gov/nasa/worldwind/render/GeographicSurfaceTileRenderer.java

   1 /*
   2 Copyright (C) 2001, 2006 United States Government
   3 as represented by the Administrator of the
   4 National Aeronautics and Space Administration.
   5 All Rights Reserved.
   6 */
   7 package gov.nasa.worldwind.render;
   8
   9 import gov.nasa.worldwind.globes.SectorGeometry;
  10 import gov.nasa.worldwind.geom.Sector;
  11
  12 import java.util.ArrayList;
  13
  14 /**
  15  * @author tag
  16  * @version $Id: GeographicSurfaceTileRenderer.java 2533 2007-08-13 05:59:08Z tgaskins $
  17  */
  18 public class GeographicSurfaceTileRenderer extends SurfaceTileRenderer
  19 {
  20     private double sgWidth;
  21     private double sgHeight;
  22     private double sgMinWE;
  23     private double sgMinSN;
  24
  25     protected void preComputeTransform(DrawContext dc, SectorGeometry sg)
  26     {
  27         Sector st = sg.getSector();
  28         this.sgWidth = st.getDeltaLonRadians();
  29         this.sgHeight = st.getDeltaLatRadians();
  30         this.sgMinWE = st.getMinLongitude().radians;
  31         this.sgMinSN = st.getMinLatitude().radians;
  32     }
  33
  34     protected void computeTransform(DrawContext dc, SurfaceTile tile, Transform t)
  35     {
  36         Sector st = tile.getSector();
  37         double tileWidth = st.getDeltaLonRadians();
  38         double tileHeight = st.getDeltaLatRadians();
  39         double minLon = st.getMinLongitude().radians;
  40         double minLat = st.getMinLatitude().radians;
  41
  42         t.VScale = tileHeight > 0 ? this.sgHeight / tileHeight : 1;
  43         t.HScale = tileWidth > 0 ? this.sgWidth / tileWidth : 1;
  44         t.VShift = -(minLat - this.sgMinSN) / this.sgHeight;
  45         t.HShift = -(minLon - this.sgMinWE) / this.sgWidth;
  46     }
  47
  48     protected Iterable<SurfaceTile> getIntersectingTiles(DrawContext dc, SectorGeometry sg,
  49         Iterable<? extends SurfaceTile> tiles)
  50     {
  51         ArrayList<SurfaceTile> intersectingTiles = null;
  52
  53         for (SurfaceTile tile : tiles)
  54         {
  55             if (!tile.getSector().intersects(sg.getSector()))
  56                 continue;
  57
  58             if (intersectingTiles == null)
  59                 intersectingTiles = new ArrayList<SurfaceTile>();
  60
  61             intersectingTiles.add(tile);
  62         }
  63
  64         if (intersectingTiles == null)
  65             return null;
  66
  67         return intersectingTiles;
  68     }
  69 }