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-rw-r--r--src/dahdsr_fexp.c342
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diff --git a/src/dahdsr_fexp.c b/src/dahdsr_fexp.c
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+/*
+ dahdsr_fexp.c - A LV2 plugin to generate DAHDSR envelopes
+ exponential attack, decay and release version.
+ Copyright 2005 Loki Davison, based on DAHDSR by Mike Rawes
+
+ 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; if not, write to the Free Software
+ Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA
+*/
+
+#define _XOPEN_SOURCE 600 /* strdup */
+#include <stdlib.h>
+#include <lv2/lv2plug.in/ns/lv2core/lv2.h>
+#include <math.h>
+
+#define DAHDSR_GATE 0
+#define DAHDSR_TRIGGER 1
+#define DAHDSR_DELAY 2
+#define DAHDSR_ATTACK 3
+#define DAHDSR_HOLD 4
+#define DAHDSR_DECAY 5
+#define DAHDSR_SUSTAIN 6
+#define DAHDSR_RELEASE 7
+#define DAHDSR_OUTPUT 8
+
+typedef enum {
+ IDLE,
+ DELAY,
+ ATTACK,
+ HOLD,
+ DECAY,
+ SUSTAIN,
+ RELEASE
+} DAHDSRState;
+
+typedef struct {
+ float *gate;
+ float *trigger;
+ float *delay;
+ float *attack;
+ float *hold;
+ float *decay;
+ float *sustain;
+ float *release;
+ float *output;
+ float srate;
+ float inv_srate;
+ float last_gate;
+ float last_trigger;
+ float from_level;
+ float level;
+ DAHDSRState state;
+ unsigned long samples;
+} Dahdsr;
+
+static void
+cleanup(LV2_Handle instance)
+{
+ free(instance);
+}
+
+static void
+connect_port(LV2_Handle instance,
+ uint32_t port,
+ void* data)
+{
+ Dahdsr *plugin = (Dahdsr *) instance;
+
+ switch (port) {
+ case DAHDSR_GATE:
+ plugin->gate = (float*)data;
+ break;
+ case DAHDSR_TRIGGER:
+ plugin->trigger = (float*)data;
+ break;
+ case DAHDSR_DELAY:
+ plugin->delay = (float*)data;
+ break;
+ case DAHDSR_ATTACK:
+ plugin->attack = (float*)data;
+ break;
+ case DAHDSR_HOLD:
+ plugin->hold = (float*)data;
+ break;
+ case DAHDSR_DECAY:
+ plugin->decay = (float*)data;
+ break;
+ case DAHDSR_SUSTAIN:
+ plugin->sustain = (float*)data;
+ break;
+ case DAHDSR_RELEASE:
+ plugin->release = (float*)data;
+ break;
+ case DAHDSR_OUTPUT:
+ plugin->output = (float*)data;
+ break;
+ }
+}
+
+static LV2_Handle
+instantiate(const LV2_Descriptor* descriptor,
+ double sample_rate,
+ const char* bundle_path,
+ const LV2_Feature* const* features)
+{
+ Dahdsr *plugin = (Dahdsr *) malloc(sizeof(Dahdsr));
+
+ plugin->srate = (float) sample_rate;
+ plugin->inv_srate = 1.0f / plugin->srate;
+
+ return (LV2_Handle) plugin;
+}
+
+static void
+activate(LV2_Handle instance)
+{
+ Dahdsr *plugin = (Dahdsr *) instance;
+
+ plugin->last_gate = 0.0f;
+ plugin->last_trigger = 0.0f;
+ plugin->from_level = 0.0f;
+ plugin->level = 0.0f;
+ plugin->state = IDLE;
+ plugin->samples = 0;
+}
+
+static void
+run(LV2_Handle instance, uint32_t sample_count)
+{
+ Dahdsr *plugin = (Dahdsr *) instance;
+
+ /* Gate */
+ float *gate = plugin->gate;
+
+ /* Trigger */
+ float *trigger = plugin->trigger;
+
+ /* Delay Time (s) */
+ float delay = *(plugin->delay);
+
+ /* Attack Time (s) */
+ float attack = *(plugin->attack);
+
+ /* Hold Time (s) */
+ float hold = *(plugin->hold);
+
+ /* Decay Time (s) */
+ float decay = *(plugin->decay);
+
+ /* Sustain Level */
+ float sustain = *(plugin->sustain);
+
+ /* Release Time (s) */
+ float release = *(plugin->release);
+
+ /* Envelope Out */
+ float *output = plugin->output;
+
+ /* Instance Data */
+ float srate = plugin->srate;
+ float inv_srate = plugin->inv_srate;
+ float last_gate = plugin->last_gate;
+ float last_trigger = plugin->last_trigger;
+ float from_level = plugin->from_level;
+ float level = plugin->level;
+ DAHDSRState state = plugin->state;
+ unsigned long samples = plugin->samples;
+
+ float gat, trg, del, att, hld, dec, sus, rel;
+ float elapsed;
+ unsigned long s;
+
+ /* Convert times into rates */
+ del = delay > 0.0f ? inv_srate / delay : srate;
+ att = attack > 0.0f ? inv_srate / attack : srate;
+ hld = hold > 0.0f ? inv_srate / hold : srate;
+ dec = decay > 0.0f ? inv_srate / decay : srate;
+ rel = release > 0.0f ? inv_srate / release : srate;
+ sus = sustain;
+
+ if (sus == 0.0f) {
+ sus = 0.001f;
+ }
+ if (sus > 1.0f) {
+ sus = 1.0f;
+ }
+
+ float ReleaseCoeff_att = (0 - log(0.001)) / (attack * srate);
+ float ReleaseCoeff_dec = (log(sus)) / (decay * srate);
+ float ReleaseCoeff_rel =
+ (log(0.001) - log(sus)) / (release * srate);
+
+ for (s = 0; s < sample_count; s++) {
+ gat = gate[s];
+ trg = trigger[s];
+
+ /* Initialise delay phase if gate is opened and was closed, or
+ we received a trigger */
+ if ((trg > 0.0f && !(last_trigger > 0.0f)) ||
+ (gat > 0.0f && !(last_gate > 0.0f))) {
+ if (del < srate) {
+ state = DELAY;
+ } else if (att < srate) {
+ state = ATTACK;
+ } else {
+ state = hld < srate ? HOLD
+ : (dec < srate ? DECAY
+ : (gat > 0.0f ? SUSTAIN
+ : (rel < srate ? RELEASE : IDLE)));
+ level = 1.0f;
+ }
+ samples = 0;
+ }
+
+ /* Release if gate was open and now closed */
+ if (state != IDLE && state != RELEASE &&
+ last_gate > 0.0f && !(gat > 0.0f)) {
+ state = rel < srate ? RELEASE : IDLE;
+ samples = 0;
+ }
+
+ if (samples == 0)
+ from_level = level;
+
+ /* Calculate level of envelope from current state */
+ switch (state) {
+ case IDLE:
+ level = 0;
+ break;
+ case DELAY:
+ samples++;
+ elapsed = (float) samples *del;
+
+ if (elapsed > 1.0f) {
+ state = att < srate ? ATTACK
+ : (hld < srate ? HOLD
+ : (dec < srate ? DECAY
+ : (gat > 0.0f ? SUSTAIN
+ : (rel < srate ? RELEASE : IDLE))));
+ samples = 0;
+ }
+ break;
+ case ATTACK:
+ samples++;
+ elapsed = (float) samples *att;
+
+ if (elapsed > 1.0f) {
+ state = hld < srate ? HOLD
+ : (dec < srate ? DECAY
+ : (gat > 0.0f ? SUSTAIN
+ : (rel < srate ? RELEASE : IDLE)));
+ level = 1.0f;
+ samples = 0;
+ } else {
+ level += level * ReleaseCoeff_att;
+ }
+ break;
+ case HOLD:
+ samples++;
+ elapsed = (float) samples *hld;
+
+ if (elapsed > 1.0f) {
+ state = dec < srate ? DECAY
+ : (gat > 0.0f ? SUSTAIN : (rel < srate ? RELEASE : IDLE));
+ samples = 0;
+ }
+ break;
+ case DECAY:
+ samples++;
+ elapsed = (float) samples *dec;
+
+ if (elapsed > 1.0f) {
+ state = gat > 0.0f ? SUSTAIN : (rel < srate ? RELEASE : IDLE);
+ level = sus;
+ samples = 0;
+ } else {
+ level += level * ReleaseCoeff_dec;
+ }
+ break;
+ case SUSTAIN:
+ level = sus;
+ break;
+ case RELEASE:
+ samples++;
+ elapsed = (float) samples *rel;
+
+ if (elapsed > 1.0f) {
+ state = IDLE;
+ level = 0.0f;
+ samples = 0;
+ } else {
+ level += level * ReleaseCoeff_rel;
+ }
+ break;
+ default:
+ /* Should never happen */
+ level = 0.0f;
+ }
+
+ output[s] = level;
+
+ last_gate = gat;
+ last_trigger = trg;
+ }
+
+ plugin->last_gate = last_gate;
+ plugin->last_trigger = last_trigger;
+ plugin->from_level = from_level;
+ plugin->level = level;
+ plugin->state = state;
+ plugin->samples = samples;
+}
+
+static const LV2_Descriptor descriptor = {
+ "http://drobilla.net/plugins/omins/dahdsr_fexp",
+ instantiate,
+ connect_port,
+ activate,
+ run,
+ NULL,
+ cleanup,
+ NULL,
+};
+
+LV2_SYMBOL_EXPORT const LV2_Descriptor*
+lv2_descriptor(uint32_t index)
+{
+ switch (index) {
+ case 0: return &descriptor;
+ default: return NULL;
+ }
+}