LovyanGFX touch sample for M5Paper and M5StackCore2

LGFX_touch

#define LGFX_AUTODETECT

#include <LovyanGFX.hpp>

LGFX gfx;
LGFX_Sprite sp(&gfx);

lgfx::touch_point_t tp;
bool touched = false;
std::int32_t clip_top    = INT32_MAX;
std::int32_t clip_left   = INT32_MAX;
std::int32_t clip_right  = INT32_MIN;
std::int32_t clip_bottom = INT32_MIN;
int32_t x = -1, y = -1;

void setup(void)
{
  gfx.init();
  gfx.clear(TFT_WHITE);

  gfx.setRotation(1);
  gfx.setEpdMode(epd_mode_t::epd_fastest);
  gfx.startWrite();

  sp.setColorDepth(1);
  sp.createSprite(gfx.width(), gfx.height());
  sp.fillScreen(0);
  sp.setColor(1);
  sp.setPaletteColor(1, TFT_BLACK);
}

void loop(void)
{
  if (gfx.getTouch(&tp))
  {
    if (x != tp.x || y != tp.y || !touched)
    {
      if (!touched)
      {
        x = tp.x;
        clip_left   = x;
        clip_right  = x;
        y = tp.y;
        clip_top    = y;
        clip_bottom = y;
      }
      else
      {
        clip_left   = std::min(clip_left  , tp.x);
        clip_right  = std::max(clip_right , tp.x);
        clip_top    = std::min(clip_top   , tp.y);
        clip_bottom = std::max(clip_bottom, tp.y);
      }

      int i = -2;
      do
      {
        int je = 2 - abs(i);
        for (int j = -je; j <= je; ++j)
        {
          sp.drawLine(x + i, y + j, tp.x + i, tp.y + j);
        }
      } while (++i <= 2);

      clip_left   -= 3;
      clip_right  += 3;
      clip_top    -= 3;
      clip_bottom += 3;
      gfx.setClipRect(clip_left, clip_top, clip_right - clip_left + 1, clip_bottom - clip_top + 1);
      sp.pushSprite(0, 0, 0);
      gfx.clearClipRect();
      gfx.display();
      x = tp.x;
      y = tp.y;
      clip_left   = x;
      clip_right  = x;
      clip_top    = y;
      clip_bottom = y;
    }
    touched = true;
  }
  else
  {
    touched = false;
    delay(10);
  }
}