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path: root/apps/codecs/lib/fixedpoint.h
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 ```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 ``` ``````/*************************************************************************** * __________ __ ___. * Open \______ \ ____ ____ | | _\_ |__ _______ ___ * Source | _// _ \_/ ___\| |/ /| __ \ / _ \ \/ / * Jukebox | | ( <_> ) \___| < | \_\ ( <_> > < < * Firmware |____|_ /\____/ \___ >__|_ \|___ /\____/__/\_ \ * \/ \/ \/ \/ \/ * \$Id\$ * * Copyright (C) 2006 Jens Arnold * * Fixed point library for plugins * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public License * as published by the Free Software Foundation; either version 2 * of the License, or (at your option) any later version. * * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY * KIND, either express or implied. * ****************************************************************************/ /** CODECS - FIXED POINT MATH ROUTINES - USAGE * * - x and y arguments are fixed point integers * - fracbits is the number of fractional bits in the argument(s) * - functions return long fixed point integers with the specified number * of fractional bits unless otherwise specified * * Calculate sin and cos of an angle: * fp_sincos(phase, *cos) * where phase is a 32 bit unsigned integer with 0 representing 0 * and 0xFFFFFFFF representing 2*pi, and *cos is the address to * a long signed integer. Value returned is a long signed integer * from -0x80000000 to 0x7fffffff, representing -1 to 1 respectively. * That is, value is a fixed point integer with 31 fractional bits. * * Take square root of a fixed point number: * fp_sqrt(x, fracbits) * */ #ifndef _FIXEDPOINT_H_CODECS #define _FIXEDPOINT_H_CODECS long fp_sincos(unsigned long phase, long *cos); long fp_sqrt(long a, unsigned int fracbits); #endif ``````