core/fxge/cfx_glyphcache.h

// Copyright 2016 The PDFium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

// Original code copyright 2014 Foxit Software Inc. http://www.foxitsoftware.com

#ifndef CORE_FXGE_CFX_GLYPHCACHE_H_
#define CORE_FXGE_CFX_GLYPHCACHE_H_

#include <map>
#include <memory>
#include <tuple>

#include "core/fxcrt/bytestring.h"
#include "core/fxcrt/observed_ptr.h"
#include "core/fxcrt/retain_ptr.h"
#include "core/fxcrt/span.h"
#include "core/fxge/cfx_face.h"
#include "core/fxge/fx_font.h"

class CFX_Font;
class CFX_GlyphBitmap;
class CFX_Matrix;
class CFX_Path;
struct CFX_TextRenderOptions;

class CFX_GlyphCache final : public Retainable, public Observable {
 public:
  CONSTRUCT_VIA_MAKE_RETAIN;

  const CFX_GlyphBitmap* LoadGlyphBitmap(const CFX_Font* font,
                                         uint32_t glyph_index,
                                         bool bFontStyle,
                                         const CFX_Matrix& matrix,
                                         int dest_width,
                                         FontAntiAliasingMode anti_alias,
                                         CFX_TextRenderOptions* text_options);
  const CFX_Path* LoadGlyphPath(const CFX_Font* font,
                                uint32_t glyph_index,
                                int dest_width);
  int GetGlyphWidth(const CFX_Font* font,
                    uint32_t glyph_index,
                    int dest_width,
                    int weight);

 private:
  explicit CFX_GlyphCache(RetainPtr<CFX_Face> face);
  ~CFX_GlyphCache() override;

  using SizeToGlyphMap = std::map<uint32_t, std::unique_ptr<CFX_GlyphBitmap>>;
  // <glyph_index, width, weight, angle, vertical>
  using PathMapKey = std::tuple<uint32_t, int, int, int, bool>;
  // <glyph_index, dest_width, weight>
  using WidthMapKey = std::tuple<uint32_t, int, int>;

  std::unique_ptr<CFX_GlyphBitmap> RenderGlyph(uint32_t glyph_index,
                                               bool font_style,
                                               bool is_vertical,
                                               const CFX_Matrix& matrix,
                                               int dest_width,
                                               FontAntiAliasingMode anti_alias,
                                               const CFX_SubstFont* subst_font);
  CFX_GlyphBitmap* LookUpGlyphBitmap(const CFX_Font* font,
                                     const CFX_Matrix& matrix,
                                     const ByteString& FaceGlyphsKey,
                                     uint32_t glyph_index,
                                     bool bFontStyle,
                                     int dest_width,
                                     FontAntiAliasingMode anti_alias);

  RetainPtr<CFX_Face> const face_;
  std::map<ByteString, SizeToGlyphMap> size_map_;
  std::map<PathMapKey, std::unique_ptr<CFX_Path>> path_map_;
  std::map<WidthMapKey, int> width_map_;
};

#endif  //  CORE_FXGE_CFX_GLYPHCACHE_H_