Moved high bitrate texture tests to engine #179906

gaaclarke · 2025-12-15T22:25:12Z

This adds a few goldens where skia supports the file format. This is a bit more scalable and direct than managing integration tests.

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I signed the CLA.
I listed at least one issue that this PR fixes in the description above.
I updated/added relevant documentation (doc comments with ///).
I added new tests to check the change I am making, or this PR is test-exempt.
I followed the breaking change policy and added Data Driven Fixes where supported.
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… tests.

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Code Review

This pull request successfully moves the high bitrate texture tests from a devicelab integration test to a more direct and scalable engine unit test. The changes involve removing the old integration test suite and adding a new test file within the engine, along with the necessary shader files and build configurations. My feedback focuses on improving the maintainability of the new test code by refactoring duplicated logic and removing an unused import.

gemini-code-assist · 2025-12-15T22:27:52Z

engine/src/flutter/testing/dart/fragment_shader_test.dart

 import 'dart:async';
 import 'dart:collection';
 import 'dart:convert' as convert;
+import 'dart:math' as math;


This dart:math import appears to be unused in the file. It's good practice to remove unused imports to keep the code clean.

gemini-code-assist · 2025-12-15T22:27:52Z

engine/src/flutter/testing/dart/high_bitrate_texture_test.dart

+void main() async {
+  final ImageComparer comparer = await ImageComparer.create();
+
+  test('decodeImageFromPixels with RGBA Float32', () async {
+    const int dimension = 1024;
+    final Image image = await _createRGBA32FloatImage(dimension, dimension);
+    final Image shaderImage = await _drawIntoImage(image);
+
+    final ByteData data = (await shaderImage.toByteData())!;
+
+    // Check top left is Red
+    int offset = 0;
+    expect(data.getUint8(offset), 255, reason: 'Top left Red');
+    expect(data.getUint8(offset + 1), 0, reason: 'Top left Green');
+    expect(data.getUint8(offset + 2), 0, reason: 'Top left Blue');
+    expect(data.getUint8(offset + 3), 255, reason: 'Top left Alpha');
+
+    // Check center is Black
+    offset = ((dimension ~/ 2) * dimension + (dimension ~/ 2)) * 4;
+    expect(data.getUint8(offset), 0, reason: 'Center Red');
+    expect(data.getUint8(offset + 1), 0, reason: 'Center Green');
+    expect(data.getUint8(offset + 2), 0, reason: 'Center Blue');
+    expect(data.getUint8(offset + 3), 255, reason: 'Center Alpha');
+
+    await comparer.addGoldenImage(shaderImage, 'decode_image_from_pixels_rgba_float32.png');
+    image.dispose();
+  });
+
+  test('decodeImageFromPixels with R Float32', () async {
+    if (!impellerEnabled) {
+      print('Skipped for Skia');
+      return;
+    }
+    const int dimension = 1024;
+    final Image image = await _createR32FloatImage(dimension, dimension);
+    final Image shaderImage = await _drawIntoImage(image);
+
+    final ByteData data = (await shaderImage.toByteData())!;
+
+    // Check top left is Red
+    int offset = 0;
+    expect(data.getUint8(offset), 255, reason: 'Top left Red');
+    expect(data.getUint8(offset + 1), 0, reason: 'Top left Green');
+    expect(data.getUint8(offset + 2), 0, reason: 'Top left Blue');
+    expect(data.getUint8(offset + 3), 255, reason: 'Top left Alpha');
+
+    // Check center is Black
+    offset = ((dimension ~/ 2) * dimension + (dimension ~/ 2)) * 4;
+    expect(data.getUint8(offset), 0, reason: 'Center Red');
+    expect(data.getUint8(offset + 1), 0, reason: 'Center Green');
+    expect(data.getUint8(offset + 2), 0, reason: 'Center Blue');
+    expect(data.getUint8(offset + 3), 255, reason: 'Center Alpha');
+
+    image.dispose();
+  });
+
+  test('Picture.toImageSync with rgbaFloat32', () async {
+    const int dimension = 1024;
+    final Image image = await _drawWithCircleShader(
+      dimension,
+      dimension,
+      TargetPixelFormat.rgbaFloat32,
+    );
+    final Image shaderImage = await _drawWithShader(image);
+
+    final ByteData data = (await shaderImage.toByteData())!;
+
+    // Check top left is Black (outside circle, d > 0 -> vec3(0.0))
+    int offset = 0;
+    expect(data.getUint8(offset), 0, reason: 'Top left Red');
+    expect(data.getUint8(offset + 1), 0, reason: 'Top left Green');
+    expect(data.getUint8(offset + 2), 0, reason: 'Top left Blue');
+    expect(data.getUint8(offset + 3), 255, reason: 'Top left Alpha');
+
+    // Check center is White (inside circle, d <= 0 -> vec3(1.0))
+    offset = ((dimension ~/ 2) * dimension + (dimension ~/ 2)) * 4;
+    expect(data.getUint8(offset), 255, reason: 'Center Red');
+    expect(data.getUint8(offset + 1), 255, reason: 'Center Green');
+    expect(data.getUint8(offset + 2), 255, reason: 'Center Blue');
+    expect(data.getUint8(offset + 3), 255, reason: 'Center Alpha');
+
+    await comparer.addGoldenImage(shaderImage, 'picture_to_image_rgba_float32.png');
+    image.dispose();
+  });
+
+  test('Picture.toImageSync with rFloat32', () async {
+    if (!impellerEnabled) {
+      print('Skipped for Skia');
+      return;
+    }
+    const int dimension = 1024;
+    final Image image = await _drawWithCircleShader(
+      dimension,
+      dimension,
+      TargetPixelFormat.rFloat32,
+    );
+    final Image shaderImage = await _drawWithShader(image);
+
+    final ByteData data = (await shaderImage.toByteData())!;
+
+    // Check top left is Black
+    int offset = 0;
+    expect(data.getUint8(offset), 0, reason: 'Top left Red');
+    expect(data.getUint8(offset + 1), 0, reason: 'Top left Green');
+    expect(data.getUint8(offset + 2), 0, reason: 'Top left Blue');
+    expect(data.getUint8(offset + 3), 255, reason: 'Top left Alpha');
+
+    // Check center is White
+    offset = ((dimension ~/ 2) * dimension + (dimension ~/ 2)) * 4;
+    expect(data.getUint8(offset), 255, reason: 'Center Red');
+    expect(data.getUint8(offset + 1), 255, reason: 'Center Green');
+    expect(data.getUint8(offset + 2), 255, reason: 'Center Blue');
+    expect(data.getUint8(offset + 3), 255, reason: 'Center Alpha');
+
+    image.dispose();
+  });
+}


There's some code duplication within the test bodies. The pixel checking logic is repeated in the decodeImageFromPixels tests, and also in the Picture.toImageSync tests. You can extract these into helper functions to make the tests cleaner and more maintainable. This suggestion also presumes the refactoring of _createRGBA32FloatImage and _createR32FloatImage into a single _createSdfImage function, which I've suggested in another comment.

void main() async { final ImageComparer comparer = await ImageComparer.create(); void checkDirectSdfRender(ByteData data, int dimension) { // Check top left is Red int offset = 0; expect(data.getUint8(offset), 255, reason: 'Top left Red'); expect(data.getUint8(offset + 1), 0, reason: 'Top left Green'); expect(data.getUint8(offset + 2), 0, reason: 'Top left Blue'); expect(data.getUint8(offset + 3), 255, reason: 'Top left Alpha'); // Check center is Black offset = ((dimension ~/ 2) * dimension + (dimension ~/ 2)) * 4; expect(data.getUint8(offset), 0, reason: 'Center Red'); expect(data.getUint8(offset + 1), 0, reason: 'Center Green'); expect(data.getUint8(offset + 2), 0, reason: 'Center Blue'); expect(data.getUint8(offset + 3), 255, reason: 'Center Alpha'); } void checkVisualizedSdfRender(ByteData data, int dimension) { // Check top left is Black (outside circle, d > 0 -> vec3(0.0)) int offset = 0; expect(data.getUint8(offset), 0, reason: 'Top left Red'); expect(data.getUint8(offset + 1), 0, reason: 'Top left Green'); expect(data.getUint8(offset + 2), 0, reason: 'Top left Blue'); expect(data.getUint8(offset + 3), 255, reason: 'Top left Alpha'); // Check center is White (inside circle, d <= 0 -> vec3(1.0)) offset = ((dimension ~/ 2) * dimension + (dimension ~/ 2)) * 4; expect(data.getUint8(offset), 255, reason: 'Center Red'); expect(data.getUint8(offset + 1), 255, reason: 'Center Green'); expect(data.getUint8(offset + 2), 255, reason: 'Center Blue'); expect(data.getUint8(offset + 3), 255, reason: 'Center Alpha'); } test('decodeImageFromPixels with RGBA Float32', () async { const int dimension = 1024; final Image image = await _createSdfImage(dimension, dimension, PixelFormat.rgbaFloat32); final Image shaderImage = await _drawIntoImage(image); final ByteData data = (await shaderImage.toByteData())!; checkDirectSdfRender(data, dimension); await comparer.addGoldenImage(shaderImage, 'decode_image_from_pixels_rgba_float32.png'); image.dispose(); }); test('decodeImageFromPixels with R Float32', () async { if (!impellerEnabled) { print('Skipped for Skia'); return; } const int dimension = 1024; final Image image = await _createSdfImage(dimension, dimension, PixelFormat.rFloat32); final Image shaderImage = await _drawIntoImage(image); final ByteData data = (await shaderImage.toByteData())!; checkDirectSdfRender(data, dimension); image.dispose(); }); test('Picture.toImageSync with rgbaFloat32', () async { const int dimension = 1024; final Image image = await _drawWithCircleShader( dimension, dimension, TargetPixelFormat.rgbaFloat32, ); final Image shaderImage = await _drawWithShader(image); final ByteData data = (await shaderImage.toByteData())!; checkVisualizedSdfRender(data, dimension); await comparer.addGoldenImage(shaderImage, 'picture_to_image_rgba_float32.png'); image.dispose(); }); test('Picture.toImageSync with rFloat32', () async { if (!impellerEnabled) { print('Skipped for Skia'); return; } const int dimension = 1024; final Image image = await _drawWithCircleShader( dimension, dimension, TargetPixelFormat.rFloat32, ); final Image shaderImage = await _drawWithShader(image); final ByteData data = (await shaderImage.toByteData())!; checkVisualizedSdfRender(data, dimension); image.dispose(); }); }

gemini-code-assist · 2025-12-15T22:27:52Z

engine/src/flutter/testing/dart/high_bitrate_texture_test.dart

+Future<Image> _createRGBA32FloatImage(int width, int height) async {
+  final double radius = width / 4.0;
+  final floats = List<double>.filled(width * height * 4, 0.0);
+  for (var i = 0; i < height; ++i) {
+    for (var j = 0; j < width; ++j) {
+      double x = j.toDouble();
+      double y = i.toDouble();
+      x -= width / 2.0;
+      y -= height / 2.0;
+      final double length = math.sqrt(x * x + y * y);
+      final int idx = i * width * 4 + j * 4;
+      floats[idx + 0] = length - radius;
+      floats[idx + 1] = 0.0;
+      floats[idx + 2] = 0.0;
+      floats[idx + 3] = 1.0;
+    }
+  }
+  final floatList = Float32List.fromList(floats);
+  final intList = Uint8List.view(floatList.buffer);
+  final completer = Completer<Image>();
+  decodeImageFromPixels(
+    intList,
+    width,
+    height,
+    PixelFormat.rgbaFloat32,
+    targetFormat: TargetPixelFormat.rgbaFloat32,
+    (Image image) {
+      completer.complete(image);
+    },
+  );
+  return completer.future;
+}
+
+Future<Image> _createR32FloatImage(int width, int height) async {
+  final double radius = width / 4.0;
+  final floats = List<double>.filled(width * height, 0.0);
+  for (var i = 0; i < height; ++i) {
+    for (var j = 0; j < width; ++j) {
+      double x = j.toDouble();
+      double y = i.toDouble();
+      x -= width / 2.0;
+      y -= height / 2.0;
+      final double length = math.sqrt(x * x + y * y);
+      final int idx = i * width + j;
+      floats[idx] = length - radius;
+    }
+  }
+  final floatList = Float32List.fromList(floats);
+  final intList = Uint8List.view(floatList.buffer);
+  final completer = Completer<Image>();
+  decodeImageFromPixels(
+    intList,
+    width,
+    height,
+    PixelFormat.rFloat32,
+    targetFormat: TargetPixelFormat.rFloat32,
+    (Image image) {
+      completer.complete(image);
+    },
+  );
+  return completer.future;
+}


The functions _createRGBA32FloatImage and _createR32FloatImage are very similar. To improve maintainability and reduce code duplication, you can merge them into a single function that takes PixelFormat as a parameter.

Future<Image> _createSdfImage(int width, int height, PixelFormat format) { final double radius = width / 4.0; final bool isRgba = format == PixelFormat.rgbaFloat32; final int componentCount = isRgba ? 4 : 1; final List<double> floats = List<double>.filled(width * height * componentCount, 0.0); for (int i = 0; i < height; ++i) { for (int j = 0; j < width; ++j) { double x = j.toDouble(); double y = i.toDouble(); x -= width / 2.0; y -= height / 2.0; final double length = math.sqrt(x * x + y * y); final int idx = (i * width + j) * componentCount; floats[idx] = length - radius; if (isRgba) { floats[idx + 1] = 0.0; floats[idx + 2] = 0.0; floats[idx + 3] = 1.0; } } } final Float32List floatList = Float32List.fromList(floats); final Uint8List intList = Uint8List.view(floatList.buffer); final Completer<Image> completer = Completer<Image>(); decodeImageFromPixels( intList, width, height, format, targetFormat: isRgba ? TargetPixelFormat.rgbaFloat32 : TargetPixelFormat.rFloat32, (Image image) { completer.complete(image); }, ); return completer.future; }

gaaclarke added 10 commits December 15, 2025 10:11

Migrated high bitrate tests from devicelab test to engine integration…

d184d19

… tests.

removed fragprogram

4c03ad9

only skip r32

5a93516

made sure they weren't skipped

0fdfe69

moved to some manual asserts in pixels

cf6c704

moved to own file

23d0bd6

brought over gpu tests

05488bc

fixed naming

8eff044

deleted devicelab tests

ef3ad02

format

3ca07af

github-actions bot added the engine flutter/engine related. See also e: labels. label Dec 15, 2025

gemini-code-assist bot reviewed Dec 15, 2025

View reviewed changes

gaaclarke and others added 3 commits December 15, 2025 15:37

Merge branch 'master' into high-bitrate-engine-tests

568db1b

Merge branch 'master' into high-bitrate-engine-tests

ffe02e9

removed straggler

19119d6

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Moved high bitrate texture tests to engine #179906

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gaaclarke commented Dec 15, 2025

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