smooth_font_v2.h

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#pragma once
 
#include <memory>
#include <type_traits>
 
#include "font.h"
#include "roo_backport.h"
#include "roo_backport/byte.h"
#include "roo_display/hal/progmem.h"
 
namespace roo_display {
 
/// Smooth font v2 with split cmap and glyph metrics format.
class SmoothFontV2 : public Font {
 public:
  /// Legacy constructor for fonts using `uint8_t` byte data.
  template <typename U = uint8_t,
            typename std::enable_if<!std::is_same<U, roo::byte>::value,
                                    int>::type = 0>
  SmoothFontV2(const U* font_data PROGMEM)
      : SmoothFontV2((const roo::byte* PROGMEM)font_data) {}
 
  /// Construct from PROGMEM font data.
  SmoothFontV2(const roo::byte* font_data PROGMEM);
 
  void drawHorizontalString(const Surface& s, const char* utf8_data,
                            uint32_t size, Color color) const override;
 
  void drawGlyph(const Surface& s, char32_t code, FontLayout layout,
                 Color color) const override;
 
  bool getGlyphMetrics(char32_t code, FontLayout layout,
                       GlyphMetrics* result) const override;
 
  int16_t getKerning(char32_t left, char32_t right) const override;
 
  GlyphMetrics getHorizontalStringMetrics(const char* utf8_data,
                                          uint32_t size) const override;
 
  uint32_t getHorizontalStringGlyphMetrics(const char* utf8_data, uint32_t size,
                                           GlyphMetrics* result,
                                           uint32_t offset,
                                           uint32_t max_count) const override;
 
 private:
  class GlyphPairIterator;
  class GlyphMetadataReader;
  struct CmapEntry {
    uint16_t range_start;
    uint16_t range_end;
    uint16_t glyph_id_offset;
    uint16_t data_entries_count;
    uint32_t data_offset;
    uint8_t format;
  };
 
  bool rle() const { return compression_method_ > 0; }
  int16_t kerning(int left_glyph_index, int right_glyph_index) const;
  int16_t kerningWithClassFormat(int left_glyph_index,
                                 int right_glyph_index) const;
 
  // Lookup the glyph index in the cmap ranges.
  int findGlyphIndex(char32_t code) const;
  const roo::byte* PROGMEM findKernPair(char32_t left, char32_t right) const;
 
  void drawGlyphModeVisible(DisplayOutput& output, int16_t x, int16_t y,
                            const GlyphMetrics& metrics, bool compressed,
                            const roo::byte* PROGMEM data, const Box& clip_box,
                            Color color, Color bgcolor,
                            BlendingMode blending_mode) const;
 
  void drawGlyphModeFill(DisplayOutput& output, int16_t x, int16_t y,
                         int16_t bgwidth, const GlyphMetrics& glyph_metrics,
                         bool compressed, const roo::byte* PROGMEM data,
                         int16_t offset, const Box& clip_box, Color color,
                         Color bgColor, BlendingMode blending_mode) const;
 
  void drawKernedGlyphsModeFill(
      DisplayOutput& output, int16_t x, int16_t y, int16_t bgwidth,
      const GlyphMetrics& left_metrics, bool left_compressed,
      const roo::byte* PROGMEM left_data, int16_t left_offset,
      const GlyphMetrics& right_metrics, bool right_compressed,
      const roo::byte* PROGMEM right_data, int16_t right_offset,
      const Box& clip_box, Color color, Color bgColor,
      BlendingMode blending_mode) const;
 
  void drawBordered(DisplayOutput& output, int16_t x, int16_t y,
                    int16_t bgwidth, const Drawable& glyph, const Box& clip_box,
                    Color bgColor, BlendingMode blending_mode) const;
 
  int glyph_count_;
  int glyph_metadata_size_;
  int alpha_bits_;
  int encoding_bytes_;
  int font_metric_bytes_;
  int offset_bytes_;
  int glyph_index_bytes_;
  int compression_method_;
  int kerning_pairs_count_;
  int glyph_kerning_size_;
  uint8_t kerning_format_;
  uint16_t kerning_class_count_;
  uint16_t kerning_source_count_;
  int kerning_source_index_bytes_;
  int kerning_class_entries_count_;
  char32_t default_glyph_;
  int default_space_width_;
  const roo::byte* font_begin_ PROGMEM;
  const roo::byte* cmap_entries_begin_ PROGMEM;
  const roo::byte* glyph_metadata_begin_ PROGMEM;
  const roo::byte* glyph_kerning_begin_ PROGMEM;
  const roo::byte* kerning_source_table_begin_ PROGMEM;
  const roo::byte* kerning_class_table_begin_ PROGMEM;
  const roo::byte* kerning_class_entries_begin_ PROGMEM;
  const roo::byte* glyph_data_begin_ PROGMEM;
  // Cached for performance; improves glyph lookup speed slightly.
  int cmap_entries_count_;
  std::unique_ptr<CmapEntry[]> cmap_entries_;
};
 
}  // namespace roo_display