tiled_texture_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_TILED_TEXTURE_CONTENTS_H_
#define FLUTTER_IMPELLER_ENTITY_CONTENTS_TILED_TEXTURE_CONTENTS_H_
 
#include <functional>
#include <memory>
 
#include "impeller/core/sampler_descriptor.h"
#include "impeller/entity/contents/color_source_contents.h"
#include "impeller/entity/contents/filters/color_filter_contents.h"
#include "impeller/entity/entity.h"
#include "impeller/renderer/capabilities.h"
 
namespace impeller {
 
class TiledTextureContents final : public ColorSourceContents {
 public:
  TiledTextureContents();
 
  ~TiledTextureContents() override;
 
  using ColorFilterProc =
      std::function<std::shared_ptr<ColorFilterContents>(FilterInput::Ref)>;
 
  // |Contents|
  bool IsOpaque(const Matrix& transform) const override;
 
  // |Contents|
  bool Render(const ContentContext& renderer,
              const Entity& entity,
              RenderPass& pass) const override;
 
  void SetTexture(std::shared_ptr<Texture> texture);
 
  void SetTileModes(Entity::TileMode x_tile_mode, Entity::TileMode y_tile_mode);
 
  void SetSamplerDescriptor(const SamplerDescriptor& desc);
 
  /// @brief Set a color filter to apply directly to this tiled texture
  /// @param color_filter
  ///
  /// When applying a color filter to a tiled texture, we can reduce the
  /// size and number of the subpasses required and the shader workload by
  /// applying the filter to the untiled image and absorbing the opacity before
  /// tiling it into the final location.
  ///
  /// This may not be a performance improvement if the image is tiled into a
  /// much smaller size that its original texture size.
  void SetColorFilter(ColorFilterProc color_filter);
 
  // |Contents|
  std::optional<Snapshot> RenderToSnapshot(
      const ContentContext& renderer,
      const Entity& entity,
      const SnapshotOptions& options) const override;
 
 private:
  std::shared_ptr<Texture> CreateFilterTexture(
      const ContentContext& renderer) const;
 
  SamplerDescriptor CreateSamplerDescriptor(
      const Capabilities& capabilities) const;
 
  bool UsesEmulatedTileMode(const Capabilities& capabilities) const;
 
  std::shared_ptr<Texture> texture_;
  SamplerDescriptor sampler_descriptor_ = {};
  Entity::TileMode x_tile_mode_ = Entity::TileMode::kClamp;
  Entity::TileMode y_tile_mode_ = Entity::TileMode::kClamp;
  ColorFilterProc color_filter_ = nullptr;
 
  TiledTextureContents(const TiledTextureContents&) = delete;
 
  TiledTextureContents& operator=(const TiledTextureContents&) = delete;
};
 
}  // namespace impeller
 
#endif  // FLUTTER_IMPELLER_ENTITY_CONTENTS_TILED_TEXTURE_CONTENTS_H_