- final double alpha = Math.atan2(py - prevY, px - prevX);
- //System.out.println("Draw arrow from (" + prevX + "," + prevY + ") to (" + px + "," + py
- // + ") with angle" + (int) (alpha * 180/Math.PI));
- final double MID_TO_VERTEX = 3.0;
- final double arrowX = MID_TO_VERTEX * Math.cos(alpha);
- final double arrowY = MID_TO_VERTEX * Math.sin(alpha);
- final double vertexX = midX + arrowX;
- final double vertexY = midY + arrowY;
- inG.drawLine((int)(midX-arrowX-2*arrowY), (int)(midY-arrowY+2*arrowX), (int)vertexX, (int)vertexY);
- inG.drawLine((int)(midX-arrowX+2*arrowY), (int)(midY-arrowY-2*arrowX), (int)vertexX, (int)vertexY);
+ final double midX = (prevX + px) / 2.0;
+ final double midY = (prevY + py) / 2.0;
+ final boolean midPointVisible = midX >= 0 && midX < winWidth && midY >= 0 && midY < winHeight;
+ if (midPointVisible)
+ {
+ final double alpha = Math.atan2(py - prevY, px - prevX);
+ //System.out.println("Draw arrow from (" + prevX + "," + prevY + ") to (" + px + "," + py
+ // + ") with angle" + (int) (alpha * 180/Math.PI));
+ final double MID_TO_VERTEX = 3.0;
+ final double arrowX = MID_TO_VERTEX * Math.cos(alpha);
+ final double arrowY = MID_TO_VERTEX * Math.sin(alpha);
+ final double vertexX = midX + arrowX;
+ final double vertexY = midY + arrowY;
+ inG.drawLine((int)(midX-arrowX-2*arrowY), (int)(midY-arrowY+2*arrowX), (int)vertexX, (int)vertexY);
+ inG.drawLine((int)(midX-arrowX+2*arrowY), (int)(midY-arrowY-2*arrowX), (int)vertexX, (int)vertexY);
+ }
+ drawnLastArrow = midPointVisible;