impeller/entity/contents/tiled_texture_contents.h

// 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 <functional>
#include <memory>
#include <vector>

#include "flutter/fml/macros.h"
#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/geometry/path.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 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(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 workloadby
  /// 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,
      std::optional<Rect> coverage_limit = std::nullopt,
      const std::optional<SamplerDescriptor>& sampler_descriptor = std::nullopt,
      bool msaa_enabled = true,
      const std::string& label = "Tiled Texture Snapshot") const override;

 private:
  std::shared_ptr<Texture> CreateFilterTexture(
      const ContentContext& renderer) const;

  SamplerDescriptor CreateDescriptor(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;

  FML_DISALLOW_COPY_AND_ASSIGN(TiledTextureContents);
};

}  // namespace impeller