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 28 var AG_CONST = 0.6072529350; 29 30 function FIXED(X) 31 { 32 return X * 65536.0; 33 } 34 35 function FLOAT(X) 36 { 37 return X / 65536.0; 38 } 39 40 function DEG2RAD(X) 41 { 42 return 0.017453 * (X); 43 } 44 45 var 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 53 function 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 83 function 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 95 cordic(25000); 96
