GrFont.h

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/*******************************************************************************
 * @file GrFont.h
 * @brief Defines the base class used by all Graphical Fonts
 ******************************************************************************/
 
#ifndef GRFONT_DEFINED
#define GRFONT_DEFINED
 
#include <arduino.h>
#include "Canvas.h"

struct CharDef_t
{
  uint16_t x;        
  uint16_t y;        
  uint16_t width;    
  uint16_t height;   
  int16_t xoffset;   
  int16_t yoffset;   
  uint16_t xadvance; 
};
 
/******************************************************************************/
/***                                                                        ***/
/***                     Class Definition: GrFont                           ***/
/***                                                                        ***/
/******************************************************************************
 * @brief Base class used by all Graphical Fonts
 ******************************************************************************/
class GrFont
{
public:
  const ROM_Image imgLoc; 
 
  const uint16_t LINE_HEIGHT; 
  const uint16_t BASE;        
 
private:
  ROM_Canvas _FontCanvas; // Canvas containing the font imagery
 
  // Tracks whether this instance has been initialized via the begin(...) method.
  bool _isInitialized = false;
 
  // Private method for initializing the font with a 12-bit color. This encoding
  // scheme uses bits 12:0 to encode RGB respectively.
  void _begin12Bit(uint16_t color12Bit);
 
public:
  GrFont(void) = delete;

  GrFont(ROM_Image imgLoc, uint16_t lineHeight, uint16_t base)
      : imgLoc{imgLoc}, LINE_HEIGHT{lineHeight}, BASE{base}, _FontCanvas{imgLoc} {};

  void begin(uint16_t color16Bit);

  void begin(uint8_t red, uint8_t green, uint8_t blue);

  virtual bool charDef(char cc, CharDef_t &results) const = 0;

  inline int8_t kerning(uint8_t first, uint8_t second) const
  {
    uint16_t ID = (static_cast<uint16_t>(first) << 8) | second;
    return kerning(ID);
  };

  uint8_t placeText(Canvas &canvas, char cc, uint16_t x, uint16_t y) const;

  uint8_t placeText(Canvas &canvas, const char *const text, uint16_t buffSize, uint16_t x, uint16_t y) const;

  uint16_t textWidth(const char cc) const;

  uint16_t textWidth(const char *const text, uint16_t buffSize) const;
 
protected:
  virtual int8_t kerning(uint16_t ID) const = 0;
};
 
#endif