/*
  ZynAddSubFX - a software synthesizer

  Util.cpp - Miscellaneous functions
  Copyright (C) 2002-2005 Nasca Octavian Paul
  Author: Nasca Octavian Paul

  This program is free software; you can redistribute it and/or modify
  it under the terms of version 2 of the GNU General Public License
  as published by the Free Software Foundation.

  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 (version 2 or later) for more details.

  You should have received a copy of the GNU General Public License (version 2)
  along with this program; if not, write to the Free Software Foundation,
  Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA

*/

#include "Util.h"
#include <vector>
#include <cassert>
#include <math.h>
#include <stdio.h>
#include <err.h>

#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <unistd.h>
#include <errno.h>
#include <string.h>
#include <sched.h>


prng_t prng_state = 0x1234;

Config config;
float *denormalkillbuf;


/*
 * Transform the velocity according the scaling parameter (velocity sensing)
 */
float VelF(float velocity, unsigned char scaling)
{
    float x;
    x = powf(VELOCITY_MAX_SCALE, (64.0f - scaling) / 64.0f);
    if((scaling == 127) || (velocity > 0.99f))
        return 1.0f;
    else
        return powf(velocity, x);
}

/*
 * Get the detune in cents
 */
float getdetune(unsigned char type,
                unsigned short int coarsedetune,
                unsigned short int finedetune)
{
    float det = 0.0f, octdet = 0.0f, cdet = 0.0f, findet = 0.0f;
    //Get Octave
    int octave = coarsedetune / 1024;
    if(octave >= 8)
        octave -= 16;
    octdet = octave * 1200.0f;

    //Coarse and fine detune
    int cdetune = coarsedetune % 1024;
    if(cdetune > 512)
        cdetune -= 1024;

    int fdetune = finedetune - 8192;

    switch(type) {
//	case 1: is used for the default (see below)
        case 2:
            cdet   = fabs(cdetune * 10.0f);
            findet = fabs(fdetune / 8192.0f) * 10.0f;
            break;
        case 3:
            cdet   = fabs(cdetune * 100);
            findet = powf(10, fabs(fdetune / 8192.0f) * 3.0f) / 10.0f - 0.1f;
            break;
        case 4:
            cdet   = fabs(cdetune * 701.95500087f); //perfect fifth
            findet =
                (powf(2, fabs(fdetune / 8192.0f) * 12.0f) - 1.0f) / 4095 * 1200;
            break;
        //case ...: need to update N_DETUNE_TYPES, if you'll add more
        default:
            cdet   = fabs(cdetune * 50.0f);
            findet = fabs(fdetune / 8192.0f) * 35.0f; //almost like "Paul's Sound Designer 2"
            break;
    }
    if(finedetune < 8192)
        findet = -findet;
    if(cdetune < 0)
        cdet = -cdet;

    det = octdet + cdet + findet;
    return det;
}


bool fileexists(const char *filename)
{
    struct stat tmp;
    int result = stat(filename, &tmp);
    if(result >= 0)
        return true;

    return false;
}

void set_realtime()
{
    sched_param sc;
    sc.sched_priority = 60;
    //if you want get "sched_setscheduler undeclared" from compilation,
    //you can safely remove the folowing line:
    sched_setscheduler(0, SCHED_FIFO, &sc);
    //if (err==0) printf("Real-time");
}

void os_sleep(long length)
{
    usleep(length);
}

std::string legalizeFilename(std::string filename)
{
    for(int i = 0; i < (int) filename.size(); ++i) {
        char c = filename[i];
        if(!(isdigit(c) || isalpha(c) || (c == '-') || (c == ' ')))
            filename[i] = '_';
    }
    return filename;
}

void invSignal(float *sig, size_t len)
{
    for(size_t i = 0; i < len; ++i)
        sig[i] *= -1.0f;
}

//Some memory pools for short term buffer use
//(avoid the use of new in RT thread(s))

struct pool_entry {
    bool   free;
    float *dat;
};
typedef std::vector<pool_entry> pool_t;
typedef pool_t::iterator        pool_itr_t;

pool_t pool;

float *getTmpBuffer()
{
    for(pool_itr_t itr = pool.begin(); itr != pool.end(); ++itr)
        if(itr->free) { //Use Pool
            itr->free = false;
            return itr->dat;
        }
    pool_entry p; //Extend Pool
    p.free = false;
    p.dat  = new float[synth->buffersize];
    pool.push_back(p);

    return p.dat;
}

void returnTmpBuffer(float *buf)
{
    for(pool_itr_t itr = pool.begin(); itr != pool.end(); ++itr)
        if(itr->dat == buf) { //Return to Pool
            itr->free = true;
            return;
        }
    fprintf(stderr,
            "ERROR: invalid buffer returned %s %d\n",
            __FILE__,
            __LINE__);
}

void clearTmpBuffers(void)
{
    for(pool_itr_t itr = pool.begin(); itr != pool.end(); ++itr) {
        if(!itr->free) //Warn about used buffers
            warn("Temporary buffer (%p) about to be freed may be in use",
                 itr->dat);
        delete [] itr->dat;
    }
    pool.clear();
}

float SYNTH_T::numRandom()
{
    return RND;
}

float interpolate(const float *data, size_t len, float pos)
{
    assert(len > (size_t)pos + 1);
    const int l_pos      = (int)pos,
              r_pos      = l_pos + 1;
    const float leftness = pos - l_pos;
    return data[l_pos] * leftness + data[r_pos] * (1.0f - leftness);
}

float cinterpolate(const float *data, size_t len, float pos)
{
    const int l_pos      = ((int)pos) % len,
              r_pos      = (l_pos + 1) % len;
    const float leftness = pos - l_pos;
    return data[l_pos] * leftness + data[r_pos] * (1.0f - leftness);
}