1 /* gAlan - Graphical Audio Language
2 * Copyright (C) 1999 Tony Garnock-Jones
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.
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.
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
28 #include "generator.h"
33 #define GENERATOR_CLASS_NAME "303vcf"
34 #define GENERATOR_CLASS_PATH "Filter/2-pole Low-pass resonant"
41 #define NUM_EVENT_INPUTS 2
43 #define NUM_EVENT_OUTPUTS 0
45 #define VCF_CONTROL_Q 0
46 #define VCF_CONTROL_CUTOFF 1
57 PRIVATE
void calc_coeffs(Generator
*g
) {
59 gdouble cutoff_ratio
= data
->cutoff
/ SAMPLE_RATE
;
62 tmp
= -M_PI
* cutoff_ratio
/ data
->q
;
64 data
->a
= 2 * cos(2 * M_PI
* cutoff_ratio
) * exp(tmp
);
65 data
->b
= -exp(2 * tmp
);
66 data
->c
= 1 - data
->a
- data
->b
;
69 PRIVATE
int init_instance(Generator
*g
) {
70 Data
*data
= safe_malloc(sizeof(Data
));
76 data
->a
= data
->b
= data
->c
= 0;
77 data
->d1
= data
->d2
= 0;
78 data
->d3
= data
->d4
= 0;
85 PRIVATE
void destroy_instance(Generator
*g
) {
89 PRIVATE
void unpickle_instance(Generator
*g
, ObjectStoreItem
*item
, ObjectStore
*db
) {
90 Data
*data
= safe_malloc(sizeof(Data
));
93 data
->q
= objectstore_item_get_double(item
, "vcf_q", 0.05);
94 data
->cutoff
= objectstore_item_get_double(item
, "vcf_cutoff", 200);
96 data
->a
= data
->b
= data
->c
= 0;
97 data
->d1
= data
->d2
= 0;
98 data
->d3
= data
->d4
= 0;
102 PRIVATE
void pickle_instance(Generator
*g
, ObjectStoreItem
*item
, ObjectStore
*db
) {
103 Data
*data
= g
->data
;
104 objectstore_item_set_double(item
, "vcf_q", data
->q
);
105 objectstore_item_set_double(item
, "vcf_cutoff", data
->cutoff
);
108 PRIVATE gboolean
output_generator(Generator
*g
, SAMPLE
*buf
, int buflen
) {
109 Data
*data
= g
->data
;
112 if (!gen_read_realtime_input(g
, SIG_INPUT
, -1, buf
, buflen
))
113 memset(buf
, 0, buflen
* sizeof(SAMPLE
));
115 for (i
= 0; i
< buflen
; i
++) {
116 buf
[i
] = data
->a
* data
->d1
+ data
->b
* data
->d2
+ data
->c
* buf
[i
];
120 buf
[i
] = data
->a
* data
->d3
+ data
->b
* data
->d4
+ data
->c
* buf
[i
];
127 PRIVATE
void evt_q_handler(Generator
*g
, AEvent
*event
) {
128 Data
*data
= g
->data
;
129 data
->q
= MAX(event
->d
.number
, 0.00001);
131 gen_update_controls(g
, VCF_CONTROL_Q
);
134 PRIVATE
void evt_cutoff_handler(Generator
*g
, AEvent
*event
) {
135 Data
*data
= g
->data
;
136 data
->cutoff
= MAX(event
->d
.number
, 0.00001);
138 gen_update_controls(g
, VCF_CONTROL_CUTOFF
);
141 PRIVATE InputSignalDescriptor input_sigs
[] = {
142 { "Input", SIG_FLAG_REALTIME
},
146 PRIVATE OutputSignalDescriptor output_sigs
[] = {
147 { "Output", SIG_FLAG_REALTIME
, { output_generator
, } },
151 PRIVATE ControlDescriptor controls
[] = {
152 /* { kind, name, min,max,step,page, size,editable, is_dst,queue_number,
153 init,destroy,refresh,refresh_data }, */
154 { CONTROL_KIND_KNOB
, "reso", 0, 100, 0.5, 0.5, 0,TRUE
, 1,EVT_Q
,
155 NULL
,NULL
, control_double_updater
, (gpointer
) offsetof(Data
, q
) },
156 { CONTROL_KIND_KNOB
, "cutoff", 1, 22050, 4, 1, 0,TRUE
, 1,EVT_CUTOFF
,
157 NULL
,NULL
, control_double_updater
, (gpointer
) offsetof(Data
, cutoff
) },
158 { CONTROL_KIND_NONE
, },
161 PRIVATE
void setup_class(void) {
162 GeneratorClass
*k
= gen_new_generatorclass(GENERATOR_CLASS_NAME
, FALSE
,
163 NUM_EVENT_INPUTS
, NUM_EVENT_OUTPUTS
,
164 input_sigs
, output_sigs
, controls
,
165 init_instance
, destroy_instance
,
166 unpickle_instance
, pickle_instance
);
168 gen_configure_event_input(k
, EVT_Q
, "Resonance", evt_q_handler
);
169 gen_configure_event_input(k
, EVT_CUTOFF
, "Cutoff", evt_cutoff_handler
);
171 gencomp_register_generatorclass(k
, FALSE
, GENERATOR_CLASS_PATH
, NULL
, NULL
);
174 PUBLIC
void init_plugin(void) {