File: envelope.c

package info (click to toggle)
freebirth 0.3.2-9.2
  • links: PTS, VCS
  • area: main
  • in suites: bullseye, buster, sid, stretch
  • size: 3,632 kB
  • ctags: 640
  • sloc: ansic: 4,724; makefile: 89; sh: 1
file content (241 lines) | stat: -rw-r--r-- 5,660 bytes parent folder | download | duplicates (4)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
/* Freebirth
 * Copyright (C) 1999 topher lafata <topher@topher.com>,
 *		      Jake Donham <jake@bitmechanic.com>
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public
 * License as published by the Free Software Foundation; either
 * version 2 of the License, or (at your option) any later version.
 *
 * This program 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
 * General Public License for more details.
 *
 * You should have received a copy of the GNU General Public
 * License along with this program (see COPYING); if not, write to the
 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
 * Boston, MA 02111-1307, USA.
 */

#ifndef __ENV_H
  #include "envelope.h"
#endif

#include <stdlib.h>
#include <math.h>
#include <stdio.h>





void env_delete(env *this)
{
  free(this->events);
  free(this);
}

static int attack(env *this) {
  return (SAMPLE_MAX - this->start) * this->current_index / this->attack 
    + this->start;
  
}


static int release(env *this) {
  return -SAMPLE_MAX * (this->current_index - this->attack) / 
    this->release + SAMPLE_MAX;
}

void env_trigger(env * this)
{
  if (this->current_index < this->attack)
    this->start = attack(this);
  else if (this->current_index < (this->attack + this->release))
    this->start = release(this);
  else
    this->start = 0;
  
  this->current_index = 0;

}

void env_set_release(env *this,int release)
{
  this->release = release;
}

void env_set_attack(env *this,int attack)
{
  this->attack = attack;
}



void env_next_buffer(env *this) {
  this->next = 1;
}

extern sample_producer *filt_e;
sample *env_get_buffer(env *this)
{
  int i;
  sample *buffer;
  event *e;

  if (this->next) {
    this->next = 0;

    if (this->sp) {
      buffer = this->sp->get_buffer(this->sp);
      for(i = 0; i < TBASS_BUFF_SIZE; i++)
	{
	
	  e = this->events[i];
	  if(e)
	    {
	      e->fire(e,(sample_producer*)this);
	      this->events[i] = NULL;
	    }

	  /* if we are in the attack phase */
	  if(this->current_index < this->attack)
	    this->buffer[i] = attack(this) * buffer[i] / SAMPLE_MAX;
	  /* if we are in the release phase */
	  else if (this->current_index < (this->attack + this->release))
	    this->buffer[i] = release(this) * buffer[i] / SAMPLE_MAX;
	  else
	    this->buffer[i] = 0;

	  this->current_index++;
	}
    }

    else {
      for(i = 0; i < TBASS_BUFF_SIZE; i++)
	{
	  e = this->events[i];
	  if(e)
	    {
	      e->fire(e,(sample_producer*)this);
	      this->events[i] = NULL;
	    }

	  /* if we are in the attack phase */
	  if(this->current_index < this->attack)
	    this->buffer[i] = attack(this);
	  /* if we are in the release phase */
	  else if (this->current_index < (this->attack + this->release))
	    this->buffer[i] = release(this);
	  else
	    this->buffer[i] = 0;

	  this->current_index++;
	}
    }
  }

  #if 0
  if (this == filt_e)
    for (i=0; i < TBASS_BUFF_SIZE; i++)
      printf("%d\n", this->buffer[i]);
  #endif

  return this->buffer;
}

static sample_producer **get_children(env *this)
{
  static sample_producer *no_kids[] = { NULL };

  if (this->sp)
    return &(this->sp);
  else
    return no_kids;
}

static char **get_header(env *this)
{
  static char *header[] = {
    "int $n_attack = ((env *)$t)->attack;",
    "int $n_release = ((env *)$t)->release;",
    NULL
  };
  return header;
}

static char **get_code(env *this)
{
  static char *code_nosp[] = {
    "if (((env *)$t)->current_index < $n_attack)",
    "  $o = (SAMPLE_MAX - ((env *)$t)->start)  * ((env *)$t)->current_index / $n_attack + ((env *)$t)->start;",
    "else if (((env *)$t)->current_index < ($n_attack + $n_release))",
    "  $o = -SAMPLE_MAX * (((env *)$t)->current_index - $n_attack) / $n_release + SAMPLE_MAX;",
    "else",
    "  $o = 0;",
    "((env *)$t)->current_index++;",
    NULL
  };

  static char *code_sp[] = {
    "if (((env *)$t)->current_index < $n_attack)",
    "  $o = ((SAMPLE_MAX - ((env *)$t)->start)  * ((env *)$t)->current_index /",
    "       $n_attack + ((env *)$t)->start) * $i0 / SAMPLE_MAX;",
    "else if (((env *)$t)->current_index < ($n_attack + $n_release))",
    "  $o = (-SAMPLE_MAX * (((env *)$t)->current_index - $n_attack) / $n_release + SAMPLE_MAX) *",
    "       $i0 / SAMPLE_MAX;",
    "else",
    "  $o = 0;",
    "((env *)$t)->current_index++;",
    NULL
  };

  if (this->sp)
    return code_sp;
  else
    return code_nosp;
}

static char **get_footer(env *this)
{
  static char *footer[] = {
    NULL
  };
  return footer;
}

env *env_new(int attack,int release,sample_producer *sp)
{
  int i;

  env *out           = (env *)malloc(sizeof(env));
  out->get_buffer    = env_get_buffer;
  out->next_buffer   = env_next_buffer;
  out->get_children	= get_children;
  out->get_header	= get_header;
  out->get_code		= get_code;
  out->get_footer	= get_footer;
  out->next	     = 0;
  out->buffer	     = (sample *)malloc(sizeof(sample) * TBASS_BUFF_SIZE);
  out->schedule      = sp_schedule_event;
  out->trigger       = (void (*)(sample_producer *))env_trigger;
  out->events = (event **)malloc(sizeof(event *) 
				 * TBASS_BUFF_SIZE);
  for(i = 0; i < TBASS_BUFF_SIZE; i++)
    out->events[i] = NULL; 

  out->sp            = sp;
  out->unused	     = NULL;
  out->current_index = release + attack; /* this is x in the function */
  out->attack        = attack;
  out->release       = release;
  out->start	     = 0;
  return out;
}

/*
  Local Variables:
  mode: font-lock
  End:
*/