/**
 *  Adafruit SSD1306 library modified by William Greiman for
 *  unbuffered LiquidCrystal character mode.
 *
 * -- Further modified by JBoyton to support character scaling
 * and to allow horizontal positioning of text to any pixel.
 * Vertical text position is still limited to a row.
 * Added H/W SPI and I2C.
*/

#include "Arduino.h"

// Select interface mode: SPI, soft SPI, or I2C:
//
// HW SPI mode:   I2C=0; HW_SPI = 1
// Soft SPI mode: I2C=0; HW_SPI = 0
// I2C mode:	  I2C=1; HW_SPI = don't care

#define I2C 1
#define HW_SPI 0

// Define to set TWBR in init() (for I2C mode only)
// If commented out, TWBR is not set in init()
#define TWBR_INIT_VALUE 12	// I2C clock: 400 KHz

// Set to false if the chip does not require a reset pulse
#define RESET_PULSE 1

// Set to true to allow scaling of the 5x7 fonts up to 8X in size
#define SCALED_FONTS 1

// Set to 1 to use large fonts for numeric characters '0'-'9'
#define USE_2X_FONT 1
#define USE_3X_FONT 1
#define USE_8X_FONT 0

// Define to proportionally space "." and ":" characters
#define PROPORTIONAL_PUNCTUATION 1

// Select display size (choose only one)
#define SSD1306_128_64 1
#define SSD1306_128_32 0

//------------------------------------------------------------------------------

#if SSD1306_128_64
  #define SSD1306_LCDWIDTH  128
  #define SSD1306_LCDHEIGHT  64
#endif

#if SSD1306_128_32
  #define SSD1306_LCDWIDTH  128
  #define SSD1306_LCDHEIGHT  32
#endif

#define SSD1306_I2C_ADDRESS   0x3C	// 011110+SA0+RW - 0x3C or 0x3D

#define SSD1306_SETCONTRAST 0x81
#define SSD1306_DISPLAYALLON_RESUME 0xA4
#define SSD1306_DISPLAYALLON 0xA5
#define SSD1306_NORMALDISPLAY 0xA6
#define SSD1306_INVERTDISPLAY 0xA7
#define SSD1306_DISPLAYOFF 0xAE
#define SSD1306_DISPLAYON 0xAF

#define SSD1306_SETDISPLAYOFFSET 0xD3
#define SSD1306_SETCOMPINS 0xDA

#define SSD1306_SETVCOMDETECT 0xDB

#define SSD1306_SETDISPLAYCLOCKDIV 0xD5
#define SSD1306_SETPRECHARGE 0xD9

#define SSD1306_SETMULTIPLEX 0xA8

#define SSD1306_SETLOWCOLUMN 0x00
#define SSD1306_SETHIGHCOLUMN 0x10

#define SSD1306_COLUMNADDR 0x21
#define SSD1306_PAGEADDR   0x22

#define SSD1306_SETSTARTLINE 0x40
#define SSD1306_SETSTARTPAGE 0XB0
#define SSD1306_MEMORYMODE 0x20

#define SSD1306_COMSCANINC 0xC0
#define SSD1306_COMSCANDEC 0xC8

#define SSD1306_SEGREMAP 0xA0

#define SSD1306_CHARGEPUMP 0x8D

#define SSD1306_EXTERNALVCC 0x1
#define SSD1306_SWITCHCAPVCC 0x2

//------------------------------------------------------------------------------
class SSD1306_text : public Print {

public:
#if I2C
#if RESET_PULSE
  SSD1306_text(int8_t rst) : rst_(rst) {}
#else
  SSD1306_text() {}
#endif
#else
#if HW_SPI
  SSD1306_text(int8_t dc, int8_t rst, int8_t cs)
    :dc_(dc), rst_(rst), cs_(cs) {}
#else // software SPI
  SSD1306_text(int8_t data, int8_t clk, int8_t dc, int8_t rst, int8_t cs)
    :data_(data), clk_(clk), dc_(dc), rst_(rst), cs_(cs) {}
#endif
#endif

  void init();
  void clear();
  void setCursor(uint8_t row, uint8_t col=0);
  uint8_t getRow() {return row_;}
  uint8_t getCol() {return col_;}
  void setTextSize(uint8_t size) {setTextSize(size, size);}
  void setTextSize(uint8_t size, uint8_t spacing) {textSize_ = size; textSpacing_ = spacing;}
#if USE_2X_FONT || USE_3X_FONT || USE_8X_FONT || SCALED_FONTS
  void setTextTransparent(bool transparent) {transparentSpacing_ = transparent;}
#endif
  size_t write(uint8_t c);
  int write(const char* str);
  size_t write(const uint8_t *buffer, size_t size);
  void sendCommand(uint8_t c);
  void sendData(uint8_t c);

private:
  void StartTransfer();
  void SelectCommand();
  void SelectData();
  void WriteData(uint8_t b);
  void EndTransfer();
  void I2CRestartTransfer();
  
  int8_t col_, row_;		// cursor position
  uint8_t textSize_, textSpacing_;	// text size and horiz char spacing (pixels between)
#if USE_2X_FONT || USE_3X_FONT || USE_8X_FONT || SCALED_FONTS
  bool transparentSpacing_;	// do not clear pixels between large characters
#endif
  
#if I2C
  int8_t data_, clk_;		// OLED pins
  uint8_t i2cCount, i2cControl, i2cIgnoreEnd;
#else // SPI
#if HW_SPI
  int8_t dc_, cs_;		// OLED pins
  volatile uint8_t *csport, *dcport;
  uint8_t cspinmask, dcpinmask;
#else // soft SPI
  int8_t data_, clk_, dc_, cs_;	// OLED pins
  volatile uint8_t *mosiport, *clkport, *csport, *dcport;
  uint8_t mosipinmask, clkpinmask, cspinmask, dcpinmask;
#endif
#endif

#if RESET_PULSE
  int8_t rst_;			// reset pin
#endif  
};