lib/ui/compositing/scene_builder.cc

// 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/lib/ui/compositing/scene_builder.h"

#include "flutter/flow/layers/backdrop_filter_layer.h"
#include "flutter/flow/layers/clip_path_layer.h"
#include "flutter/flow/layers/clip_rect_layer.h"
#include "flutter/flow/layers/clip_rrect_layer.h"
#include "flutter/flow/layers/color_filter_layer.h"
#include "flutter/flow/layers/container_layer.h"
#include "flutter/flow/layers/display_list_layer.h"
#include "flutter/flow/layers/image_filter_layer.h"
#include "flutter/flow/layers/layer.h"
#include "flutter/flow/layers/layer_tree.h"
#include "flutter/flow/layers/opacity_layer.h"
#include "flutter/flow/layers/performance_overlay_layer.h"
#include "flutter/flow/layers/physical_shape_layer.h"
#include "flutter/flow/layers/platform_view_layer.h"
#include "flutter/flow/layers/shader_mask_layer.h"
#include "flutter/flow/layers/texture_layer.h"
#include "flutter/flow/layers/transform_layer.h"
#include "flutter/fml/build_config.h"
#include "flutter/lib/ui/painting/matrix.h"
#include "flutter/lib/ui/painting/shader.h"
#include "third_party/skia/include/core/SkColorFilter.h"
#include "third_party/tonic/converter/dart_converter.h"
#include "third_party/tonic/dart_args.h"
#include "third_party/tonic/dart_binding_macros.h"
#include "third_party/tonic/dart_library_natives.h"

namespace flutter {

static void SceneBuilder_constructor(Dart_NativeArguments args) {
  UIDartState::ThrowIfUIOperationsProhibited();
  DartCallConstructor(&SceneBuilder::create, args);
}

IMPLEMENT_WRAPPERTYPEINFO(ui, SceneBuilder);

#define FOR_EACH_BINDING(V)                         \
  V(SceneBuilder, pushOffset)                       \
  V(SceneBuilder, pushTransform)                    \
  V(SceneBuilder, pushClipRect)                     \
  V(SceneBuilder, pushClipRRect)                    \
  V(SceneBuilder, pushClipPath)                     \
  V(SceneBuilder, pushOpacity)                      \
  V(SceneBuilder, pushColorFilter)                  \
  V(SceneBuilder, pushImageFilter)                  \
  V(SceneBuilder, pushBackdropFilter)               \
  V(SceneBuilder, pushShaderMask)                   \
  V(SceneBuilder, pushPhysicalShape)                \
  V(SceneBuilder, pop)                              \
  V(SceneBuilder, addPlatformView)                  \
  V(SceneBuilder, addRetained)                      \
  V(SceneBuilder, addPicture)                       \
  V(SceneBuilder, addTexture)                       \
  V(SceneBuilder, addPerformanceOverlay)            \
  V(SceneBuilder, setRasterizerTracingThreshold)    \
  V(SceneBuilder, setCheckerboardOffscreenLayers)   \
  V(SceneBuilder, setCheckerboardRasterCacheImages) \
  V(SceneBuilder, build)

FOR_EACH_BINDING(DART_NATIVE_CALLBACK)

void SceneBuilder::RegisterNatives(tonic::DartLibraryNatives* natives) {
  natives->Register(
      {{"SceneBuilder_constructor", SceneBuilder_constructor, 1, true},
       FOR_EACH_BINDING(DART_REGISTER_NATIVE)});
}

SceneBuilder::SceneBuilder() {
  // Add a ContainerLayer as the root layer, so that AddLayer operations are
  // always valid.
  PushLayer(std::make_shared<flutter::ContainerLayer>());
}

SceneBuilder::~SceneBuilder() = default;

void SceneBuilder::pushTransform(Dart_Handle layer_handle,
                                 tonic::Float64List& matrix4,
                                 fml::RefPtr<EngineLayer> oldLayer) {
  SkMatrix sk_matrix = ToSkMatrix(matrix4);
  auto layer = std::make_shared<flutter::TransformLayer>(sk_matrix);
  PushLayer(layer);
  // matrix4 has to be released before we can return another Dart object
  matrix4.Release();
  EngineLayer::MakeRetained(layer_handle, layer);

  if (oldLayer && oldLayer->Layer()) {
    layer->AssignOldLayer(oldLayer->Layer().get());
  }
}

void SceneBuilder::pushOffset(Dart_Handle layer_handle,
                              double dx,
                              double dy,
                              fml::RefPtr<EngineLayer> oldLayer) {
  SkMatrix sk_matrix = SkMatrix::Translate(dx, dy);
  auto layer = std::make_shared<flutter::TransformLayer>(sk_matrix);
  PushLayer(layer);
  EngineLayer::MakeRetained(layer_handle, layer);

  if (oldLayer && oldLayer->Layer()) {
    layer->AssignOldLayer(oldLayer->Layer().get());
  }
}

void SceneBuilder::pushClipRect(Dart_Handle layer_handle,
                                double left,
                                double right,
                                double top,
                                double bottom,
                                int clipBehavior,
                                fml::RefPtr<EngineLayer> oldLayer) {
  SkRect clipRect = SkRect::MakeLTRB(left, top, right, bottom);
  flutter::Clip clip_behavior = static_cast<flutter::Clip>(clipBehavior);
  auto layer =
      std::make_shared<flutter::ClipRectLayer>(clipRect, clip_behavior);
  PushLayer(layer);
  EngineLayer::MakeRetained(layer_handle, layer);

  if (oldLayer && oldLayer->Layer()) {
    layer->AssignOldLayer(oldLayer->Layer().get());
  }
}

void SceneBuilder::pushClipRRect(Dart_Handle layer_handle,
                                 const RRect& rrect,
                                 int clipBehavior,
                                 fml::RefPtr<EngineLayer> oldLayer) {
  flutter::Clip clip_behavior = static_cast<flutter::Clip>(clipBehavior);
  auto layer =
      std::make_shared<flutter::ClipRRectLayer>(rrect.sk_rrect, clip_behavior);
  PushLayer(layer);
  EngineLayer::MakeRetained(layer_handle, layer);

  if (oldLayer && oldLayer->Layer()) {
    layer->AssignOldLayer(oldLayer->Layer().get());
  }
}

void SceneBuilder::pushClipPath(Dart_Handle layer_handle,
                                const CanvasPath* path,
                                int clipBehavior,
                                fml::RefPtr<EngineLayer> oldLayer) {
  flutter::Clip clip_behavior = static_cast<flutter::Clip>(clipBehavior);
  FML_DCHECK(clip_behavior != flutter::Clip::none);
  auto layer =
      std::make_shared<flutter::ClipPathLayer>(path->path(), clip_behavior);
  PushLayer(layer);
  EngineLayer::MakeRetained(layer_handle, layer);

  if (oldLayer && oldLayer->Layer()) {
    layer->AssignOldLayer(oldLayer->Layer().get());
  }
}

void SceneBuilder::pushOpacity(Dart_Handle layer_handle,
                               int alpha,
                               double dx,
                               double dy,
                               fml::RefPtr<EngineLayer> oldLayer) {
  auto layer =
      std::make_shared<flutter::OpacityLayer>(alpha, SkPoint::Make(dx, dy));
  PushLayer(layer);
  EngineLayer::MakeRetained(layer_handle, layer);

  if (oldLayer && oldLayer->Layer()) {
    layer->AssignOldLayer(oldLayer->Layer().get());
  }
}

void SceneBuilder::pushColorFilter(Dart_Handle layer_handle,
                                   const ColorFilter* color_filter,
                                   fml::RefPtr<EngineLayer> oldLayer) {
  auto layer = std::make_shared<flutter::ColorFilterLayer>(
      color_filter->filter()->skia_object());
  PushLayer(layer);
  EngineLayer::MakeRetained(layer_handle, layer);

  if (oldLayer && oldLayer->Layer()) {
    layer->AssignOldLayer(oldLayer->Layer().get());
  }
}

void SceneBuilder::pushImageFilter(Dart_Handle layer_handle,
                                   const ImageFilter* image_filter,
                                   fml::RefPtr<EngineLayer> oldLayer) {
  auto layer = std::make_shared<flutter::ImageFilterLayer>(
      image_filter->filter()->skia_object());
  PushLayer(layer);
  EngineLayer::MakeRetained(layer_handle, layer);

  if (oldLayer && oldLayer->Layer()) {
    layer->AssignOldLayer(oldLayer->Layer().get());
  }
}

void SceneBuilder::pushBackdropFilter(Dart_Handle layer_handle,
                                      ImageFilter* filter,
                                      int blendMode,
                                      fml::RefPtr<EngineLayer> oldLayer) {
  auto layer = std::make_shared<flutter::BackdropFilterLayer>(
      filter->filter()->skia_object(), static_cast<SkBlendMode>(blendMode));
  PushLayer(layer);
  EngineLayer::MakeRetained(layer_handle, layer);

  if (oldLayer && oldLayer->Layer()) {
    layer->AssignOldLayer(oldLayer->Layer().get());
  }
}

void SceneBuilder::pushShaderMask(Dart_Handle layer_handle,
                                  Shader* shader,
                                  double maskRectLeft,
                                  double maskRectRight,
                                  double maskRectTop,
                                  double maskRectBottom,
                                  int blendMode,
                                  int filterQualityIndex,
                                  fml::RefPtr<EngineLayer> oldLayer) {
  SkRect rect = SkRect::MakeLTRB(maskRectLeft, maskRectTop, maskRectRight,
                                 maskRectBottom);
  auto sampling = ImageFilter::SamplingFromIndex(filterQualityIndex);
  auto layer = std::make_shared<flutter::ShaderMaskLayer>(
      shader->shader(sampling)->skia_object(), rect,
      static_cast<SkBlendMode>(blendMode));
  PushLayer(layer);
  EngineLayer::MakeRetained(layer_handle, layer);

  if (oldLayer && oldLayer->Layer()) {
    layer->AssignOldLayer(oldLayer->Layer().get());
  }
}

void SceneBuilder::pushPhysicalShape(Dart_Handle layer_handle,
                                     const CanvasPath* path,
                                     double elevation,
                                     int color,
                                     int shadow_color,
                                     int clipBehavior,
                                     fml::RefPtr<EngineLayer> oldLayer) {
  auto layer = std::make_shared<flutter::PhysicalShapeLayer>(
      static_cast<SkColor>(color), static_cast<SkColor>(shadow_color),
      static_cast<float>(elevation), path->path(),
      static_cast<flutter::Clip>(clipBehavior));
  PushLayer(layer);
  EngineLayer::MakeRetained(layer_handle, layer);

  if (oldLayer && oldLayer->Layer()) {
    layer->AssignOldLayer(oldLayer->Layer().get());
  }
}

void SceneBuilder::addRetained(fml::RefPtr<EngineLayer> retainedLayer) {
  AddLayer(retainedLayer->Layer());
}

void SceneBuilder::pop() {
  PopLayer();
}

void SceneBuilder::addPicture(double dx,
                              double dy,
                              Picture* picture,
                              int hints) {
  if (!picture) {
    // Picture::dispose was called and it has been collected.
    return;
  }

  // Explicitly check for display_list, since the picture object might have
  // been disposed but not collected yet, but the display list is null.
  if (picture->display_list()) {
    auto layer = std::make_unique<flutter::DisplayListLayer>(
        SkPoint::Make(dx, dy),
        UIDartState::CreateGPUObject(picture->display_list()), !!(hints & 1),
        !!(hints & 2));
    AddLayer(std::move(layer));
  }
}

void SceneBuilder::addTexture(double dx,
                              double dy,
                              double width,
                              double height,
                              int64_t textureId,
                              bool freeze,
                              int filterQualityIndex) {
  auto sampling = ImageFilter::SamplingFromIndex(filterQualityIndex);
  auto layer = std::make_unique<flutter::TextureLayer>(
      SkPoint::Make(dx, dy), SkSize::Make(width, height), textureId, freeze,
      sampling);
  AddLayer(std::move(layer));
}

void SceneBuilder::addPlatformView(double dx,
                                   double dy,
                                   double width,
                                   double height,
                                   int64_t viewId) {
  auto layer = std::make_unique<flutter::PlatformViewLayer>(
      SkPoint::Make(dx, dy), SkSize::Make(width, height), viewId);
  AddLayer(std::move(layer));
}

void SceneBuilder::addPerformanceOverlay(uint64_t enabledOptions,
                                         double left,
                                         double right,
                                         double top,
                                         double bottom) {
  SkRect rect = SkRect::MakeLTRB(left, top, right, bottom);
  auto layer =
      std::make_unique<flutter::PerformanceOverlayLayer>(enabledOptions);
  layer->set_paint_bounds(rect);
  AddLayer(std::move(layer));
}

void SceneBuilder::setRasterizerTracingThreshold(uint32_t frameInterval) {
  rasterizer_tracing_threshold_ = frameInterval;
}

void SceneBuilder::setCheckerboardRasterCacheImages(bool checkerboard) {
  checkerboard_raster_cache_images_ = checkerboard;
}

void SceneBuilder::setCheckerboardOffscreenLayers(bool checkerboard) {
  checkerboard_offscreen_layers_ = checkerboard;
}

void SceneBuilder::build(Dart_Handle scene_handle) {
  FML_DCHECK(layer_stack_.size() >= 1);

  Scene::create(
      scene_handle, std::move(layer_stack_[0]), rasterizer_tracing_threshold_,
      checkerboard_raster_cache_images_, checkerboard_offscreen_layers_);
  layer_stack_.clear();
  ClearDartWrapper();  // may delete this object.
}

void SceneBuilder::AddLayer(std::shared_ptr<Layer> layer) {
  FML_DCHECK(layer);

  if (!layer_stack_.empty()) {
    layer_stack_.back()->Add(std::move(layer));
  }
}

void SceneBuilder::PushLayer(std::shared_ptr<ContainerLayer> layer) {
  AddLayer(layer);
  layer_stack_.push_back(std::move(layer));
}

void SceneBuilder::PopLayer() {
  // We never pop the root layer, so that AddLayer operations are always valid.
  if (layer_stack_.size() > 1) {
    layer_stack_.pop_back();
  }
}

}  // namespace flutter