effect.c

   1 /*
   2
   3     PROGRAM_NAME PROGRAM_VERSION - PROGRAM_DESCRIPTION
   4
   5     Copyright (C) 2003 Angel Ortega <angel@triptico.com>
   6
   7     This program is free software; you can redistribute it and/or
   8     modify it under the terms of the GNU General Public License
   9     as published by the Free Software Foundation; either version 2
  10     of the License, or (at your option) any later version.
  11
  12     This program is distributed in the hope that it will be useful,
  13     but WITHOUT ANY WARRANTY; without even the implied warranty of
  14     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15     GNU General Public License for more details.
  16
  17     You should have received a copy of the GNU General Public License
  18     along with this program; if not, write to the Free Software
  19     Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
  20
  21     http://www.triptico.com
  22
  23 */
  24
  25 #include "config.h"
  26
  27 #include <stdlib.h>
  28 #include <math.h>
  29
  30 #include "core.h"
  31 #include "effect.h"
  32
  33 /*******************
  34         Data
  35 ********************/
  36
  37 /*******************
  38         Code
  39 ********************/
  40
  41 void init_delay(struct effect_delay * e, int size, float gain,
  42         double depth, double lfo_freq, double llfo, double rlfo)
  43 {
  44         int n;
  45
  46         e->lbuffer=(float *) malloc(size * sizeof(float));
  47         e->rbuffer=(float *) malloc(size * sizeof(float));
  48
  49         for(n=0;n < size;n++)
  50                 e->lbuffer[n]=e->rbuffer[n]=0;
  51
  52         e->size=size;
  53         e->gain=gain;
  54         e->depth=depth;
  55         e->lfo_freq=lfo_freq;
  56         e->llfo=llfo;
  57         e->rlfo=rlfo;
  58
  59         /* calculates lfo increment */
  60         e->lfo_inc=(lfo_freq * 6.28) / (double) _frequency;
  61
  62         e->cursor=0;
  63 }
  64
  65
  66 void process_delay(struct effect_delay * e, float * lsample, float * rsample)
  67 {
  68         float l,r;
  69
  70         l=e->lbuffer[e->cursor] * e->gain;
  71         r=e->lbuffer[e->cursor] * e->gain;
  72
  73         e->lbuffer[e->cursor]=*lsample;
  74         e->rbuffer[e->cursor]=*rsample;
  75
  76         if(++e->cursor == e->size) e->cursor=0;
  77
  78         *lsample+=l;
  79         *rsample+=r;
  80 }
  81
  82
  83 void process_comb(struct effect_delay * e, float * lsample, float * rsample)
  84 {
  85         float l,r;
  86
  87         l=e->lbuffer[e->cursor];
  88         r=e->lbuffer[e->cursor];
  89
  90         e->lbuffer[e->cursor]=*lsample + (l * e->gain);
  91         e->rbuffer[e->cursor]=*rsample + (r * e->gain);
  92
  93         if(++e->cursor == e->size) e->cursor=0;
  94
  95         *lsample+=l;
  96         *rsample+=r;
  97 }
  98
  99
 100 void process_flanger(struct effect_delay * e, float * lsample, float * rsample)
 101 {
 102         float l,r;
 103         double s,c;
 104
 105         s=(double) e->size;
 106
 107         c=(double) e->cursor - e->depth;
 108         c-=e->depth * sin(e->llfo);
 109         e->llfo += e->lfo_inc;
 110         if(c < 0) c+=s;
 111
 112         l=get_sample(e->lbuffer, s, c) * e->gain;
 113
 114         c=(double) e->cursor - e->depth;
 115         c-=e->depth * sin(e->rlfo);
 116         e->rlfo += e->lfo_inc;
 117         if(c < 0) c+=s;
 118
 119         r=get_sample(e->rbuffer, s, c) * e->gain;
 120
 121         e->lbuffer[e->cursor]=*lsample;
 122         e->rbuffer[e->cursor]=*rsample;
 123
 124         if(++e->cursor == e->size) e->cursor=0;
 125
 126         *lsample+=l;
 127         *rsample+=r;
 128 }