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2b4c960885
* Remove more references to dart:ui.window * two more doc referenes * revert icon_color_test.dart
70 lines
2.6 KiB
Dart
70 lines
2.6 KiB
Dart
// Copyright 2014 The Flutter Authors. All rights reserved.
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// Use of this source code is governed by a BSD-style license that can be
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// found in the LICENSE file.
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// This example shows how to perform a simple animation using the raw interface
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// to the engine.
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import 'dart:math' as math;
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import 'dart:typed_data';
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import 'dart:ui' as ui;
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// The FlutterView into which this example will draw; set in the main method.
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late final ui.FlutterView view;
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void beginFrame(Duration timeStamp) {
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// The timeStamp argument to beginFrame indicates the timing information we
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// should use to clock our animations. It's important to use timeStamp rather
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// than reading the system time because we want all the parts of the system to
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// coordinate the timings of their animations. If each component read the
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// system clock independently, the animations that we processed later would be
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// slightly ahead of the animations we processed earlier.
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// PAINT
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final ui.Rect paintBounds = ui.Offset.zero & (view.physicalSize / view.devicePixelRatio);
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final ui.PictureRecorder recorder = ui.PictureRecorder();
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final ui.Canvas canvas = ui.Canvas(recorder, paintBounds);
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canvas.translate(paintBounds.width / 2.0, paintBounds.height / 2.0);
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// Here we determine the rotation according to the timeStamp given to us by
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// the engine.
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final double t = timeStamp.inMicroseconds / Duration.microsecondsPerMillisecond / 1800.0;
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canvas.rotate(math.pi * (t % 1.0));
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canvas.drawRect(
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const ui.Rect.fromLTRB(-100.0, -100.0, 100.0, 100.0),
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ui.Paint()..color = const ui.Color.fromARGB(255, 0, 255, 0),
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);
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final ui.Picture picture = recorder.endRecording();
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// COMPOSITE
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final double devicePixelRatio = view.devicePixelRatio;
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final Float64List deviceTransform = Float64List(16)
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..[0] = devicePixelRatio
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..[5] = devicePixelRatio
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..[10] = 1.0
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..[15] = 1.0;
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final ui.SceneBuilder sceneBuilder = ui.SceneBuilder()
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..pushTransform(deviceTransform)
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..addPicture(ui.Offset.zero, picture)
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..pop();
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view.render(sceneBuilder.build());
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// After rendering the current frame of the animation, we ask the engine to
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// schedule another frame. The engine will call beginFrame again when its time
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// to produce the next frame.
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ui.PlatformDispatcher.instance.scheduleFrame();
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}
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void main() {
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// TODO(goderbauer): Create a window if embedder doesn't provide an implicit view to draw into.
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assert(ui.PlatformDispatcher.instance.implicitView != null);
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view = ui.PlatformDispatcher.instance.implicitView!;
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ui.PlatformDispatcher.instance
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..onBeginFrame = beginFrame
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..scheduleFrame();
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}
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