smooth_font.h

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#pragma once
 
#include <type_traits>
 
#include "font.h"
#include "roo_backport.h"
#include "roo_backport/byte.h"
#include "roo_display/hal/progmem.h"
 
namespace roo_display {
 
/// Anti-aliased font implementation based on PROGMEM data.
class SmoothFont : 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>
  SmoothFont(const U* font_data PROGMEM)
      : SmoothFont((const roo::byte* PROGMEM)font_data) {}
 
  /// Construct from PROGMEM font data.
  SmoothFont(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:
  bool rle() const { return compression_method_ > 0; }
  int16_t kerning(char32_t left, char32_t right) const;
 
  friend class GlyphPairIterator;
 
  class GlyphMetadataReader;
 
  // Binary-search for the glyph data.
  const roo::byte* PROGMEM findGlyph(char32_t code) const;
  const roo::byte* PROGMEM findKernPair(char32_t left, char32_t right) const;
 
  // Helper methods for drawing glyphs.
  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 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;
 
  void drawGlyphModeFill(DisplayOutput& output, int16_t x, int16_t y,
                         int16_t bgwidth, const GlyphMetrics& 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;
 
  int glyph_count_;
  int glyph_metadata_size_;
  int alpha_bits_;
  int encoding_bytes_;
  int font_metric_bytes_;
  int offset_bytes_;
  int compression_method_;
  int kerning_pairs_count_;
  int glyph_kerning_size_;
  char32_t default_glyph_;
  int default_space_width_;
  const roo::byte* glyph_metadata_begin_ PROGMEM;
  const roo::byte* glyph_kerning_begin_ PROGMEM;
  const roo::byte* glyph_data_begin_ PROGMEM;
};
 
}  // namespace roo_display