testing/dart/compositing_test.dart - mirrors/engine - Git at Google

 // Copyright 2013 The Flutter Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.

 import 'dart:typed_data';
 import 'dart:ui';

 import 'package:litetest/litetest.dart';

 void main() {
   test('Scene.toImageSync succeeds', () async {
     final PictureRecorder recorder = PictureRecorder();
     final Canvas canvas = Canvas(recorder);
     const Color color = Color(0xFF123456);
     canvas.drawPaint(Paint()..color = color);
     final Picture picture = recorder.endRecording();
     final SceneBuilder builder = SceneBuilder();
     builder.pushOffset(10, 10);
     builder.addPicture(const Offset(5, 5), picture);
     final Scene scene = builder.build();

     final Image image = scene.toImageSync(6, 8);
     picture.dispose();
     scene.dispose();

     expect(image.width, 6);
     expect(image.height, 8);

     final ByteData? data = await image.toByteData();

     expect(data, isNotNull);
     expect(data!.lengthInBytes, 6 * 8 * 4);
     expect(data.buffer.asUint8List()[0], 0x12);
     expect(data.buffer.asUint8List()[1], 0x34);
     expect(data.buffer.asUint8List()[2], 0x56);
     expect(data.buffer.asUint8List()[3], 0xFF);
   });

   test('Scene.toImageSync succeeds with texture layer', () async {
     final SceneBuilder builder = SceneBuilder();
     builder.pushOffset(10, 10);
     builder.addTexture(0, width: 10, height: 10);

     final Scene scene = builder.build();
     final Image image = scene.toImageSync(20, 20);
     scene.dispose();

     expect(image.width, 20);
     expect(image.height, 20);

     final ByteData? data = await image.toByteData();

     expect(data, isNotNull);
     expect(data!.lengthInBytes, 20 * 20 * 4);
     expect(data.buffer.asUint8List()[0], 0);
     expect(data.buffer.asUint8List()[1], 0);
     expect(data.buffer.asUint8List()[2], 0);
     expect(data.buffer.asUint8List()[3], 0);
   });

   test('addPicture with disposed picture does not crash', () {
     bool assertsEnabled = false;
     assert(() {
       assertsEnabled = true;
       return true;
     }());
     final PictureRecorder recorder = PictureRecorder();
     final Canvas canvas = Canvas(recorder);
     canvas.drawPaint(Paint());
     final Picture picture = recorder.endRecording();
     picture.dispose();

     assert(picture.debugDisposed);

     final SceneBuilder builder = SceneBuilder();
     if (assertsEnabled) {
       expect(
         () => builder.addPicture(Offset.zero, picture),
         throwsA(isInstanceOf<AssertionError>()),
       );
     } else {
       builder.addPicture(Offset.zero, picture);
     }

     final Scene scene = builder.build();
     scene.dispose();
   });

   test('pushTransform validates the matrix', () {
     final SceneBuilder builder = SceneBuilder();
     final Float64List matrix4 = Float64List.fromList(<double>[
       1, 0, 0, 0,
       0, 1, 0, 0,
       0, 0, 1, 0,
       0, 0, 0, 1,
     ]);
     expect(builder.pushTransform(matrix4), isNotNull);

     final Float64List matrix4WrongLength = Float64List.fromList(<double>[
       1, 0, 0, 0,
       0, 1, 0,
       0, 0, 1, 0,
       0, 0, 0,
     ]);
     assert(() {
       expect(
         () => builder.pushTransform(matrix4WrongLength),
         expectAssertion,
       );
       return true;
     }());

     final Float64List matrix4NaN = Float64List.fromList(<double>[
       1, 0, 0, 0,
       0, 1, 0, 0,
       0, 0, 1, 0,
       0, 0, 0, double.nan,
     ]);
     assert(() {
       expect(
         () => builder.pushTransform(matrix4NaN),
         expectAssertion,
       );
       return true;
     }());

     final Float64List matrix4Infinity = Float64List.fromList(<double>[
       1, 0, 0, 0,
       0, 1, 0, 0,
       0, 0, 1, 0,
       0, 0, 0, double.infinity,
     ]);
     assert(() {
       expect(
         () => builder.pushTransform(matrix4Infinity),
         expectAssertion,
       );
       return true;
     }());
   });

   test('SceneBuilder accepts typed layers', () {
     final SceneBuilder builder1 = SceneBuilder();
     final OpacityEngineLayer opacity1 = builder1.pushOpacity(100);
     expect(opacity1, isNotNull);
     builder1.pop();
     builder1.build();

     final SceneBuilder builder2 = SceneBuilder();
     final OpacityEngineLayer opacity2 = builder2.pushOpacity(200, oldLayer: opacity1);
     expect(opacity2, isNotNull);
     builder2.pop();
     builder2.build();
   });

   // Attempts to use the same layer first as `oldLayer` then in `addRetained`.
   void testPushThenIllegalRetain(_TestNoSharingFunction pushFunction) {
     final SceneBuilder builder1 = SceneBuilder();
     final EngineLayer layer = pushFunction(builder1, null);
     builder1.pop();
     builder1.build();

     final SceneBuilder builder2 = SceneBuilder();
     pushFunction(builder2, layer);
     builder2.pop();
     assert(() {
       try {
         builder2.addRetained(layer);
         fail('Expected addRetained to throw AssertionError but it returned successully');
       } on AssertionError catch (error) {
         expect(error.toString(), contains('The layer is already being used'));
       }
       return true;
     }());
     builder2.build();
   }

   // Attempts to use the same layer first in `addRetained` then as `oldLayer`.
   void testAddRetainedThenIllegalPush(_TestNoSharingFunction pushFunction) {
     final SceneBuilder builder1 = SceneBuilder();
     final EngineLayer layer = pushFunction(builder1, null);
     builder1.pop();
     builder1.build();

     final SceneBuilder builder2 = SceneBuilder();
     builder2.addRetained(layer);
     assert(() {
       try {
         pushFunction(builder2, layer);
         fail('Expected push to throw AssertionError but it returned successully');
       } on AssertionError catch (error) {
         expect(error.toString(), contains('The layer is already being used'));
       }
       return true;
     }());
     builder2.build();
   }

   // Attempts to retain the same layer twice in the same scene.
   void testDoubleAddRetained(_TestNoSharingFunction pushFunction) {
     final SceneBuilder builder1 = SceneBuilder();
     final EngineLayer layer = pushFunction(builder1, null);
     builder1.pop();
     builder1.build();

     final SceneBuilder builder2 = SceneBuilder();
     builder2.addRetained(layer);
     assert(() {
       try {
         builder2.addRetained(layer);
         fail('Expected second addRetained to throw AssertionError but it returned successully');
       } on AssertionError catch (error) {
         expect(error.toString(), contains('The layer is already being used'));
       }
       return true;
     }());
     builder2.build();
   }

   // Attempts to use the same layer as `oldLayer` twice in the same scene.
   void testPushOldLayerTwice(_TestNoSharingFunction pushFunction) {
     final SceneBuilder builder1 = SceneBuilder();
     final EngineLayer layer = pushFunction(builder1, null);
     builder1.pop();
     builder1.build();

     final SceneBuilder builder2 = SceneBuilder();
     pushFunction(builder2, layer);
     assert(() {
       try {
         pushFunction(builder2, layer);
         fail('Expected push to throw AssertionError but it returned successully');
       } on AssertionError catch (error) {
         expect(error.toString(), contains('was previously used as oldLayer'));
       }
       return true;
     }());
     builder2.build();
   }

   // Attempts to use a child of a retained layer as an `oldLayer`.
   void testPushChildLayerOfRetainedLayer(_TestNoSharingFunction pushFunction) {
     final SceneBuilder builder1 = SceneBuilder();
     final EngineLayer layer = pushFunction(builder1, null);
     final OpacityEngineLayer childLayer = builder1.pushOpacity(123);
     builder1.pop();
     builder1.pop();
     builder1.build();

     final SceneBuilder builder2 = SceneBuilder();
     builder2.addRetained(layer);
     assert(() {
       try {
         builder2.pushOpacity(321, oldLayer: childLayer);
         fail('Expected pushOpacity to throw AssertionError but it returned successully');
       } on AssertionError catch (error) {
         expect(error.toString(), contains('The layer is already being used'));
       }
       return true;
     }());
     builder2.build();
   }

   // Attempts to retain a layer whose child is already used as `oldLayer` elsewhere in the scene.
   void testRetainParentLayerOfPushedChild(_TestNoSharingFunction pushFunction) {
     final SceneBuilder builder1 = SceneBuilder();
     final EngineLayer layer = pushFunction(builder1, null);
     final OpacityEngineLayer childLayer = builder1.pushOpacity(123);
     builder1.pop();
     builder1.pop();
     builder1.build();

     final SceneBuilder builder2 = SceneBuilder();
     builder2.pushOpacity(234, oldLayer: childLayer);
     builder2.pop();
     assert(() {
       try {
         builder2.addRetained(layer);
         fail('Expected addRetained to throw AssertionError but it returned successully');
       } on AssertionError catch (error) {
         expect(error.toString(), contains('The layer is already being used'));
       }
       return true;
     }());
     builder2.build();
   }

   // Attempts to retain a layer that has been used as `oldLayer` in a previous frame.
   void testRetainOldLayer(_TestNoSharingFunction pushFunction) {
     final SceneBuilder builder1 = SceneBuilder();
     final EngineLayer layer = pushFunction(builder1, null);
     builder1.pop();
     builder1.build();

     final SceneBuilder builder2 = SceneBuilder();
     pushFunction(builder2, layer);
     builder2.pop();
     assert(() {
       try {
         final SceneBuilder builder3 = SceneBuilder();
         builder3.addRetained(layer);
         fail('Expected addRetained to throw AssertionError but it returned successully');
       } on AssertionError catch (error) {
         expect(error.toString(), contains('was previously used as oldLayer'));
       }
       return true;
     }());
     builder2.build();
   }

   // Attempts to pass layer as `oldLayer` that has been used as `oldLayer` in a previous frame.
   void testPushOldLayer(_TestNoSharingFunction pushFunction) {
     final SceneBuilder builder1 = SceneBuilder();
     final EngineLayer layer = pushFunction(builder1, null);
     builder1.pop();
     builder1.build();

     final SceneBuilder builder2 = SceneBuilder();
     pushFunction(builder2, layer);
     builder2.pop();
     assert(() {
       try {
         final SceneBuilder builder3 = SceneBuilder();
         pushFunction(builder3, layer);
         fail('Expected addRetained to throw AssertionError but it returned successully');
       } on AssertionError catch (error) {
         expect(error.toString(), contains('was previously used as oldLayer'));
       }
       return true;
     }());
     builder2.build();
   }

   // Attempts to retain a parent of a layer used as `oldLayer` in a previous frame.
   void testRetainsParentOfOldLayer(_TestNoSharingFunction pushFunction) {
     final SceneBuilder builder1 = SceneBuilder();
     final EngineLayer parentLayer = pushFunction(builder1, null);
     final OpacityEngineLayer childLayer = builder1.pushOpacity(123);
     builder1.pop();
     builder1.pop();
     builder1.build();

     final SceneBuilder builder2 = SceneBuilder();
     builder2.pushOpacity(321, oldLayer: childLayer);
     builder2.pop();
     assert(() {
       try {
         final SceneBuilder builder3 = SceneBuilder();
         builder3.addRetained(parentLayer);
         fail('Expected addRetained to throw AssertionError but it returned successully');
       } on AssertionError catch (error) {
         expect(error.toString(), contains('was previously used as oldLayer'));
       }
       return true;
     }());
     builder2.build();
   }

   void testNoSharing(_TestNoSharingFunction pushFunction) {
     testPushThenIllegalRetain(pushFunction);
     testAddRetainedThenIllegalPush(pushFunction);
     testDoubleAddRetained(pushFunction);
     testPushOldLayerTwice(pushFunction);
     testPushChildLayerOfRetainedLayer(pushFunction);
     testRetainParentLayerOfPushedChild(pushFunction);
     testRetainOldLayer(pushFunction);
     testPushOldLayer(pushFunction);
     testRetainsParentOfOldLayer(pushFunction);
   }

   test('SceneBuilder does not share a layer between addRetained and push*', () {
     testNoSharing((SceneBuilder builder, EngineLayer? oldLayer) {
       return builder.pushOffset(0, 0, oldLayer: oldLayer as OffsetEngineLayer?);
     });
     testNoSharing((SceneBuilder builder, EngineLayer? oldLayer) {
       return builder.pushTransform(Float64List(16), oldLayer: oldLayer as TransformEngineLayer?);
     });
     testNoSharing((SceneBuilder builder, EngineLayer? oldLayer) {
       return builder.pushClipRect(Rect.zero, oldLayer: oldLayer as ClipRectEngineLayer?);
     });
     testNoSharing((SceneBuilder builder, EngineLayer? oldLayer) {
       return builder.pushClipRRect(RRect.zero, oldLayer: oldLayer as ClipRRectEngineLayer?);
     });
     testNoSharing((SceneBuilder builder, EngineLayer? oldLayer) {
       return builder.pushClipPath(Path(), oldLayer: oldLayer as ClipPathEngineLayer?);
     });
     testNoSharing((SceneBuilder builder, EngineLayer? oldLayer) {
       return builder.pushOpacity(100, oldLayer: oldLayer as OpacityEngineLayer?);
     });
     testNoSharing((SceneBuilder builder, EngineLayer? oldLayer) {
       return builder.pushBackdropFilter(ImageFilter.blur(), oldLayer: oldLayer as BackdropFilterEngineLayer?);
     });
     testNoSharing((SceneBuilder builder, EngineLayer? oldLayer) {
       return builder.pushShaderMask(
         Gradient.radial(
           Offset.zero,
           10,
           const <Color>[Color.fromARGB(0, 0, 0, 0), Color.fromARGB(0, 255, 255, 255)],
         ),
         Rect.zero,
         BlendMode.color,
         oldLayer: oldLayer as ShaderMaskEngineLayer?,
       );
     });
     testNoSharing((SceneBuilder builder, EngineLayer? oldLayer) {
       return builder.pushColorFilter(
         const ColorFilter.mode(
           Color.fromARGB(0, 0, 0, 0),
           BlendMode.color,
         ),
         oldLayer: oldLayer as ColorFilterEngineLayer?,
       );
     });
     testNoSharing((SceneBuilder builder, EngineLayer? oldLayer) {
       return builder.pushColorFilter(
         const ColorFilter.matrix(<double>[
           1, 0, 0, 0, 0,
           0, 1, 0, 0, 0,
           0, 0, 1, 0, 0,
           0, 0, 0, 1, 0,
         ]),
         oldLayer: oldLayer as ColorFilterEngineLayer?,
       );
     });
     testNoSharing((SceneBuilder builder, EngineLayer? oldLayer) {
       return builder.pushColorFilter(
         const ColorFilter.linearToSrgbGamma(),
         oldLayer: oldLayer as ColorFilterEngineLayer?,
       );
     });
     testNoSharing((SceneBuilder builder, EngineLayer? oldLayer) {
       return builder.pushColorFilter(
         const ColorFilter.srgbToLinearGamma(),
         oldLayer: oldLayer as ColorFilterEngineLayer?,
       );
     });
     testNoSharing((SceneBuilder builder, EngineLayer? oldLayer) {
       return builder.pushImageFilter(
         ImageFilter.blur(sigmaX: 10.0, sigmaY: 10.0),
         oldLayer: oldLayer as ImageFilterEngineLayer?,
       );
     });
     testNoSharing((SceneBuilder builder, EngineLayer? oldLayer) {
       return builder.pushImageFilter(
         ImageFilter.dilate(radiusX: 10.0, radiusY: 10.0),
         oldLayer: oldLayer as ImageFilterEngineLayer?,
       );
     });
     testNoSharing((SceneBuilder builder, EngineLayer? oldLayer) {
       return builder.pushImageFilter(
         ImageFilter.erode(radiusX: 10.0, radiusY: 10.0),
         oldLayer: oldLayer as ImageFilterEngineLayer?,
       );
     });
     testNoSharing((SceneBuilder builder, EngineLayer? oldLayer) {
       return builder.pushImageFilter(
         ImageFilter.matrix(Float64List.fromList(<double>[
           1, 0, 0, 0,
           0, 1, 0, 0,
           0, 0, 1, 0,
           0, 0, 0, 1,
         ])),
         oldLayer: oldLayer as ImageFilterEngineLayer?,
       );
     });
   });
 }

 typedef _TestNoSharingFunction = EngineLayer Function(SceneBuilder builder, EngineLayer? oldLayer);
	// Copyright 2013 The Flutter Authors. All rights reserved.
	// Use of this source code is governed by a BSD-style license that can be
	// found in the LICENSE file.

	import 'dart:typed_data';
	import 'dart:ui';

	import 'package:litetest/litetest.dart';

	void main() {
	test('Scene.toImageSync succeeds', () async {
	final PictureRecorder recorder = PictureRecorder();
	final Canvas canvas = Canvas(recorder);
	const Color color = Color(0xFF123456);
	canvas.drawPaint(Paint()..color = color);
	final Picture picture = recorder.endRecording();
	final SceneBuilder builder = SceneBuilder();
	builder.pushOffset(10, 10);
	builder.addPicture(const Offset(5, 5), picture);
	final Scene scene = builder.build();

	final Image image = scene.toImageSync(6, 8);
	picture.dispose();
	scene.dispose();

	expect(image.width, 6);
	expect(image.height, 8);

	final ByteData? data = await image.toByteData();

	expect(data, isNotNull);
	expect(data!.lengthInBytes, 6 * 8 * 4);
	expect(data.buffer.asUint8List()[0], 0x12);
	expect(data.buffer.asUint8List()[1], 0x34);
	expect(data.buffer.asUint8List()[2], 0x56);
	expect(data.buffer.asUint8List()[3], 0xFF);
	});

	test('Scene.toImageSync succeeds with texture layer', () async {
	final SceneBuilder builder = SceneBuilder();
	builder.pushOffset(10, 10);
	builder.addTexture(0, width: 10, height: 10);

	final Scene scene = builder.build();
	final Image image = scene.toImageSync(20, 20);
	scene.dispose();

	expect(image.width, 20);
	expect(image.height, 20);

	final ByteData? data = await image.toByteData();

	expect(data, isNotNull);
	expect(data!.lengthInBytes, 20 * 20 * 4);
	expect(data.buffer.asUint8List()[0], 0);
	expect(data.buffer.asUint8List()[1], 0);
	expect(data.buffer.asUint8List()[2], 0);
	expect(data.buffer.asUint8List()[3], 0);
	});

	test('addPicture with disposed picture does not crash', () {
	bool assertsEnabled = false;
	assert(() {
	assertsEnabled = true;
	return true;
	}());
	final PictureRecorder recorder = PictureRecorder();
	final Canvas canvas = Canvas(recorder);
	canvas.drawPaint(Paint());
	final Picture picture = recorder.endRecording();
	picture.dispose();

	assert(picture.debugDisposed);

	final SceneBuilder builder = SceneBuilder();
	if (assertsEnabled) {
	expect(
	() => builder.addPicture(Offset.zero, picture),
	throwsA(isInstanceOf<AssertionError>()),
	);
	} else {
	builder.addPicture(Offset.zero, picture);
	}

	final Scene scene = builder.build();
	scene.dispose();
	});

	test('pushTransform validates the matrix', () {
	final SceneBuilder builder = SceneBuilder();
	final Float64List matrix4 = Float64List.fromList(<double>[
	1, 0, 0, 0,
	0, 1, 0, 0,
	0, 0, 1, 0,
	0, 0, 0, 1,
	]);
	expect(builder.pushTransform(matrix4), isNotNull);

	final Float64List matrix4WrongLength = Float64List.fromList(<double>[
	1, 0, 0, 0,
	0, 1, 0,
	0, 0, 1, 0,
	0, 0, 0,
	]);
	assert(() {
	expect(
	() => builder.pushTransform(matrix4WrongLength),
	expectAssertion,
	);
	return true;
	}());

	final Float64List matrix4NaN = Float64List.fromList(<double>[
	1, 0, 0, 0,
	0, 1, 0, 0,
	0, 0, 1, 0,
	0, 0, 0, double.nan,
	]);
	assert(() {
	expect(
	() => builder.pushTransform(matrix4NaN),
	expectAssertion,
	);
	return true;
	}());

	final Float64List matrix4Infinity = Float64List.fromList(<double>[
	1, 0, 0, 0,
	0, 1, 0, 0,
	0, 0, 1, 0,
	0, 0, 0, double.infinity,
	]);
	assert(() {
	expect(
	() => builder.pushTransform(matrix4Infinity),
	expectAssertion,
	);
	return true;
	}());
	});

	test('SceneBuilder accepts typed layers', () {
	final SceneBuilder builder1 = SceneBuilder();
	final OpacityEngineLayer opacity1 = builder1.pushOpacity(100);
	expect(opacity1, isNotNull);
	builder1.pop();
	builder1.build();

	final SceneBuilder builder2 = SceneBuilder();
	final OpacityEngineLayer opacity2 = builder2.pushOpacity(200, oldLayer: opacity1);
	expect(opacity2, isNotNull);
	builder2.pop();
	builder2.build();
	});

	// Attempts to use the same layer first as `oldLayer` then in `addRetained`.
	void testPushThenIllegalRetain(_TestNoSharingFunction pushFunction) {
	final SceneBuilder builder1 = SceneBuilder();
	final EngineLayer layer = pushFunction(builder1, null);
	builder1.pop();
	builder1.build();

	final SceneBuilder builder2 = SceneBuilder();
	pushFunction(builder2, layer);
	builder2.pop();
	assert(() {
	try {
	builder2.addRetained(layer);
	fail('Expected addRetained to throw AssertionError but it returned successully');
	} on AssertionError catch (error) {
	expect(error.toString(), contains('The layer is already being used'));
	}
	return true;
	}());
	builder2.build();
	}

	// Attempts to use the same layer first in `addRetained` then as `oldLayer`.
	void testAddRetainedThenIllegalPush(_TestNoSharingFunction pushFunction) {
	final SceneBuilder builder1 = SceneBuilder();
	final EngineLayer layer = pushFunction(builder1, null);
	builder1.pop();
	builder1.build();

	final SceneBuilder builder2 = SceneBuilder();
	builder2.addRetained(layer);
	assert(() {
	try {
	pushFunction(builder2, layer);
	fail('Expected push to throw AssertionError but it returned successully');
	} on AssertionError catch (error) {
	expect(error.toString(), contains('The layer is already being used'));
	}
	return true;
	}());
	builder2.build();
	}

	// Attempts to retain the same layer twice in the same scene.
	void testDoubleAddRetained(_TestNoSharingFunction pushFunction) {
	final SceneBuilder builder1 = SceneBuilder();
	final EngineLayer layer = pushFunction(builder1, null);
	builder1.pop();
	builder1.build();

	final SceneBuilder builder2 = SceneBuilder();
	builder2.addRetained(layer);
	assert(() {
	try {
	builder2.addRetained(layer);
	fail('Expected second addRetained to throw AssertionError but it returned successully');
	} on AssertionError catch (error) {
	expect(error.toString(), contains('The layer is already being used'));
	}
	return true;
	}());
	builder2.build();
	}

	// Attempts to use the same layer as `oldLayer` twice in the same scene.
	void testPushOldLayerTwice(_TestNoSharingFunction pushFunction) {
	final SceneBuilder builder1 = SceneBuilder();
	final EngineLayer layer = pushFunction(builder1, null);
	builder1.pop();
	builder1.build();

	final SceneBuilder builder2 = SceneBuilder();
	pushFunction(builder2, layer);
	assert(() {
	try {
	pushFunction(builder2, layer);
	fail('Expected push to throw AssertionError but it returned successully');
	} on AssertionError catch (error) {
	expect(error.toString(), contains('was previously used as oldLayer'));
	}
	return true;
	}());
	builder2.build();
	}

	// Attempts to use a child of a retained layer as an `oldLayer`.
	void testPushChildLayerOfRetainedLayer(_TestNoSharingFunction pushFunction) {
	final SceneBuilder builder1 = SceneBuilder();
	final EngineLayer layer = pushFunction(builder1, null);
	final OpacityEngineLayer childLayer = builder1.pushOpacity(123);
	builder1.pop();
	builder1.pop();
	builder1.build();

	final SceneBuilder builder2 = SceneBuilder();
	builder2.addRetained(layer);
	assert(() {
	try {
	builder2.pushOpacity(321, oldLayer: childLayer);
	fail('Expected pushOpacity to throw AssertionError but it returned successully');
	} on AssertionError catch (error) {
	expect(error.toString(), contains('The layer is already being used'));
	}
	return true;
	}());
	builder2.build();
	}

	// Attempts to retain a layer whose child is already used as `oldLayer` elsewhere in the scene.
	void testRetainParentLayerOfPushedChild(_TestNoSharingFunction pushFunction) {
	final SceneBuilder builder1 = SceneBuilder();
	final EngineLayer layer = pushFunction(builder1, null);
	final OpacityEngineLayer childLayer = builder1.pushOpacity(123);
	builder1.pop();
	builder1.pop();
	builder1.build();

	final SceneBuilder builder2 = SceneBuilder();
	builder2.pushOpacity(234, oldLayer: childLayer);
	builder2.pop();
	assert(() {
	try {
	builder2.addRetained(layer);
	fail('Expected addRetained to throw AssertionError but it returned successully');
	} on AssertionError catch (error) {
	expect(error.toString(), contains('The layer is already being used'));
	}
	return true;
	}());
	builder2.build();
	}

	// Attempts to retain a layer that has been used as `oldLayer` in a previous frame.
	void testRetainOldLayer(_TestNoSharingFunction pushFunction) {
	final SceneBuilder builder1 = SceneBuilder();
	final EngineLayer layer = pushFunction(builder1, null);
	builder1.pop();
	builder1.build();

	final SceneBuilder builder2 = SceneBuilder();
	pushFunction(builder2, layer);
	builder2.pop();
	assert(() {
	try {
	final SceneBuilder builder3 = SceneBuilder();
	builder3.addRetained(layer);
	fail('Expected addRetained to throw AssertionError but it returned successully');
	} on AssertionError catch (error) {
	expect(error.toString(), contains('was previously used as oldLayer'));
	}
	return true;
	}());
	builder2.build();
	}

	// Attempts to pass layer as `oldLayer` that has been used as `oldLayer` in a previous frame.
	void testPushOldLayer(_TestNoSharingFunction pushFunction) {
	final SceneBuilder builder1 = SceneBuilder();
	final EngineLayer layer = pushFunction(builder1, null);
	builder1.pop();
	builder1.build();

	final SceneBuilder builder2 = SceneBuilder();
	pushFunction(builder2, layer);
	builder2.pop();
	assert(() {
	try {
	final SceneBuilder builder3 = SceneBuilder();
	pushFunction(builder3, layer);
	fail('Expected addRetained to throw AssertionError but it returned successully');
	} on AssertionError catch (error) {
	expect(error.toString(), contains('was previously used as oldLayer'));
	}
	return true;
	}());
	builder2.build();
	}

	// Attempts to retain a parent of a layer used as `oldLayer` in a previous frame.
	void testRetainsParentOfOldLayer(_TestNoSharingFunction pushFunction) {
	final SceneBuilder builder1 = SceneBuilder();
	final EngineLayer parentLayer = pushFunction(builder1, null);
	final OpacityEngineLayer childLayer = builder1.pushOpacity(123);
	builder1.pop();
	builder1.pop();
	builder1.build();

	final SceneBuilder builder2 = SceneBuilder();
	builder2.pushOpacity(321, oldLayer: childLayer);
	builder2.pop();
	assert(() {
	try {
	final SceneBuilder builder3 = SceneBuilder();
	builder3.addRetained(parentLayer);
	fail('Expected addRetained to throw AssertionError but it returned successully');
	} on AssertionError catch (error) {
	expect(error.toString(), contains('was previously used as oldLayer'));
	}
	return true;
	}());
	builder2.build();
	}

	void testNoSharing(_TestNoSharingFunction pushFunction) {
	testPushThenIllegalRetain(pushFunction);
	testAddRetainedThenIllegalPush(pushFunction);
	testDoubleAddRetained(pushFunction);
	testPushOldLayerTwice(pushFunction);
	testPushChildLayerOfRetainedLayer(pushFunction);
	testRetainParentLayerOfPushedChild(pushFunction);
	testRetainOldLayer(pushFunction);
	testPushOldLayer(pushFunction);
	testRetainsParentOfOldLayer(pushFunction);
	}

	test('SceneBuilder does not share a layer between addRetained and push*', () {
	testNoSharing((SceneBuilder builder, EngineLayer? oldLayer) {
	return builder.pushOffset(0, 0, oldLayer: oldLayer as OffsetEngineLayer?);
	});
	testNoSharing((SceneBuilder builder, EngineLayer? oldLayer) {
	return builder.pushTransform(Float64List(16), oldLayer: oldLayer as TransformEngineLayer?);
	});
	testNoSharing((SceneBuilder builder, EngineLayer? oldLayer) {
	return builder.pushClipRect(Rect.zero, oldLayer: oldLayer as ClipRectEngineLayer?);
	});
	testNoSharing((SceneBuilder builder, EngineLayer? oldLayer) {
	return builder.pushClipRRect(RRect.zero, oldLayer: oldLayer as ClipRRectEngineLayer?);
	});
	testNoSharing((SceneBuilder builder, EngineLayer? oldLayer) {
	return builder.pushClipPath(Path(), oldLayer: oldLayer as ClipPathEngineLayer?);
	});
	testNoSharing((SceneBuilder builder, EngineLayer? oldLayer) {
	return builder.pushOpacity(100, oldLayer: oldLayer as OpacityEngineLayer?);
	});
	testNoSharing((SceneBuilder builder, EngineLayer? oldLayer) {
	return builder.pushBackdropFilter(ImageFilter.blur(), oldLayer: oldLayer as BackdropFilterEngineLayer?);
	});
	testNoSharing((SceneBuilder builder, EngineLayer? oldLayer) {
	return builder.pushShaderMask(
	Gradient.radial(
	Offset.zero,
	10,
	const <Color>[Color.fromARGB(0, 0, 0, 0), Color.fromARGB(0, 255, 255, 255)],
	),
	Rect.zero,
	BlendMode.color,
	oldLayer: oldLayer as ShaderMaskEngineLayer?,
	);
	});
	testNoSharing((SceneBuilder builder, EngineLayer? oldLayer) {
	return builder.pushColorFilter(
	const ColorFilter.mode(
	Color.fromARGB(0, 0, 0, 0),
	BlendMode.color,
	),
	oldLayer: oldLayer as ColorFilterEngineLayer?,
	);
	});
	testNoSharing((SceneBuilder builder, EngineLayer? oldLayer) {
	return builder.pushColorFilter(
	const ColorFilter.matrix(<double>[
	1, 0, 0, 0, 0,
	0, 1, 0, 0, 0,
	0, 0, 1, 0, 0,
	0, 0, 0, 1, 0,
	]),
	oldLayer: oldLayer as ColorFilterEngineLayer?,
	);
	});
	testNoSharing((SceneBuilder builder, EngineLayer? oldLayer) {
	return builder.pushColorFilter(
	const ColorFilter.linearToSrgbGamma(),
	oldLayer: oldLayer as ColorFilterEngineLayer?,
	);
	});
	testNoSharing((SceneBuilder builder, EngineLayer? oldLayer) {
	return builder.pushColorFilter(
	const ColorFilter.srgbToLinearGamma(),
	oldLayer: oldLayer as ColorFilterEngineLayer?,
	);
	});
	testNoSharing((SceneBuilder builder, EngineLayer? oldLayer) {
	return builder.pushImageFilter(
	ImageFilter.blur(sigmaX: 10.0, sigmaY: 10.0),
	oldLayer: oldLayer as ImageFilterEngineLayer?,
	);
	});
	testNoSharing((SceneBuilder builder, EngineLayer? oldLayer) {
	return builder.pushImageFilter(
	ImageFilter.dilate(radiusX: 10.0, radiusY: 10.0),
	oldLayer: oldLayer as ImageFilterEngineLayer?,
	);
	});
	testNoSharing((SceneBuilder builder, EngineLayer? oldLayer) {
	return builder.pushImageFilter(
	ImageFilter.erode(radiusX: 10.0, radiusY: 10.0),
	oldLayer: oldLayer as ImageFilterEngineLayer?,
	);
	});
	testNoSharing((SceneBuilder builder, EngineLayer? oldLayer) {
	return builder.pushImageFilter(
	ImageFilter.matrix(Float64List.fromList(<double>[
	1, 0, 0, 0,
	0, 1, 0, 0,
	0, 0, 1, 0,
	0, 0, 0, 1,
	])),
	oldLayer: oldLayer as ImageFilterEngineLayer?,
	);
	});
	});
	}

	typedef _TestNoSharingFunction = EngineLayer Function(SceneBuilder builder, EngineLayer? oldLayer);