1// Copyright 2013 The Flutter Authors. All rights reserved.
2// Use of this source code is governed by a BSD-style license that can be
3// found in the LICENSE file.
4
5#include "flutter/flow/layers/layer_tree.h"
6
7#include "flutter/flow/layers/layer.h"
8#include "flutter/fml/trace_event.h"
9#include "third_party/skia/include/core/SkPictureRecorder.h"
10#include "third_party/skia/include/utils/SkNWayCanvas.h"
11
12namespace flutter {
13
14LayerTree::LayerTree(const SkISize& frame_size, float device_pixel_ratio)
15 : frame_size_(frame_size),
16 device_pixel_ratio_(device_pixel_ratio),
17 rasterizer_tracing_threshold_(0),
18 checkerboard_raster_cache_images_(false),
19 checkerboard_offscreen_layers_(false) {
20 FML_CHECK(device_pixel_ratio_ != 0.0f);
21}
22
23void LayerTree::RecordBuildTime(fml::TimePoint vsync_start,
24 fml::TimePoint build_start,
25 fml::TimePoint target_time) {
26 vsync_start_ = vsync_start;
27 build_start_ = build_start;
28 target_time_ = target_time;
29 build_finish_ = fml::TimePoint::Now();
30}
31
32bool LayerTree::Preroll(CompositorContext::ScopedFrame& frame,
33 bool ignore_raster_cache) {
34 TRACE_EVENT0("flutter", "LayerTree::Preroll");
35
36 if (!root_layer_) {
37 FML_LOG(ERROR) << "The scene did not specify any layers.";
38 return false;
39 }
40
41 SkColorSpace* color_space =
42 frame.canvas() ? frame.canvas()->imageInfo().colorSpace() : nullptr;
43 frame.context().raster_cache().SetCheckboardCacheImages(
44 checkerboard_raster_cache_images_);
45 MutatorsStack stack;
46 PrerollContext context = {
47 ignore_raster_cache ? nullptr : &frame.context().raster_cache(),
48 frame.gr_context(),
49 frame.view_embedder(),
50 stack,
51 color_space,
52 kGiantRect,
53 false,
54 frame.context().raster_time(),
55 frame.context().ui_time(),
56 frame.context().texture_registry(),
57 checkerboard_offscreen_layers_,
58 device_pixel_ratio_};
59
60 root_layer_->Preroll(&context, frame.root_surface_transformation());
61 return context.surface_needs_readback;
62}
63
64#if defined(LEGACY_FUCHSIA_EMBEDDER)
65void LayerTree::UpdateScene(SceneUpdateContext& context) {
66 TRACE_EVENT0("flutter", "LayerTree::UpdateScene");
67
68 // Reset for a new Scene.
69 context.Reset();
70
71 const float inv_dpr = 1.0f / device_pixel_ratio_;
72 SceneUpdateContext::Transform transform(context, inv_dpr, inv_dpr, 1.0f);
73
74 SceneUpdateContext::Frame frame(
75 context,
76 SkRRect::MakeRect(
77 SkRect::MakeWH(frame_size_.width(), frame_size_.height())),
78 SK_ColorTRANSPARENT, SK_AlphaOPAQUE, "flutter::LayerTree");
79 if (root_layer_->needs_system_composite()) {
80 root_layer_->UpdateScene(context);
81 }
82 if (root_layer_->needs_painting()) {
83 frame.AddPaintLayer(root_layer_.get());
84 }
85 context.root_node().AddChild(transform.entity_node());
86}
87#endif
88
89void LayerTree::Paint(CompositorContext::ScopedFrame& frame,
90 bool ignore_raster_cache) const {
91 TRACE_EVENT0("flutter", "LayerTree::Paint");
92
93 if (!root_layer_) {
94 FML_LOG(ERROR) << "The scene did not specify any layers to paint.";
95 return;
96 }
97
98 SkISize canvas_size = frame.canvas()->getBaseLayerSize();
99 SkNWayCanvas internal_nodes_canvas(canvas_size.width(), canvas_size.height());
100 internal_nodes_canvas.addCanvas(frame.canvas());
101 if (frame.view_embedder() != nullptr) {
102 auto overlay_canvases = frame.view_embedder()->GetCurrentCanvases();
103 for (size_t i = 0; i < overlay_canvases.size(); i++) {
104 internal_nodes_canvas.addCanvas(overlay_canvases[i]);
105 }
106 }
107
108 Layer::PaintContext context = {
109 static_cast<SkCanvas*>(&internal_nodes_canvas),
110 frame.canvas(),
111 frame.gr_context(),
112 frame.view_embedder(),
113 frame.context().raster_time(),
114 frame.context().ui_time(),
115 frame.context().texture_registry(),
116 ignore_raster_cache ? nullptr : &frame.context().raster_cache(),
117 checkerboard_offscreen_layers_,
118 device_pixel_ratio_};
119
120 if (root_layer_->needs_painting()) {
121 root_layer_->Paint(context);
122 }
123}
124
125sk_sp<SkPicture> LayerTree::Flatten(const SkRect& bounds) {
126 TRACE_EVENT0("flutter", "LayerTree::Flatten");
127
128 SkPictureRecorder recorder;
129 auto* canvas = recorder.beginRecording(bounds);
130
131 if (!canvas) {
132 return nullptr;
133 }
134
135 MutatorsStack unused_stack;
136 const Stopwatch unused_stopwatch;
137 TextureRegistry unused_texture_registry;
138 SkMatrix root_surface_transformation;
139 // No root surface transformation. So assume identity.
140 root_surface_transformation.reset();
141
142 PrerollContext preroll_context{
143 nullptr, // raster_cache (don't consult the cache)
144 nullptr, // gr_context (used for the raster cache)
145 nullptr, // external view embedder
146 unused_stack, // mutator stack
147 nullptr, // SkColorSpace* dst_color_space
148 kGiantRect, // SkRect cull_rect
149 false, // layer reads from surface
150 unused_stopwatch, // frame time (dont care)
151 unused_stopwatch, // engine time (dont care)
152 unused_texture_registry, // texture registry (not supported)
153 false, // checkerboard_offscreen_layers
154 device_pixel_ratio_ // ratio between logical and physical
155 };
156
157 SkISize canvas_size = canvas->getBaseLayerSize();
158 SkNWayCanvas internal_nodes_canvas(canvas_size.width(), canvas_size.height());
159 internal_nodes_canvas.addCanvas(canvas);
160
161 Layer::PaintContext paint_context = {
162 static_cast<SkCanvas*>(&internal_nodes_canvas),
163 canvas, // canvas
164 nullptr,
165 nullptr,
166 unused_stopwatch, // frame time (dont care)
167 unused_stopwatch, // engine time (dont care)
168 unused_texture_registry, // texture registry (not supported)
169 nullptr, // raster cache
170 false, // checkerboard offscreen layers
171 device_pixel_ratio_ // ratio between logical and physical
172 };
173
174 // Even if we don't have a root layer, we still need to create an empty
175 // picture.
176 if (root_layer_) {
177 root_layer_->Preroll(&preroll_context, root_surface_transformation);
178 // The needs painting flag may be set after the preroll. So check it after.
179 if (root_layer_->needs_painting()) {
180 root_layer_->Paint(paint_context);
181 }
182 }
183
184 return recorder.finishRecordingAsPicture();
185}
186
187} // namespace flutter
188