/*----------------------------------------------------------------------+
|	Title:	Functional_PickscheFormel.java					                      |
|																																		|
|	Autor:	Timo Ehmke	                                                  |
|         ehmke@uni-flensburg.de																		|
| 																																	|
| Beginn:					 16.08.99																					|
| Letzte Änderung: 16.08.99                                					|
+----------------------------------------------------------------------*/


public class Functional_PickscheFormel extends Functional{

  int type, numBorder, numInside, n, step, choice;
  String term;
  PolygonElement polygon;  
  PointElement V[];
  int minX, maxX, minY, maxY;
  PointElement P;
  
  public void init(int numElem, String[] eList, Slate sl, Measure parent) {
      slate = sl;
      numElement = numElem;
      elementList = eList;
      
      String c = elementList[1];
      polygon = (PolygonElement) slate.lookupElement(elementList[2]);
      parent.addParent(polygon);
      step = slate.GRID_SIZE;

      V = polygon.V;
      n = polygon.n;
      P = new PointElement();
      
      if (c.equals("r")) {
          choice = 0;
      } // if
      if (c.equals("i")) {
          choice = 1;
      } // if
  }
  
  public double getValue() {     
           

      
      // Bestimme minX, minY, maxX und maxY
      minX = Integer.MAX_VALUE;
      minY = Integer.MAX_VALUE;
      maxX = Integer.MIN_VALUE;
      maxY = Integer.MIN_VALUE;
      
      for (int i=0;i<n;i++) {
          if (V[i].x<minX) {
              minX = (int) Math.round( V[i].x );
          } // if
          if (V[i].y<minY) {
              minY = (int) Math.round( V[i].y );
          } // if
          if (V[i].x>maxX) {
              maxX = (int) Math.round( V[i].x );
          } // if
          if (V[i].y>maxY) {
              maxY = (int) Math.round( V[i].y );
          } // if
      } // for
/*      
      System.out.println("minX = " + minX);
      System.out.println("minY = " + minY);
      System.out.println("maxX = " + maxX);
      System.out.println("maxY = " + maxY);
      System.out.println("step = " + step);
      System.out.println();
*/
      switch (choice) {
        case 0:
            numBorder = 0;
            for (int i=minX;i<=maxX;i+=step) {
                for (int j=minY;j<=maxY;j+=step) {
                
                    P.x = i;
                    P.y = j;                                
                
                    // Prüfe, ob P auf dem Rand des Polygons liegt
                    label:
                    for (int k=0;k<n;k++) {
                        if (P.isCollinear(V[k],V[(k+1)%n])&& Math.abs(V[k].distance(P)+V[(k+1)%n].distance(P)-V[k].distance(V[(k+1)%n]))<0.0001) {
                            numBorder++;      
                            //System.out.println("numBorder = " + numBorder + " " + P);
                            break label;
                        } // if
                    } // for                
                } // for
            } // for
            return (double) numBorder;
        case 1:
            numInside = 0;
            for (int i=minX;i<=maxX;i+=step) {
                for (int j=minY;j<=maxY;j+=step) {
                
                    P.x = i;
                    P.y = j;                                
                
                    // Prüfe, ob P innerhalb des Polygons liegt
                    if (!isPointOnBorder(P) && polygon.contains(P)) {
                        numInside++;
                         //System.out.println("numInside = " + numInside + " " + P);
                    } // if
                } // for
            } // for
            return (double) numInside;
      } // switch
                  
      // should never reach here
      return -1;
  }
  
  private boolean isPointOnBorder( PointElement P ) {
      // Prüfe, ob P auf dem Rand des Polygons liegt
      for (int k=0;k<n;k++) {
          if (P.isCollinear(V[k],V[(k+1)%n]) && Math.abs(V[k].distance(P)+V[(k+1)%n].distance(P)-V[k].distance(V[(k+1)%n]))<0.0001) {
              return true;
          } // if
      } // for                
      return false;
  }

  
}