cwMath.h/cpp : Populate cwMath from libcm and move some functions from cwUtility to cwMath.

This commit is contained in:
kevin 2021-08-15 15:51:09 -04:00
parent f8e0a24032
commit c9bf328a6d
4 changed files with 674 additions and 6 deletions

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@ -5,7 +5,7 @@
#include "cwFile.h"
#include "cwObject.h"
#include "cwAudioFile.h"
#include "cwUtility.h"
#include "cwMath.h"
#include "cwFileSys.h"
// #define _24to32_aif( p ) ((int)( ((p[0]>127?255:0) << 24) + (((int)p[0]) << 16) + (((int)p[1]) <<8) + p[2])) // no-swap equivalent
@ -179,7 +179,7 @@ namespace cw
if((rc = _read(p,s,10,1)) != kOkRC )
return rc;
*x80Ptr = x80ToDouble(s);
*x80Ptr = math::x80ToDouble(s);
return kOkRC;
}
@ -557,7 +557,7 @@ namespace cw
rc_t rc = kOkRC;
unsigned char srateX80[10];
doubleToX80( p->info.srate, srateX80 );
math::doubleToX80( p->info.srate, srateX80 );
unsigned hdrByteCnt = 54;
unsigned ssndByteCnt = 8 + (p->info.chCnt * p->info.frameCnt * (p->info.bits/kBitsPerByte));

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@ -2,8 +2,403 @@
#include "cwLog.h"
#include "cwCommonImpl.h"
#include "cwMath.h"
#include "cwMem.h"
#include <algorithm>
unsigned cw::math::randUInt( unsigned minVal, unsigned maxVal )
// TODO: rewrite to avoid copying
// this code comes via csound source ...
double cw::math::x80ToDouble( unsigned char rate[10] )
{
return std::max(minVal,std::min(maxVal,minVal + (unsigned)round(((maxVal - minVal) * rand())/RAND_MAX)));
char sign;
short exp = 0;
unsigned long mant1 = 0;
unsigned long mant0 = 0;
double val;
unsigned char* p = (unsigned char*)rate;
exp = *p++;
exp <<= 8;
exp |= *p++;
sign = (exp & 0x8000) ? 1 : 0;
exp &= 0x7FFF;
mant1 = *p++;
mant1 <<= 8;
mant1 |= *p++;
mant1 <<= 8;
mant1 |= *p++;
mant1 <<= 8;
mant1 |= *p++;
mant0 = *p++;
mant0 <<= 8;
mant0 |= *p++;
mant0 <<= 8;
mant0 |= *p++;
mant0 <<= 8;
mant0 |= *p++;
/* special test for all bits zero meaning zero
- else pow(2,-16383) bombs */
if (mant1 == 0 && mant0 == 0 && exp == 0 && sign == 0)
return 0.0;
else {
val = ((double)mant0) * pow(2.0,-63.0);
val += ((double)mant1) * pow(2.0,-31.0);
val *= pow(2.0,((double) exp) - 16383.0);
return sign ? -val : val;
}
}
// TODO: rewrite to avoid copying
/*
* Convert double to IEEE 80 bit floating point
* Should be portable to all C compilers.
* 19aug91 aldel/dpwe covered for MSB bug in Ultrix 'cc'
*/
void cw::math::doubleToX80(double val, unsigned char rate[10])
{
char sign = 0;
short exp = 0;
unsigned long mant1 = 0;
unsigned long mant0 = 0;
unsigned char* p = (unsigned char*)rate;
if (val < 0.0) { sign = 1; val = -val; }
if (val != 0.0) /* val identically zero -> all elements zero */
{
exp = (short)(std::log(val)/std::log(2.0) + 16383.0);
val *= pow(2.0, 31.0+16383.0-(double)exp);
mant1 =((unsigned)val);
val -= ((double)mant1);
val *= pow(2.0, 32.0);
mant0 =((double)val);
}
*p++ = ((sign<<7)|(exp>>8));
*p++ = (u_char)(0xFF & exp);
*p++ = (u_char)(0xFF & (mant1>>24));
*p++ = (u_char)(0xFF & (mant1>>16));
*p++ = (u_char)(0xFF & (mant1>> 8));
*p++ = (u_char)(0xFF & (mant1));
*p++ = (u_char)(0xFF & (mant0>>24));
*p++ = (u_char)(0xFF & (mant0>>16));
*p++ = (u_char)(0xFF & (mant0>> 8));
*p++ = (u_char)(0xFF & (mant0));
}
bool cw::math::isPowerOfTwo( unsigned x )
{
return !( (x < 2) || (x & (x-1)) );
}
unsigned cw::math::nextPowerOfTwo( unsigned val )
{
unsigned i;
unsigned mask = 1;
unsigned msb = 0;
unsigned cnt = 0;
// if val is a power of two return it
if( isPowerOfTwo(val) )
return val;
// next pow of zero is 2
if( val == 0 )
return 2;
// if the next power of two can't be represented in 32 bits
if( val > 0x80000000)
{
assert(0);
return 0;
}
// find most sig. bit that is set - the number with only the next msb set is next pow 2
for(i=0; i<31; i++,mask<<=1)
if( mask & val )
{
msb = i;
cnt++;
}
return 1 << (msb + 1);
}
unsigned cw::math::nearPowerOfTwo( unsigned i )
{
unsigned vh = nextPowerOfTwo(i);
if( vh == 2 )
return vh;
unsigned vl = vh / 2;
if( vh - i < i - vl )
return vh;
return vl;
}
bool cw::math::isOddU( unsigned v ) { return v % 2 == 1; }
bool cw::math::isEvenU( unsigned v ) { return !isOddU(v); }
unsigned cw::math::nextOddU( unsigned v ) { return isOddU(v) ? v : v+1; }
unsigned cw::math::prevOddU( unsigned v ) { return isOddU(v) ? v : v-1; }
unsigned cw::math::nextEvenU( unsigned v ) { return isEvenU(v) ? v : v+1; }
unsigned cw::math::prevEvenU( unsigned v ) { return isEvenU(v) ? v : v-1; }
unsigned cw::math::modIncr(int idx, int delta, int maxN )
{
int sum = idx + delta;
if( sum >= maxN )
return sum - maxN;
if( sum < 0 )
return maxN + sum;
return sum;
}
unsigned cw::math::hzToMidi( double hz )
{
float midi = 12.0 * std::log2(hz/13.75) + 9;
if( midi < 0 )
midi = 0;
if( midi > 127 )
midi = 127;
return (unsigned)lround(midi);
}
float cw::math::midiToHz( unsigned midi )
{
double m = midi <= 127 ? midi : 127;
return (float)( 13.75 * pow(2.0,(m - 9.0)/12.0));
}
//=================================================================
// Random numbers
int cw::math::randInt( int min, int max )
{
assert( min <= max );
int range = max - min;
return min + std::max(0,std::min(range,(int)round(range * (double)rand() / RAND_MAX)));
}
unsigned cw::math::randUInt( unsigned min, unsigned max )
{
assert( min <= max );
unsigned range = max - min;
unsigned val = (unsigned)round(range * (double)rand() / RAND_MAX);
return min + std::max((unsigned)0,std::min(range,val));
}
float cw::math::randFloat( float min, float max )
{
assert( min <= max );
float range = max - min;
float val = (float)(range * (double)rand() / RAND_MAX);
return min + std::max(0.0f,std::min(range,val));
}
double cw::math::randDouble( double min, double max )
{
assert( min <= max );
double range = max - min;
double val = range * (double)rand() / RAND_MAX;
return min + std::max(0.0,std::min(range,val));
}
//=================================================================
// Base on: http://stackoverflow.com/questions/3874627/floating-point-comparison-functions-for-c-sharp
bool cw::math::isCloseD( double x0, double x1, double eps )
{
double d = fabs(x0-x1);
if( x0 == x1 )
return true;
if( x0==0 || x1==0 || d<DBL_MIN )
return d < (eps * DBL_MIN);
return (d / std::min( fabs(x0) + fabs(x1), DBL_MAX)) < eps;
}
bool cw::math::isCloseF( float x0, float x1, double eps_d )
{
float eps = (float)eps_d;
float d = fabsf(x0-x1);
if( x0 == x1 )
return true;
if( x0==0 || x1==0 || d<FLT_MIN )
return d < (eps * FLT_MIN);
return (d / std::min( fabsf(x0) + fabsf(x1), FLT_MAX)) < eps;
}
bool cw::math::isCloseI( int x0, int x1, double eps )
{
if( x0 == x1 )
return true;
return abs(x0-x1)/(abs(x0)+abs(x1)) < eps;
}
bool cw::math::isCloseU( unsigned x0, unsigned x1, double eps )
{
if( x0 == x1 )
return true;
if( x0 > x1 )
return (x0-x1)/(x0+x1) < eps;
else
return (x1-x0)/(x0+x1) < eps;
}
//=================================================================
// lFSR() implementation based on note at bottom of:
// http://www.ece.u.edu/~koopman/lfsr/index.html
void cw::math::lFSR( unsigned lfsrN, unsigned tapMask, unsigned seed, unsigned* yV, unsigned yN )
{
assert( 0 < lfsrN && lfsrN < 32 );
unsigned i;
for(i=0; i<yN; ++i)
{
if( (yV[i] = seed & 1)==1 )
seed = (seed >> 1) ^ tapMask;
else
seed = (seed >> 1);
}
}
namespace cw
{
namespace math
{
bool mLS_IsBalanced( const unsigned* xV, int xN)
{
int a = 0;
int i;
for(i=0; i<xN; ++i)
if( xV[i] == 1 )
++a;
return abs(a - (xN-a)) == 1;
}
}
unsigned _genGoldCopy( int* y, unsigned yi, unsigned yN, unsigned* x, unsigned xN)
{
unsigned i;
for(i=0; i<xN; ++i,++yi)
y[yi] = x[i]==1 ? -1 : 1;
assert(yi <= yN);
return yi;
}
}
bool cw::math::genGoldCodes( unsigned lfsrN, unsigned poly_coeff0, unsigned poly_coeff1, unsigned goldN, int* yM, unsigned mlsN )
{
bool retFl = true;
unsigned yi = 0;
unsigned yN = goldN * mlsN;
unsigned* mls0V = mem::allocZ<unsigned>(mlsN);
unsigned* mls1V = mem::allocZ<unsigned>(mlsN);
unsigned* xorV = mem::allocZ<unsigned>(mlsN);
unsigned i,j;
lFSR(lfsrN, poly_coeff0, 1 << (lfsrN-1), mls0V, mlsN);
lFSR(lfsrN, poly_coeff1, 1 << (lfsrN-1), mls1V, mlsN);
if( mLS_IsBalanced(mls0V,mlsN) )
yi = _genGoldCopy(yM, yi, yN, mls0V, mlsN);
if( yi<yN && mLS_IsBalanced(mls1V,mlsN) )
yi = _genGoldCopy(yM, yi, yN, mls1V, mlsN);
for(i=0; yi < yN && i<mlsN-1; ++i )
{
for(j=0; j<mlsN; ++j)
xorV[j] = (mls0V[j] + mls1V[ (i+j) % mlsN ]) % 2;
if( mLS_IsBalanced(xorV,mlsN) )
yi = _genGoldCopy(yM,yi,yN,xorV,mlsN);
}
if(yi < yN )
{
//rc = errMsg(err,kOpFailAtRC,"Gold code generation failed. Insuffient balanced pairs.");
retFl = false;
}
mem::release(mls0V);
mem::release(mls1V);
mem::release(xorV);
return retFl;
}
bool cw::math::lFSR_Test()
{
// lfsrN = 5; % 5 6 7;
// poly_coeff0 = 0x12; % 0x12 0x21 0x41;
// poly_coeff1 = 0x1e; % 0x1e 0x36 0x72;
unsigned lfsrN = 7;
unsigned pc0 = 0x41;
unsigned pc1 = 0x72;
unsigned mlsN = (1 << lfsrN)-1;
unsigned yN = mlsN*2;
unsigned yV[ yN ];
unsigned i;
lFSR( lfsrN, pc0, 1 << (lfsrN-1), yV, yN );
for(i=0; i<mlsN; ++i)
if( yV[i] != yV[i+mlsN] )
return false;
//atVOU_PrintL(NULL,"0x12",yV,mlsN,2);
lFSR( lfsrN, pc1, 1 << (lfsrN-1), yV, yN );
//atVOU_PrintL(NULL,"0x17",yV,mlsN,2);
for(i=0; i<mlsN; ++i)
if( yV[i] != yV[i+mlsN] )
return false;
return true;
}

272
cwMath.h
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@ -5,7 +5,277 @@ namespace cw
{
namespace math
{
unsigned randUInt(unsigned minVal, unsigned maxVal );
double x80ToDouble( unsigned char s[10] );
void doubleToX80( double v, unsigned char s[10] );
bool isPowerOfTwo( unsigned i );
unsigned nextPowerOfTwo( unsigned i );
unsigned nearPowerOfTwo( unsigned i );
bool isOddU( unsigned v );
bool isEvenU( unsigned v );
unsigned nextOddU( unsigned v );
unsigned prevOddU( unsigned v );
unsigned nextEvenU( unsigned v );
unsigned prevEvenU( unsigned v );
/// Increment or decrement 'idx' by 'delta' always wrapping the result into the range
/// 0 to (maxN-1).
/// 'idx': initial value
/// 'delta': incremental amount
/// 'maxN' - 1 : maximum return value.
unsigned modIncr(int idx, int delta, int maxN );
// modified bessel function of first kind, order 0
// ref: orfandis appendix B io.m
template< typename T >
T bessel0( T x )
{
T eps = pow(10.0,-9.0);
T n = 1.0;
T S = 1.0;
T D = 1.0;
while(D > eps*S)
{
T t = x /(2.0*n);
n = n+1;
D = D * pow(t,2.0);
S = S + D;
}
return S;
}
//=================================================================
// The following elliptic-related function approximations come from
// Parks & Burrus, Digital Filter Design, Appendix program 9, pp. 317-326
// which in turn draws directly on other sources
// Calculate complete elliptic integral (quarter period) K
// given *complimentary* modulus kc.
template< typename T >
T ellipK( T kc )
{
T a = 1, b = kc, c = 1, tmp;
while( c > std::numeric_limits<T>::epsilon )
{
c = 0.5*(a-b);
tmp = 0.5*(a+b);
b = sqrt(a*b);
a = tmp;
}
return M_PI/(2*a);
}
// Calculate elliptic modulus k
// given ratio of complete elliptic integrals r = K/K'
// (solves the "degree equation" for fixed N = K*K1'/K'K1)
template< typename T >
T ellipDeg( T r )
{
T q,a,b,c,d;
a = b = c = 1;
d = q = exp(-M_PI*r);
while( c > std::numeric_limits<T>::epsilon )
{
a = a + 2*c*d;
c = c*d*d;
b = b + c;
d = d*q;
}
return 4*sqrt(q)*pow(b/a,2);
}
// calculate arc elliptic tangent u (elliptic integral of the 1st kind)
// given argument x = sc(u,k) and *complimentary* modulus kc
template< typename T >
T ellipArcSc( T x, T kc )
{
T a = 1, b = kc, y = 1/x, tmp;
unsigned L = 0;
while( true )
{
tmp = a*b;
a += b;
b = 2*sqrt(tmp);
y -= tmp/y;
if( y == 0 )
y = sqrt(tmp) * 1E-10;
if( fabs(a-b)/a < std::numeric_limits<T>::epsilon )
break;
L *= 2;
if( y < 0 )
L++;
}
if( y < 0 )
L++;
return (atan(a/y) + M_PI*L)/a;
}
// calculate Jacobi elliptic functions sn, cn, and dn
// given argument u and *complimentary* modulus kc
template< typename T >
rc_t ellipJ( T u, T kc, T* sn, T* cn, T* dn )
{
assert( sn != NULL || cn != NULL || dn != NULL );
if( u == 0 )
{
if( sn != NULL ) *sn = 0;
if( cn != NULL ) *cn = 1;
if( dn != NULL ) *dn = 1;
return kOkRC;
}
int i;
T a,b,c,d,e,tmp,_sn,_cn,_dn;
T aa[16], bb[16];
a = 1;
b = kc;
for( i = 0; i < 16; i++ )
{
aa[i] = a;
bb[i] = b;
tmp = (a+b)/2;
b = sqrt(a*b);
a = tmp;
if( (a-b)/a < std::numeric_limits<T>::epsilon )
break;
}
c = a/tan(u*a);
d = 1;
for( ; i >= 0; i-- )
{
e = c*c/a;
c = c*d;
a = aa[i];
d = (e + bb[i]) / (e+a);
}
_sn = 1/sqrt(1+c*c);
_cn = _sn*c;
_dn = d;
if( sn != NULL ) *sn = _sn;
if( cn != NULL ) *cn = _cn;
if( dn != NULL ) *dn = _dn;
return kOkRC;
}
//=================================================================
// bilinear transform
// z = (2*sr + s)/(2*sr - s)
template< typename T >
rc_t blt( unsigned n, T sr, T* rp, T* ip )
{
unsigned i;
T a = 2*sr,
tr, ti, td;
for( i = 0; i < n; i++ )
{
tr = rp[i];
ti = ip[i];
td = pow(a-tr, 2) + ti*ti;
rp[i] = (a*a - tr*tr - ti*ti)/td;
ip[i] = 2*a*ti/td;
if( tr < -1E15 )
rp[i] = 0;
if( fabs(ti) > 1E15 )
ip[i] = 0;
}
return kOkRC;
}
//=================================================================
// Pitch conversion
unsigned hzToMidi( double hz );
float midiToHz( unsigned midi );
//=================================================================
// Floating point byte swapping
unsigned ffSwapFloatToUInt( float v );
float ffSwapUIntToFloat( unsigned v );
unsigned long long ffSwapDoubleToULLong( double v );
double ffSwapULLongToDouble( unsigned long long v );
//=================================================================
template< typename T >
T rand_range(T min, T max )
{
assert( min <= max );
T range = max - min;
return min + std::max(0,std::min(range,(T)range * rand() / RAND_MAX));
}
int randInt( int min, int max );
unsigned randUInt( unsigned min, unsigned max );
float randFloat( float min, float max );
double randDouble( double min, double max );
//=================================================================
bool isCloseD( double x0, double x1, double eps );
bool isCloseF( float x0, float x1, double eps );
bool isCloseI( int x0, int x1, double eps );
bool isCloseU( unsigned x0, unsigned x1, double eps );
//=================================================================
// Run a length 'lfsrN' linear feedback shift register (LFSR) for 'yN' iterations to
// produce a length 'yN' bit string in yV[yN].
// 'lfsrN' count of bits in the shift register range: 2<= lfsrN <= 32.
// 'tapMask' is a bit mask which gives the tap indexes positions for the LFSR.
// The least significant bit corresponds to the maximum delay tap position.
// The min tap position is therefore denoted by the tap mask bit location 1 << (lfsrN-1).
// A minimum of two taps must exist.
// 'seed' sets the initial delay state.
// 'yV[yN]' is the the output vector
// 'yN' is count of elements in yV.
// The function resturn kOkAtRC on success or kInvalidArgsRCRC if any arguments are invalid.
// /sa lFSR_Test.
void lFSR( unsigned lfsrN, unsigned tapMask, unsigned seed, unsigned* yV, unsigned yN );
// Example and test code for lFSR()
bool lFSR_Test();
// Generate a set of 'goldN' Gold codes using the Maximum Length Sequences (MLS) generated
// by a length 'lfsrN' linear feedback shift register.
// 'err' is an error object to be set if the the function fails.
// 'lfsrN' is the length of the Linear Feedback Shift Registers (LFSR) used to generate the MLS.
// 'poly_coeff0' tap mask for the first LFSR.
// 'coeff1' tap mask the the second LFSR.
// 'goldN' is the count of Gold codes to generate.
// 'yM[mlsN', goldN] is a column major output matrix where each column contains a Gold code.
// 'mlsN' is the length of the maximum length sequence for each Gold code which can be
// calculated as mlsN = (1 << a->lfsrN) - 1.
// Note that values of 'lfsrN' and the 'poly_coeffx' must be carefully selected such that
// they will produce a MLS. For example to generate a MLS with length 31 set 'lfsrN' to 5 and
// then select poly_coeff from two different elements of the set {0x12 0x14 0x17 0x1B 0x1D 0x1E}.
// See http://www.ece.u.edu/~koopman/lfsr/index.html for a complete set of MSL polynomial
// coefficients for given LFSR lengths.
// Returns false if insufficient balanced pairs exist.
bool genGoldCodes( unsigned lfsrN, unsigned poly_coeff0, unsigned poly_coeff1, unsigned goldN, int* yM, unsigned mlsN );
}
}

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@ -36,6 +36,7 @@ void cw::printHex( const void* buf, unsigned bufByteN, bool asciiFl )
}
}
#ifdef NOT_DEF
// TODO: rewrite to avoid copying
// this code comes via csound source ...
@ -174,3 +175,5 @@ unsigned cw::nearestPowerOfTwo( unsigned i )
return vh;
return vl;
}
#endif