plugins/libreverse.c

   1 /* gAlan - Graphical Audio Language
   2  * Copyright (C) 1999 Tony Garnock-Jones
   3  *
   4  * This program is free software; you can redistribute it and/or modify
   5  * it under the terms of the GNU General Public License as published by
   6  * the Free Software Foundation; either version 2 of the License, or
   7  * (at your option) any later version.
   8  *
   9  * This program is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  * GNU General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU General Public License
  15  * along with this program; if not, write to the Free Software
  16  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  17  */
  18
  19 #include <stdlib.h>
  20 #include <string.h>
  21 #include <stdio.h>
  22 #include <stddef.h>
  23
  24 #include <gdk/gdk.h>
  25 #include <gtk/gtk.h>
  26 #include <gmodule.h>
  27
  28 #include "global.h"
  29 #include "generator.h"
  30 #include "comp.h"
  31 #include "control.h"
  32 #include "gencomp.h"
  33
  34 #define GENERATOR_CLASS_NAME    "reverse"
  35 #define GENERATOR_CLASS_PATH    "Timebase/Reverse"
  36
  37 #define SIG_INPUT               0
  38 #define SIG_OUTPUT              0
  39
  40 PRIVATE SAMPLETIME output_range(Generator *g, OutputSignalDescriptor *sig) {
  41   return gen_get_randomaccess_input_range(g, SIG_INPUT, 0);
  42 }
  43
  44 PRIVATE gboolean output_generator(Generator *g, OutputSignalDescriptor *sig,
  45                                   SAMPLETIME offset, SAMPLE *buf, int buflen) {
  46   SAMPLETIME inoffset;
  47   SAMPLETIME len = gen_get_randomaccess_input_range(g, SIG_INPUT, 0);
  48   int inbuflen = buflen;
  49   SAMPLE *inbuf = buf;
  50   int i, j;
  51
  52   inoffset = len - offset - buflen;
  53
  54   if (inoffset <= -buflen)
  55     return FALSE;
  56
  57   if (inoffset < 0) {
  58     memset(buf, 0, -inoffset * sizeof(SAMPLE));
  59     inbuflen += inoffset;               /* *decrease* inbuflen */
  60     inbuf += (-inoffset);               /* *advance* inbuf */
  61     inoffset = 0;
  62   }
  63
  64   if (!gen_read_randomaccess_input(g, SIG_INPUT, 0, inoffset, inbuf, inbuflen))
  65     return FALSE;
  66
  67   for (i = 0, j = (buflen - 1); i < j; i++, j--) {
  68     SAMPLE tmp = buf[i];
  69     buf[i] = buf[j];
  70     buf[j] = tmp;
  71   }
  72
  73   return TRUE;
  74 }
  75
  76 PRIVATE InputSignalDescriptor input_sigs[] = {
  77   { "Input", SIG_FLAG_RANDOMACCESS },
  78   { NULL, }
  79 };
  80
  81 PRIVATE OutputSignalDescriptor output_sigs[] = {
  82   { "Output", SIG_FLAG_RANDOMACCESS, { NULL, { output_range, output_generator } } },
  83   { NULL, }
  84 };
  85
  86 PRIVATE ControlDescriptor controls[] = {
  87   /* { kind, name, min,max,step,page, size,editable, is_dst,queue_number,
  88        init,destroy,refresh,refresh_data }, */
  89   { CONTROL_KIND_NONE, }
  90 };
  91
  92 PRIVATE void setup_class(void) {
  93   GeneratorClass *k = gen_new_generatorclass(GENERATOR_CLASS_NAME, FALSE, 0, 0,
  94                                              input_sigs, output_sigs, controls,
  95                                              NULL, NULL, NULL, NULL);
  96
  97   gencomp_register_generatorclass(k, FALSE, GENERATOR_CLASS_PATH,
  98                                   NULL,
  99                                   NULL);
 100 }
 101
 102 PUBLIC void init_plugin(void) {
 103   setup_class();
 104 }