timidity_mix.cpp

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/*

    TiMidity -- Experimental MIDI to WAVE converter
    Copyright (C) 1995 Tuukka Toivonen <toivonen@clinet.fi>

    Suddenly, you realize that this program is free software; you get
    an overwhelming urge to 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 another copy of the GNU General Public
    License along with this program; if not, write to the Free
    Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
    I bet they'll be amazed.

    mix.c */

#include "pent_include.h"

#ifdef USE_TIMIDITY_MIDI

#include <cmath>
#include <cstdio>
#include <cstdlib>

#include "timidity.h"
#include "timidity_common.h"
#include "timidity_instrum.h"
#include "timidity_playmidi.h"
#include "timidity_output.h"
#include "timidity_controls.h"
#include "timidity_tables.h"
#include "timidity_resample.h"
#include "timidity_mix.h"

#ifdef NS_TIMIDITY
namespace NS_TIMIDITY {
#endif

/* Returns 1 if envelope runs out */
int recompute_envelope(int v)
{
  int stage;

  stage = voice[v].envelope_stage;

  if (stage>5)
    {
      /* Envelope ran out. */
      int tmp=(voice[v].status == VOICE_DIE); /* Already displayed as dead */
      voice[v].status = VOICE_FREE;
      if(!tmp)
        ctl->note(v);
      return 1;
    }

  if (voice[v].sample->modes & MODES_ENVELOPE)
    {
      if (voice[v].status==VOICE_ON || voice[v].status==VOICE_SUSTAINED)
        {
          if (stage>2)
            {
              /* Freeze envelope until note turns off. Trumpets want this. */
              voice[v].envelope_increment=0;
              return 0;
            }
        }
    }
  voice[v].envelope_stage=stage+1;

  if (voice[v].envelope_volume==voice[v].sample->envelope_offset[stage])
    return recompute_envelope(v);
  voice[v].envelope_target=voice[v].sample->envelope_offset[stage];
  voice[v].envelope_increment = voice[v].sample->envelope_rate[stage];
  if (voice[v].envelope_target<voice[v].envelope_volume)
    voice[v].envelope_increment = -voice[v].envelope_increment;
  return 0;
}

void apply_envelope_to_amp(int v)
{
  float lamp=voice[v].left_amp, ramp;
  sint32 la,ra;
  if (voice[v].panned == PANNED_MYSTERY)
    {
      ramp=voice[v].right_amp;
      if (voice[v].tremolo_phase_increment)
        {
          lamp *= voice[v].tremolo_volume;
          ramp *= voice[v].tremolo_volume;
        }
      if (voice[v].sample->modes & MODES_ENVELOPE)
        {
          lamp *= (float)vol_table[voice[v].envelope_volume>>23];
          ramp *= (float)vol_table[voice[v].envelope_volume>>23];
        }

      la = (sint32)FSCALE(lamp,AMP_BITS);
      
      if (la>MAX_AMP_VALUE)
        la=MAX_AMP_VALUE;

      ra = (sint32)FSCALE(ramp,AMP_BITS);
      if (ra>MAX_AMP_VALUE)
        ra=MAX_AMP_VALUE;

      
      voice[v].left_mix=FINAL_VOLUME(la);
      voice[v].right_mix=FINAL_VOLUME(ra);
    }
  else
    {
      if (voice[v].tremolo_phase_increment)
        lamp *= voice[v].tremolo_volume;
      if (voice[v].sample->modes & MODES_ENVELOPE)
        lamp *= (float)vol_table[voice[v].envelope_volume>>23];

      la = (sint32)FSCALE(lamp,AMP_BITS);

      if (la>MAX_AMP_VALUE)
        la=MAX_AMP_VALUE;

      voice[v].left_mix=FINAL_VOLUME(la);
    }
}

static int update_envelope(int v)
{
  voice[v].envelope_volume += voice[v].envelope_increment;
  /* Why is there no ^^ operator?? */
  if (((voice[v].envelope_increment < 0) &&
       (voice[v].envelope_volume <= voice[v].envelope_target)) ||
      ((voice[v].envelope_increment > 0) &&
           (voice[v].envelope_volume >= voice[v].envelope_target)))
    {
      voice[v].envelope_volume = voice[v].envelope_target;
      if (recompute_envelope(v))
        return 1;
    }
  return 0;
}

static void update_tremolo(int v)
{
  sint32 depth=voice[v].sample->tremolo_depth<<7;

  if (voice[v].tremolo_sweep)
    {
      /* Update sweep position */

      voice[v].tremolo_sweep_position += voice[v].tremolo_sweep;
      if (voice[v].tremolo_sweep_position>=(1<<SWEEP_SHIFT))
        voice[v].tremolo_sweep=0; /* Swept to max amplitude */
      else
        {
          /* Need to adjust depth */
          depth *= voice[v].tremolo_sweep_position;
          depth >>= SWEEP_SHIFT;
        }
    }

  voice[v].tremolo_phase += voice[v].tremolo_phase_increment;

  /* if (voice[v].tremolo_phase >= (SINE_CYCLE_LENGTH<<RATE_SHIFT))
     voice[v].tremolo_phase -= SINE_CYCLE_LENGTH<<RATE_SHIFT;  */

  voice[v].tremolo_volume = (float) 
    (1.0 - FSCALENEG((sine(voice[v].tremolo_phase >> RATE_SHIFT) + 1.0)
                    * depth * TREMOLO_AMPLITUDE_TUNING,
                    17));

  /* I'm not sure about the +1.0 there -- it makes tremoloed voices'
     volumes on average the lower the higher the tremolo amplitude. */
}

/* Returns 1 if the note died */
static int update_signal(int v)
{
  if (voice[v].envelope_increment && update_envelope(v))
    return 1;

  if (voice[v].tremolo_phase_increment)
    update_tremolo(v);

  apply_envelope_to_amp(v);
  return 0;
}

#ifdef LOOKUP_HACK
#  define MIXATION(a)   *lp++ += mixup[(a<<8) | (uint8)s];
#else
#  define MIXATION(a)   *lp++ += (a)*s;
#endif

static void mix_mystery_signal(sample_t *sp, sint32 *lp, int v, int count)
{
  Voice *vp = voice + v;
  final_volume_t 
    left=vp->left_mix, 
    right=vp->right_mix;
  int cc;
  sample_t s;

  if (!(cc = vp->control_counter))
    {
      cc = control_ratio;
      if (update_signal(v))
        return; /* Envelope ran out */
      left = vp->left_mix;
      right = vp->right_mix;
    }
  
  while (count)
    if (cc < count)
      {
        count -= cc;
        while (cc--)
          {
            s = *sp++;
            MIXATION(left);
            MIXATION(right);
          }
        cc = control_ratio;
        if (update_signal(v))
          return;       /* Envelope ran out */
        left = vp->left_mix;
        right = vp->right_mix;
      }
    else
      {
        vp->control_counter = cc - count;
        while (count--)
          {
            s = *sp++;
            MIXATION(left);
            MIXATION(right);
          }
        return;
      }
}

static void mix_center_signal(sample_t *sp, sint32 *lp, int v, int count)
{
  Voice *vp = voice + v;
  final_volume_t 
    left=vp->left_mix;
  int cc;
  sample_t s;

  if (!(cc = vp->control_counter))
    {
      cc = control_ratio;
      if (update_signal(v))
        return; /* Envelope ran out */
      left = vp->left_mix;
    }
  
  while (count)
    if (cc < count)
      {
        count -= cc;
        while (cc--)
          {
            s = *sp++;
            MIXATION(left);
            MIXATION(left);
          }
        cc = control_ratio;
        if (update_signal(v))
          return;       /* Envelope ran out */
        left = vp->left_mix;
      }
    else
      {
        vp->control_counter = cc - count;
        while (count--)
          {
            s = *sp++;
            MIXATION(left);
            MIXATION(left);
          }
        return;
      }
}

static void mix_single_signal(sample_t *sp, sint32 *lp, int v, int count)
{
  Voice *vp = voice + v;
  final_volume_t 
    left=vp->left_mix;
  int cc;
  sample_t s;
  
  if (!(cc = vp->control_counter))
    {
      cc = control_ratio;
      if (update_signal(v))
        return; /* Envelope ran out */
      left = vp->left_mix;
    }
  
  while (count)
    if (cc < count)
      {
        count -= cc;
        while (cc--)
          {
            s = *sp++;
            MIXATION(left);
            lp++;
          }
        cc = control_ratio;
        if (update_signal(v))
          return;       /* Envelope ran out */
        left = vp->left_mix;
      }
    else
      {
        vp->control_counter = cc - count;
        while (count--)
          {
            s = *sp++;
            MIXATION(left);
            lp++;
          }
        return;
      }
}

static void mix_mono_signal(sample_t *sp, sint32 *lp, int v, int count)
{
  Voice *vp = voice + v;
  final_volume_t 
    left=vp->left_mix;
  int cc;
  sample_t s;
  
  if (!(cc = vp->control_counter))
    {
      cc = control_ratio;
      if (update_signal(v))
        return; /* Envelope ran out */
      left = vp->left_mix;
    }
  
  while (count)
    if (cc < count)
      {
        count -= cc;
        while (cc--)
          {
            s = *sp++;
            MIXATION(left);
          }
        cc = control_ratio;
        if (update_signal(v))
          return;       /* Envelope ran out */
        left = vp->left_mix;
      }
    else
      {
        vp->control_counter = cc - count;
        while (count--)
          {
            s = *sp++;
            MIXATION(left);
          }
        return;
      }
}

static void mix_mystery(sample_t *sp, sint32 *lp, int v, int count)
{
  final_volume_t 
    left=voice[v].left_mix, 
    right=voice[v].right_mix;
  sample_t s;
  
  while (count--)
    {
      s = *sp++;
      MIXATION(left);
      MIXATION(right);
    }
}

static void mix_center(sample_t *sp, sint32 *lp, int v, int count)
{
  final_volume_t 
    left=voice[v].left_mix;
  sample_t s;
  
  while (count--)
    {
      s = *sp++;
      MIXATION(left);
      MIXATION(left);
    }
}

static void mix_single(sample_t *sp, sint32 *lp, int v, int count)
{
  final_volume_t 
    left=voice[v].left_mix;
  sample_t s;
  
  while (count--)
    {
      s = *sp++;
      MIXATION(left);
      lp++;
    }
}

static void mix_mono(sample_t *sp, sint32 *lp, int v, int count)
{
  final_volume_t 
    left=voice[v].left_mix;
  sample_t s;
  
  while (count--)
    {
      s = *sp++;
      MIXATION(left);
    }
}

/* Ramp a note out in c samples */
static void ramp_out(sample_t *sp, sint32 *lp, int v, sint32 c)
{

  /* should be final_volume_t, but uint8 gives trouble. */
  sint32 left, right, li, ri;

  sample_t s=0; /* silly warning about uninitialized s */

  /* Fix by James Caldwell */
  if ( c == 0 ) c = 1;

  left=voice[v].left_mix;
  li=-(left/c);
  if (!li) li=-1;

  /* printf("Ramping out: left=%d, c=%d, li=%d\n", left, c, li); */

  if (!(play_mode->encoding & PE_MONO))
    {
      if (voice[v].panned==PANNED_MYSTERY)
        {
          right=voice[v].right_mix;
          ri=-(right/c);
          while (c--)
            {
              left += li;
              if (left<0)
                left=0;
              right += ri;
              if (right<0)
                right=0;
              s=*sp++;
              MIXATION(left);
              MIXATION(right);
            }
        }
      else if (voice[v].panned==PANNED_CENTER)
        {
          while (c--)
            {
              left += li;
              if (left<0)
                return;
              s=*sp++;  
              MIXATION(left);
              MIXATION(left);
            }
        }
      else if (voice[v].panned==PANNED_LEFT)
        {
          while (c--)
            {
              left += li;
              if (left<0)
                return;
              s=*sp++;
              MIXATION(left);
              lp++;
            }
        }
      else if (voice[v].panned==PANNED_RIGHT)
        {
          while (c--)
            {
              left += li;
              if (left<0)
                return;
              s=*sp++;
              lp++;
              MIXATION(left);
            }
        }
    }
  else
    {
      /* Mono output.  */
      while (c--)
        {
          left += li;
          if (left<0)
            return;
          s=*sp++;
          MIXATION(left);
        }
    }
}


/**************** interface function ******************/

void mix_voice(sint32 *buf, int v, sint32 c)
{
  Voice *vp=voice+v;
  sample_t *sp;
  if (vp->status==VOICE_DIE)
    {
      if (c>=MAX_DIE_TIME)
        c=MAX_DIE_TIME;
      sp=resample_voice(v, &c);
      ramp_out(sp, buf, v, c);
      vp->status=VOICE_FREE;
    }
  else
    {
      sp=resample_voice(v, &c);
      if (play_mode->encoding & PE_MONO)
        {
          /* Mono output. */
          if (vp->envelope_increment || vp->tremolo_phase_increment)
            mix_mono_signal(sp, buf, v, c);
          else
            mix_mono(sp, buf, v, c);
        }
      else
        {
          if (vp->panned == PANNED_MYSTERY)
            {
              if (vp->envelope_increment || vp->tremolo_phase_increment)
                mix_mystery_signal(sp, buf, v, c);
              else
                mix_mystery(sp, buf, v, c);
            }
          else if (vp->panned == PANNED_CENTER)
            {
              if (vp->envelope_increment || vp->tremolo_phase_increment)
                mix_center_signal(sp, buf, v, c);
              else
                mix_center(sp, buf, v, c);
            }
          else
            { 
              /* It's either full left or full right. In either case,
                 every other sample is 0. Just get the offset right: */
              if (vp->panned == PANNED_RIGHT) buf++;
              
              if (vp->envelope_increment || vp->tremolo_phase_increment)
                mix_single_signal(sp, buf, v, c);
              else 
                mix_single(sp, buf, v, c);
            }
        }
    }
}

#ifdef NS_TIMIDITY
};
#endif

#endif //USE_TIMIDITY_MIDI

---