text: /*
   * Copyright (c) 2018-2020, Andreas Kling <kling@serenityos.org>
   * All rights reserved.
   *
   * Redistribution and use in source and binary forms, with or without
   * modification, are permitted provided that the following conditions are met:
   *
   * 1. Redistributions of source code must retain the above copyright notice, this
   *    list of conditions and the following disclaimer.
   *
   * 2. Redistributions in binary form must reproduce the above copyright notice,
   *    this list of conditions and the following disclaimer in the documentation
   *    and/or other materials provided with the distribution.
   *
   * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
   * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
   * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
   * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
   * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
   * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
   * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
   * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
   * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
   * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
   */
  
  #pragma once
  
  #include <AK/Forward.h>
  #include <AK/RefCounted.h>
  #include <AK/RefPtr.h>
  #include <LibGfx/Color.h>
  #include <LibGfx/Forward.h>
  #include <LibGfx/Rect.h>
  
  #define ENUMERATE_IMAGE_FORMATS           \
      __ENUMERATE_IMAGE_FORMAT(pbm, ".pbm") \
      __ENUMERATE_IMAGE_FORMAT(pgm, ".pgm") \
      __ENUMERATE_IMAGE_FORMAT(png, ".png") \
      __ENUMERATE_IMAGE_FORMAT(ppm, ".ppm") \
      __ENUMERATE_IMAGE_FORMAT(gif, ".gif") \
      __ENUMERATE_IMAGE_FORMAT(bmp, ".bmp") \
      __ENUMERATE_IMAGE_FORMAT(ico, ".ico") \
      __ENUMERATE_IMAGE_FORMAT(jpg, ".jpg") \
      __ENUMERATE_IMAGE_FORMAT(jpg, ".jpeg")
  
  namespace Gfx {
  
  enum class BitmapFormat {
      Invalid,
      Indexed1,
      Indexed2,
      Indexed4,
      Indexed8,
      RGB32,
      RGBA32,
  };
  
  enum class StorageFormat {
      Indexed8,
      RGB32,
      RGBA32,
  };
  
  static StorageFormat determine_storage_format(BitmapFormat format)
  {
      switch (format) {
      case BitmapFormat::RGB32:
          return StorageFormat::RGB32;
      case BitmapFormat::RGBA32:
          return StorageFormat::RGBA32;
      case BitmapFormat::Indexed1:
      case BitmapFormat::Indexed2:
      case BitmapFormat::Indexed4:
      case BitmapFormat::Indexed8:
          return StorageFormat::Indexed8;
      default:
          ASSERT_NOT_REACHED();
      }
  }
  
  struct BackingStore;
  
  enum RotationDirection {
      Left,
      Right
  };
  
  class Bitmap : public RefCounted<Bitmap> {
  public:
      static RefPtr<Bitmap> create(BitmapFormat, const IntSize&);
      static RefPtr<Bitmap> create_purgeable(BitmapFormat, const IntSize&);
      static RefPtr<Bitmap> create_wrapper(BitmapFormat, const IntSize&, size_t pitch, void*);
      static RefPtr<Bitmap> load_from_file(const StringView& path);
      static RefPtr<Bitmap> create_with_shared_buffer(BitmapFormat, NonnullRefPtr<SharedBuffer>&&, const IntSize&);
      static RefPtr<Bitmap> create_with_shared_buffer(BitmapFormat, NonnullRefPtr<SharedBuffer>&&, const IntSize&, const Vector<RGBA32>& palette);
      static bool is_path_a_supported_image_format(const StringView& path)
      {
  #define __ENUMERATE_IMAGE_FORMAT(Name, Ext) \
      if (path.ends_with(Ext))                \
          return true;
          ENUMERATE_IMAGE_FORMATS
  #undef __ENUMERATE_IMAGE_FORMAT
  
          return false;
      }
  
      RefPtr<Gfx::Bitmap> clone() const;
  
      RefPtr<Gfx::Bitmap> rotated(Gfx::RotationDirection) const;
      RefPtr<Gfx::Bitmap> flipped(Gfx::Orientation) const;
      RefPtr<Bitmap> to_bitmap_backed_by_shared_buffer() const;
  
      ShareableBitmap to_shareable_bitmap(pid_t peer_pid = -1) const;
  
      ~Bitmap();
  
      u8* scanline_u8(int y);
      const u8* scanline_u8(int y) const;
      RGBA32* scanline(int y);
      const RGBA32* scanline(int y) const;
  
      IntRect rect() const { return { {}, m_size }; }
      IntSize size() const { return m_size; }
      int width() const { return m_size.width(); }
      int height() const { return m_size.height(); }
      size_t pitch() const { return m_pitch; }
      int shbuf_id() const;
  
      SharedBuffer* shared_buffer() { return m_shared_buffer.ptr(); }
      const SharedBuffer* shared_buffer() const { return m_shared_buffer.ptr(); }
  
      ALWAYS_INLINE bool is_indexed() const
      {
          return is_indexed(m_format);
      }
  
      ALWAYS_INLINE static bool is_indexed(BitmapFormat format)
      {
          return format == BitmapFormat::Indexed8 || format == BitmapFormat::Indexed4
              || format == BitmapFormat::Indexed2 || format == BitmapFormat::Indexed1;
      }
  
      size_t palette_size(BitmapFormat format) const
      {
          switch (format) {
          case BitmapFormat::Indexed1:
              return 2;
          case BitmapFormat::Indexed2:
              return 4;
          case BitmapFormat::Indexed4:
              return 16;
          case BitmapFormat::Indexed8:
              return 256;
          default:
              return 0;
          }
      }
  
      Vector<RGBA32> palette_to_vector() const;
  
      static unsigned bpp_for_format(BitmapFormat format)
      {
          switch (format) {
          case BitmapFormat::Indexed1:
              return 1;
          case BitmapFormat::Indexed2:
              return 2;
          case BitmapFormat::Indexed4:
              return 4;
          case BitmapFormat::Indexed8:
              return 8;
          case BitmapFormat::RGB32:
          case BitmapFormat::RGBA32:
              return 32;
          default:
              ASSERT_NOT_REACHED();
          case BitmapFormat::Invalid:
              return 0;
          }
      }
  
      static size_t minimum_pitch(size_t width, BitmapFormat);
  
      unsigned bpp() const
      {
          return bpp_for_format(m_format);
      }
  
      void fill(Color);
  
      bool has_alpha_channel() const { return m_format == BitmapFormat::RGBA32; }
      BitmapFormat format() const { return m_format; }
  
      void set_mmap_name(const StringView&);
  
      static constexpr size_t size_in_bytes(size_t pitch, int height) { return pitch * height; }
      size_t size_in_bytes() const { return size_in_bytes(m_pitch, height()); }
  
      Color palette_color(u8 index) const { return Color::from_rgba(m_palette[index]); }
      void set_palette_color(u8 index, Color color) { m_palette[index] = color.value(); }
  
      template<StorageFormat>
      Color get_pixel(int x, int y) const;
      Color get_pixel(int x, int y) const;
      Color get_pixel(const IntPoint& position) const
      {
          return get_pixel(position.x(), position.y());
      }
  
      template<StorageFormat>
      void set_pixel(int x, int y, Color);
      void set_pixel(int x, int y, Color);
      void set_pixel(const IntPoint& position, Color color)
      {
          set_pixel(position.x(), position.y(), color);
      }
  
      bool is_purgeable() const { return m_purgeable; }
      bool is_volatile() const { return m_volatile; }
      void set_volatile();
      [[nodiscard]] bool set_nonvolatile();
  
  private:
      enum class Purgeable {
          No,
          Yes
      };
      Bitmap(BitmapFormat, const IntSize&, Purgeable, const BackingStore&);
      Bitmap(BitmapFormat, const IntSize&, size_t pitch, void*);
      Bitmap(BitmapFormat, NonnullRefPtr<SharedBuffer>&&, const IntSize&, const Vector<RGBA32>& palette);
  
      static Optional<BackingStore> allocate_backing_store(BitmapFormat, const IntSize&, Purgeable);
  
      void allocate_palette_from_format(BitmapFormat, const Vector<RGBA32>& source_palette);
  
      IntSize m_size;
      void* m_data { nullptr };
      RGBA32* m_palette { nullptr };
      size_t m_pitch { 0 };
      BitmapFormat m_format { BitmapFormat::Invalid };
      bool m_needs_munmap { false };
      bool m_purgeable { false };
      bool m_volatile { false };
      RefPtr<SharedBuffer> m_shared_buffer;
  };
  
  inline u8* Bitmap::scanline_u8(int y)
  {
      return reinterpret_cast<u8*>(m_data) + (y * m_pitch);
  }
  
  inline const u8* Bitmap::scanline_u8(int y) const
  {
      return reinterpret_cast<const u8*>(m_data) + (y * m_pitch);
  }
  
  inline RGBA32* Bitmap::scanline(int y)
  {
      return reinterpret_cast<RGBA32*>(scanline_u8(y));
  }
  
  inline const RGBA32* Bitmap::scanline(int y) const
  {
      return reinterpret_cast<const RGBA32*>(scanline_u8(y));
  }
  
  template<>
  inline Color Bitmap::get_pixel<StorageFormat::RGB32>(int x, int y) const
  {
      return Color::from_rgb(scanline(y)[x]);
  }
  
  template<>
  inline Color Bitmap::get_pixel<StorageFormat::RGBA32>(int x, int y) const
  {
      return Color::from_rgba(scanline(y)[x]);
  }
  
  template<>
  inline Color Bitmap::get_pixel<StorageFormat::Indexed8>(int x, int y) const
  {
      return Color::from_rgb(m_palette[scanline_u8(y)[x]]);
  }
  
  inline Color Bitmap::get_pixel(int x, int y) const
  {
      switch (determine_storage_format(m_format)) {
      case StorageFormat::RGB32:
          return get_pixel<StorageFormat::RGB32>(x, y);
      case StorageFormat::RGBA32:
          return get_pixel<StorageFormat::RGBA32>(x, y);
      case StorageFormat::Indexed8:
          return get_pixel<StorageFormat::Indexed8>(x, y);
      default:
          ASSERT_NOT_REACHED();
      }
  }
  
  template<>
  inline void Bitmap::set_pixel<StorageFormat::RGB32>(int x, int y, Color color)
  {
      scanline(y)[x] = color.value();
  }
  template<>
  inline void Bitmap::set_pixel<StorageFormat::RGBA32>(int x, int y, Color color)
  {
      scanline(y)[x] = color.value(); // drop alpha
  }
  inline void Bitmap::set_pixel(int x, int y, Color color)
  {
      switch (determine_storage_format(m_format)) {
      case StorageFormat::RGB32:
          set_pixel<StorageFormat::RGB32>(x, y, color);
          break;
      case StorageFormat::RGBA32:
          set_pixel<StorageFormat::RGBA32>(x, y, color);
          break;
      case StorageFormat::Indexed8:
          ASSERT_NOT_REACHED();
      default:
          ASSERT_NOT_REACHED();
      }
  }
  
  }
  