// Display Library for SPI e-paper panels from Dalian Good Display and boards from Waveshare.
// Requires HW SPI and Adafruit_GFX. Caution: these e-papers require 3.3V supply AND data lines!
//
// based on Demo Example from Good Display: http://www.e-paper-display.com/download_list/downloadcategoryid=34&isMode=false.html
// Controller: UC8176 (IL0398) : https://www.good-display.com/public/html/pdfjs/viewer/viewernew.html?file=https://v4.cecdn.yun300.cn/100001_1909185148/UC8176-1.pdf
// Controller: IL0398 (UC8176) : http://www.e-paper-display.com/download_detail/downloadsId=537.html
//
// Author: Jean-Marc Zingg
//
// Version: see library.properties
//
// Library: https://github.com/ZinggJM/GxEPD2

#include "GxEPD2_420_M01.h"

GxEPD2_420_M01::GxEPD2_420_M01(int16_t cs, int16_t dc, int16_t rst, int16_t busy) :
  GxEPD2_EPD(cs, dc, rst, busy, LOW, 10000000, WIDTH, HEIGHT, panel, hasColor, hasPartialUpdate, hasFastPartialUpdate)
{
}

void GxEPD2_420_M01::clearScreen(uint8_t value)
{
  writeScreenBuffer(value);
  refresh(true);
  writeScreenBuffer(value);
}

void GxEPD2_420_M01::writeScreenBuffer(uint8_t value)
{
  _initial_write = false; // initial full screen buffer clean done
  if (!_using_partial_mode) _Init_Part();
  if (_initial_refresh)
  {
    _writeCommand(0x10); // init old data
    _startTransfer();
    for (uint32_t i = 0; i < uint32_t(WIDTH) * uint32_t(HEIGHT) / 8; i++)
    {
      _transfer(value);
    }
    _endTransfer();
  }
  _writeCommand(0x13);
  _startTransfer();
  for (uint32_t i = 0; i < uint32_t(WIDTH) * uint32_t(HEIGHT) / 8; i++)
  {
    _transfer(value);
  }
  _endTransfer();
}

void GxEPD2_420_M01::writeImage(const uint8_t bitmap[], int16_t x, int16_t y, int16_t w, int16_t h, bool invert, bool mirror_y, bool pgm)
{
  if (_initial_write) writeScreenBuffer(); // initial full screen buffer clean
  delay(1); // yield() to avoid WDT on ESP8266 and ESP32
  int16_t wb = (w + 7) / 8; // width bytes, bitmaps are padded
  x -= x % 8; // byte boundary
  w = wb * 8; // byte boundary
  int16_t x1 = x < 0 ? 0 : x; // limit
  int16_t y1 = y < 0 ? 0 : y; // limit
  int16_t w1 = x + w < int16_t(WIDTH) ? w : int16_t(WIDTH) - x; // limit
  int16_t h1 = y + h < int16_t(HEIGHT) ? h : int16_t(HEIGHT) - y; // limit
  int16_t dx = x1 - x;
  int16_t dy = y1 - y;
  w1 -= dx;
  h1 -= dy;
  if ((w1 <= 0) || (h1 <= 0)) return;
  if (!_using_partial_mode) _Init_Part();
  //uint32_t start = micros();
  _writeCommand(0x91); // partial in
  _setPartialRamArea(x1, y1, w1, h1);
  _writeCommand(0x13);
  _startTransfer();
  for (int16_t i = 0; i < h1; i++)
  {
    for (int16_t j = 0; j < w1 / 8; j++)
    {
      uint8_t data;
      // use wb, h of bitmap for index!
      int16_t idx = mirror_y ? j + dx / 8 + ((h - 1 - (i + dy))) * wb : j + dx / 8 + (i + dy) * wb;
      if (pgm)
      {
#if defined(__AVR) || defined(ESP8266) || defined(ESP32)
        data = pgm_read_byte(&bitmap[idx]);
#else
        data = bitmap[idx];
#endif
      }
      else
      {
        data = bitmap[idx];
      }
      if (invert) data = ~data;
      _transfer(data);
    }
  }
  _endTransfer();
  _writeCommand(0x92); // partial out
  //Serial.print("GxEPD2_420_M01::writeImage took "); Serial.println(micros() - start);
  delay(1); // yield() to avoid WDT on ESP8266 and ESP32
}

void GxEPD2_420_M01::writeImagePart(const uint8_t bitmap[], int16_t x_part, int16_t y_part, int16_t w_bitmap, int16_t h_bitmap,
                                    int16_t x, int16_t y, int16_t w, int16_t h, bool invert, bool mirror_y, bool pgm)
{
  if (_initial_write) writeScreenBuffer(); // initial full screen buffer clean
  delay(1); // yield() to avoid WDT on ESP8266 and ESP32
  if ((w_bitmap < 0) || (h_bitmap < 0) || (w < 0) || (h < 0)) return;
  if ((x_part < 0) || (x_part >= w_bitmap)) return;
  if ((y_part < 0) || (y_part >= h_bitmap)) return;
  int16_t wb_bitmap = (w_bitmap + 7) / 8; // width bytes, bitmaps are padded
  x_part -= x_part % 8; // byte boundary
  w = w_bitmap - x_part < w ? w_bitmap - x_part : w; // limit
  h = h_bitmap - y_part < h ? h_bitmap - y_part : h; // limit
  x -= x % 8; // byte boundary
  w = 8 * ((w + 7) / 8); // byte boundary, bitmaps are padded
  int16_t x1 = x < 0 ? 0 : x; // limit
  int16_t y1 = y < 0 ? 0 : y; // limit
  int16_t w1 = x + w < int16_t(WIDTH) ? w : int16_t(WIDTH) - x; // limit
  int16_t h1 = y + h < int16_t(HEIGHT) ? h : int16_t(HEIGHT) - y; // limit
  int16_t dx = x1 - x;
  int16_t dy = y1 - y;
  w1 -= dx;
  h1 -= dy;
  if ((w1 <= 0) || (h1 <= 0)) return;
  if (!_using_partial_mode) _Init_Part();
  _writeCommand(0x91); // partial in
  _setPartialRamArea(x1, y1, w1, h1);
  _writeCommand(0x13);
  _startTransfer();
  for (int16_t i = 0; i < h1; i++)
  {
    for (int16_t j = 0; j < w1 / 8; j++)
    {
      uint8_t data;
      // use wb_bitmap, h_bitmap of bitmap for index!
      int16_t idx = mirror_y ? x_part / 8 + j + dx / 8 + ((h_bitmap - 1 - (y_part + i + dy))) * wb_bitmap : x_part / 8 + j + dx / 8 + (y_part + i + dy) * wb_bitmap;
      if (pgm)
      {
#if defined(__AVR) || defined(ESP8266) || defined(ESP32)
        data = pgm_read_byte(&bitmap[idx]);
#else
        data = bitmap[idx];
#endif
      }
      else
      {
        data = bitmap[idx];
      }
      if (invert) data = ~data;
      _transfer(data);
    }
  }
  _endTransfer();
  _writeCommand(0x92); // partial out
  delay(1); // yield() to avoid WDT on ESP8266 and ESP32
}

void GxEPD2_420_M01::writeImage(const uint8_t* black, const uint8_t* color, int16_t x, int16_t y, int16_t w, int16_t h, bool invert, bool mirror_y, bool pgm)
{
  if (black)
  {
    writeImage(black, x, y, w, h, invert, mirror_y, pgm);
  }
}

void GxEPD2_420_M01::writeImagePart(const uint8_t* black, const uint8_t* color, int16_t x_part, int16_t y_part, int16_t w_bitmap, int16_t h_bitmap,
                                    int16_t x, int16_t y, int16_t w, int16_t h, bool invert, bool mirror_y, bool pgm)
{
  if (black)
  {
    writeImagePart(black, x_part, y_part, w_bitmap, h_bitmap, x, y, w, h, invert, mirror_y, pgm);
  }
}

void GxEPD2_420_M01::writeNative(const uint8_t* data1, const uint8_t* data2, int16_t x, int16_t y, int16_t w, int16_t h, bool invert, bool mirror_y, bool pgm)
{
  if (data1)
  {
    writeImage(data1, x, y, w, h, invert, mirror_y, pgm);
  }
}

void GxEPD2_420_M01::drawImage(const uint8_t bitmap[], int16_t x, int16_t y, int16_t w, int16_t h, bool invert, bool mirror_y, bool pgm)
{
  writeImage(bitmap, x, y, w, h, invert, mirror_y, pgm);
  refresh(x, y, w, h);
  writeImage(bitmap, x, y, w, h, invert, mirror_y, pgm);
}

void GxEPD2_420_M01::drawImagePart(const uint8_t bitmap[], int16_t x_part, int16_t y_part, int16_t w_bitmap, int16_t h_bitmap,
                                   int16_t x, int16_t y, int16_t w, int16_t h, bool invert, bool mirror_y, bool pgm)
{
  writeImagePart(bitmap, x_part, y_part, w_bitmap, h_bitmap, x, y, w, h, invert, mirror_y, pgm);
  refresh(x, y, w, h);
  writeImagePart(bitmap, x_part, y_part, w_bitmap, h_bitmap, x, y, w, h, invert, mirror_y, pgm);
}

void GxEPD2_420_M01::drawImage(const uint8_t* black, const uint8_t* color, int16_t x, int16_t y, int16_t w, int16_t h, bool invert, bool mirror_y, bool pgm)
{
  writeImage(black, color, x, y, w, h, invert, mirror_y, pgm);
  refresh(x, y, w, h);
  writeImage(black, color, x, y, w, h, invert, mirror_y, pgm);
}

void GxEPD2_420_M01::drawImagePart(const uint8_t* black, const uint8_t* color, int16_t x_part, int16_t y_part, int16_t w_bitmap, int16_t h_bitmap,
                                   int16_t x, int16_t y, int16_t w, int16_t h, bool invert, bool mirror_y, bool pgm)
{
  writeImagePart(black, color, x_part, y_part, w_bitmap, h_bitmap, x, y, w, h, invert, mirror_y, pgm);
  refresh(x, y, w, h);
  writeImagePart(black, color, x_part, y_part, w_bitmap, h_bitmap, x, y, w, h, invert, mirror_y, pgm);
}

void GxEPD2_420_M01::drawNative(const uint8_t* data1, const uint8_t* data2, int16_t x, int16_t y, int16_t w, int16_t h, bool invert, bool mirror_y, bool pgm)
{
  writeNative(data1, data2, x, y, w, h, invert, mirror_y, pgm);
  refresh(x, y, w, h);
  writeNative(data1, data2, x, y, w, h, invert, mirror_y, pgm);
}

void GxEPD2_420_M01::refresh(bool partial_update_mode)
{
  if (partial_update_mode) refresh(0, 0, WIDTH, HEIGHT);
  else
  {
    if (_using_partial_mode) _Init_Full();
    _Update_Full();
    _initial_refresh = false; // initial full update done
  }
}

void GxEPD2_420_M01::refresh(int16_t x, int16_t y, int16_t w, int16_t h)
{
  if (_initial_refresh) return refresh(false); // initial update needs be full update
  // intersection with screen
  int16_t w1 = x < 0 ? w + x : w; // reduce
  int16_t h1 = y < 0 ? h + y : h; // reduce
  int16_t x1 = x < 0 ? 0 : x; // limit
  int16_t y1 = y < 0 ? 0 : y; // limit
  w1 = x1 + w1 < int16_t(WIDTH) ? w1 : int16_t(WIDTH) - x1; // limit
  h1 = y1 + h1 < int16_t(HEIGHT) ? h1 : int16_t(HEIGHT) - y1; // limit
  if ((w1 <= 0) || (h1 <= 0)) return; 
  // make x1, w1 multiple of 8
  w1 += x1 % 8;
  if (w1 % 8 > 0) w1 += 8 - w1 % 8;
  x1 -= x1 % 8;
  if (!_using_partial_mode) _Init_Part();
  if (usePartialUpdateWindow) _writeCommand(0x91); // partial in
  _setPartialRamArea(x1, y1, w1, h1);
  _Update_Part();
  if (usePartialUpdateWindow) _writeCommand(0x92); // partial out
}

void GxEPD2_420_M01::powerOff(void)
{
  _PowerOff();
}

void GxEPD2_420_M01::hibernate()
{
  _PowerOff();
  if (_rst >= 0)
  {
    _writeCommand(0x07); // deep sleep
    _writeData(0xA5);    // check code
    _hibernating = true;
  }
}

void GxEPD2_420_M01::_setPartialRamArea(uint16_t x, uint16_t y, uint16_t w, uint16_t h)
{
  uint16_t xe = (x + w - 1) | 0x0007; // byte boundary inclusive (last byte)
  uint16_t ye = y + h - 1;
  x &= 0xFFF8; // byte boundary
  _writeCommand(0x90); // partial window
  _writeData(x / 256);
  _writeData(x % 256);
  _writeData(xe / 256);
  _writeData(xe % 256);
  _writeData(y / 256);
  _writeData(y % 256);
  _writeData(ye / 256);
  _writeData(ye % 256);
  _writeData(0x01); // don't see any difference
  //_writeData(0x00); // don't see any difference
}

void GxEPD2_420_M01::_PowerOn()
{
  if (!_power_is_on)
  {
    _writeCommand(0x04);
    _waitWhileBusy("_PowerOn", power_on_time);
  }
  _power_is_on = true;
}

void GxEPD2_420_M01::_PowerOff()
{
  _writeCommand(0x02); // power off
  _waitWhileBusy("_PowerOff", power_off_time);
  _power_is_on = false;
  _using_partial_mode = false;
}

void GxEPD2_420_M01::_InitDisplay()
{
  if (_hibernating) _reset();
  _writeCommand(0x00);     //panel setting
  _writeData(0x1f);    //LUT from OTP
  _writeData(0x0d);    //waiting for the electronic paper IC to release the idle signal
  _writeCommand(0x50);  //VCOM AND DATA INTERVAL SETTING
  _writeData(0x97);
}

// experimental partial screen update LUTs with balanced charge
// LUTs are filled with zeroes

#define T1 20 // charge balance pre-phase
#define T2 20 // optional extension
#define T3 40 // color change phase (b/w)
#define T4 40 // optional extension for one color
#define T5  3 // white sustain phase
#define T6  3 // black sustain phase

const unsigned char GxEPD2_420_M01::lut_20_vcom0_partial[] PROGMEM =
{
  0x00, T1, T2, T3, T4, 1, // 00 00 00 00
};

const unsigned char GxEPD2_420_M01::lut_21_ww_partial[] PROGMEM =
{ // 10 w
  0x02, T1, T2, T3, T5, 1, // 00 00 00 10
};

const unsigned char GxEPD2_420_M01::lut_22_bw_partial[] PROGMEM =
{ // 10 w
  //0x48, T1, T2, T3, T4, 1, // 01 00 10 00
  0x5A, T1, T2, T3, T4, 1, // 01 01 10 10 more white
};

const unsigned char GxEPD2_420_M01::lut_23_wb_partial[] PROGMEM =
{ // 01 b
  0x84, T1, T2, T3, T4, 1, // 10 00 01 00
  //0xA5, T1, T2, T3, T4, 1, // 10 10 01 01 more black
};

const unsigned char GxEPD2_420_M01::lut_24_bb_partial[] PROGMEM =
{ // 01 b
  0x01, T1, T2, T3, T6, 1, // 00 00 00 01
};

void GxEPD2_420_M01::_Init_Full()
{
  _InitDisplay();
  _PowerOn();
  _using_partial_mode = false;
}

void GxEPD2_420_M01::_Init_Part()
{
  _InitDisplay();
  if (hasPartialUpdate)
  {
    _writeCommand(0x01); // POWER SETTING
    _writeData (0x03);   // VDS_EN, VDG_EN internal
    _writeData (0x00);   // VCOM_HV, VGHL_LV=16V
    _writeData (0x2b);   // VDH=11V
    _writeData (0x2b);   // VDL=11V
    _writeCommand(0x06); // boost soft start
    _writeData (0x17);   // A
    _writeData (0x17);   // B
    _writeData (0x17);   // C
    _writeCommand(0x00); // panel setting
    _writeData(0x3f);    // 300x400 B/W mode, LUT set by register
    _writeCommand(0x30); // PLL setting
    _writeData (0x3a);   // 3a 100HZ   29 150Hz 39 200HZ 31 171HZ
    _writeCommand(0x61); // resolution setting
    _writeData (WIDTH / 256);
    _writeData (WIDTH % 256);
    _writeData (HEIGHT / 256);
    _writeData (HEIGHT % 256);
    _writeCommand(0x82); // vcom_DC setting
    _writeData (0x1A);   // -0.1 + 26 * -0.05 = -1.4V from OTP
    _writeCommand(0x50); // VCOM AND DATA INTERVAL SETTING
    //_writeData(0x97);    // WBmode:VBDF 17|D7 VBDW 97 VBDB 57   WBRmode:VBDF F7 VBDW 77 VBDB 37  VBDR B7
    _writeData(0xd7);    // border floating to avoid flashing
    _writeCommand(0x20);
    _writeDataPGM(lut_20_vcom0_partial, sizeof(lut_20_vcom0_partial), 44 - sizeof(lut_20_vcom0_partial));
    _writeCommand(0x21);
    _writeDataPGM(lut_21_ww_partial, sizeof(lut_21_ww_partial), 42 - sizeof(lut_21_ww_partial));
    _writeCommand(0x22);
    _writeDataPGM(lut_22_bw_partial, sizeof(lut_22_bw_partial), 42 - sizeof(lut_22_bw_partial));
    _writeCommand(0x23);
    _writeDataPGM(lut_23_wb_partial, sizeof(lut_23_wb_partial), 42 - sizeof(lut_23_wb_partial));
    _writeCommand(0x24);
    _writeDataPGM(lut_24_bb_partial, sizeof(lut_24_bb_partial), 42 - sizeof(lut_24_bb_partial));
  }
  _PowerOn();
  _using_partial_mode = true;
}

void GxEPD2_420_M01::_Update_Full()
{
  _writeCommand(0x12); //display refresh
  _waitWhileBusy("_Update_Full", full_refresh_time);
}

void GxEPD2_420_M01::_Update_Part()
{
  _writeCommand(0x12); //display refresh
  _waitWhileBusy("_Update_Part", partial_refresh_time);
}
