git.gag.com Git - debian/openrocket/blob - 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 /**
  14  * A MassObject is an internal component that can a specific weight, but not
  15  * necessarily a strictly bound shape.  It is represented as a homogeneous
  16  * cylinder and drawn in the rocket figure with rounded corners.
  17  * <p>
  18  * Subclasses of this class need only implement the {@link #getComponentMass()},
  19  * {@link #getComponentName()} and {@link #isCompatible(RocketComponent)}
  20  * methods.
  21  *
  22  * @author Sampo Niskanen <sampo.niskanen@iki.fi>
  23  */
  24 public abstract class MassObject extends InternalComponent {
  25
  26         private double radius;
  27
  28         private double radialPosition;
  29         private double radialDirection;
  30
  31         private double shiftY = 0;
  32         private double shiftZ = 0;
  33
  34
  35         public MassObject() {
  36                 this(0.03, 0.015);
  37         }
  38
  39         public MassObject(double length, double radius) {
  40                 super();
  41
  42                 this.length = length;
  43                 this.radius = radius;
  44
  45                 this.setRelativePosition(Position.TOP);
  46                 this.setPositionValue(0.0);
  47         }
  48
  49
  50
  51
  52         public void setLength(double length) {
  53                 length = Math.max(length, 0);
  54                 if (MathUtil.equals(this.length, length))
  55                         return;
  56                 this.length = length;
  57                 fireComponentChangeEvent(ComponentChangeEvent.MASS_CHANGE);
  58         }
  59
  60
  61
  62         public final double getRadius() {
  63                 return radius;
  64         }
  65
  66
  67         public final void setRadius(double radius) {
  68                 radius = Math.max(radius, 0);
  69                 if (MathUtil.equals(this.radius, radius))
  70                         return;
  71                 this.radius = radius;
  72                 fireComponentChangeEvent(ComponentChangeEvent.MASS_CHANGE);
  73         }
  74
  75
  76
  77         public final double getRadialPosition() {
  78                 return radialPosition;
  79         }
  80
  81         public final void setRadialPosition(double radialPosition) {
  82                 radialPosition = Math.max(radialPosition, 0);
  83                 if (MathUtil.equals(this.radialPosition, radialPosition))
  84                         return;
  85                 this.radialPosition = radialPosition;
  86                 shiftY = radialPosition * Math.cos(radialDirection);
  87                 shiftZ = radialPosition * Math.sin(radialDirection);
  88                 fireComponentChangeEvent(ComponentChangeEvent.MASS_CHANGE);
  89         }
  90
  91         public final double getRadialDirection() {
  92                 return radialDirection;
  93         }
  94
  95         public final void setRadialDirection(double radialDirection) {
  96                 radialDirection = MathUtil.reduce180(radialDirection);
  97                 if (MathUtil.equals(this.radialDirection, radialDirection))
  98                         return;
  99                 this.radialDirection = radialDirection;
 100                 shiftY = radialPosition * Math.cos(radialDirection);
 101                 shiftZ = radialPosition * Math.sin(radialDirection);
 102                 fireComponentChangeEvent(ComponentChangeEvent.MASS_CHANGE);
 103         }
 104
 105
 106
 107
 108         /**
 109          * Shift the coordinates according to the radial position and direction.
 110          */
 111         @Override
 112         public final Coordinate[] shiftCoordinates(Coordinate[] array) {
 113                 for (int i=0; i < array.length; i++) {
 114                         array[i] = array[i].add(0, shiftY, shiftZ);
 115                 }
 116                 return array;
 117         }
 118
 119         @Override
 120         public final Coordinate getComponentCG() {
 121                 return new Coordinate(length/2, shiftY, shiftZ, getComponentMass());
 122         }
 123
 124         @Override
 125         public final double getLongitudalUnitInertia() {
 126                 return (3*pow2(radius) + pow2(length)) / 12;
 127         }
 128
 129         @Override
 130         public final double getRotationalUnitInertia() {
 131                 return pow2(radius) / 2;
 132         }
 133
 134         @Override
 135         public final Collection<Coordinate> getComponentBounds() {
 136                 Collection<Coordinate> c = new ArrayList<Coordinate>();
 137                 addBound(c, 0, radius);
 138                 addBound(c, length, radius);
 139                 return c;
 140         }
 141 }