1/*
2 * Copyright (C) Rich Moore.  All rights reserved.
3 *
4 * Redistribution and use in source and binary forms, with or without
5 * modification, are permitted provided that the following conditions
6 * are met:
7 * 1. Redistributions of source code must retain the above copyright
8 *    notice, this list of conditions and the following disclaimer.
9 * 2. Redistributions in binary form must reproduce the above copyright
10 *    notice, this list of conditions and the following disclaimer in the
11 *    documentation and/or other materials provided with the distribution.
12 *
13 * THIS SOFTWARE IS PROVIDED BY CONTRIBUTORS ``AS IS'' AND ANY
14 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
15 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
16 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE COMPUTER, INC. OR
17 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
18 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
19 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
20 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
21 * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
22 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
23 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
24 */
25
26/////. Start CORDIC
27
28var AG_CONST = 0.6072529350;
29
30function FIXED(X)
31{
32  return X * 65536.0;
33}
34
35function FLOAT(X)
36{
37  return X / 65536.0;
38}
39
40function DEG2RAD(X)
41{
42  return 0.017453 * (X);
43}
44
45var Angles = [
46  FIXED(45.0), FIXED(26.565), FIXED(14.0362), FIXED(7.12502),
47  FIXED(3.57633), FIXED(1.78991), FIXED(0.895174), FIXED(0.447614),
48  FIXED(0.223811), FIXED(0.111906), FIXED(0.055953),
49  FIXED(0.027977)
50              ];
51
52
53function cordicsincos() {
54    var X;
55    var Y;
56    var TargetAngle;
57    var CurrAngle;
58    var Step;
59
60    X = FIXED(AG_CONST);         /* AG_CONST * cos(0) */
61    Y = 0;                       /* AG_CONST * sin(0) */
62
63    TargetAngle = FIXED(28.027);
64    CurrAngle = 0;
65    for (Step = 0; Step < 12; Step++) {
66        var NewX;
67        if (TargetAngle > CurrAngle) {
68            NewX = X - (Y >> Step);
69            Y = (X >> Step) + Y;
70            X = NewX;
71            CurrAngle += Angles[Step];
72        } else {
73            NewX = X + (Y >> Step);
74            Y = -(X >> Step) + Y;
75            X = NewX;
76            CurrAngle -= Angles[Step];
77        }
78    }
79}
80
81///// End CORDIC
82
83function cordic( runs ) {
84  var start = new Date();
85
86  for ( var i = 0 ; i < runs ; i++ ) {
87      cordicsincos();
88  }
89
90  var end = new Date();
91
92  return end.getTime() - start.getTime();
93}
94
95cordic(25000);
96