git.gag.com Git - debian/openrocket/blob - src/net/sf/openrocket/rocketcomponent/TrapezoidFinSet.java

   1 package net.sf.openrocket.rocketcomponent;
   2
   3 import net.sf.openrocket.l10n.Translator;
   4 import net.sf.openrocket.startup.Application;
   5 import net.sf.openrocket.util.Coordinate;
   6
   7 /**
   8  * A set of trapezoidal fins.  The root and tip chords are perpendicular to the rocket
   9  * base line, while the leading and aft edges may be slanted.
  10  *
  11  * @author Sampo Niskanen <sampo.niskanen@iki.fi>
  12  */
  13
  14 public class TrapezoidFinSet extends FinSet {
  15         private static final Translator trans = Application.getTranslator();
  16
  17         public static final double MAX_SWEEP_ANGLE=(89*Math.PI/180.0);
  18
  19         /*
  20          *           sweep   tipChord
  21          *           |    |___________
  22          *           |   /            |
  23          *           |  /             |
  24          *           | /              |  height
  25          *            /               |
  26          * __________/________________|_____________
  27          *                length
  28          *              == rootChord
  29          */
  30
  31         // rootChord == length
  32         private double tipChord = 0;
  33         private double height = 0;
  34         private double sweep = 0;
  35
  36
  37         public TrapezoidFinSet() {
  38                 this (3, 0.05, 0.05, 0.025, 0.05);
  39         }
  40
  41         // TODO: HIGH:  height=0 -> CP = NaN
  42         public TrapezoidFinSet(int fins, double rootChord, double tipChord, double sweep,
  43                         double height) {
  44                 super();
  45
  46                 this.setFinCount(fins);
  47                 this.length = rootChord;
  48                 this.tipChord = tipChord;
  49                 this.sweep = sweep;
  50                 this.height = height;
  51         }
  52
  53
  54         public void setFinShape(double rootChord, double tipChord, double sweep, double height,
  55                         double thickness) {
  56                 if (this.length==rootChord && this.tipChord==tipChord && this.sweep==sweep &&
  57                                 this.height==height && this.thickness==thickness)
  58                         return;
  59                 this.length=rootChord;
  60                 this.tipChord=tipChord;
  61                 this.sweep=sweep;
  62                 this.height=height;
  63                 this.thickness=thickness;
  64                 fireComponentChangeEvent(ComponentChangeEvent.BOTH_CHANGE);
  65         }
  66
  67         public double getRootChord() {
  68                 return length;
  69         }
  70         public void setRootChord(double r) {
  71                 if (length == r)
  72                         return;
  73                 length = Math.max(r,0);
  74                 fireComponentChangeEvent(ComponentChangeEvent.BOTH_CHANGE);
  75         }
  76
  77         public double getTipChord() {
  78                 return tipChord;
  79         }
  80         public void setTipChord(double r) {
  81                 if (tipChord == r)
  82                         return;
  83                 tipChord = Math.max(r,0);
  84                 fireComponentChangeEvent(ComponentChangeEvent.BOTH_CHANGE);
  85         }
  86
  87         /**
  88          * Get the sweep length.
  89          */
  90         public double getSweep() {
  91                 return sweep;
  92         }
  93         /**
  94          * Set the sweep length.
  95          */
  96         public void setSweep(double r) {
  97                 if (sweep == r)
  98                         return;
  99                 sweep = r;
 100                 fireComponentChangeEvent(ComponentChangeEvent.BOTH_CHANGE);
 101         }
 102
 103         /**
 104          * Get the sweep angle.  This is calculated from the true sweep and height, and is not
 105          * stored separetely.
 106          */
 107         public double getSweepAngle() {
 108                 if (height == 0) {
 109                         if (sweep > 0)
 110                                 return Math.PI/2;
 111                         if (sweep < 0)
 112                                 return -Math.PI/2;
 113                         return 0;
 114                 }
 115                 return Math.atan(sweep/height);
 116         }
 117         /**
 118          * Sets the sweep by the sweep angle.  The sweep is calculated and set by this method,
 119          * and the angle itself is not stored.
 120          */
 121         public void setSweepAngle(double r) {
 122                 if (r > MAX_SWEEP_ANGLE)
 123                         r = MAX_SWEEP_ANGLE;
 124                 if (r < -MAX_SWEEP_ANGLE)
 125                         r = -MAX_SWEEP_ANGLE;
 126                 double sweep = Math.tan(r) * height;
 127                 if (Double.isNaN(sweep) || Double.isInfinite(sweep))
 128                         return;
 129                 setSweep(sweep);
 130         }
 131
 132         public double getHeight() {
 133                 return height;
 134         }
 135         public void setHeight(double r) {
 136                 if (height == r)
 137                         return;
 138                 height = Math.max(r,0);
 139                 fireComponentChangeEvent(ComponentChangeEvent.BOTH_CHANGE);
 140         }
 141
 142
 143
 144         /**
 145          * Returns the geometry of a trapezoidal fin.
 146          */
 147         @Override
 148         public Coordinate[] getFinPoints() {
 149                 Coordinate[] c = new Coordinate[4];
 150
 151                 c[0] = Coordinate.NUL;
 152                 c[1] = new Coordinate(sweep,height);
 153                 c[2] = new Coordinate(sweep+tipChord,height);
 154                 c[3] = new Coordinate(length,0);
 155
 156                 return c;
 157         }
 158
 159         /**
 160          * Returns the span of a trapezoidal fin.
 161          */
 162         @Override
 163         public double getSpan() {
 164                 return height;
 165         }
 166
 167
 168         @Override
 169         public String getComponentName() {
 170                 //// Trapezoidal fin set
 171                 return trans.get("TrapezoidFinSet.TrapezoidFinSet");
 172         }
 173
 174 }