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

   1 package net.sf.openrocket.rocketcomponent;
   2
   3 import static net.sf.openrocket.util.MathUtil.pow2;
   4
   5 import java.util.ArrayList;
   6 import java.util.Collection;
   7
   8 import net.sf.openrocket.util.Coordinate;
   9 import net.sf.openrocket.util.MathUtil;
  10
  11
  12 /**
  13  * A MassObject is an internal component that can a specific weight, but not necessarily a strictly bound shape.  It is
  14  * represented as a homogeneous cylinder and drawn in the rocket figure with rounded corners.
  15  * <p/>
  16  * Subclasses of this class need only implement the {@link #getComponentMass()}, {@link #getComponentName()} and {@link
  17  * #isCompatible(RocketComponent)} methods.
  18  *
  19  * @author Sampo Niskanen <sampo.niskanen@iki.fi>
  20  */
  21 public abstract class MassObject extends InternalComponent {
  22
  23         private double radius;
  24
  25         private double radialPosition;
  26         private double radialDirection;
  27
  28         private double shiftY = 0;
  29         private double shiftZ = 0;
  30
  31
  32         public MassObject() {
  33                 this(0.025, 0.0125);
  34         }
  35
  36         public MassObject(double length, double radius) {
  37                 super();
  38
  39                 this.length = length;
  40                 this.radius = radius;
  41
  42                 this.setRelativePosition(Position.TOP);
  43                 this.setPositionValue(0.0);
  44         }
  45
  46
  47         public void setLength(double length) {
  48                 length = Math.max(length, 0);
  49                 if (MathUtil.equals(this.length, length)) {
  50                         return;
  51                 }
  52                 this.length = length;
  53                 fireComponentChangeEvent(ComponentChangeEvent.MASS_CHANGE);
  54         }
  55
  56
  57         public final double getRadius() {
  58                 return radius;
  59         }
  60
  61
  62         public final void setRadius(double radius) {
  63                 radius = Math.max(radius, 0);
  64                 if (MathUtil.equals(this.radius, radius)) {
  65                         return;
  66                 }
  67                 this.radius = radius;
  68                 fireComponentChangeEvent(ComponentChangeEvent.MASS_CHANGE);
  69         }
  70
  71
  72
  73         public final double getRadialPosition() {
  74                 return radialPosition;
  75         }
  76
  77         public final void setRadialPosition(double radialPosition) {
  78                 radialPosition = Math.max(radialPosition, 0);
  79                 if (MathUtil.equals(this.radialPosition, radialPosition)) {
  80                         return;
  81                 }
  82                 this.radialPosition = radialPosition;
  83                 shiftY = radialPosition * Math.cos(radialDirection);
  84                 shiftZ = radialPosition * Math.sin(radialDirection);
  85                 fireComponentChangeEvent(ComponentChangeEvent.MASS_CHANGE);
  86         }
  87
  88         public final double getRadialDirection() {
  89                 return radialDirection;
  90         }
  91
  92         public final void setRadialDirection(double radialDirection) {
  93                 radialDirection = MathUtil.reduce180(radialDirection);
  94                 if (MathUtil.equals(this.radialDirection, radialDirection)) {
  95                         return;
  96                 }
  97                 this.radialDirection = radialDirection;
  98                 shiftY = radialPosition * Math.cos(radialDirection);
  99                 shiftZ = radialPosition * Math.sin(radialDirection);
 100                 fireComponentChangeEvent(ComponentChangeEvent.MASS_CHANGE);
 101         }
 102
 103
 104         /**
 105          * Shift the coordinates according to the radial position and direction.
 106          */
 107         @Override
 108         public final Coordinate[] shiftCoordinates(Coordinate[] array) {
 109                 for (int i = 0; i < array.length; i++) {
 110                         array[i] = array[i].add(0, shiftY, shiftZ);
 111                 }
 112                 return array;
 113         }
 114
 115         @Override
 116         public final Coordinate getComponentCG() {
 117                 return new Coordinate(length / 2, shiftY, shiftZ, getComponentMass());
 118         }
 119
 120         @Override
 121         public final double getLongitudinalUnitInertia() {
 122                 return (3 * pow2(radius) + pow2(length)) / 12;
 123         }
 124
 125         @Override
 126         public final double getRotationalUnitInertia() {
 127                 return pow2(radius) / 2;
 128         }
 129
 130         @Override
 131         public final Collection<Coordinate> getComponentBounds() {
 132                 Collection<Coordinate> c = new ArrayList<Coordinate>();
 133                 addBound(c, 0, radius);
 134                 addBound(c, length, radius);
 135                 return c;
 136         }
 137
 138 }