/***************************************************************************************
// The following class creates Sprites in RAM, graphics can then be drawn in the Sprite
// and rendered quickly onto the TFT screen. The class inherits the graphics functions
// from the TFT_eSPI class. Some functions are overridden by this class so that the
// graphics are written to the Sprite rather than the TFT.
***************************************************************************************/

class TFT_eSprite : public TFT_eSPI {

 public:

  TFT_eSprite(TFT_eSPI *tft);

           // Create a sprite of width x height pixels, return a pointer to the RAM area
           // Sketch can cast returned value to (uint16_t*) for 16 bit depth if needed
           // RAM required is 1 byte per pixel for 8 bit colour depth, 2 bytes for 16 bit
  void*    createSprite(int16_t width, int16_t height);  

           // Delete the sprite to free up the RAM
  void     deleteSprite(void);

           // Set the colour depth to 8 or 16 bits. Can be used to change depth an existing
           // sprite, but clears it to black, returns a new pointer if sprite is re-created.
  void*    setColorDepth(int8_t b);

  void     drawPixel(uint32_t x, uint32_t y, uint32_t color);

  void     drawChar(int32_t x, int32_t y, unsigned char c, uint32_t color, uint32_t bg, uint8_t size),

           fillSprite(uint32_t color),

           // Define a window to push 16 bit colour pixels into is a raster order
           // Colours are converted to 8 bit if depth is set to 8
           setWindow(int32_t x0, int32_t y0, int32_t x1, int32_t y1),
           pushColor(uint32_t color),
           pushColor(uint32_t color, uint16_t len),
           // Push a pixel preformatted as a 8 or 16 bit colour (avoids conversion overhead)
           writeColor(uint16_t color),

           // Set the scroll zone, top left corner at x,y with defined width and height
           // The colour (optional, black is default) is used to fill the gap after the scroll
           setScrollRect(int32_t x, int32_t y, uint32_t w, uint32_t h, uint16_t color = TFT_BLACK),
           // Scroll the defined zone dx,dy pixels. Negative values left,up, positive right,down
           // dy is optional (default is then no up/down scroll).
           // The sprite coordinate frame does not move because pixels are moved
           scroll(int16_t dx, int16_t dy = 0),

           drawLine(int32_t x0, int32_t y0, int32_t x1, int32_t y1, uint32_t color),
           drawFastVLine(int32_t x, int32_t y, int32_t h, uint32_t color),
           drawFastHLine(int32_t x, int32_t y, int32_t w, uint32_t color),

           fillRect(int32_t x, int32_t y, int32_t w, int32_t h, uint32_t color),

           // Set the sprite text cursor position for print class (does not change the TFT screen cursor)
           setCursor(int16_t x, int16_t y);

           // Read the colour of a pixel at x,y and return value in 565 format 
  uint16_t readPixel(int32_t x0, int32_t y0);

           // Write an image (colour bitmap) to the sprite
  void     pushImage(int32_t x0, int32_t y0, uint32_t w, uint32_t h, uint16_t *data);
  void     pushImage(int32_t x0, int32_t y0, uint32_t w, uint32_t h, const uint16_t *data);

           // Swap the byte order for pushImage() - corrects different image endianness
  void     setSwapBytes(bool swap);
  bool     getSwapBytes(void);

           // Push the sprite to the TFT screen, this fn calls pushImage() in the TFT class.
           // Optionally a "transparent" colour can be defined, pixels of that colour will not be rendered
  void     pushSprite(int32_t x, int32_t y);
  void     pushSprite(int32_t x, int32_t y, uint16_t transparent);

  int16_t  drawChar(unsigned int uniCode, int x, int y, int font),
           drawChar(unsigned int uniCode, int x, int y);

           // Return the width and height of the sprite
  int16_t  width(void),
           height(void);

           // Used by print class to print text to cursor position
  size_t   write(uint8_t);

           // Functions associated with anti-aliased fonts
  void     drawGlyph(uint16_t code);
  void     printToSprite(String string);
  void     printToSprite(char *cbuffer, int len);
  int16_t  printToSprite(int16_t x, int16_t y, uint16_t index);

 private:

  TFT_eSPI *_tft;

 protected:

  uint16_t *_img;  // pointer to 16 bit sprite
  uint8_t  *_img8; // pointer to  8 bit sprite
  bool     _created, _bpp16; // created and bits per pixel depth flags

  bool     _gFont = false; 

  int32_t  _icursor_x, _icursor_y;
  int32_t  _xs, _ys, _xe, _ye, _xptr, _yptr; // for setWindow
  int32_t  _sx, _sy; // x,y for scroll zone
  uint32_t _sw, _sh; // w,h for scroll zone
  uint32_t _scolor;  // gap fill colour for scroll zone

  boolean  _iswapBytes; // Swap the byte order for Sprite pushImage()

  int32_t  _iwidth, _iheight; // Sprite image width and height

};