// mas964 ps5

import java.applet.*;
import java.awt.*;
import java.lang.Math;
import java.lang.String;
import StrokeAnimator;

public class SpinStroke extends StrokeAnimator {
  // draw line segments for each recorded input. Rotate them
  // over time.
  public void drawFrame(int ms) {
    Graphics g = imageBuffer.getGraphics();
    this.clearImageBuffer();
    g.setColor(this.getForeground());

    int i;
    if (numPoints > 0) {
      int length = 5;
      double theta;

      if (ms < 800)				  // pause the first 1.5 secs
	theta = 0;
      else
	theta = (double)(ms - 800) / 600.0;	  // radians!
      double costheta = Math.cos(theta);
      double sintheta = Math.sin(theta);

      // draw the line segment rotated
      for (i = 0; i < numPoints; i++) {
	int y1 = -length, y2 = length;		  // vertical line
	g.drawLine(x[i] + (int)(-y1 * sintheta), y[i] + (int)(y1 * costheta),
		   x[i] + (int)(-y2 * sintheta), y[i] + (int)(y2 * costheta));
      }
    }      
    repaint(); 
  }

  public void init() {
    this.setBackground(Color.white);
    this.setForeground(Color.black);
    super.init();
    if (frameDelay == 0) {
      frameDelay = 100;
    }
  }
}