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/*

        sintable: sine wave table generator

        Based on MAME's fm.c file.

  (c) Jose Tejada Gomez, May 2013

  You can use this file following the GNU GENERAL PUBLIC LICENSE version 3

  Read the details of the license in:

  http://www.gnu.org/licenses/gpl.txt

  Send comments to: jose.tejada at ieee.org

*/

#include <iostream>

#include <cmath>

#include "../cpp/args.h"

using namespace std;

#define ENV_BITS        10

#define ENV_LEN         (1<<ENV_BITS)

#define ENV_STEP        (128.0/ENV_LEN)

#define TL_RES_LEN      (256) /* 8 bits addressing (real chip) */

#define SIN_BITS        10

#define SIN_LEN         (1<<SIN_BITS)

#define SIN_MASK        (SIN_LEN-1)

signed int tl_tab[TL_RES_LEN];

unsigned int sin_tab[SIN_LEN];

void init_tables(void) // copied from fm.c

{

        signed int i,x;

        signed int n;

        double o,m;

        for (x=0; x<TL_RES_LEN; x++)

        {

                m = (1<<16) / pow(2, (x+1) * (ENV_STEP/4.0) / 8.0);

                m = floor(m);

                /* we never reach (1<<16) here due to the (x+1) */

                /* result fits within 16 bits at maximum */

                n = (int)m;     /* 16 bits here */

                n >>= 4;        /* 12 bits here */

                if (n&1)        /* round to nearest */

                        n = (n>>1)+1;

                else

                        n = n>>1;

                                                /* 11 bits here (rounded) */

                n <<= 2;        /* 13 bits here (as in real chip) */

                tl_tab[ x ] = n;

        }

        for (i=0; i<SIN_LEN; i++)

        {

                /* non-standard sinus */

                m = sin( ((i*2)+1) * M_PI / SIN_LEN ); /* checked against the real chip */

                /* we never reach zero here due to ((i*2)+1) */

                if (m>0.0)

                        o = 8*log(1.0/m)/log(2.0);  /* convert to 'decibels' */

                else

                        o = 8*log(-1.0/m)/log(2.0); /* convert to 'decibels' */

                o = o / (ENV_STEP/4);

                n = (int)(2.0*o);

                if (n&1)                        /* round to nearest */

                        n = (n>>1)+1;

                else

                        n = n>>1;

                sin_tab[ i ] = n*2 + (m>=0.0? 0: 1 );

                /*logerror("FM.C: sin [%4i]= %4i (tl_tab value=%5i)\n", i, sin_tab[i],tl_tab[sin_tab[i]]);*/

        }

}

void dump_tl_tab() {

  for( int i=0; i<TL_RES_LEN; i++ ) {

    cout <<  tl_tab[i] << "\n";

  }

}

void dump_sin_tab() {

  for( int i=0; i<SIN_LEN; i++ ) {

    cout << sin_tab[i] << "\n";

  }

}

void dump_composite() {

  for( int i=0; i<SIN_LEN; i++ ) {

    int v = sin_tab[i];

    int m = (v>>1)&0xFF;

    int lin = tl_tab[m];

    int exp = v>>9;

    int adj0 = lin>>exp;

    int adj1 = (v&1) ? -1*adj0 : adj0;

    cout << v << "," << lin << "," << exp << "," << adj0 << "," << adj1 << "\n";

  }

}

unsigned conv( double x ) {

  double xmax = 0xFFFFF; // 20 bits, all ones

  return (unsigned)(xmax* 20*log(x+0.5));

}

int main(int argc, char *argv[]) {

  arg_vector_t legal_args;

  argument_t arg_hex( legal_args, "hex", argument_t::flag,

    "set output to hexadecimal mode" );

  argument_t arg_sin( legal_args, "sin", argument_t::flag,

    "dump sine wave" );

  argument_t arg_pow( legal_args, "pow", argument_t::flag,

    "dump power table" );

  argument_t arg_comp( legal_args, "composite", argument_t::flag,

    "dump pow[ sine ] composite function" );

  Args args_parser( argc, argv, legal_args );

  if( args_parser.help_request() ) { return 0; }

  if( argc==1 ) { args_parser.show_help(); return 0; }

  init_tables();

        if( arg_hex.is_set() ) cout.setf( ios::hex, ios::basefield );

        if( arg_pow.is_set() ) dump_tl_tab();

        if( arg_sin.is_set() ) dump_sin_tab();

        if( arg_comp.is_set() ) dump_composite();

        return 0;

}