plugins/libdcbias.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
  27 #include "global.h"
  28 #include "generator.h"
  29 #include "comp.h"
  30 #include "control.h"
  31 #include "gencomp.h"
  32
  33 #define GENERATOR_CLASS_NAME    "bias"
  34 #define GENERATOR_CLASS_PATH    "Levels/DC Bias"
  35
  36 #define SIG_INPUT               0
  37 #define SIG_OUTPUT              0
  38
  39 #define EVT_BIAS                0
  40 #define NUM_EVENT_INPUTS        1
  41
  42 #define NUM_EVENT_OUTPUTS       0
  43
  44 typedef struct Data {
  45   gdouble bias;
  46 } Data;
  47
  48 PRIVATE int init_instance(Generator *g) {
  49   Data *data = safe_malloc(sizeof(Data));
  50   g->data = data;
  51
  52   data->bias = 0;
  53
  54   return 1;
  55 }
  56
  57 PRIVATE void destroy_instance(Generator *g) {
  58   free(g->data);
  59 }
  60
  61 PRIVATE void unpickle_instance(Generator *g, ObjectStoreItem *item, ObjectStore *db) {
  62   Data *data = safe_malloc(sizeof(Data));
  63   g->data = data;
  64
  65   data->bias = objectstore_item_get_double(item, "dcbias_bias", 0);
  66 }
  67
  68 PRIVATE void pickle_instance(Generator *g, ObjectStoreItem *item, ObjectStore *db) {
  69   Data *data = g->data;
  70   objectstore_item_set_double(item, "dcbias_bias", data->bias);
  71 }
  72
  73 PRIVATE gboolean output_generator(Generator *g, SAMPLE *buf, int buflen) {
  74   Data *data = g->data;
  75   SAMPLE delta = data->bias * SAMPLE_UNIT;
  76   int i;
  77
  78   if (!gen_read_realtime_input(g, SIG_INPUT, 0, buf, buflen)) {
  79     for (i = 0; i < buflen; i++)
  80       buf[i] = delta;
  81   } else {
  82     for (i = 0; i < buflen; i++)
  83       buf[i] += delta;
  84   }
  85
  86   return TRUE;
  87 }
  88
  89 PRIVATE void evt_bias_handler(Generator *g, AEvent *event) {
  90   Data *data = g->data;
  91   data->bias = event->d.number;
  92   gen_update_controls(g, 0);
  93 }
  94
  95 PRIVATE InputSignalDescriptor input_sigs[] = {
  96   { "Input", SIG_FLAG_REALTIME },
  97   { NULL, }
  98 };
  99
 100 PRIVATE OutputSignalDescriptor output_sigs[] = {
 101   { "Output", SIG_FLAG_REALTIME, { output_generator, } },
 102   { NULL, }
 103 };
 104
 105 PRIVATE ControlDescriptor controls[] = {
 106   { CONTROL_KIND_KNOB, "bias", -1, 1, 0.1, 0.01, 0,TRUE, 1,EVT_BIAS,
 107     NULL, NULL, control_double_updater, (gpointer) offsetof(Data, bias) },
 108   { CONTROL_KIND_NONE, }
 109 };
 110
 111 PRIVATE void setup_class(void) {
 112   GeneratorClass *k = gen_new_generatorclass(GENERATOR_CLASS_NAME, FALSE,
 113                                              NUM_EVENT_INPUTS, NUM_EVENT_OUTPUTS,
 114                                              input_sigs, output_sigs, controls,
 115                                              init_instance, destroy_instance,
 116                                              unpickle_instance, pickle_instance);
 117
 118   gen_configure_event_input(k, EVT_BIAS, "Bias", evt_bias_handler);
 119
 120   gencomp_register_generatorclass(k, FALSE, GENERATOR_CLASS_PATH, NULL, NULL);
 121 }
 122
 123 PUBLIC void init_plugin(void) {
 124   setup_class();
 125 }