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49 lines
1.6 KiB
Dart
49 lines
1.6 KiB
Dart
// Copyright 2015 The Chromium 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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import 'dart:math' as math;
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import 'dart:ui' as ui;
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import 'dart:typed_data';
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double timeBase = null;
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void beginFrame(double timeStamp) {
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ui.tracing.begin('beginFrame');
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if (timeBase == null)
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timeBase = timeStamp;
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double delta = timeStamp - timeBase;
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// paint
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ui.Rect paintBounds = new ui.Rect.fromLTWH(0.0, 0.0, ui.view.width, ui.view.height);
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ui.PictureRecorder recorder = new ui.PictureRecorder();
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ui.Canvas canvas = new ui.Canvas(recorder, paintBounds);
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canvas.translate(paintBounds.width / 2.0, paintBounds.height / 2.0);
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canvas.rotate(math.PI * delta / 1800);
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canvas.drawRect(new ui.Rect.fromLTRB(-100.0, -100.0, 100.0, 100.0),
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new ui.Paint()..color = const ui.Color.fromARGB(255, 0, 255, 0));
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ui.Picture picture = recorder.endRecording();
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// composite
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final double devicePixelRatio = ui.view.devicePixelRatio;
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ui.Rect sceneBounds = new ui.Rect.fromLTWH(0.0, 0.0, ui.view.width * devicePixelRatio, ui.view.height * devicePixelRatio);
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Float64List deviceTransform = new 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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ui.SceneBuilder sceneBuilder = new ui.SceneBuilder(sceneBounds)
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..pushTransform(deviceTransform)
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..addPicture(ui.Offset.zero, picture, paintBounds)
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..pop();
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ui.view.scene = sceneBuilder.build();
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ui.tracing.end('beginFrame');
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ui.view.scheduleFrame();
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}
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void main() {
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ui.view.setFrameCallback(beginFrame);
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ui.view.scheduleFrame();
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}
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