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

   1 package net.sf.openrocket.rocketcomponent;
   2
   3 import java.util.ArrayList;
   4 import java.util.Arrays;
   5
   6 import net.sf.openrocket.util.BugException;
   7 import net.sf.openrocket.util.Coordinate;
   8
   9
  10 public class FreeformFinSet extends FinSet {
  11
  12         private ArrayList<Coordinate> points = new ArrayList<Coordinate>();
  13
  14         public FreeformFinSet() {
  15                 points.add(Coordinate.NUL);
  16                 points.add(new Coordinate(0.025,0.05));
  17                 points.add(new Coordinate(0.075,0.05));
  18                 points.add(new Coordinate(0.05,0));
  19
  20                 this.length = 0.05;
  21         }
  22
  23
  24         public FreeformFinSet(Coordinate[] finpoints) throws IllegalFinPointException {
  25                 setPoints(finpoints);
  26         }
  27
  28         /*
  29         public FreeformFinSet(FinSet finset) {
  30                 Coordinate[] finpoints = finset.getFinPoints();
  31                 this.copyFrom(finset);
  32
  33                 points.clear();
  34                 for (Coordinate c: finpoints) {
  35                         points.add(c);
  36                 }
  37                 this.length = points.get(points.size()-1).x - points.get(0).x;
  38         }
  39         */
  40
  41
  42         /**
  43          * Convert an existing fin set into a freeform fin set.  The specified
  44          * fin set is taken out of the rocket tree (if any) and the new component
  45          * inserted in its stead.
  46          * <p>
  47          * The specified fin set should not be used after the call!
  48          *
  49          * @param finset        the fin set to convert.
  50          * @return                      the new freeform fin set.
  51          */
  52         public static FreeformFinSet convertFinSet(FinSet finset) {
  53                 final RocketComponent root = finset.getRoot();
  54                 FreeformFinSet freeform;
  55
  56                 try {
  57                         if (root instanceof Rocket) {
  58                                 ((Rocket)root).freeze();
  59                         }
  60
  61                         // Get fin set position and remove fin set
  62                         final RocketComponent parent = finset.getParent();
  63                         final int position;
  64                         if (parent != null) {
  65                                 position = parent.getChildPosition(finset);
  66                                 parent.removeChild(position);
  67                         } else {
  68                                 position = -1;
  69                         }
  70
  71
  72                         // Create the freeform fin set
  73                         Coordinate[] finpoints = finset.getFinPoints();
  74                         try {
  75                                 freeform = new FreeformFinSet(finpoints);
  76                         } catch (IllegalFinPointException e) {
  77                                 throw new BugException("Illegal fin points when converting existing fin to " +
  78                                                 "freeform fin, fin=" + finset + " points="+Arrays.toString(finpoints),
  79                                                 e);
  80                         }
  81
  82                         // Copy component attributes
  83                         freeform.copyFrom(finset);
  84
  85                         // Set name
  86                         final String componentTypeName = finset.getComponentName();
  87                         final String name = freeform.getName();
  88
  89                         if (name.startsWith(componentTypeName)) {
  90                                 freeform.setName(freeform.getComponentName() +
  91                                                 name.substring(componentTypeName.length()));
  92                         }
  93
  94                         // Add freeform fin set to parent
  95                         if (parent != null) {
  96                                 parent.addChild(freeform, position);
  97                         }
  98
  99                 } finally {
 100                         if (root instanceof Rocket) {
 101                                 ((Rocket)root).thaw();
 102                         }
 103                 }
 104                 return freeform;
 105         }
 106
 107
 108
 109         /**
 110          * Add a fin point between indices <code>index-1</code> and <code>index</code>.
 111          * The point is placed at the midpoint of the current segment.
 112          *
 113          * @param index   the fin point before which to add the new point.
 114          */
 115         public void addPoint(int index) {
 116                 double x0, y0, x1, y1;
 117
 118                 x0 = points.get(index-1).x;
 119                 y0 = points.get(index-1).y;
 120                 x1 = points.get(index).x;
 121                 y1 = points.get(index).y;
 122
 123                 points.add(index, new Coordinate((x0+x1)/2, (y0+y1)/2));
 124                 // adding a point within the segment affects neither mass nor aerodynamics
 125                 fireComponentChangeEvent(ComponentChangeEvent.NONFUNCTIONAL_CHANGE);
 126         }
 127
 128
 129         /**
 130          * Remove the fin point with the given index.  The first and last fin points
 131          * cannot be removed, and will cause an <code>IllegalFinPointException</code>
 132          * if attempted.
 133          *
 134          * @param index   the fin point index to remove
 135          * @throws IllegalFinPointException if removing the first or last fin point was attempted.
 136          */
 137         public void removePoint(int index) throws IllegalFinPointException {
 138                 if (index == 0  ||  index == points.size()-1) {
 139                         throw new IllegalFinPointException("cannot remove first or last point");
 140                 }
 141                 // TODO: CRITICAL: Can result in invalid fin points
 142                 points.remove(index);
 143                 fireComponentChangeEvent(ComponentChangeEvent.BOTH_CHANGE);
 144         }
 145
 146
 147         public int getPointCount() {
 148                 return points.size();
 149         }
 150
 151         public void setPoints(Coordinate[] p) throws IllegalFinPointException {
 152                 if (p[0].x != 0 || p[0].y != 0 || p[p.length-1].x < 0 || p[p.length-1].y != 0) {
 153                         throw new IllegalFinPointException("Start or end point illegal.");
 154                 }
 155                 for (int i=0; i < p.length-1; i++) {
 156                         for (int j=i+2; j < p.length-1; j++) {
 157                                 if (intersects(p[i].x, p[i].y, p[i+1].x, p[i+1].y,
 158                                                        p[j].x, p[j].y, p[j+1].x, p[j+1].y)) {
 159                                         throw new IllegalFinPointException("segments intersect");
 160                                 }
 161                         }
 162                         if (p[i].z != 0) {
 163                                 throw new IllegalFinPointException("z-coordinate not zero");
 164                         }
 165                 }
 166
 167                 points.clear();
 168                 for (Coordinate c: p) {
 169                         points.add(c);
 170                 }
 171                 this.length = p[p.length-1].x;
 172                 fireComponentChangeEvent(ComponentChangeEvent.BOTH_CHANGE);
 173         }
 174
 175
 176         /**
 177          * Set the point at position <code>i</code> to coordinates (x,y).
 178          * <p>
 179          * Note that this method enforces basic fin shape restrictions (non-negative y,
 180          * first and last point locations) silently, but throws an
 181          * <code>IllegalFinPointException</code> if the point causes fin segments to
 182          * intersect.
 183          * <p>
 184          * Moving of the first point in the X-axis is allowed, but this actually moves
 185          * all of the other points the corresponding distance back.
 186          *
 187          * @param index the point index to modify.
 188          * @param x             the x-coordinate.
 189          * @param y             the y-coordinate.
 190          * @throws IllegalFinPointException     if the specified fin point would cause intersecting
 191          *                                                                      segments
 192          */
 193         public void setPoint(int index, double x, double y) throws IllegalFinPointException {
 194                 if (y < 0)
 195                         y = 0;
 196
 197                 double x0,y0,x1,y1;
 198
 199                 if (index == 0) {
 200
 201                         // Restrict point
 202                         x = Math.min(x, points.get(points.size()-1).x);
 203                         y = 0;
 204                         x0 = Double.NaN;
 205                         y0 = Double.NaN;
 206                         x1 = points.get(1).x;
 207                         y1 = points.get(1).y;
 208
 209                 } else if (index == points.size()-1) {
 210
 211                         // Restrict point
 212                         x = Math.max(x, 0);
 213                         y = 0;
 214                         x0 = points.get(index-1).x;
 215                         y0 = points.get(index-1).y;
 216                         x1 = Double.NaN;
 217                         y1 = Double.NaN;
 218
 219                 } else {
 220
 221                         x0 = points.get(index-1).x;
 222                         y0 = points.get(index-1).y;
 223                         x1 = points.get(index+1).x;
 224                         y1 = points.get(index+1).y;
 225
 226                 }
 227
 228
 229
 230                 // Check for intersecting
 231                 double px0, py0, px1, py1;
 232                 px0 = 0;
 233                 py0 = 0;
 234                 for (int i=1; i < points.size(); i++) {
 235                         px1 = points.get(i).x;
 236                         py1 = points.get(i).y;
 237
 238                         if (i != index-1 && i != index && i != index+1) {
 239                                 if (intersects(x0,y0,x,y,px0,py0,px1,py1)) {
 240                                         throw new IllegalFinPointException("segments intersect");
 241                                 }
 242                         }
 243                         if (i != index && i != index+1 && i != index+2) {
 244                                 if (intersects(x,y,x1,y1,px0,py0,px1,py1)) {
 245                                         throw new IllegalFinPointException("segments intersect");
 246                                 }
 247                         }
 248
 249                         px0 = px1;
 250                         py0 = py1;
 251                 }
 252
 253                 if (index == 0) {
 254
 255                         System.out.println("Set point zero to x:"+x);
 256                         for (int i=1; i < points.size(); i++) {
 257                                 Coordinate c = points.get(i);
 258                                 points.set(i, c.setX(c.x - x));
 259                         }
 260
 261                 } else {
 262
 263                         points.set(index,new Coordinate(x,y));
 264
 265                 }
 266                 if (index == 0 || index == points.size()-1) {
 267                         this.length = points.get(points.size()-1).x;
 268                 }
 269                 fireComponentChangeEvent(ComponentChangeEvent.BOTH_CHANGE);
 270         }
 271
 272
 273
 274         private boolean intersects(double ax0, double ay0, double ax1, double ay1,
 275                         double bx0, double by0, double bx1, double by1) {
 276
 277                 double d = ((by1-by0)*(ax1-ax0) - (bx1-bx0)*(ay1-ay0));
 278
 279                 double ua = ((bx1-bx0)*(ay0-by0) - (by1-by0)*(ax0-bx0)) / d;
 280                 double ub = ((ax1-ax0)*(ay0-by0) - (ay1-ay0)*(ax0-bx0)) / d;
 281
 282                 return (ua >= 0) && (ua <= 1) && (ub >= 0) && (ub <= 1);
 283         }
 284
 285
 286         @Override
 287         public Coordinate[] getFinPoints() {
 288                 return points.toArray(new Coordinate[0]);
 289         }
 290
 291         @Override
 292         public double getSpan() {
 293                 double max = 0;
 294                 for (Coordinate c: points) {
 295                         if (c.y > max)
 296                                 max = c.y;
 297                 }
 298                 return max;
 299         }
 300
 301         @Override
 302         public String getComponentName() {
 303                 return "Freeform fin set";
 304         }
 305
 306
 307         @SuppressWarnings("unchecked")
 308         @Override
 309         public RocketComponent copy() {
 310                 RocketComponent c = super.copy();
 311                 ((FreeformFinSet)c).points = (ArrayList<Coordinate>) this.points.clone();
 312                 return c;
 313         }
 314
 315 }