gov/nasa/worldwind/geom/Quadrilateral.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.geom;
   8
   9 import com.sun.opengl.util.*;
  10 import gov.nasa.worldwind.*;
  11
  12 import javax.media.opengl.*;
  13 import java.awt.*;
  14 import java.nio.*;
  15
  16 /**
  17  * @author tag
  18  * @version $Id: Quadrilateral.java 1787 2007-05-08 17:11:30Z dcollins $
  19  */
  20 public class Quadrilateral implements Renderable
  21 {
  22     private LatLon southwestCorner;
  23     private LatLon northeastCorner;
  24     private double elevation;
  25     private Point referenceCenter;
  26     private DoubleBuffer vertices;
  27     private int antiAliasHint = GL.GL_FASTEST;
  28     private Color color = Color.WHITE;
  29
  30     public Quadrilateral(LatLon southwestCorner, LatLon northeastCorner, double elevation)
  31     {
  32         if (southwestCorner == null || northeastCorner == null)
  33         {
  34             String msg = WorldWind.retrieveErrMsg("nullValue.PositionIsNull");
  35             WorldWind.logger().log(java.util.logging.Level.FINE, msg);
  36             throw new IllegalArgumentException(msg);
  37         }
  38
  39         this.southwestCorner = southwestCorner;
  40         this.northeastCorner = northeastCorner;
  41         this.elevation = elevation;
  42     }
  43
  44     public Color getColor()
  45     {
  46         return color;
  47     }
  48
  49     public void setColor(Color color)
  50     {
  51         if (color == null)
  52         {
  53             String msg = WorldWind.retrieveErrMsg("nullValue.ColorIsNull");
  54             WorldWind.logger().log(java.util.logging.Level.FINE, msg);
  55             throw new IllegalArgumentException(msg);
  56         }
  57
  58         this.color = color;
  59     }
  60
  61     public int getAntiAliasHint()
  62     {
  63         return antiAliasHint;
  64     }
  65
  66     public void setAntiAliasHint(int hint)
  67     {
  68         if (!(hint == GL.GL_DONT_CARE || hint == GL.GL_FASTEST || hint == GL.GL_NICEST))
  69         {
  70             String msg = WorldWind.retrieveErrMsg("generic.InvalidHint");
  71             WorldWind.logger().log(java.util.logging.Level.FINE, msg);
  72             throw new IllegalArgumentException(msg);
  73         }
  74
  75         this.antiAliasHint = hint;
  76     }
  77
  78     public void setCorners(LatLon southWest, LatLon northEast)
  79     {
  80         this.southwestCorner = southWest;
  81         this.northeastCorner = northEast;
  82         this.vertices = null;
  83     }
  84
  85     public LatLon[] getCorners()
  86     {
  87         LatLon[] retVal = new LatLon[2];
  88
  89         retVal[0] = this.southwestCorner;
  90         retVal[1] = this.northeastCorner;
  91
  92         return retVal;
  93     }
  94
  95     public double getElevation()
  96     {
  97         return elevation;
  98     }
  99
 100     public void setElevation(double elevation)
 101     {
 102         this.elevation = elevation;
 103         this.vertices = null;
 104     }
 105
 106     private void intializeGeometry(DrawContext dc)
 107     {
 108         DoubleBuffer verts = BufferUtil.newDoubleBuffer(12);
 109
 110         Point[] p = new Point[4];
 111
 112         p[0] = dc.getGlobe().computePointFromPosition(this.southwestCorner.getLatitude(),
 113             this.southwestCorner.getLongitude(), this.elevation);
 114         p[1] = dc.getGlobe().computePointFromPosition(this.southwestCorner.getLatitude(),
 115             this.northeastCorner.getLongitude(), this.elevation);
 116         p[2] = dc.getGlobe().computePointFromPosition(this.northeastCorner.getLatitude(),
 117             this.northeastCorner.getLongitude(), this.elevation);
 118         p[3] = dc.getGlobe().computePointFromPosition(this.northeastCorner.getLatitude(),
 119             this.southwestCorner.getLongitude(), this.elevation);
 120
 121         Point refcenter = Point.midPoint(p[0], p[2]);
 122
 123         for (int i = 0; i < 4; i++)
 124         {
 125             verts.put(p[i].x() - refcenter.x());
 126             verts.put(p[i].y() - refcenter.y());
 127             verts.put(p[i].z() - refcenter.z());
 128         }
 129
 130         this.referenceCenter = refcenter;
 131         this.vertices = verts;
 132     }
 133
 134     public void render(DrawContext dc)
 135     {
 136         if (dc == null)
 137         {
 138             String message = WorldWind.retrieveErrMsg("nullValue.DrawContextIsNull");
 139             WorldWind.logger().log(java.util.logging.Level.FINE, message);
 140             throw new IllegalStateException(message);
 141         }
 142
 143         if (this.vertices == null)
 144         {
 145             this.intializeGeometry(dc);
 146
 147             if (this.vertices == null)
 148                 return; // TODO: log a warning
 149         }
 150
 151         GL gl = dc.getGL();
 152
 153         int attrBits = GL.GL_HINT_BIT | GL.GL_CURRENT_BIT;
 154         if (!dc.isPickingMode())
 155         {
 156             attrBits += GL.GL_CURRENT_BIT;
 157             if (this.color.getAlpha() != 255)
 158                 attrBits += GL.GL_COLOR_BUFFER_BIT;
 159         }
 160
 161         gl.glPushAttrib(attrBits);
 162         gl.glPushClientAttrib(GL.GL_CLIENT_VERTEX_ARRAY_BIT);
 163         dc.getView().pushReferenceCenter(dc, this.referenceCenter);
 164
 165         try
 166         {
 167             if (!dc.isPickingMode())
 168             {
 169                 if (this.color.getAlpha() != 255)
 170                 {
 171                     gl.glEnable(GL.GL_BLEND);
 172                     gl.glBlendFunc(GL.GL_SRC_ALPHA, GL.GL_ONE_MINUS_SRC_ALPHA);
 173                 }
 174                 dc.getGL().glColor4ub((byte) this.color.getRed(), (byte) this.color.getGreen(),
 175                     (byte) this.color.getBlue(), (byte) this.color.getAlpha());
 176             }
 177
 178             gl.glHint(GL.GL_POLYGON_SMOOTH_HINT, this.antiAliasHint);
 179             gl.glEnableClientState(GL.GL_VERTEX_ARRAY);
 180             gl.glVertexPointer(3, GL.GL_DOUBLE, 0, this.vertices.rewind());
 181             gl.glDrawArrays(GL.GL_QUADS, 0, 4);
 182         }
 183         finally
 184         {
 185             gl.glPopClientAttrib();
 186             gl.glPopAttrib();
 187             dc.getView().popReferenceCenter(dc);
 188         }
 189     }
 190 }