/*----------------------------------------------------------------------------    ChucK Concurrent, On-the-fly Audio Programming Language      Compiler and Virtual Machine     Copyright (c) 2004 Ge Wang and Perry R. Cook.  All rights reserved.      http://chuck.cs.princeton.edu/      http://soundlab.cs.princeton.edu/     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 program is distributed in the hope that it will be useful,    but WITHOUT ANY WARRANTY; without even the implied warranty of    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the    GNU General Public License for more details.     You should have received a copy of the GNU General Public License    along with this program; if not, write to the Free Software    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307    U.S.A.-----------------------------------------------------------------------------*/ //-----------------------------------------------------------------------------// name: util_math.c// desc: ...//// author: Ge Wang (gewang@cs.princeton.edu)//         Perry R. Cook (prc@cs.princeton.edu)//         Philip Davidson (philipd@alumni.princeton.edu)// date: Spring 2004//-----------------------------------------------------------------------------#include "util_math.h"#include <math.h>#include <random>  // windows / visual c++#ifdef __PLATFORM_WIN32__   #ifdef __CK_MATH_DEFINE_ROUND_TRUNC__//-----------------------------------------------------------------------------// name: round()// desc: ...//-----------------------------------------------------------------------------double round( double a ){    if( a >= 0 ) return (double)(t_CKINT)( a + .5 );    else return (double)(t_CKINT)( a - .5 );}  //-----------------------------------------------------------------------------// name: trunc()// desc: ...//-----------------------------------------------------------------------------double trunc( double a ){    return (double)(long)a;}#endif // #ifdef __CK_MATH_DEFINE_ROUND_TRUNC   #endif  //-----------------------------------------------------------------------------#ifndef __OLDSCHOOL_RANDOM__ // not using old school, pre-c++11 compatibility//-----------------------------------------------------------------------------// name: ck_random() and ck_srandom()// desc: chuck wrappers for random number generators// 1.5.0.1 (ge) using mt19937 (requires c++11)//-----------------------------------------------------------------------------// mersenne twister RNG, based on the Mersenne prime (2^19937-1)static std::mt19937 g_ck_global_rng;// ck_random() returns a signed int no greater than CK_RANDOM_MAX// to maintain parity between 64-bit and 32-bit systems, CK_RANDOM_MAX is set// to 0x7fffffff (or 2,147,483,647--the largest 32-bit signed number) rather// than mt19937's actual max of 0xffffffff (or 4,294,967,295, 2^32-1); this// is ensured using modulo; the slight skewing of the resulting RNG distribution// is considered acceptablet_CKINT ck_random() { return g_ck_global_rng() % CK_RANDOM_MAX; }// seed the random number generatorvoid ck_srandom( unsigned s ) { g_ck_global_rng.seed(s); }//-----------------------------------------------------------------------------#else // using old school random (pre-c++11)//-----------------------------------------------------------------------------// name: ck_random() and ck_srandom()// desc: chuck wrappers for random number generators | 1.4.2.0 (ge)//-----------------------------------------------------------------------------#ifndef __PLATFORM_WIN32__  t_CKINT ck_random() { return random(); }  void ck_srandom( unsigned s ) { srandom( s ); }#else // __WINDOWS_DS__  t_CKINT ck_random() { return rand(); }  void ck_srandom( unsigned s ) { srand( s ); }#endif//-----------------------------------------------------------------------------#endif // __OLDSCHOOL_RANDOM__   //-----------------------------------------------------------------------------// name: ck_remainder()// desc: ...//-----------------------------------------------------------------------------double ck_remainder( double a, double b ){#ifdef __PLATFORM_WIN32__    t_CKINT div = a/b;    return a - b*div;#else    return remainder( a, b );#endif}   // the following 6 functions are lifted from PD source// specifically x_acoustics.c// http://puredata.info/downloads#define LOGTWO 0.69314718055994528623#define LOGTEN 2.302585092994  //-----------------------------------------------------------------------------// name: mtof()// desc: midi to freq//-----------------------------------------------------------------------------double mtof( double f ){    if( f <= -1500 ) return (0);    else if( f > 1499 ) return (mtof(1499));    // else return (8.17579891564 * exp(.0577622650 * f));    // TODO: optimize    else return ( pow(2,(f-69)/12.0) * 440.0 );}  //-----------------------------------------------------------------------------// name: ftom()// desc: freq to midi//-----------------------------------------------------------------------------double ftom( double f ){       // return (f > 0 ? 17.3123405046 * log(.12231220585 * f) : -1500);    // TODO: optimize    return (f > 0 ? (log(f/440.0) / LOGTWO) * 12.0 + 69 : -1500);}  //-----------------------------------------------------------------------------// name: powtodb()// desc: ...//-----------------------------------------------------------------------------double powtodb( double f ){    if( f <= 0 ) return (0);    else    {        double val = 100 + 10./LOGTEN * log(f);        return (val < 0 ? 0 : val);    }}  //-----------------------------------------------------------------------------// name: rmstodb()// desc: ...//-----------------------------------------------------------------------------double rmstodb( double f ){    if( f <= 0 ) return (0);    else    {        double val = 100 + 20./LOGTEN * log(f);        return (val < 0 ? 0 : val);    }}  //-----------------------------------------------------------------------------// name: dbtopow()// desc: ...//-----------------------------------------------------------------------------double dbtopow( double f ){    if( f <= 0 )        return (0);    else    {        if( f > 870 ) f = 870;        return (exp((LOGTEN * 0.1) * (f-100.)));    }}  //-----------------------------------------------------------------------------// name: dbtorms()// desc: ...//-----------------------------------------------------------------------------double dbtorms( double f ){    if( f <= 0 )        return (0);    else    {        if( f > 485 ) f = 485;        return (exp((LOGTEN * 0.05) * (f-100.)));    }}    //-----------------------------------------------------------------------------// name: nextpow2()// desc: ...//-----------------------------------------------------------------------------unsigned long nextpow2( unsigned long n ){    unsigned long nn = n;    for( ; n &= n-1; nn = n );    return nn * 2;}    //-----------------------------------------------------------------------------// name: ensurepow2()// desc: ...//-----------------------------------------------------------------------------unsigned long ensurepow2( unsigned long n ){    return nextpow2( n-1 );}