/**
    * 
    */
   
   package math.geom2d.grid;
   
   import java.util.ArrayList;
   import java.util.Collection;
   
  import math.geom2d.Box2D;
  import math.geom2d.Point2D;
  import math.geom2d.point.PointArray2D;
  import math.geom2d.point.PointSet2D;
  import math.geom2d.Shape2D;
  import math.geom2d.line.LineSegment2D;
  
  /**
   * Defines a square grid, which can have different size in each direction. The
   * grid is always parallel to the main axes.
   * 
   * @author dlegland
   */
  public class SquareGrid2D implements Grid2D {
  
      double x0 = 0;
      double y0 = 0;
  
      double sx = 1;
      double sy = 1;
  
      public SquareGrid2D() {
  
      }
  
      public SquareGrid2D(java.awt.geom.Point2D origin) {
          this(origin.getX(), origin.getY(), 1, 1);
      }
  
      public SquareGrid2D(java.awt.geom.Point2D origin, double s) {
          this(origin.getX(), origin.getY(), s, s);
      }
  
      public SquareGrid2D(java.awt.geom.Point2D origin, double sx, double sy) {
          this(origin.getX(), origin.getY(), sx, sy);
      }
  
      public SquareGrid2D(double x0, double y0, double s) {
          this(x0, y0, s, s);
      }
  
      public SquareGrid2D(double s) {
          this(0, 0, s, s);
      }
  
      public SquareGrid2D(double sx, double sy) {
          this(0, 0, sx, sy);
      }
  
      public SquareGrid2D(double x0, double y0, double sx, double sy) {
          this.x0 = x0;
          this.y0 = y0;
          this.sx = sx;
          this.sy = sy;
      }
  
      /**
       * @deprecated grids are supposed to be immutable (0.8.0)
       */
      @Deprecated
      public void setOrigin(Point2D point) {
          this.x0 = point.getX();
          this.y0 = point.getY();
      }
  
      public Point2D getOrigin() {
          return new Point2D(x0, y0);
      }
  
      public double getSizeX() {
          return sx;
      }
  
      public double getSizeY() {
          return sy;
      }
  
      /**
       * @deprecated grids are supposed to be immutable (0.8.0)
       */
      @Deprecated
      public void setSize(double s) {
          sx = s;
          sy = s;
      }
  
      /**
       * @deprecated grids are supposed to be immutable (0.8.0)
       */
      @Deprecated
     public void setSize(double sx, double sy) {
         this.sx = sx;
         this.sy = sy;
     }
 
     /*
      * (non-Javadoc)
      * 
      * @see math.geom2d.grid.Grid2D#getClosestVertex(math.geom2d.Point2D)
      */
     public Point2D getClosestVertex(java.awt.geom.Point2D point) {
         double nx = Math.round((point.getX()-x0)/sx);
         double ny = Math.round((point.getY()-y0)/sy);
         return new Point2D(nx*sx+x0, ny*sy+y0);
     }
 
     /*
      * (non-Javadoc)
      * 
      * @see math.geom2d.grid.Grid2D#getEdges(math.geom2d.Box2D)
      */
     public Collection<LineSegment2D> getEdges(Box2D box) {
         double x, y; // iterations
         double xmin, ymin, xmax, ymax; // limits
         double xi, yi; // first point in the box
 
         // extract bounds of the box
         xmin = box.getMinX();
         ymin = box.getMinY();
         xmax = box.getMaxX();
         ymax = box.getMaxY();
 
         // coordinates of first vertex in the box
         xi = Math.ceil((xmin-x0)/sx)*sx+x0;
         yi = Math.ceil((ymin-y0)/sy)*sy+y0;
 
         ArrayList<LineSegment2D> array = new ArrayList<LineSegment2D>();
 
         // add horizontal lines
         for (y = yi; y-ymax<Shape2D.ACCURACY; y += sy)
             array.add(new LineSegment2D(xmin, y, xmax, y));
 
         // add vertical lines
         for (x = xi; x-xmax<Shape2D.ACCURACY; x += sx)
             array.add(new LineSegment2D(x, ymin, x, ymax));
 
         // return the set of lines
         return array;
     }
 
     /*
      * (non-Javadoc)
      * 
      * @see math.geom2d.grid.Grid2D#getVertices(math.geom2d.Box2D)
      */
     public PointSet2D getVertices(Box2D box) {
         double x, y; // iterations
         double xmin, ymin, xmax, ymax; // limits
         double xi, yi; // first point in the box
 
         // extract bounds of the box
         xmin = box.getMinX();
         ymin = box.getMinY();
         xmax = box.getMaxX();
         ymax = box.getMaxY();
 
         // coordinates of first vertex in the box
         xi = Math.ceil((xmin-x0)/sx)*sx+x0;
         yi = Math.ceil((ymin-y0)/sy)*sy+y0;
 
         ArrayList<Point2D> array = new ArrayList<Point2D>();
 
         // iterate on lines in each direction
         for (y = yi; y-ymax<Shape2D.ACCURACY; y += sy)
             for (x = xi; x-xmax<Shape2D.ACCURACY; x += sx)
                 array.add(new Point2D(x, y));
 
         // return the set of lines
         return new PointArray2D(array);
     }
 }