plugins/libevtsgn.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 #include <math.h>
  24
  25 #include <gdk/gdk.h>
  26 #include <gtk/gtk.h>
  27
  28 #include "global.h"
  29 #include "generator.h"
  30 #include "comp.h"
  31 #include "control.h"
  32 #include "gencomp.h"
  33 #include "msgbox.h"
  34
  35 #define GENERATOR_CLASS_NAME    "evtsgn"
  36 #define GENERATOR_CLASS_PATH    "Events/Sgn"
  37
  38 #define EVT_VALUE 0
  39 #define EVT_OUTPUT 0
  40
  41 typedef struct Data {
  42     gdouble oldvalue;
  43 } Data;
  44
  45 PRIVATE int init_instance(Generator *g) {
  46
  47     Data *data = safe_malloc( sizeof(Data) );
  48
  49     data->oldvalue = 0.0;
  50
  51     g->data = data;
  52
  53     return 1;
  54 }
  55
  56 PRIVATE void destroy_instance(Generator *g) {
  57     if( g->data )
  58         free(g->data);
  59
  60 }
  61
  62 PRIVATE void unpickle_instance(Generator *g, ObjectStoreItem *item, ObjectStore *db) {
  63   Data *data = safe_malloc(sizeof(Data));
  64   g->data = data;
  65
  66   data->oldvalue = objectstore_item_get_double(item, "sgn_oldvalue", 0);
  67 }
  68
  69 PRIVATE void pickle_instance(Generator *g, ObjectStoreItem *item, ObjectStore *db) {
  70   Data *data = g->data;
  71   objectstore_item_set_double(item, "sgn_oldvalue", data->oldvalue);
  72
  73 }
  74
  75
  76 PRIVATE void evt_value_handler(Generator *g, AEvent *event) {
  77
  78     Data *data = g->data;
  79
  80     event->d.number = event->d.number == 0 ? 0 : (event->d.number < 0 ? -1 : 1);
  81     if( event->d.number != data->oldvalue ) {
  82         data->oldvalue = event->d.number;
  83         gen_send_events(g, EVT_OUTPUT, -1, event);
  84     }
  85 }
  86
  87 PRIVATE ControlDescriptor controls[] = {
  88   { CONTROL_KIND_NONE, }
  89 };
  90
  91
  92
  93 PRIVATE void setup_class(void) {
  94   GeneratorClass *k = gen_new_generatorclass(GENERATOR_CLASS_NAME, FALSE, 1, 1,
  95                                              NULL, NULL, controls,
  96                                              init_instance, destroy_instance,
  97                                              unpickle_instance, pickle_instance);
  98
  99   gen_configure_event_input(k, EVT_VALUE, "Input", evt_value_handler);
 100   gen_configure_event_output(k, EVT_OUTPUT, "Sgn");
 101
 102   gencomp_register_generatorclass(k, FALSE, GENERATOR_CLASS_PATH, NULL, NULL);
 103 }
 104
 105 PUBLIC void init_plugin(void) {
 106   setup_class();
 107 }