Method drawLine

Code/Arduino_libraries/SSD1306/OLEDDisplay.cpp:169–206

Bresenham's algorithm - thx wikipedia and Adafruit_GFX

// Bresenham's algorithm - thx wikipedia and Adafruit_GFX
void OLEDDisplay::drawLine(int16_t x0, int16_t y0, int16_t x1, int16_t y1) {
  int16_t steep = abs(y1 - y0) > abs(x1 - x0);
  if (steep) {
    _swap_int16_t(x0, y0);
    _swap_int16_t(x1, y1);
  }

  if (x0 > x1) {
    _swap_int16_t(x0, x1);
    _swap_int16_t(y0, y1);
  }

  int16_t dx, dy;
  dx = x1 - x0;
  dy = abs(y1 - y0);

  int16_t err = dx / 2;
  int16_t ystep;

  if (y0 < y1) {
    ystep = 1;
  } else {
    ystep = -1;
  }

  for (; x0<=x1; x0++) {
    if (steep) {
      setPixel(y0, x0);
    } else {
      setPixel(x0, y0);
    }
    err -= dy;
    if (err < 0) {
      y0 += ystep;
      err += dx;
    }
  }
}

void OLEDDisplay::drawRect(int16_t x, int16_t y, int16_t width, int16_t height) {
  drawHorizontalLine(x, y, width);