please include function drawThoughtLine.

static int drawThoughtArrow_size = 15;

static void drawThoughtArrow(BufferedImage bg,
  BufferedImage img1, int x1, int y1,
  BufferedImage img2, int x2, int y2, Color color) {
  double cs = thoughtCircleSize(img2)/2-1;
  double dist = pointDistance(x1, y1, x2, y2);
  double arrowLen = drawThoughtArrow_size*drawArrowHead_length-1;
  Pt v = blendPoints(new Pt(x2, y2), new Pt(x1, y1), (cs+arrowLen)/dist);
  Pt p = blendPoints(new Pt(x2, y2), new Pt(x1, y1), cs/dist);
  Graphics2D g = imageGraphics(bg);
  g.setColor(color);
  g.setStroke(new BasicStroke(drawThoughtLine_width));
  g.drawLine(x1, y1, v.x, v.y);
  drawArrowHead(g, x1, y1, p.x, p.y, drawThoughtArrow_size);
  g.dispose();
}