michael@0: /*
michael@0:  * Copyright (C) Rich Moore.  All rights reserved.
michael@0:  *
michael@0:  * Redistribution and use in source and binary forms, with or without
michael@0:  * modification, are permitted provided that the following conditions
michael@0:  * are met:
michael@0:  * 1. Redistributions of source code must retain the above copyright
michael@0:  *    notice, this list of conditions and the following disclaimer.
michael@0:  * 2. Redistributions in binary form must reproduce the above copyright
michael@0:  *    notice, this list of conditions and the following disclaimer in the
michael@0:  *    documentation and/or other materials provided with the distribution.
michael@0:  *
michael@0:  * THIS SOFTWARE IS PROVIDED BY CONTRIBUTORS ``AS IS'' AND ANY
michael@0:  * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
michael@0:  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
michael@0:  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE COMPUTER, INC. OR
michael@0:  * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
michael@0:  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
michael@0:  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
michael@0:  * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
michael@0:  * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
michael@0:  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
michael@0:  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 
michael@0:  */
michael@0: 
michael@0: /////. Start CORDIC
michael@0: 
michael@0: var AG_CONST = 0.6072529350;
michael@0: 
michael@0: function FIXED(X)
michael@0: {
michael@0:   return X * 65536.0;
michael@0: }
michael@0: 
michael@0: function FLOAT(X)
michael@0: {
michael@0:   return X / 65536.0;
michael@0: }
michael@0: 
michael@0: function DEG2RAD(X)
michael@0: {
michael@0:   return 0.017453 * (X);
michael@0: }
michael@0: 
michael@0: var Angles = [
michael@0:   FIXED(45.0), FIXED(26.565), FIXED(14.0362), FIXED(7.12502),
michael@0:   FIXED(3.57633), FIXED(1.78991), FIXED(0.895174), FIXED(0.447614),
michael@0:   FIXED(0.223811), FIXED(0.111906), FIXED(0.055953),
michael@0:   FIXED(0.027977) 
michael@0:               ];
michael@0: 
michael@0: 
michael@0: function cordicsincos() {
michael@0:     var X;
michael@0:     var Y;
michael@0:     var TargetAngle;
michael@0:     var CurrAngle;
michael@0:     var Step;
michael@0:  
michael@0:     X = FIXED(AG_CONST);         /* AG_CONST * cos(0) */
michael@0:     Y = 0;                       /* AG_CONST * sin(0) */
michael@0: 
michael@0:     TargetAngle = FIXED(28.027);
michael@0:     CurrAngle = 0;
michael@0:     for (Step = 0; Step < 12; Step++) {
michael@0:         var NewX;
michael@0:         if (TargetAngle > CurrAngle) {
michael@0:             NewX = X - (Y >> Step);
michael@0:             Y = (X >> Step) + Y;
michael@0:             X = NewX;
michael@0:             CurrAngle += Angles[Step];
michael@0:         } else {
michael@0:             NewX = X + (Y >> Step);
michael@0:             Y = -(X >> Step) + Y;
michael@0:             X = NewX;
michael@0:             CurrAngle -= Angles[Step];
michael@0:         }
michael@0:     }
michael@0:     return CurrAngle;
michael@0: }
michael@0: 
michael@0: ///// End CORDIC
michael@0: 
michael@0: function cordic( runs ) {
michael@0:   var actual;
michael@0: 
michael@0:   for ( var i = 0 ; i < runs ; i++ ) {
michael@0:     actual = cordicsincos();
michael@0:   }
michael@0: 
michael@0:   assertEq(actual, 1834995.3515519998)
michael@0: }
michael@0: 
michael@0: cordic(25000);