Add 'blip', an LV2 port of the LADSPA 'blop' collection.

git-svn-id: http://svn.drobilla.net/lad/trunk/plugins/blip.lv2@3525 a436a847-0d15-0410-975c-d299462d15a1

1 files changed, 256 insertions, 0 deletions

diff --git a/src/adsr.c b/src/adsr.c
new file mode 100644
index 0000000..ef4b27e
--- /dev/null
+++ b/src/adsr.c
@@ -0,0 +1,256 @@
+/*
+  An LV2 plugin to generate ADSR envelopes.
+  Copyright 2011 David Robillard
+  Copyright 2002 Mike Rawes
+
+  This 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 3 of the License, or
+  (at your option) any later version.
+
+  This software 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 software.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+#include <stdlib.h>
+#include "lv2/lv2plug.in/ns/lv2core/lv2.h"
+#include "common.h"
+
+#define ADSR_SIGNAL  0
+#define ADSR_TRIGGER 1
+#define ADSR_ATTACK  2
+#define ADSR_DECAY   3
+#define ADSR_SUSTAIN 4
+#define ADSR_RELEASE 5
+#define ADSR_OUTPUT  6
+
+typedef enum {
+	IDLE,
+	ATTACK,
+	DECAY,
+	SUSTAIN,
+	RELEASE
+} ADSRState;
+
+typedef struct {
+	float*    signal;
+	float*    trigger;
+	float*    attack;
+	float*    decay;
+	float*    sustain;
+	float*    release;
+	float*    output;
+	float     srate;
+	float     inv_srate;
+	float     from_level;
+	float     level;
+	ADSRState state;
+	uint32_t  samples;
+} Adsr;
+
+static void
+cleanup(LV2_Handle instance)
+{
+	free(instance);
+}
+
+static void
+connect_port(LV2_Handle instance,
+             uint32_t   port,
+             void*      data)
+{
+	Adsr* plugin = (Adsr*)instance;
+
+	switch (port) {
+	case ADSR_SIGNAL:
+		plugin->signal = data;
+		break;
+	case ADSR_TRIGGER:
+		plugin->trigger = data;
+		break;
+	case ADSR_ATTACK:
+		plugin->attack = data;
+		break;
+	case ADSR_DECAY:
+		plugin->decay = data;
+		break;
+	case ADSR_SUSTAIN:
+		plugin->sustain = data;
+		break;
+	case ADSR_RELEASE:
+		plugin->release = data;
+		break;
+	case ADSR_OUTPUT:
+		plugin->output = data;
+		break;
+	}
+}
+
+static LV2_Handle
+instantiate(const LV2_Descriptor*     descriptor,
+            double                    sample_rate,
+            const char*               bundle_path,
+            const LV2_Feature* const* features)
+{
+	Adsr* plugin = (Adsr*)malloc(sizeof(Adsr));
+
+	plugin->srate     = (float)sample_rate;
+	plugin->inv_srate = 1.0f / plugin->srate;
+
+	return (LV2_Handle)plugin;
+}
+
+static void
+activate(LV2_Handle instance)
+{
+	Adsr* plugin = (Adsr*)instance;
+
+	plugin->from_level = 0.0f;
+	plugin->level      = 0.0f;
+	plugin->state      = IDLE;
+	plugin->samples    = 0;
+}
+
+static void
+runAdsr(LV2_Handle instance,
+        uint32_t   sample_count)
+{
+	Adsr* plugin = (Adsr*)instance;
+
+	/* Driving signal */
+	float* signal = plugin->signal;
+
+	/* Trigger Threshold */
+	float trigger = *(plugin->trigger);
+
+	/* Attack Time (s) */
+	float attack = *(plugin->attack);
+
+	/* Decay Time (s) */
+	float decay = *(plugin->decay);
+
+	/* Sustain Level */
+	float sustain = f_clip(*(plugin->sustain), 0.0f, 1.0f);
+
+	/* Release Time (s) */
+	float release = *(plugin->release);
+
+	/* Envelope Out */
+	float* output = plugin->output;
+
+	float     srate      = plugin->srate;
+	float     inv_srate  = plugin->inv_srate;
+	float     from_level = plugin->from_level;
+	float     level      = plugin->level;
+	ADSRState state      = plugin->state;
+	uint32_t  samples    = plugin->samples;
+
+	float         elapsed;
+
+	/* Convert times into rates */
+	attack  = attack > 0.0f ? inv_srate / attack : srate;
+	decay   = decay > 0.0f ? inv_srate / decay : srate;
+	release = release > 0.0f ? inv_srate / release : srate;
+
+	for (uint32_t s = 0; s < sample_count; s++) {
+		/* Determine if attack or release happened */
+		if ((state == IDLE) || (state == RELEASE)) {
+			if (signal[s] > trigger) {
+				if (attack < srate) {
+					state = ATTACK;
+				} else {
+					state = decay < srate ? DECAY : SUSTAIN;
+					level = 1.0f;
+				}
+				samples = 0;
+			}
+		} else {
+			if (signal[s] <= trigger) {
+				state   = release < 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 ATTACK:
+			samples++;
+			elapsed = (float)samples * attack;
+			if (elapsed > 1.0f) {
+				state   = decay < srate ? DECAY : SUSTAIN;
+				level   = 1.0f;
+				samples = 0;
+			} else {
+				level = from_level + elapsed * (1.0f - from_level);
+			}
+			break;
+		case DECAY:
+			samples++;
+			elapsed = (float)samples * decay;
+			if (elapsed > 1.0f) {
+				state   = SUSTAIN;
+				level   = sustain;
+				samples = 0;
+			} else {
+				level = from_level + elapsed * (sustain - from_level);
+			}
+			break;
+		case SUSTAIN:
+			level = sustain;
+			break;
+		case RELEASE:
+			samples++;
+			elapsed = (float)samples * release;
+			if (elapsed > 1.0f) {
+				state   = IDLE;
+				level   = 0.0f;
+				samples = 0;
+			} else {
+				level = from_level - elapsed * from_level;
+			}
+			break;
+		default:
+			/* Should never happen */
+			level = 0.0f;
+		}
+
+		output[s] = level;
+	}
+
+	plugin->from_level = from_level;
+	plugin->level      = level;
+	plugin->state      = state;
+	plugin->samples    = samples;
+}
+
+static const LV2_Descriptor descriptor = {
+	"http://drobilla.net/plugins/blip/adsr",
+	instantiate,
+	connect_port,
+	activate,
+	runAdsr,
+	NULL,
+	cleanup,
+	NULL,
+};
+
+LV2_SYMBOL_EXPORT const LV2_Descriptor*
+lv2_descriptor(uint32_t index)
+{
+	switch (index) {
+	case 0:  return &descriptor;
+	default: return NULL;
+	}
+}