[Impeller Scene] Wire up pipelines (#37961)

Author: bdero

ci/licenses_golden/licenses_flutter

@@ -1598,11 +1598,15 @@ FILE: ../../../flutter/impeller/scene/material.cc
 FILE: ../../../flutter/impeller/scene/material.h
 FILE: ../../../flutter/impeller/scene/scene.cc
 FILE: ../../../flutter/impeller/scene/scene.h
+FILE: ../../../flutter/impeller/scene/scene_context.cc
+FILE: ../../../flutter/impeller/scene/scene_context.h
 FILE: ../../../flutter/impeller/scene/scene_encoder.cc
 FILE: ../../../flutter/impeller/scene/scene_encoder.h
 FILE: ../../../flutter/impeller/scene/scene_entity.cc
 FILE: ../../../flutter/impeller/scene/scene_entity.h
 FILE: ../../../flutter/impeller/scene/scene_unittests.cc
+FILE: ../../../flutter/impeller/scene/shaders/geometry.vert
+FILE: ../../../flutter/impeller/scene/shaders/unlit.frag
 FILE: ../../../flutter/impeller/scene/static_mesh_entity.cc
 FILE: ../../../flutter/impeller/scene/static_mesh_entity.h
 FILE: ../../../flutter/impeller/tessellator/c/tessellator.cc

impeller/playground/BUILD.gn

@@ -43,6 +43,7 @@ impeller_component("playground") {
     "../entity:modern_entity_shaders",
     "../fixtures:shader_fixtures",
     "../renderer",
+    "../scene/shaders",
     "imgui:imgui_impeller_backend",
     "//flutter/fml",
     "//third_party/glfw",

impeller/playground/backend/gles/playground_impl_gles.cc

@@ -13,6 +13,7 @@
 #include "impeller/playground/imgui/gles/imgui_shaders_gles.h"
 #include "impeller/renderer/backend/gles/context_gles.h"
 #include "impeller/renderer/backend/gles/surface_gles.h"
+#include "impeller/scene/shaders/gles/scene_shaders_gles.h"
 
 namespace impeller {
 
@@ -94,6 +95,8 @@ ShaderLibraryMappingsForPlayground() {
           impeller_fixtures_shaders_gles_length),
       std::make_shared<fml::NonOwnedMapping>(
           impeller_imgui_shaders_gles_data, impeller_imgui_shaders_gles_length),
+      std::make_shared<fml::NonOwnedMapping>(
+          impeller_scene_shaders_gles_data, impeller_scene_shaders_gles_length),
   };
 }
 

impeller/playground/backend/metal/playground_impl_mtl.mm

@@ -22,6 +22,7 @@
 #include "impeller/renderer/backend/metal/formats_mtl.h"
 #include "impeller/renderer/backend/metal/surface_mtl.h"
 #include "impeller/renderer/backend/metal/texture_mtl.h"
+#include "impeller/scene/shaders/mtl/scene_shaders.h"
 
 namespace impeller {
 
@@ -40,6 +41,8 @@
                                              impeller_fixtures_shaders_length),
       std::make_shared<fml::NonOwnedMapping>(impeller_imgui_shaders_data,
                                              impeller_imgui_shaders_length),
+      std::make_shared<fml::NonOwnedMapping>(impeller_scene_shaders_data,
+                                             impeller_scene_shaders_length),
 
   };
 }

impeller/playground/backend/vulkan/playground_impl_vk.cc

@@ -19,6 +19,7 @@
 #include "impeller/renderer/backend/vulkan/formats_vk.h"
 #include "impeller/renderer/backend/vulkan/surface_vk.h"
 #include "impeller/renderer/backend/vulkan/texture_vk.h"
+#include "impeller/scene/shaders/vk/scene_shaders_vk.h"
 
 namespace impeller {
 
@@ -34,6 +35,8 @@ ShaderLibraryMappingsForPlayground() {
           impeller_fixtures_shaders_vk_length),
       std::make_shared<fml::NonOwnedMapping>(impeller_imgui_shaders_vk_data,
                                              impeller_imgui_shaders_vk_length),
+      std::make_shared<fml::NonOwnedMapping>(impeller_scene_shaders_vk_data,
+                                             impeller_scene_shaders_vk_length),
 
   };
 }

impeller/scene/BUILD.gn

@@ -14,6 +14,8 @@ impeller_component("scene") {
     "material.h",
     "scene.cc",
     "scene.h",
+    "scene_context.cc",
+    "scene_context.h",
     "scene_encoder.cc",
     "scene_encoder.h",
     "scene_entity.cc",
@@ -22,7 +24,10 @@ impeller_component("scene") {
     "static_mesh_entity.h",
   ]
 
-  public_deps = [ "../renderer" ]
+  public_deps = [
+    "../renderer",
+    "shaders",
+  ]
 
   deps = [ "//flutter/fml" ]
 }

impeller/scene/scene.cc

@@ -9,12 +9,14 @@
 
 #include "flutter/fml/logging.h"
 #include "impeller/renderer/render_target.h"
+#include "impeller/scene/scene_context.h"
 #include "impeller/scene/scene_encoder.h"
 
 namespace impeller {
 namespace scene {
 
-Scene::Scene(const std::shared_ptr<Context>& context) : context_(context){};
+Scene::Scene(std::shared_ptr<Context> context)
+    : scene_context_(std::make_unique<SceneContext>(std::move(context))){};
 
 void Scene::Add(const std::shared_ptr<SceneEntity>& child) {
   root_.Add(child);
@@ -31,7 +33,8 @@ bool Scene::Render(const RenderTarget& render_target,
 
   // Encode the commands.
   std::shared_ptr<CommandBuffer> command_buffer =
-      encoder.BuildSceneCommandBuffer(*context_, render_target);
+      encoder.BuildSceneCommandBuffer(*scene_context_->GetContext(),
+                                      render_target);
 
   // TODO(bdero): Do post processing.
 

impeller/scene/scene.h

@@ -11,6 +11,7 @@
 
 #include "impeller/renderer/render_target.h"
 #include "impeller/scene/camera.h"
+#include "impeller/scene/scene_context.h"
 #include "impeller/scene/scene_entity.h"
 
 namespace impeller {
@@ -19,13 +20,13 @@ namespace scene {
 class Scene {
  public:
   Scene() = delete;
-  explicit Scene(const std::shared_ptr<Context>& context);
+  explicit Scene(std::shared_ptr<Context> context);
 
   void Add(const std::shared_ptr<SceneEntity>& child);
   bool Render(const RenderTarget& render_target, const Camera& camera) const;
 
  private:
-  std::shared_ptr<Context> context_;
+  std::unique_ptr<SceneContext> scene_context_;
   SceneEntity root_;
 
   FML_DISALLOW_COPY_AND_ASSIGN(Scene);

impeller/scene/scene_context.cc

@@ -0,0 +1,50 @@
+// 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/scene/scene_context.h"
+
+namespace impeller {
+namespace scene {
+
+void SceneContextOptions::ApplyToPipelineDescriptor(
+    PipelineDescriptor& desc) const {
+  desc.SetSampleCount(sample_count);
+  desc.SetPrimitiveType(primitive_type);
+}
+
+template <typename PipelineT>
+static std::unique_ptr<PipelineT> CreateDefaultPipeline(
+    const Context& context) {
+  auto desc = PipelineT::Builder::MakeDefaultPipelineDescriptor(context);
+  if (!desc.has_value()) {
+    return nullptr;
+  }
+  // Apply default ContentContextOptions to the descriptor.
+  SceneContextOptions{}.ApplyToPipelineDescriptor(*desc);
+  return std::make_unique<PipelineT>(context, desc);
+}
+
+SceneContext::SceneContext(std::shared_ptr<Context> context)
+    : context_(std::move(context)) {
+  if (!context_ || !context_->IsValid()) {
+    return;
+  }
+
+  unlit_pipeline_[{}] = CreateDefaultPipeline<UnlitPipeline>(*context_);
+
+  is_valid_ = true;
+}
+
+SceneContext::~SceneContext() = default;
+
+bool SceneContext::IsValid() const {
+  return is_valid_;
+}
+
+std::shared_ptr<Context> SceneContext::GetContext() const {
+  return context_;
+}
+
+}  // namespace scene
+}  // namespace impeller

impeller/scene/scene_context.h

@@ -0,0 +1,100 @@
+// 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.
+
+#pragma once
+
+#include "impeller/renderer/context.h"
+#include "impeller/renderer/pipeline_descriptor.h"
+#include "impeller/scene/shaders/geometry.vert.h"
+#include "impeller/scene/shaders/unlit.frag.h"
+
+namespace impeller {
+namespace scene {
+
+using UnlitPipeline =
+    RenderPipelineT<GeometryVertexShader, UnlitFragmentShader>;
+
+struct SceneContextOptions {
+  SampleCount sample_count = SampleCount::kCount1;
+  PrimitiveType primitive_type = PrimitiveType::kTriangle;
+
+  struct Hash {
+    constexpr std::size_t operator()(const SceneContextOptions& o) const {
+      return fml::HashCombine(o.sample_count, o.primitive_type);
+    }
+  };
+
+  struct Equal {
+    constexpr bool operator()(const SceneContextOptions& lhs,
+                              const SceneContextOptions& rhs) const {
+      return lhs.sample_count == rhs.sample_count &&
+             lhs.primitive_type == rhs.primitive_type;
+    }
+  };
+
+  void ApplyToPipelineDescriptor(PipelineDescriptor& desc) const;
+};
+
+class SceneContext {
+ public:
+  explicit SceneContext(std::shared_ptr<Context> context);
+
+  ~SceneContext();
+
+  bool IsValid() const;
+
+  std::shared_ptr<Context> GetContext() const;
+
+  std::shared_ptr<Pipeline<PipelineDescriptor>> GetUnlitPipeline(
+      SceneContextOptions opts) const {
+    return GetPipeline(unlit_pipeline_, opts);
+  }
+
+ private:
+  std::shared_ptr<Context> context_;
+
+  template <class T>
+  using Variants = std::unordered_map<SceneContextOptions,
+                                      std::unique_ptr<T>,
+                                      SceneContextOptions::Hash,
+                                      SceneContextOptions::Equal>;
+
+  mutable Variants<UnlitPipeline> unlit_pipeline_;
+
+  template <class TypedPipeline>
+  std::shared_ptr<Pipeline<PipelineDescriptor>> GetPipeline(
+      Variants<TypedPipeline>& container,
+      SceneContextOptions opts) const {
+    if (!IsValid()) {
+      return nullptr;
+    }
+
+    if (auto found = container.find(opts); found != container.end()) {
+      return found->second->WaitAndGet();
+    }
+
+    auto prototype = container.find({});
+
+    // The prototype must always be initialized in the constructor.
+    FML_CHECK(prototype != container.end());
+
+    auto variant_future = prototype->second->WaitAndGet()->CreateVariant(
+        [&opts, variants_count = container.size()](PipelineDescriptor& desc) {
+          opts.ApplyToPipelineDescriptor(desc);
+          desc.SetLabel(
+              SPrintF("%s V#%zu", desc.GetLabel().c_str(), variants_count));
+        });
+    auto variant = std::make_unique<TypedPipeline>(std::move(variant_future));
+    auto variant_pipeline = variant->WaitAndGet();
+    container[opts] = std::move(variant);
+    return variant_pipeline;
+  }
+
+  bool is_valid_ = false;
+
+  FML_DISALLOW_COPY_AND_ASSIGN(SceneContext);
+};
+
+}  // namespace scene
+}  // namespace impeller