ const int _opVectorTimesMatrix = 144;
 const int _opMatrixTimesVector = 145;
 const int _opMatrixTimesMatrix = 146;
 const int _opDot = 148;
+const int _opSelect = 169;
 const int _opLabel = 248;
 const int _opReturn = 253;
 const int _opReturnValue = 254;
@@ -85,7 +100,6 @@ const int _opReturnValue = 254;
 const String _glslStd450 = 'GLSL.std.450';
 
 // Supported GLSL ops
-const int _glslStd450Trunc = 3;
 const int _glslStd450FAbs = 4;
 const int _glslStd450FSign = 6;
 const int _glslStd450Floor = 8;
@@ -121,7 +135,6 @@ const int _glslStd450FaceForward = 70;
 const int _glslStd450Reflect = 71;
 
 const Map<int, String> _glslStd450OpNames = <int, String>{
-  _glslStd450Trunc: 'trunc',
   _glslStd450FAbs: 'abs',
   _glslStd450FSign: 'sign',
   _glslStd450Floor: 'floor',
@@ -158,7 +171,6 @@ const Map<int, String> _glslStd450OpNames = <int, String>{
 };
 
 const Map<int, int> _glslStd450OpArgc = <int, int>{
-  _glslStd450Trunc: 1,
   _glslStd450FAbs: 1,
   _glslStd450FSign: 1,
   _glslStd450Floor: 1,
@@ -174,7 +186,7 @@ const Map<int, int> _glslStd450OpArgc = <int, int>{
   _glslStd450Atan: 1,
   _glslStd450Atan2: 2,
   _glslStd450Pow: 2,
-  _glslStd450Exp: 2,
+  _glslStd450Exp: 1,
   _glslStd450Log: 1,
   _glslStd450Exp2: 1,
   _glslStd450Log2: 1,