summaryrefslogtreecommitdiffstats
path: root/src/net/java/joglutils/msg/collections/Vec2fCollection.java
blob: bf4ebb809bf827fe27cf420ee214290c4d1ddfcd (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
/*
 * Copyright (c) 2007 Sun Microsystems, Inc. All Rights Reserved.
 * 
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are
 * met:
 * 
 * - Redistribution of source code must retain the above copyright
 *   notice, this list of conditions and the following disclaimer.
 * 
 * - Redistribution in binary form must reproduce the above copyright
 *   notice, this list of conditions and the following disclaimer in the
 *   documentation and/or other materials provided with the distribution.
 * 
 * Neither the name of Sun Microsystems, Inc. or the names of
 * contributors may be used to endorse or promote products derived from
 * this software without specific prior written permission.
 * 
 * This software is provided "AS IS," without a warranty of any kind. ALL
 * EXPRESS OR IMPLIED CONDITIONS, REPRESENTATIONS AND WARRANTIES,
 * INCLUDING ANY IMPLIED WARRANTY OF MERCHANTABILITY, FITNESS FOR A
 * PARTICULAR PURPOSE OR NON-INFRINGEMENT, ARE HEREBY EXCLUDED. SUN
 * MICROSYSTEMS, INC. ("SUN") AND ITS LICENSORS SHALL NOT BE LIABLE FOR
 * ANY DAMAGES SUFFERED BY LICENSEE AS A RESULT OF USING, MODIFYING OR
 * DISTRIBUTING THIS SOFTWARE OR ITS DERIVATIVES. IN NO EVENT WILL SUN OR
 * ITS LICENSORS BE LIABLE FOR ANY LOST REVENUE, PROFIT OR DATA, OR FOR
 * DIRECT, INDIRECT, SPECIAL, CONSEQUENTIAL, INCIDENTAL OR PUNITIVE
 * DAMAGES, HOWEVER CAUSED AND REGARDLESS OF THE THEORY OF LIABILITY,
 * ARISING OUT OF THE USE OF OR INABILITY TO USE THIS SOFTWARE, EVEN IF
 * SUN HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES.
 * 
 * You acknowledge that this software is not designed or intended for use
 * in the design, construction, operation or maintenance of any nuclear
 * facility.
 * 
 */

package net.java.joglutils.msg.collections;

import java.nio.FloatBuffer;

import net.java.joglutils.msg.impl.BufferFactory;
import net.java.joglutils.msg.math.Vec2f;

/** Provides the abstraction of a collection of Vec2f objects while
    allowing access to the backing store in the form of a direct
    FloatBuffer to make it easy to pass down to OpenGL. */

public class Vec2fCollection {
  // Data is stored as a direct FloatBuffer
  private FloatBuffer data;

  private static final int ELEMENT_SIZE = 2;

  /** Creates an empty Vec2fCollection. */
  public Vec2fCollection() {
    // Assume you'll probably want at least four vertices
    this(4);
  }

  /** Creates an empty Vec2fCollection with the backing store sized to
      hold roughly the given number of vectors. */
  public Vec2fCollection(int estimatedSize) {
    data = BufferFactory.newFloatBuffer(ELEMENT_SIZE * estimatedSize);
    data.limit(0);
  }

  /** Returns the number of Vec2fs currently in this collection. */
  public int size() {
    return data.limit() / ELEMENT_SIZE;
  }

  /** Stores the given Vec2f at the given index. If the collection has
      not grown to the given size, throws an exception. */
  public void set(int index, Vec2f value) throws IndexOutOfBoundsException {
    if (index >= size()) {
      throw new IndexOutOfBoundsException("" + index + " >= " + size());
    }
    int base = index * ELEMENT_SIZE;
    FloatBuffer buf = data;
    buf.put(base,     value.x());
    buf.put(base + 1, value.y());
  }

  /** Fetches the Vec2f at the given index. If the collection has not
      grown to the given size, throws an exception. */
  public Vec2f get(int index) throws IndexOutOfBoundsException {
    if (index >= size()) {
      throw new IndexOutOfBoundsException("" + index + " >= " + size());
    }
    int base = index * ELEMENT_SIZE;
    // Note: could use a small pool of Vec2fs here if allocation rate
    // is an issue. However, escape analysis should eventually take
    // care of this.
    FloatBuffer buf = data;
    return new Vec2f(buf.get(base), buf.get(base + 1));
  }

  /** Adds the given Vec2f to this collection, expanding it if
      necessary. */
  public void add(Vec2f value) {
    FloatBuffer buf = data;
    if (buf.limit() == buf.capacity()) {
      FloatBuffer newBuf = BufferFactory.newFloatBuffer(Math.max(buf.capacity() + ELEMENT_SIZE,
                                                                 round((int) (buf.capacity() * 1.5f))));
      newBuf.put(buf);
      newBuf.rewind();
      newBuf.limit(buf.limit());
      data = newBuf;
      buf = newBuf;
    }
    int pos = buf.limit();
    buf.limit(pos + ELEMENT_SIZE);
    buf.put(pos,     value.x());
    buf.put(pos + 1, value.y());
  }

  /** Removes the given Vec2f from this collection. Moves all Vec2fs
      above it down one slot. */
  public Vec2f remove(int index) throws IndexOutOfBoundsException {
    if (index >= size()) {
      throw new IndexOutOfBoundsException("" + index + " >= " + size());
    }
    FloatBuffer buf = data;
    int pos = index * ELEMENT_SIZE;
    Vec2f res = new Vec2f(buf.get(pos), buf.get(pos + 1));
    if (index == size() - 1) {
      // Simply lower the limit
      buf.limit(buf.limit() - ELEMENT_SIZE);
    } else {
      buf.position(pos + ELEMENT_SIZE);
      FloatBuffer rest = buf.slice();
      buf.position(pos);
      buf.put(rest);
      buf.limit(buf.limit() - ELEMENT_SIZE);
      buf.rewind();
    }
    return res;
  }
  
  /** Returns the backing buffer of this collection. */
  public FloatBuffer getData() {
    FloatBuffer buf = data;
    buf.position(0);
    return buf.slice();
  }

  //----------------------------------------------------------------------
  // Internals only below this point
  //

  private static int round(int size) {
    return size - (size % ELEMENT_SIZE);
  }
}