/* FluidSynth - A Software Synthesizer
 *
 * Copyright (C) 2003  Peter Hanappe and others.
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public License
 * as published by the Free Software Foundation; either version 2.1 of
 * the License, or (at your option) any later version.
 *
 * This library 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
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free
 * Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
 * 02110-1301, USA
 */

#include "fluid_mod.h"
#include "fluid_chan.h"
#include "fluid_voice.h"

/**
 * Clone the modulators destination, sources, flags and amount.
 * @param mod the modulator to store the copy to
 * @param src the source modulator to retrieve the information from
 * @note The \c next member of \c mod will be left unchanged.
 */
void
fluid_mod_clone(fluid_mod_t* mod, fluid_mod_t* src)
{
  mod->dest = src->dest;
  mod->src1 = src->src1;
  mod->flags1 = src->flags1;
  mod->src2 = src->src2;
  mod->flags2 = src->flags2;
  mod->amount = src->amount;
}

/**
 * Set a modulator's primary source controller and flags.
 * @param mod Modulator
 * @param src Modulator source (#fluid_mod_src or a MIDI controller number)
 * @param flags Flags determining mapping function and whether the source
 *   controller is a general controller (#FLUID_MOD_GC) or a MIDI CC controller
 *   (#FLUID_MOD_CC), see #fluid_mod_flags.
 */
void
fluid_mod_set_source1(fluid_mod_t* mod, int src, int flags)
{
  mod->src1 = src;
  mod->flags1 = flags;
}

/**
 * Set a modulator's secondary source controller and flags.
 * @param mod Modulator
 * @param src Modulator source (#fluid_mod_src or a MIDI controller number)
 * @param flags Flags determining mapping function and whether the source
 *   controller is a general controller (#FLUID_MOD_GC) or a MIDI CC controller
 *   (#FLUID_MOD_CC), see #fluid_mod_flags.
 */
void
fluid_mod_set_source2(fluid_mod_t* mod, int src, int flags)
{
  mod->src2 = src;
  mod->flags2 = flags;
}

/**
 * Set the destination effect of a modulator.
 * @param mod Modulator
 * @param dest Destination generator (#fluid_gen_type)
 */
void
fluid_mod_set_dest(fluid_mod_t* mod, int dest)
{
  mod->dest = dest;
}

/**
 * Set the scale amount of a modulator.
 * @param mod Modulator
 * @param amount Scale amount to assign
 */
void
fluid_mod_set_amount(fluid_mod_t* mod, double amount)
{
  mod->amount = (double) amount;
}

/**
 * Get the primary source value from a modulator.
 * @param mod Modulator
 * @return The primary source value (#fluid_mod_src or a MIDI CC controller value).
 */
int
fluid_mod_get_source1(fluid_mod_t* mod)
{
  return mod->src1;
}

/**
 * Get primary source flags from a modulator.
 * @param mod Modulator
 * @return The primary source flags (#fluid_mod_flags).
 */
int
fluid_mod_get_flags1(fluid_mod_t* mod)
{
  return mod->flags1;
}

/**
 * Get the secondary source value from a modulator.
 * @param mod Modulator
 * @return The secondary source value (#fluid_mod_src or a MIDI CC controller value).
 */
int
fluid_mod_get_source2(fluid_mod_t* mod)
{
  return mod->src2;
}

/**
 * Get secondary source flags from a modulator.
 * @param mod Modulator
 * @return The secondary source flags (#fluid_mod_flags).
 */
int
fluid_mod_get_flags2(fluid_mod_t* mod)
{
  return mod->flags2;
}

/**
 * Get destination effect from a modulator.
 * @param mod Modulator
 * @return Destination generator (#fluid_gen_type)
 */
int
fluid_mod_get_dest(fluid_mod_t* mod)
{
  return mod->dest;
}

/**
 * Get the scale amount from a modulator.
 * @param mod Modulator
 * @return Scale amount
 */
double
fluid_mod_get_amount(fluid_mod_t* mod)
{
  return (double) mod->amount;
}

/*
 * retrieves the initial value from the given source of the modulator
 */
static fluid_real_t
fluid_mod_get_source_value(const unsigned char mod_src,
                           const unsigned char mod_flags,
                           fluid_real_t* range,
                           const fluid_channel_t* chan,
                           const fluid_voice_t* voice
                          )
{
    fluid_real_t val;
    
    if (mod_flags & FLUID_MOD_CC)
    {
        val = fluid_channel_get_cc(chan, mod_src);
    }
    else
    {
        switch (mod_src)
        {
        case FLUID_MOD_NONE:         /* SF 2.01 8.2.1 item 0: src enum=0 => value is 1 */
            val = *range;
            break;
        case FLUID_MOD_VELOCITY:
            val = fluid_voice_get_actual_velocity(voice);
            break;
        case FLUID_MOD_KEY:
            val = fluid_voice_get_actual_key(voice);
            break;
        case FLUID_MOD_KEYPRESSURE:
            val = fluid_channel_get_key_pressure(chan, voice->key);
            break;
        case FLUID_MOD_CHANNELPRESSURE:
            val = fluid_channel_get_channel_pressure (chan);
            break;
        case FLUID_MOD_PITCHWHEEL:
            val = fluid_channel_get_pitch_bend (chan);
            *range = 0x4000;
            break;
        case FLUID_MOD_PITCHWHEELSENS:
            val = fluid_channel_get_pitch_wheel_sensitivity (chan);
            break;
        default:
	    FLUID_LOG(FLUID_ERR, "Unknown modulator source '%d', disabling modulator.", mod_src);
            val = 0.0;
        }
    }
    return val;
}

/**
 * transforms the initial value retrieved by \c fluid_mod_get_source_value into [0.0;1.0]
 */
static fluid_real_t
fluid_mod_transform_source_value(fluid_real_t val, unsigned char mod_flags, const fluid_real_t range)
{
    /* normalized value, i.e. usually in the range [0;1]
     * 
     * if val was retrieved from pitch_bend then [-0.5;0.5]
     */
    const fluid_real_t val_norm = val / range;
    
    /* we could also only switch case the lower nibble of mod_flags, however
     * this would keep us from adding further mod types in the future
     * 
     * instead just remove the flag(s) we already took care of
     */
    mod_flags &= ~FLUID_MOD_CC;
    
    switch (mod_flags/* & 0x0f*/)
    {
    case FLUID_MOD_LINEAR | FLUID_MOD_UNIPOLAR | FLUID_MOD_POSITIVE: /* =0 */
      val = val_norm;
      break;
    case FLUID_MOD_LINEAR | FLUID_MOD_UNIPOLAR | FLUID_MOD_NEGATIVE: /* =1 */
      val = 1.0f - val_norm;
      break;
    case FLUID_MOD_LINEAR | FLUID_MOD_BIPOLAR | FLUID_MOD_POSITIVE: /* =2 */
      val = -1.0f + 2.0f * val_norm;
      break;
    case FLUID_MOD_LINEAR | FLUID_MOD_BIPOLAR | FLUID_MOD_NEGATIVE: /* =3 */
      val = 1.0f - 2.0f * val_norm;
      break;
    case FLUID_MOD_CONCAVE | FLUID_MOD_UNIPOLAR | FLUID_MOD_POSITIVE: /* =4 */
      val = fluid_concave(127 * (val_norm));
      break;
    case FLUID_MOD_CONCAVE | FLUID_MOD_UNIPOLAR | FLUID_MOD_NEGATIVE: /* =5 */
      val = fluid_concave(127 * (1.0f - val_norm));
      break;
    case FLUID_MOD_CONCAVE | FLUID_MOD_BIPOLAR | FLUID_MOD_POSITIVE: /* =6 */
      val = (val_norm > 0.5f) ?  fluid_concave(127 * 2 * (val_norm - 0.5f)) 
                              : -fluid_concave(127 * 2 * (0.5f - val_norm));
      break;
    case FLUID_MOD_CONCAVE | FLUID_MOD_BIPOLAR | FLUID_MOD_NEGATIVE: /* =7 */
      val = (val_norm > 0.5f) ? -fluid_concave(127 * 2 * (val_norm - 0.5f))
                              :  fluid_concave(127 * 2 * (0.5f - val_norm));
      break;
    case FLUID_MOD_CONVEX | FLUID_MOD_UNIPOLAR | FLUID_MOD_POSITIVE: /* =8 */
      val = fluid_convex(127 * (val_norm));
      break;
    case FLUID_MOD_CONVEX | FLUID_MOD_UNIPOLAR | FLUID_MOD_NEGATIVE: /* =9 */
      val = fluid_convex(127 * (1.0f - val_norm));
      break;
    case FLUID_MOD_CONVEX | FLUID_MOD_BIPOLAR | FLUID_MOD_POSITIVE: /* =10 */
      val = (val_norm > 0.5f) ?  fluid_convex(127 * 2 * (val_norm - 0.5f)) 
                              : -fluid_convex(127 * 2 * (0.5f - val_norm));
      break;
    case FLUID_MOD_CONVEX | FLUID_MOD_BIPOLAR | FLUID_MOD_NEGATIVE: /* =11 */
      val = (val_norm > 0.5f) ? -fluid_convex(127 * 2 * (val_norm - 0.5f))
                              :  fluid_convex(127 * 2 * (0.5f - val_norm));
      break;
    case FLUID_MOD_SWITCH | FLUID_MOD_UNIPOLAR | FLUID_MOD_POSITIVE: /* =12 */
      val = (val_norm >= 0.5f)? 1.0f : 0.0f;
      break;
    case FLUID_MOD_SWITCH | FLUID_MOD_UNIPOLAR | FLUID_MOD_NEGATIVE: /* =13 */
      val = (val_norm >= 0.5f)? 0.0f : 1.0f;
      break;
    case FLUID_MOD_SWITCH | FLUID_MOD_BIPOLAR | FLUID_MOD_POSITIVE: /* =14 */
      val = (val_norm >= 0.5f)? 1.0f : -1.0f;
      break;
    case FLUID_MOD_SWITCH | FLUID_MOD_BIPOLAR | FLUID_MOD_NEGATIVE: /* =15 */
      val = (val_norm >= 0.5f)? -1.0f : 1.0f;
      break;
    default:
      FLUID_LOG(FLUID_ERR, "Unknown modulator type '%d', disabling modulator.", mod_flags);
      val = 0.0f;
      break;
    }
    
    return val;
}

/*
 * fluid_mod_get_value
 */
fluid_real_t
fluid_mod_get_value(fluid_mod_t* mod, fluid_channel_t* chan, fluid_voice_t* voice)
{
  fluid_real_t v1 = 0.0, v2 = 1.0;
  fluid_real_t range1 = 127.0, range2 = 127.0;

  if (chan == NULL) {
    return 0.0f;
  }

  /* 'special treatment' for default controller
   *
   *  Reference: SF2.01 section 8.4.2
   *
   * The GM default controller 'vel-to-filter cut off' is not clearly
   * defined: If implemented according to the specs, the filter
   * frequency jumps between vel=63 and vel=64.  To maintain
   * compatibility with existing sound fonts, the implementation is
   * 'hardcoded', it is impossible to implement using only one
   * modulator otherwise.
   *
   * I assume here, that the 'intention' of the paragraph is one
   * octave (1200 cents) filter frequency shift between vel=127 and
   * vel=64.  'amount' is (-2400), at least as long as the controller
   * is set to default.
   *
   * Further, the 'appearance' of the modulator (source enumerator,
   * destination enumerator, flags etc) is different from that
   * described in section 8.4.2, but it matches the definition used in
   * several SF2.1 sound fonts (where it is used only to turn it off).
   * */
  if ((mod->src2 == FLUID_MOD_VELOCITY) &&
      (mod->src1 == FLUID_MOD_VELOCITY) &&
      (mod->flags1 == (FLUID_MOD_GC | FLUID_MOD_UNIPOLAR
		       | FLUID_MOD_NEGATIVE | FLUID_MOD_LINEAR)) &&
      (mod->flags2 == (FLUID_MOD_GC | FLUID_MOD_UNIPOLAR
		       | FLUID_MOD_POSITIVE | FLUID_MOD_SWITCH)) &&
      (mod->dest == GEN_FILTERFC)) {
// S. Christian Collins' mod, to stop forcing velocity based filtering
/*
    if (voice->vel < 64){
      return (fluid_real_t) mod->amount / 2.0;
    } else {
      return (fluid_real_t) mod->amount * (127 - voice->vel) / 127;
    }
*/
     return 0; // (fluid_real_t) mod->amount / 2.0;
  }
// end S. Christian Collins' mod

  /* get the initial value of the first source */
  if (mod->src1 > 0)
  {
    v1 = fluid_mod_get_source_value(mod->src1, mod->flags1, &range1, chan, voice);

    /* transform the input value */
    v1 = fluid_mod_transform_source_value(v1, mod->flags1, range1);
  }
  else
  {
    return 0.0;
  }

  /* no need to go further */
  if (v1 == 0.0f) {
    return 0.0f;
  }

  /* get the second input source */
  if (mod->src2 > 0)
  {
    v2 = fluid_mod_get_source_value(mod->src2, mod->flags2, &range2, chan, voice);

    /* transform the second input value */
    v2 = fluid_mod_transform_source_value(v2, mod->flags2, range2);
  }
  else
  {
    v2 = 1.0f;
  }

  /* it's as simple as that: */
  return (fluid_real_t) mod->amount * v1 * v2;
}

/**
 * Create a new uninitialized modulator structure.
 * @return New allocated modulator or NULL if out of memory
 */
fluid_mod_t*
fluid_mod_new()
{
  fluid_mod_t* mod = FLUID_NEW (fluid_mod_t);
  if (mod == NULL) {
    FLUID_LOG(FLUID_ERR, "Out of memory");
    return NULL;
  }
  return mod;
}

/**
 * Free a modulator structure.
 * @param mod Modulator to free
 */
void
fluid_mod_delete (fluid_mod_t *mod)
{
  FLUID_FREE(mod);
}

/**
 * Checks if two modulators are identical in sources, flags and destination.
 * @param mod1 First modulator
 * @param mod2 Second modulator
 * @return TRUE if identical, FALSE otherwise
 *
 * SF2.01 section 9.5.1 page 69, 'bullet' 3 defines 'identical'.
 */
int
fluid_mod_test_identity (fluid_mod_t *mod1, fluid_mod_t *mod2)
{
  return mod1->dest == mod2->dest
    && mod1->src1 == mod2->src1
    && mod1->src2 == mod2->src2
    && mod1->flags1 == mod2->flags1
    && mod1->flags2 == mod2->flags2;
}

/**
 * Check if the modulator has the given source.
 * 
 * @param cc Boolean value indicating if ctrl is a CC controller or not
 * @param ctrl The source to check for (if \c cc == FALSE : a value of type #fluid_mod_src, else the value of the MIDI CC to check for)
 * 
 * @return TRUE if the modulator has the given source, FALSE otherwise.
 */
int fluid_mod_has_source(fluid_mod_t * mod, int cc, int ctrl)
{
    return
    (
        (
            ((mod->src1 == ctrl) && ((mod->flags1 & FLUID_MOD_CC) != 0) && (cc != 0))
         || ((mod->src1 == ctrl) && ((mod->flags1 & FLUID_MOD_CC) == 0) && (cc == 0))
        )
        ||
        (
            ((mod->src2 == ctrl) && ((mod->flags2 & FLUID_MOD_CC) != 0) && (cc != 0))
        ||  ((mod->src2 == ctrl) && ((mod->flags2 & FLUID_MOD_CC) == 0) && (cc == 0))
        )
    );
}

/**
 * Check if the modulator has the given destination.
 * @param gen The destination generator of type #fluid_gen_type to check for
 * @return TRUE if the modulator has the given destination, FALSE otherwise.
 */
int fluid_mod_has_dest(fluid_mod_t * mod, int gen)
{
    return mod->dest == gen;
}


/* debug function: Prints the contents of a modulator */
#ifdef DEBUG
void fluid_dump_modulator(fluid_mod_t * mod){
  int src1=mod->src1;
  int dest=mod->dest;
  int src2=mod->src2;
  int flags1=mod->flags1;
  int flags2=mod->flags2;
  fluid_real_t amount=(fluid_real_t)mod->amount;

  printf("Src: ");
  if (flags1 & FLUID_MOD_CC){
    printf("MIDI CC=%i",src1);
  } else {
    switch(src1){
	case FLUID_MOD_NONE:
	  printf("None"); break;
	case FLUID_MOD_VELOCITY:
	  printf("note-on velocity"); break;
	case FLUID_MOD_KEY:
	  printf("Key nr"); break;
	  case FLUID_MOD_KEYPRESSURE:
	    printf("Poly pressure"); break;
	case FLUID_MOD_CHANNELPRESSURE:
	  printf("Chan pressure"); break;
	case FLUID_MOD_PITCHWHEEL:
	  printf("Pitch Wheel"); break;
	case FLUID_MOD_PITCHWHEELSENS:
	  printf("Pitch Wheel sens"); break;
	default:
	  printf("(unknown: %i)", src1);
    }; /* switch src1 */
  }; /* if not CC */
  if (flags1 & FLUID_MOD_NEGATIVE){printf("- ");} else {printf("+ ");};
  if (flags1 & FLUID_MOD_BIPOLAR){printf("bip ");} else {printf("unip ");};
  printf("-> ");
  switch(dest){
      case GEN_FILTERQ: printf("Q"); break;
      case GEN_FILTERFC: printf("fc"); break;
      case GEN_VIBLFOTOPITCH: printf("VibLFO-to-pitch"); break;
      case GEN_MODENVTOPITCH: printf("ModEnv-to-pitch"); break;
      case GEN_MODLFOTOPITCH: printf("ModLFO-to-pitch"); break;
      case GEN_CHORUSSEND: printf("Chorus send"); break;
      case GEN_REVERBSEND: printf("Reverb send"); break;
      case GEN_PAN: printf("pan"); break;
      case GEN_ATTENUATION: printf("att"); break;
      default: printf("dest %i",dest);
  }; /* switch dest */
  printf(", amount %f flags %i src2 %i flags2 %i\n",amount, flags1, src2, flags2);
};
#endif