@@ -22,27 +22,16 @@ import 'framework.dart';
2222/// [MaterialApp.showPerformanceOverlay] or [WidgetsApp.showPerformanceOverlay]
2323/// to true.
2424class PerformanceOverlay extends LeafRenderObjectWidget {
25- // TODO(abarth): We should have a page on the web site with a screenshot and
26- // an explanation of all the various readouts.
27-
2825 /// Create a performance overlay that only displays specific statistics. The
2926 /// mask is created by shifting 1 by the index of the specific
3027 /// [PerformanceOverlayOption] to enable.
3128const PerformanceOverlay ({
3229 super .key,
3330 this .optionsMask = 0 ,
34- this .rasterizerThreshold = 0 ,
35- this .checkerboardRasterCacheImages = false ,
36- this .checkerboardOffscreenLayers = false ,
3731 });
3832
3933 /// Create a performance overlay that displays all available statistics.
40- PerformanceOverlay .allEnabled ({
41- super .key,
42- this .rasterizerThreshold = 0 ,
43- this .checkerboardRasterCacheImages = false ,
44- this .checkerboardOffscreenLayers = false ,
45- }) : optionsMask =
34+ PerformanceOverlay .allEnabled ({ super .key }) : optionsMask =
4635 1 << PerformanceOverlayOption .displayRasterizerStatistics.index |
4736 1 << PerformanceOverlayOption .visualizeRasterizerStatistics.index |
4837 1 << PerformanceOverlayOption .displayEngineStatistics.index |
@@ -52,71 +41,13 @@ class PerformanceOverlay extends LeafRenderObjectWidget {
5241 /// [PerformanceOverlayOption] to enable.
5342final int optionsMask;
5443
55- /// The rasterizer threshold is an integer specifying the number of frame
56- /// intervals that the rasterizer must miss before it decides that the frame
57- /// is suitable for capturing an SkPicture trace for further analysis.
58- ///
59- /// For example, if you want a trace of all pictures that could not be
60- /// rendered by the rasterizer within the frame boundary (and hence caused
61- /// jank), specify 1. Specifying 2 will trace all pictures that took more
62- /// than 2 frame intervals to render. Adjust this value to only capture
63- /// the particularly expensive pictures while skipping the others. Specifying
64- /// 0 disables all capture.
65- ///
66- /// Captured traces are placed on your device in the application documents
67- /// directory in this form "trace_<collection_time>.skp". These can
68- /// be viewed in the Skia debugger.
69- ///
70- /// Notes:
71- /// The rasterizer only takes into account the time it took to render
72- /// the already constructed picture. This include the Skia calls (which is
73- /// also why an SkPicture trace is generated) but not any of the time spent in
74- /// dart to construct that picture. To profile that part of your code, use
75- /// the instrumentation available in observatory.
76- ///
77- /// To decide what threshold interval to use, count the number of horizontal
78- /// lines displayed in the performance overlay for the rasterizer (not the
79- /// engine). That should give an idea of how often frames are skipped (and by
80- /// how many frame intervals).
81- final int rasterizerThreshold;
82-
83- /// Whether the raster cache should checkerboard cached entries.
84- ///
85- /// The compositor can sometimes decide to cache certain portions of the
86- /// widget hierarchy. Such portions typically don't change often from frame to
87- /// frame and are expensive to render. This can speed up overall rendering. However,
88- /// there is certain upfront cost to constructing these cache entries. And, if
89- /// the cache entries are not used very often, this cost may not be worth the
90- /// speedup in rendering of subsequent frames. If the developer wants to be certain
91- /// that populating the raster cache is not causing stutters, this option can be
92- /// set. Depending on the observations made, hints can be provided to the compositor
93- /// that aid it in making better decisions about caching.
94- final bool checkerboardRasterCacheImages;
95-
96- /// Whether the compositor should checkerboard layers that are rendered to offscreen
97- /// bitmaps. This can be useful for debugging rendering performance.
98- ///
99- /// Render target switches are caused by using opacity layers (via a [FadeTransition] or
100- /// [Opacity] widget), clips, shader mask layers, etc. Selecting a new render target
101- /// and merging it with the rest of the scene has a performance cost. This can sometimes
102- /// be avoided by using equivalent widgets that do not require these layers (for example,
103- /// replacing an [Opacity] widget with an [widgets.Image] using a [BlendMode] ).
104- final bool checkerboardOffscreenLayers;
105-
10644 @override
10745 RenderPerformanceOverlay createRenderObject (BuildContext context) => RenderPerformanceOverlay (
10846 optionsMask: optionsMask,
109- rasterizerThreshold: rasterizerThreshold,
110- checkerboardRasterCacheImages: checkerboardRasterCacheImages,
111- checkerboardOffscreenLayers: checkerboardOffscreenLayers,
11247 );
11348
11449 @override
11550 void updateRenderObject (BuildContext context, RenderPerformanceOverlay renderObject) {
116- renderObject
117- ..optionsMask = optionsMask
118- ..rasterizerThreshold = rasterizerThreshold
119- ..checkerboardRasterCacheImages = checkerboardRasterCacheImages
120- ..checkerboardOffscreenLayers = checkerboardOffscreenLayers;
51+ renderObject.optionsMask = optionsMask;
12152 }
12253}
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