| // 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. |
| |
| #include "flutter/flow/layers/opacity_layer.h" |
| |
| #include "flutter/fml/trace_event.h" |
| #include "third_party/skia/include/core/SkPaint.h" |
| |
| namespace flutter { |
| |
| // The OpacityLayer has no real "elevation", but we want to avoid Z-fighting |
| // when using the system compositor. Choose a small but non-zero value for |
| // this. |
| constexpr float kOpacityElevationWhenUsingSystemCompositor = 0.01f; |
| |
| OpacityLayer::OpacityLayer(SkAlpha alpha, const SkPoint& offset) |
| : alpha_(alpha), offset_(offset) { |
| // Ensure OpacityLayer has only one direct child. |
| // |
| // This is needed to ensure that retained rendering can always be applied to |
| // save the costly saveLayer. |
| // |
| // Any children will be actually added as children of this empty |
| // ContainerLayer. |
| ContainerLayer::Add(std::make_shared<ContainerLayer>()); |
| } |
| |
| void OpacityLayer::Add(std::shared_ptr<Layer> layer) { |
| GetChildContainer()->Add(std::move(layer)); |
| } |
| |
| void OpacityLayer::Preroll(PrerollContext* context, const SkMatrix& matrix) { |
| TRACE_EVENT0("flutter", "OpacityLayer::Preroll"); |
| |
| ContainerLayer* container = GetChildContainer(); |
| FML_DCHECK(!container->layers().empty()); // OpacityLayer can't be a leaf. |
| |
| const bool parent_is_opaque = context->is_opaque; |
| SkMatrix child_matrix = matrix; |
| child_matrix.postTranslate(offset_.fX, offset_.fY); |
| |
| total_elevation_ = context->total_elevation; |
| context->total_elevation += kOpacityElevationWhenUsingSystemCompositor; |
| context->is_opaque = parent_is_opaque && (alpha_ == SK_AlphaOPAQUE); |
| context->mutators_stack.PushTransform( |
| SkMatrix::MakeTrans(offset_.fX, offset_.fY)); |
| context->mutators_stack.PushOpacity(alpha_); |
| Layer::AutoPrerollSaveLayerState save = |
| Layer::AutoPrerollSaveLayerState::Create(context); |
| ContainerLayer::Preroll(context, child_matrix); |
| context->mutators_stack.Pop(); |
| context->mutators_stack.Pop(); |
| context->is_opaque = parent_is_opaque; |
| context->total_elevation = total_elevation_; |
| |
| #if defined(OS_FUCHSIA) |
| if (needs_system_composite()) { |
| // When using the system compositor, do not include the offset since we |
| // are rendering as a separate piece of geometry and the offset will be |
| // baked into that geometry's transform. |
| frameRRect_ = SkRRect::MakeRect(paint_bounds()); |
| set_paint_bounds(SkRect::MakeEmpty()); |
| } else |
| #endif |
| { |
| set_paint_bounds(paint_bounds().makeOffset(offset_.fX, offset_.fY)); |
| if (!context->has_platform_view && context->raster_cache && |
| SkRect::Intersects(context->cull_rect, paint_bounds())) { |
| SkMatrix ctm = child_matrix; |
| #ifndef SUPPORT_FRACTIONAL_TRANSLATION |
| ctm = RasterCache::GetIntegralTransCTM(ctm); |
| #endif |
| context->raster_cache->Prepare(context, container, ctm); |
| } |
| } |
| } |
| |
| void OpacityLayer::Paint(PaintContext& context) const { |
| TRACE_EVENT0("flutter", "OpacityLayer::Paint"); |
| FML_DCHECK(needs_painting()); |
| |
| SkPaint paint; |
| paint.setAlpha(alpha_); |
| |
| SkAutoCanvasRestore save(context.internal_nodes_canvas, true); |
| context.internal_nodes_canvas->translate(offset_.fX, offset_.fY); |
| |
| #ifndef SUPPORT_FRACTIONAL_TRANSLATION |
| context.internal_nodes_canvas->setMatrix(RasterCache::GetIntegralTransCTM( |
| context.leaf_nodes_canvas->getTotalMatrix())); |
| #endif |
| |
| if (context.raster_cache) { |
| ContainerLayer* container = GetChildContainer(); |
| const SkMatrix& ctm = context.leaf_nodes_canvas->getTotalMatrix(); |
| RasterCacheResult child_cache = context.raster_cache->Get(container, ctm); |
| if (child_cache.is_valid()) { |
| child_cache.draw(*context.leaf_nodes_canvas, &paint); |
| return; |
| } |
| } |
| |
| // Skia may clip the content with saveLayerBounds (although it's not a |
| // guaranteed clip). So we have to provide a big enough saveLayerBounds. To do |
| // so, we first remove the offset from paint bounds since it's already in the |
| // matrix. Then we round out the bounds because of our |
| // RasterCache::GetIntegralTransCTM optimization. |
| // |
| // Note that the following lines are only accessible when the raster cache is |
| // not available (e.g., when we're using the software backend in golden |
| // tests). |
| SkRect saveLayerBounds; |
| paint_bounds() |
| .makeOffset(-offset_.fX, -offset_.fY) |
| .roundOut(&saveLayerBounds); |
| |
| Layer::AutoSaveLayer save_layer = |
| Layer::AutoSaveLayer::Create(context, saveLayerBounds, &paint); |
| PaintChildren(context); |
| } |
| |
| #if defined(OS_FUCHSIA) |
| |
| void OpacityLayer::UpdateScene(SceneUpdateContext& context) { |
| FML_DCHECK(needs_system_composite()); |
| TRACE_EVENT0("flutter", "OpacityLayer::UpdateScene"); |
| |
| ContainerLayer* container = GetChildContainer(); |
| FML_DCHECK(!container->layers().empty()); // OpacityLayer can't be a leaf. |
| |
| SceneUpdateContext::Transform transform( |
| context, SkMatrix::MakeTrans(offset_.fX, offset_.fY)); |
| |
| // Retained rendering: speedup by reusing a retained entity node if possible. |
| // When an entity node is reused, no paint layer is added to the frame so we |
| // won't call PhysicalShapeLayer::Paint. |
| LayerRasterCacheKey key(unique_id(), context.Matrix()); |
| if (context.HasRetainedNode(key)) { |
| TRACE_EVENT_INSTANT0("flutter", "retained layer cache hit"); |
| const scenic::EntityNode& retained_node = context.GetRetainedNode(key); |
| FML_DCHECK(context.top_entity()); |
| FML_DCHECK(retained_node.session() == context.session()); |
| context.top_entity()->embedder_node().AddChild(retained_node); |
| return; |
| } |
| |
| TRACE_EVENT_INSTANT0("flutter", "cache miss, creating"); |
| // If we can't find an existing retained surface, create one. |
| SceneUpdateContext::Frame frame( |
| context, frameRRect_, SK_ColorTRANSPARENT, alpha_, |
| kOpacityElevationWhenUsingSystemCompositor, total_elevation_, this); |
| frame.AddPaintLayer(container); |
| |
| UpdateSceneChildren(context); |
| } |
| |
| #endif // defined(OS_FUCHSIA) |
| |
| ContainerLayer* OpacityLayer::GetChildContainer() const { |
| FML_DCHECK(layers().size() == 1); |
| |
| return static_cast<ContainerLayer*>(layers()[0].get()); |
| } |
| |
| } // namespace flutter |