package OSI.OPE.MVU.OVU.OVU.PQE.nodeEdit.C;
import java.awt.Graphics2D;
//作者,著作权人： 罗瑶光，浏阳
public interface DrawArrow{
  public void doDrawArrow(Graphics2D graphics2D
  , int x, int y, int connectX, int connectY);
  public void drawCurve(Graphics2D graphics2D
  , int x, int y, int connectX, int connectY, double scale);
}
///////////////////////////////////////////

package OSI.OPE.OVU.MVU.OVU.PQE.nodeEdit;
import java.awt.*;

import OSI.OPE.MVU.OVU.OVU.PQE.nodeEdit.C.DrawArrow;
//作者,著作权人： 罗瑶光，浏阳
public class DrawArrowVPS implements DrawArrow {
  public void doDrawArrow(Graphics2D graphics2D
  , int x, int y, int connectX, int connectY) {
    x+= 10;
    connectX-= 10;
    graphics2D.setStroke(new BasicStroke(2
    , BasicStroke.CAP_SQUARE, BasicStroke.JOIN_ROUND));
    drawCurve(graphics2D, x, y, connectX, connectY, 6);
    DrawSinLineVPS.drawHead(connectX- 8, connectY- 3, graphics2D);
  }
    //下面这个化三角箭头函数是JAVA2D awt demo
  //罗瑶光先生进行了2次修改.
  public void drawCurve(Graphics2D graphics2D
  , int x, int y, int connectX, int connectY
      , double scale) {
    double distanceX= Math.abs(x- connectX);
    double distanceY= Math.abs(y- connectY);    
    double signOfPointX= (x - connectX < 0)? 1: -1;
    double signOfPointY= (y - connectY < 0)? 1: -1;
    double averageOfDistanceY= (distanceX== 0)
    ? 0: distanceY/ distanceX;  
    double signOfPointYWithaverageOfDistanceY
    = averageOfDistanceY* signOfPointY;
    double oldRegisterY= 0;
    boolean firstTime= true;
    double signOfPointYWithaverageOfDistanceYKernel
    = signOfPointYWithaverageOfDistanceY* 8;
    double averageOfDistanceYKernel= averageOfDistanceY* 8/ 6;
    double signOfPointYWithaverageOfDistanceYCount
    = signOfPointYWithaverageOfDistanceYKernel;
    double averageOfDistanceYCount= averageOfDistanceYKernel;
    if(1== signOfPointX) {
      double registerY = y;
      int endX= x;
      for(int i = x; i < connectX- 16; i+= 8) {
        registerY= y+ signOfPointYWithaverageOfDistanceYCount+ scale 
            * Math.sin(averageOfDistanceYCount);
        graphics2D.drawLine(i, true== firstTime
        ? (int)registerY: (int)oldRegisterY
            , i+ 8, (int)registerY);
        oldRegisterY= registerY;
        endX= i+ 8;
        firstTime= false;
        signOfPointYWithaverageOfDistanceYCount
        += signOfPointYWithaverageOfDistanceYKernel;
        averageOfDistanceYCount+= averageOfDistanceYKernel;
      }
      graphics2D.drawLine(endX, (int)registerY, connectX-8, connectY);
      return;
    }  
    if(-1== signOfPointX) {
      for(int i= x; i> connectX+ 2; i-= 8) {
        double registerY
        = y+ signOfPointYWithaverageOfDistanceYCount+ scale 
            * Math.sin(averageOfDistanceYCount);
        graphics2D.drawLine(i, true== firstTime
        ? (int)registerY: (int)oldRegisterY
            , i- 8, (int)registerY);
        oldRegisterY= registerY;
        firstTime= false;
        signOfPointYWithaverageOfDistanceYCount
        += signOfPointYWithaverageOfDistanceYKernel;
        averageOfDistanceYCount+= averageOfDistanceYKernel;
      }
    }
  }
}