[Impeller Scene] Add ColorSourceContents for drawing a node

ci/licenses_golden/licenses_flutter

@@ -1259,6 +1259,8 @@ ORIGIN: ../../../flutter/impeller/entity/contents/rrect_shadow_contents.cc + ../
 ORIGIN: ../../../flutter/impeller/entity/contents/rrect_shadow_contents.h + ../../../flutter/LICENSE
 ORIGIN: ../../../flutter/impeller/entity/contents/runtime_effect_contents.cc + ../../../flutter/LICENSE
 ORIGIN: ../../../flutter/impeller/entity/contents/runtime_effect_contents.h + ../../../flutter/LICENSE
+ORIGIN: ../../../flutter/impeller/entity/contents/scene_contents.cc + ../../../flutter/LICENSE
+ORIGIN: ../../../flutter/impeller/entity/contents/scene_contents.h + ../../../flutter/LICENSE
 ORIGIN: ../../../flutter/impeller/entity/contents/solid_color_contents.cc + ../../../flutter/LICENSE
 ORIGIN: ../../../flutter/impeller/entity/contents/solid_color_contents.h + ../../../flutter/LICENSE
 ORIGIN: ../../../flutter/impeller/entity/contents/sweep_gradient_contents.cc + ../../../flutter/LICENSE
@@ -3716,6 +3718,8 @@ FILE: ../../../flutter/impeller/entity/contents/rrect_shadow_contents.cc
 FILE: ../../../flutter/impeller/entity/contents/rrect_shadow_contents.h
 FILE: ../../../flutter/impeller/entity/contents/runtime_effect_contents.cc
 FILE: ../../../flutter/impeller/entity/contents/runtime_effect_contents.h
+FILE: ../../../flutter/impeller/entity/contents/scene_contents.cc
+FILE: ../../../flutter/impeller/entity/contents/scene_contents.h
 FILE: ../../../flutter/impeller/entity/contents/solid_color_contents.cc
 FILE: ../../../flutter/impeller/entity/contents/solid_color_contents.h
 FILE: ../../../flutter/impeller/entity/contents/sweep_gradient_contents.cc

impeller/aiks/aiks_unittests.cc

@@ -5,14 +5,17 @@
 #include <array>
 #include <cmath>
 #include <iostream>
+#include <memory>
 #include <tuple>
 #include <utility>
 
 #include "flutter/testing/testing.h"
 #include "impeller/aiks/aiks_playground.h"
 #include "impeller/aiks/canvas.h"
 #include "impeller/aiks/image.h"
+#include "impeller/entity/contents/color_source_contents.h"
 #include "impeller/entity/contents/filters/inputs/filter_input.h"
+#include "impeller/entity/contents/scene_contents.h"
 #include "impeller/entity/contents/tiled_texture_contents.h"
 #include "impeller/geometry/color.h"
 #include "impeller/geometry/geometry_unittests.h"
@@ -21,6 +24,8 @@
 #include "impeller/playground/widgets.h"
 #include "impeller/renderer/command_buffer.h"
 #include "impeller/renderer/snapshot.h"
+#include "impeller/scene/material.h"
+#include "impeller/scene/node.h"
 #include "impeller/typographer/backends/skia/text_frame_skia.h"
 #include "impeller/typographer/backends/skia/text_render_context_skia.h"
 #include "third_party/skia/include/core/SkData.h"
@@ -1700,5 +1705,53 @@ TEST_P(AiksTest, SaveLayerFiltersScaleWithTransform) {
   ASSERT_TRUE(OpenPlaygroundHere(canvas.EndRecordingAsPicture()));
 }
 
+TEST_P(AiksTest, SceneColorSource) {
+  // Load up the scene.
+  auto mapping =
+      flutter::testing::OpenFixtureAsMapping("flutter_logo.glb.ipscene");
+  ASSERT_NE(mapping, nullptr);
+
+  std::shared_ptr<scene::Node> gltf_scene = scene::Node::MakeFromFlatbuffer(
+      *mapping, *GetContext()->GetResourceAllocator());
+  ASSERT_NE(gltf_scene, nullptr);
+
+  // Assign a material (temporary stopgap).
+  std::shared_ptr<scene::UnlitMaterial> material = scene::Material::MakeUnlit();
+  auto color_baked = CreateTextureForFixture("flutter_logo_baked.png");
+  ASSERT_NE(color_baked, nullptr);
+  material->SetColorTexture(std::move(color_baked));
+  material->SetVertexColorWeight(0);
+
+  ASSERT_EQ(gltf_scene->GetChildren().size(), 1u);
+  ASSERT_EQ(gltf_scene->GetChildren()[0]->GetMesh().GetPrimitives().size(), 1u);
+  gltf_scene->GetChildren()[0]->GetMesh().GetPrimitives()[0].material =
+      std::move(material);
+
+  auto callback = [&](AiksContext& renderer, RenderTarget& render_target) {
+    Paint paint;
+
+    paint.color_source_type = Paint::ColorSourceType::kScene;
+    paint.color_source = [this, gltf_scene]() {
+      Scalar angle = GetSecondsElapsed();
+      Scalar distance = 2;
+      auto camera_position =
+          Vector3(distance * std::sin(angle), 2, -distance * std::cos(angle));
+      auto contents = std::make_shared<SceneContents>();
+      contents->SetNode(gltf_scene);
+      contents->SetCameraTransform(
+          Matrix::MakePerspective(Degrees(45), GetWindowSize(), 0.1, 1000) *
+          Matrix::MakeLookAt(camera_position, {0, 0, 0}, {0, 1, 0}));
+      return contents;
+    };
+
+    Canvas canvas;
+    canvas.Scale(GetContentScale());
+    canvas.DrawPaint(paint);
+    return renderer.Render(canvas.EndRecordingAsPicture(), render_target);
+  };
+
+  ASSERT_TRUE(OpenPlaygroundHere(callback));
+}
+
 }  // namespace testing
 }  // namespace impeller

impeller/aiks/paint.h

@@ -44,6 +44,7 @@ struct Paint {
     kConicalGradient,
     kSweepGradient,
     kRuntimeEffect,
+    kScene,
   };
 
   struct MaskBlurDescriptor {

impeller/display_list/display_list_dispatcher.cc

@@ -27,6 +27,7 @@
 #include "impeller/entity/contents/linear_gradient_contents.h"
 #include "impeller/entity/contents/radial_gradient_contents.h"
 #include "impeller/entity/contents/runtime_effect_contents.h"
+#include "impeller/entity/contents/scene_contents.h"
 #include "impeller/entity/contents/sweep_gradient_contents.h"
 #include "impeller/entity/contents/tiled_texture_contents.h"
 #include "impeller/entity/entity.h"
@@ -500,6 +501,20 @@ void DisplayListDispatcher::setColorSource(
       };
       return;
     }
+    case Paint::ColorSourceType::kScene: {
+      // const flutter::DlSceneColorSource* scene_color_source =
+      // source->asScene(); std::shared_ptr<scene::Node> scene_node =
+      // scene_color_source->node(); Matrix camera_transform =
+      //   scene_color_node->camera_transform();
+
+      paint_.color_source = [/*scene_node, camera_transform*/]() {
+        auto contents = std::make_shared<SceneContents>();
+        // contents->SetNode(scene_node);
+        // contents->SetCameraTransform(camera_transform);
+        return contents;
+      };
+    }
+      return;
     case Paint::ColorSourceType::kConicalGradient:
       UNIMPLEMENTED;
       break;

impeller/entity/BUILD.gn

@@ -134,6 +134,8 @@ impeller_component("entity") {
     "contents/rrect_shadow_contents.h",
     "contents/runtime_effect_contents.cc",
     "contents/runtime_effect_contents.h",
+    "contents/scene_contents.cc",
+    "contents/scene_contents.h",
     "contents/solid_color_contents.cc",
     "contents/solid_color_contents.h",
     "contents/sweep_gradient_contents.cc",
@@ -164,6 +166,7 @@ impeller_component("entity") {
     "../archivist",
     "../image",
     "../renderer",
+    "../scene",
     "../typographer",
   ]
 

impeller/entity/contents/color_source_contents.cc

@@ -13,11 +13,11 @@ ColorSourceContents::ColorSourceContents() = default;
 
 ColorSourceContents::~ColorSourceContents() = default;
 
-void ColorSourceContents::SetGeometry(std::unique_ptr<Geometry> geometry) {
+void ColorSourceContents::SetGeometry(std::shared_ptr<Geometry> geometry) {
   geometry_ = std::move(geometry);
 }
 
-const std::unique_ptr<Geometry>& ColorSourceContents::GetGeometry() const {
+const std::shared_ptr<Geometry>& ColorSourceContents::GetGeometry() const {
   return geometry_;
 }
 

impeller/entity/contents/color_source_contents.h

@@ -18,7 +18,7 @@ class ColorSourceContents : public Contents {
 
   ~ColorSourceContents() override;
 
-  void SetGeometry(std::unique_ptr<Geometry> geometry);
+  void SetGeometry(std::shared_ptr<Geometry> geometry);
 
   void SetMatrix(Matrix matrix);
 
@@ -32,14 +32,14 @@ class ColorSourceContents : public Contents {
                     const std::optional<Rect>& stencil_coverage) const override;
 
  protected:
-  const std::unique_ptr<Geometry>& GetGeometry() const;
+  const std::shared_ptr<Geometry>& GetGeometry() const;
 
   const Matrix& GetInverseMatrix() const;
 
   Scalar GetAlpha() const;
 
  private:
-  std::unique_ptr<Geometry> geometry_;
+  std::shared_ptr<Geometry> geometry_;
   Matrix inverse_matrix_;
   Scalar alpha_ = 1.0;
 

impeller/entity/contents/content_context.cc

@@ -4,6 +4,7 @@
 
 #include "impeller/entity/contents/content_context.h"
 
+#include <memory>
 #include <sstream>
 
 #include "impeller/entity/entity.h"
@@ -146,7 +147,8 @@ static std::unique_ptr<PipelineT> CreateDefaultPipeline(
 ContentContext::ContentContext(std::shared_ptr<Context> context)
     : context_(std::move(context)),
       tessellator_(std::make_shared<Tessellator>()),
-      glyph_atlas_context_(std::make_shared<GlyphAtlasContext>()) {
+      glyph_atlas_context_(std::make_shared<GlyphAtlasContext>()),
+      scene_context_(std::make_shared<scene::SceneContext>(context_)) {
   if (!context_ || !context_->IsValid()) {
     return;
   }
@@ -298,6 +300,10 @@ std::shared_ptr<Texture> ContentContext::MakeSubpass(
   return subpass_texture;
 }
 
+std::shared_ptr<scene::SceneContext> ContentContext::GetSceneContext() const {
+  return scene_context_;
+}
+
 std::shared_ptr<Tessellator> ContentContext::GetTessellator() const {
   return tessellator_;
 }

impeller/entity/contents/content_context.h

@@ -8,8 +8,8 @@
 #include <unordered_map>
 
 #include "flutter/fml/hash_combine.h"
+#include "flutter/fml/logging.h"
 #include "flutter/fml/macros.h"
-#include "fml/logging.h"
 #include "impeller/base/validation.h"
 #include "impeller/entity/advanced_blend.vert.h"
 #include "impeller/entity/advanced_blend_color.frag.h"
@@ -65,11 +65,13 @@
 #include "impeller/entity/yuv_to_rgb_filter.vert.h"
 #include "impeller/renderer/formats.h"
 #include "impeller/renderer/pipeline.h"
+#include "impeller/scene/scene_context.h"
 
 #include "impeller/entity/position.vert.h"
 #include "impeller/entity/position_color.vert.h"
 #include "impeller/entity/position_uv.vert.h"
 
+#include "impeller/scene/scene_context.h"
 #include "impeller/typographer/glyph_atlas.h"
 
 #include "impeller/entity/linear_gradient_ssbo_fill.frag.h"
@@ -216,6 +218,8 @@ class ContentContext {
 
   bool IsValid() const;
 
+  std::shared_ptr<scene::SceneContext> GetSceneContext() const;
+
   std::shared_ptr<Tessellator> GetTessellator() const;
 
   std::shared_ptr<Pipeline<PipelineDescriptor>> GetLinearGradientFillPipeline(
@@ -522,6 +526,7 @@ class ContentContext {
   bool is_valid_ = false;
   std::shared_ptr<Tessellator> tessellator_;
   std::shared_ptr<GlyphAtlasContext> glyph_atlas_context_;
+  std::shared_ptr<scene::SceneContext> scene_context_;
 
   FML_DISALLOW_COPY_AND_ASSIGN(ContentContext);
 };

impeller/entity/contents/scene_contents.cc

@@ -0,0 +1,77 @@
+// 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 "impeller/entity/contents/scene_contents.h"
+
+#include "impeller/entity/contents/content_context.h"
+#include "impeller/entity/contents/tiled_texture_contents.h"
+#include "impeller/entity/entity.h"
+#include "impeller/geometry/path_builder.h"
+#include "impeller/renderer/formats.h"
+#include "impeller/scene/camera.h"
+#include "impeller/scene/scene.h"
+
+namespace impeller {
+
+SceneContents::SceneContents() = default;
+
+SceneContents::~SceneContents() = default;
+
+void SceneContents::SetCameraTransform(Matrix matrix) {
+  camera_transform_ = matrix;
+}
+
+void SceneContents::SetNode(std::shared_ptr<scene::Node> node) {
+  node_ = std::move(node);
+}
+
+bool SceneContents::Render(const ContentContext& renderer,
+                           const Entity& entity,
+                           RenderPass& pass) const {
+  if (!node_) {
+    return true;
+  }
+
+  auto coverage = GetCoverage(entity);
+  if (!coverage.has_value()) {
+    return true;
+  }
+
+  // This happens for CoverGeometry (DrawPaint). In this situation,
+  // Draw the scene to the full layer.
+  if (coverage.value().IsMaximum()) {
+    coverage = Rect::MakeSize(pass.GetRenderTargetSize());
+  }
+
+  RenderTarget subpass_target = RenderTarget::CreateOffscreenMSAA(
+      *renderer.GetContext(),            // context
+      ISize(coverage.value().size),      // size
+      "SceneContents",                   // label
+      StorageMode::kDeviceTransient,     // color_storage_mode
+      StorageMode::kDevicePrivate,       // color_resolve_storage_mode
+      LoadAction::kClear,                // color_load_action
+      StoreAction::kMultisampleResolve,  // color_store_action
+      StorageMode::kDeviceTransient,     // stencil_storage_mode
+      LoadAction::kDontCare,             // stencil_load_action
+      StoreAction::kDontCare             // stencil_store_action
+  );
+  if (!subpass_target.IsValid()) {
+    return false;
+  }
+
+  scene::Scene scene(renderer.GetSceneContext());
+  scene.GetRoot().AddChild(node_);
+
+  if (!scene.Render(subpass_target, camera_transform_)) {
+    return false;
+  }
+
+  // Render the texture to the pass.
+  TiledTextureContents contents;
+  contents.SetGeometry(GetGeometry());
+  contents.SetTexture(subpass_target.GetRenderTargetTexture());
+  return contents.Render(renderer, entity, pass);
+}
+
+}  // namespace impeller

impeller/entity/contents/scene_contents.h

@@ -0,0 +1,35 @@
+// 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 <memory>
+
+#include "impeller/entity/contents/color_source_contents.h"
+
+#include "impeller/geometry/matrix.h"
+#include "impeller/geometry/rect.h"
+#include "impeller/scene/node.h"
+
+namespace impeller {
+
+class SceneContents final : public ColorSourceContents {
+ public:
+  SceneContents();
+
+  ~SceneContents() override;
+
+  void SetCameraTransform(Matrix matrix);
+
+  void SetNode(std::shared_ptr<scene::Node> node);
+
+  // |Contents|
+  bool Render(const ContentContext& renderer,
+              const Entity& entity,
+              RenderPass& pass) const override;
+
+ private:
+  Matrix camera_transform_;
+  std::shared_ptr<scene::Node> node_;
+};
+
+}  // namespace impeller