Add box shader sample.

engine/src/flutter/impeller/compiler/code_gen_template.h

@@ -17,6 +17,7 @@ namespace impeller {
 namespace shader {
 
 struct {{camel_case(shader_name)}}{{camel_case(shader_stage)}}Info {
+  static constexpr std::string_view kLabel = "{{camel_case(shader_name)}}";
   static constexpr std::string_view kEntrypointName = "{{entrypoint}}";
   static constexpr ShaderStage kShaderStage = {{to_shader_stage(shader_stage)}};
 

engine/src/flutter/impeller/impeller/compositor/context.mm

@@ -64,4 +64,8 @@ id<MTLCommandQueue> Context::GetTransferQueue() const {
   return transfer_queue_;
 }
 
+std::shared_ptr<ShaderLibrary> Context::GetShaderLibrary() const {
+  return shader_library_;
+}
+
 }  // namespace impeller

engine/src/flutter/impeller/impeller/compositor/pipeline_builder.h

@@ -4,7 +4,10 @@
 
 #pragma once
 
+#include <functional>
 #include <memory>
+#include <type_traits>
+#include <unordered_map>
 
 #include "flutter/fml/macros.h"
 #include "impeller/compositor/pipeline_descriptor.h"
@@ -19,19 +22,21 @@ class PipelineBuilder {
 
   ~PipelineBuilder();
 
-  PipelineBuilder& SetLabel();
+  PipelineBuilder& SetLabel(const std::string_view& label);
 
-  PipelineBuilder& SetSampleCountCount(size_t samples);
+  PipelineBuilder& SetSampleCount(size_t samples);
 
-  PipelineBuilder& SetVertexFunction(std::shared_ptr<ShaderFunction> function);
-
-  PipelineBuilder& SetFragmentFunction(
-      std::shared_ptr<ShaderFunction> function);
+  PipelineBuilder& AddStageEntrypoint(std::shared_ptr<ShaderFunction> function);
 
   PipelineBuilder& SetVertexDescriptor(
       std::shared_ptr<VertexDescriptor> vertex_descriptor);
 
  private:
+  std::string label_;
+  size_t sample_count_ = 1;
+  std::unordered_map<ShaderStage, std::shared_ptr<ShaderFunction>> entrypoints_;
+  std::shared_ptr<VertexDescriptor> vertex_descriptor_;
+
   FML_DISALLOW_COPY_AND_ASSIGN(PipelineBuilder);
 };
 

engine/src/flutter/impeller/impeller/compositor/pipeline_builder.mm

@@ -10,4 +10,35 @@ PipelineBuilder::PipelineBuilder() = default;
 
 PipelineBuilder::~PipelineBuilder() = default;
 
+PipelineBuilder& PipelineBuilder::SetLabel(const std::string_view& label) {
+  label_ = {label.data(), label.size()};
+  return *this;
+}
+
+PipelineBuilder& PipelineBuilder::SetSampleCount(size_t samples) {
+  sample_count_ = samples;
+  return *this;
+}
+
+PipelineBuilder& PipelineBuilder::AddStageEntrypoint(
+    std::shared_ptr<ShaderFunction> function) {
+  if (!function) {
+    return *this;
+  }
+
+  if (function->GetStage() == ShaderStage::kUnknown) {
+    return *this;
+  }
+
+  entrypoints_[function->GetStage()] = std::move(function);
+
+  return *this;
+}
+
+PipelineBuilder& PipelineBuilder::SetVertexDescriptor(
+    std::shared_ptr<VertexDescriptor> vertex_descriptor) {
+  vertex_descriptor_ = std::move(vertex_descriptor);
+  return *this;
+}
+
 }  // namespace impeller

engine/src/flutter/impeller/impeller/compositor/shader_library.h

@@ -8,6 +8,7 @@
 
 #include <memory>
 #include <string>
+#include <string_view>
 
 #include "flutter/fml/macros.h"
 #include "impeller/shader_glue/shader_types.h"
@@ -37,7 +38,7 @@ class ShaderLibrary {
  public:
   ~ShaderLibrary();
 
-  std::shared_ptr<ShaderFunction> GetFunction(const std::string& name,
+  std::shared_ptr<ShaderFunction> GetFunction(const std::string_view& name,
                                               ShaderStage stage);
 
  private:

engine/src/flutter/impeller/impeller/compositor/shader_library.mm

@@ -20,9 +20,9 @@ ShaderLibrary::ShaderLibrary(id<MTLLibrary> library) : library_(library) {}
 ShaderLibrary::~ShaderLibrary() = default;
 
 std::shared_ptr<ShaderFunction> ShaderLibrary::GetFunction(
-    const std::string& name,
+    const std::string_view& name,
     ShaderStage stage) {
-  auto function = [library_ newFunctionWithName:@(name.c_str())];
+  auto function = [library_ newFunctionWithName:@(name.data())];
   if (!function) {
     return nullptr;
   }

engine/src/flutter/impeller/impeller/primitives/BUILD.gn

@@ -14,8 +14,8 @@ impeller_shaders("impeller_shaders") {
 
 impeller_component("primitives") {
   sources = [
-    "box.cc",
     "box.h",
+    "box.mm",
   ]
 
   public_deps = [ "../compositor" ]

engine/src/flutter/impeller/impeller/primitives/box.cc

@@ -1,14 +0,0 @@
-// 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/primitives/box.h"
-
-#include "box.frag.h"
-#include "box.vert.h"
-
-namespace impeller {
-
-void RenderBox() {}
-
-}  // namespace impeller

engine/src/flutter/impeller/impeller/primitives/box.h

@@ -2,8 +2,10 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
+#include "impeller/compositor/context.h"
+
 namespace impeller {
 
-void RenderBox();
+void RenderBox(std::shared_ptr<Context> context);
 
 }  // namespace impeller

engine/src/flutter/impeller/impeller/primitives/box.mm

@@ -0,0 +1,26 @@
+// 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/primitives/box.h"
+
+#include "box.frag.h"
+#include "box.vert.h"
+#include "impeller/compositor/pipeline_builder.h"
+
+namespace impeller {
+
+void RenderBox(std::shared_ptr<Context> context) {
+  PipelineBuilder builder;
+
+  auto fragment_function = context->GetShaderLibrary()->GetFunction(
+      shader::BoxFragmentInfo::kEntrypointName, ShaderStage::kFragment);
+  auto vertex_function = context->GetShaderLibrary()->GetFunction(
+      shader::BoxVertexInfo::kEntrypointName, ShaderStage::kVertex);
+
+  builder.AddStageEntrypoint(vertex_function);
+  builder.AddStageEntrypoint(fragment_function);
+  builder.SetLabel(shader::BoxVertexInfo::kLabel);
+}
+
+}  // namespace impeller