1 package org.lcsim.recon.tracking.vsegment.geom;
2
3 import java.util.*;
4
5 import org.lcsim.detector.IDetectorElement;
6 import org.lcsim.detector.IGeometryInfo;
7 import org.lcsim.detector.IPhysicalVolume;
8
9 /**
10 * Base class for {@link ForwardingSegmenter}s and {@link RegionSegmenter}s that
11 * can be chained together to describe virtual segmentation of the entire detector.
12 * <p>
13 * A <tt>ForwardingSegmenter</tt> can have any number of daughter segmenters, each
14 * handling a particular part of the detector. Each daughter is either another
15 * <tt>ForwardingSegmenter</tt>, or a <tt>RegionSegmenter</tt> that does the actual
16 * {@link Sensor} object creation, and assigns an integer ID (<tt>postfix</tt>) to
17 * each <tt>Sensor</tt> within the region it is responsible for. The result is a tree
18 * of segmenters, with <tt>ForwardingSegmenter</tt>s at its top and intermediate nodes,
19 * and <tt>RegionSegmenter</tt>s as its leaves. {@link SegmentationManager} automatically
20 * assigns prefixes to all <tt>RegionSegmenter</tt>s, making sure that <tt>SensorID</tt>
21 * they assign to <tt>Sensors</tt> are unique within the whole detector.
22 * <p>
23 * See {@link org.lcsim.contrib.onoprien.tracking.ExampleDriver1} for an example of
24 * chaining several different segmenters.
25 *
26 * @author D. Onoprienko
27 * @version $Id: AbstractSegmenter.java,v 1.1 2008/12/06 21:53:43 onoprien Exp $
28 */
29 abstract public class AbstractSegmenter implements Segmenter {
30
31 // -- Constructors : ----------------------------------------------------------
32
33 AbstractSegmenter() {
34 }
35 // -- Handling of prefixes and postfixes : ------------------------------------
36
37 /**
38 * Set <tt>prefix</tt> for this <tt>Segmenter</tt>.
39 * The number of bits reserved for <tt>postfix</tt> will be calculated automatically.
40 * For the top level <tt>Segmenter</tt>, this method will be called by
41 * <tt>SegmentationManager</tt> with <tt>prefix</tt> equal to zero.
42 */
43 void setPrefix(int prefix) {
44 setPrefix(prefix, getNativePostfixLength());
45 }
46
47 /**
48 * Set <tt>pretfix</tt> value and <tt>postfix</tt> length for this <tt>Segmenter</tt>.
49 */
50 void setPrefix(int prefix, int postfixLength) {
51 _prefix = prefix;
52 _postfixLength = postfixLength;
53 _postfixMask = 0;
54 for (int i=0; i<postfixLength; i++) _postfixMask = (_postfixMask << 1) | 1;
55 _prefixTemplate = prefix << _postfixLength;
56 }
57
58
59 /**
60 * Returns minimum number of bits required to hold any postfix that can be used
61 * by this <tt>Segmenter</tt>.
62 */
63 abstract protected int getNativePostfixLength();
64
65 /**
66 * Get <tt>prefix</tt> used by this <tt>OldSegmenter</tt>.
67 */
68 final protected int getPrefix() {
69 return _prefix;
70 }
71
72 /** Convert <tt>postfix</tt> to full <tt>SensorID</tt>. */
73 final protected int postfixToID(int postfix) {
74 return (postfix == -1) ? -1 : (_prefixTemplate | postfix);
75 }
76
77 /** Extract <tt>postfix</tt> from full <tt>SensorID</tt>. */
78 final protected int idToPostfix(int sensorID) {
79 return sensorID & _postfixMask;
80 }
81
82 // -- Static utility methods : ------------------------------------------------
83
84 /**
85 * Returns the number of bits required to hold an integer between <tt>0</tt> and <tt>maxID</tt>.
86 */
87 static int getIdSize(int maxID) {
88 return (int) Math.ceil(Math.log(maxID+0.8)/Math.log(2.));
89 }
90
91 /**
92 * Returns a list of sensitive lowest-level decendents of the diven detector element.
93 * FIXME: This should be a DetectorElement method !
94 */
95 static public List<IDetectorElement> getLeaves(IDetectorElement del) {
96 ArrayList<IDetectorElement> out = new ArrayList<IDetectorElement>();
97 if (del.hasChildren()) {
98 for (IDetectorElement child : del.getChildren()) {
99 out.addAll(getLeaves(child));
100 }
101 } else {
102 IGeometryInfo gInfo = del.getGeometry();
103 if (gInfo != null) {
104 IPhysicalVolume pVol = gInfo.getPhysicalVolume();
105 if (pVol != null) out.add(del);
106 // if (pVol != null && pVol.isSensitive()) out.add(del); Returns false for every volume - why ?
107 }
108 }
109 return out;
110 }
111
112 // -- Private parts : ---------------------------------------------------------
113
114 protected int _prefix;
115 protected int _postfixLength;
116 protected int _postfixMask;
117 protected int _prefixTemplate;
118
119 }