runtime_effect_contents.h

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// 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.
 
#ifndef FLUTTER_IMPELLER_ENTITY_CONTENTS_RUNTIME_EFFECT_CONTENTS_H_
#define FLUTTER_IMPELLER_ENTITY_CONTENTS_RUNTIME_EFFECT_CONTENTS_H_
 
#include <memory>
#include <vector>
 
#include "impeller/core/host_buffer.h"
#include "impeller/core/sampler_descriptor.h"
#include "impeller/entity/contents/color_source_contents.h"
#include "impeller/runtime_stage/runtime_stage.h"
 
namespace impeller {
 
class RuntimeEffectContents final : public ColorSourceContents {
 public:
  explicit RuntimeEffectContents(const Geometry* geometry);
 
  ~RuntimeEffectContents() override;
  struct TextureInput {
    SamplerDescriptor sampler_descriptor;
    std::shared_ptr<Texture> texture;
  };
 
  void SetRuntimeStage(std::shared_ptr<RuntimeStage> runtime_stage);
 
  void SetUniformData(std::shared_ptr<std::vector<uint8_t>> uniform_data);
 
  void SetTextureInputs(std::vector<TextureInput> texture_inputs);
 
  const Geometry* GetGeometry() const override;
 
  // |Contents|
  bool Render(const ContentContext& renderer,
              const Entity& entity,
              RenderPass& pass) const override;
 
  /// Load the runtime effect and ensure a default PSO is initialized.
  bool BootstrapShader(const ContentContext& renderer) const;
 
  // Visible for testing
  /// Copies the uniform data into the host buffer.
  ///
  /// If the `uniform` has a `padding_layout`, it is used to repack the data.
  ///
  /// @param source_data The pointer to the start of the uniform data in the
  ///        source.
  /// @param host_buffer The host buffer to emplace the uniform data into.
  /// @param uniform The description of the uniform being emplaced.
  static BufferView EmplaceUniform(const uint8_t* source_data,
                                   HostBuffer& host_buffer,
                                   const RuntimeUniformDescription& uniform);
 
 private:
  bool RegisterShader(const ContentContext& renderer) const;
 
  // If async is true, this will always return nullptr as pipeline creation
  // is not blocked on.
  std::shared_ptr<Pipeline<PipelineDescriptor>> CreatePipeline(
      const ContentContext& renderer,
      ContentContextOptions options,
      bool async) const;
 
  const Geometry* geometry_ = nullptr;
  std::shared_ptr<RuntimeStage> runtime_stage_;
  // Scoped registry name for `runtime_stage_`'s fragment function. Stable
  // across the lifetime of a single `runtime_stage_` value, so we compute
  // it once in `SetRuntimeStage` rather than per `Render`.
  std::string scoped_fragment_name_;
  std::shared_ptr<std::vector<uint8_t>> uniform_data_;
  std::vector<TextureInput> texture_inputs_;
};
 
}  // namespace impeller
 
#endif  // FLUTTER_IMPELLER_ENTITY_CONTENTS_RUNTIME_EFFECT_CONTENTS_H_