<br />
<b>Warning</b>:  session_start(): open(/var/lib/php/sessions/sess_tb1bes7o93op4b0ati1c7n3t72, O_RDWR) failed: No space left on device (28) in <b>/var/www/tb-usercake/models/config.php</b> on line <b>51</b><br />
<br />
<b>Warning</b>:  session_start(): Failed to read session data: files (path: /var/lib/php/sessions) in <b>/var/www/tb-usercake/models/config.php</b> on line <b>51</b><br />
import java.awt.geom.*;

static float drawArrowHead_length = 2f;

static void drawArrowHead(Graphics2D g, double x1, double y1, double x2, double y2, double size) {
  if (y2 == y1 && x2 == x1) ret;
  
  Path2D.Double arrowHead = new Path2D.Double();
  arrowHead.moveTo(0, 0);
  double l = drawArrowHead_length*size;
  arrowHead.lineTo(-size, -l);
  arrowHead.lineTo(size, -l);
  arrowHead.closePath();

  new AffineTransform tx;
  double angle = Math.atan2(y2-y1, x2-x1);
  tx.translate(x2, y2);
  tx.rotate(angle-Math.PI/2d);

  AffineTransform old = g.getTransform();
  g.setTransform(tx);
  g.fill(arrowHead);
  g.setTransform(old);
}