/*
   Item7: link movement+color of items to movement of an item
*/

import java.awt.*;

public class Item7 extends Item6
{
   final static int NKEYS = 10;

   // MAINTAIN INTERNAL DATABASE FOR PUPPETEERING OTHER ITEMS

   boolean highlight = false;
   boolean isLinkingMode = false;
   int nKeys = 0, nLinked = 0;
   int xKey[] = new int[NKEYS];
   int yKey[] = new int[NKEYS];
   int ckx[][] = new int[NKEYS][20];
   int cky[][] = new int[NKEYS][20];
   int ckc[][] = new int[NKEYS][20];
   Item linkedItem[] = new Item[20];

   public void setHighlighted(boolean tf) { highlight = tf; }
   public void setLinkingMode(boolean tf) { isLinkingMode = tf; }
   public void setKey(int k) {
      xKey[k] = x0;
      yKey[k] = y0;
      nKeys = Math.max(nKeys, k+1);
   }

   // ADD LINK FROM THE LINK ITEM TO POSITION/COLOR OF A PUPPETEERED ITEM

   public void linkAtKey(int k, Item7 item) {
      int n = findLinkedItem(item);
      for (int kk = k ; kk >= 0 && ckx[kk][n] == 0 ; kk--) {
         ckx[kk][n] = 1;
         ckc[kk][n] = item.color;
      }
         
      for (int kk = k ; kk < NKEYS ; kk++) {
         ckx[kk][n] = item.x0;
         cky[kk][n] = item.y0;
         ckc[kk][n] = item.color;
         if (item.x0 == 0 && item.y0 == 0)
            ckx[kk][n] = 1;
      }
   }

   // HIGHLIGHT THE LINK ITEM - DRAW IT IN BLACK AND GIVE IT A WHITE HALO

   public void draw(Graphics g, Color palette[]) {
      if (highlight) {
         g.setColor(Color.white);
         draw(g, 0, 0, thicken ? r * 5 / 2 : r * 2);
      }
      g.setColor(palette[color] == Color.white ? faintColor : Color.black);
      draw(g, 0, 0, thicken ? 3*r/2 : r);
      if (! highlight) {
         g.setColor(palette[color]);
         draw(g, 0, 0, r-2);
      }
   }

   // MOVING A LINK ITEM FORCES MOVEMENT OR COLOR CHANGES TO OTHER ITEMS

   public void move(int dx, int dy) {
      x0 += dx;
      y0 += dy;

      if (! isLinkingMode && nKeys > 0) {

         int xx, yy, rr, k0 = 0, rr0 = 100000, k1 = 0, rr1 = 100000;

         // FIND TWO NEAREST KEYS

         for (int k = 0 ; k < nKeys ; k++)
            if ((rr = distSqr(k)) < rr0) {
               rr0 = rr;
               k0 = k;
            }

         for (int k = 0 ; k < nKeys ; k++)
            if ((rr = distSqr(k)) > rr0 && rr < rr1) {
               rr1 = rr;
               k1 = k;
            }

         // BLEND BETWEEN THEM

         for (int n = 0 ; n < nLinked ; n++) {
            Item7 it = (Item7)linkedItem[n];
            it.setX( ( rr1 * ckx[k0][n] + rr0 * ckx[k1][n] ) / ( rr0 + rr1 ) );
            it.setY( ( rr1 * cky[k0][n] + rr0 * cky[k1][n] ) / ( rr0 + rr1 ) );
            it.setColor(ckc[k0][n]);
         }
      }
   }

   int distSqr(int k) {
      int x = x0 - xKey[k], y = y0 - yKey[k];
      return x * x + y * y;
   }

   int findLinkedItem(Item item) {
      for (int j = 0 ; j < nLinked ; j++)
         if (item == linkedItem[j])
            return j;
      linkedItem[nLinked] = item;
      return nLinked++;
   }
}