From 6a651aca0de7262e805ff8edb12cdc4692009997 Mon Sep 17 00:00:00 2001
From: David Robillard <d@drobilla.net>
Date: Sun, 19 Aug 2012 19:24:44 +0000
Subject: Move omins to plugins directory.

git-svn-id: http://svn.drobilla.net/lad/trunk/plugins/omins.lv2@4725 a436a847-0d15-0410-975c-d299462d15a1
---
 src/slew_limiter.c | 149 +++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 149 insertions(+)
 create mode 100644 src/slew_limiter.c

(limited to 'src/slew_limiter.c')

diff --git a/src/slew_limiter.c b/src/slew_limiter.c
new file mode 100644
index 0000000..c663543
--- /dev/null
+++ b/src/slew_limiter.c
@@ -0,0 +1,149 @@
+/* slew_limiter - A LV2 plugin that limits the rate of change of a
+ *                signal. Increases and decreases in the signal can be
+ *                limited separately.
+ *
+ * Copyright 2005 Lars Luthman
+ * LV2 skeleton code taken from dahdsr_fexp.c by Loki Davison
+ *
+ * This plugin 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 plugin 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
+ * 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 500 /* strdup */
+#include <stdlib.h>
+#include <lv2/lv2plug.in/ns/lv2core/lv2.h>
+#include <math.h>
+
+/* These are the port numbers */
+#define SLIM_INPUT                     0
+#define SLIM_MAXRISE                   1
+#define SLIM_MAXFALL                   2
+#define SLIM_OUTPUT                    3
+
+/* This is an array pointer to the descriptors of the different variants */
+LV2_Descriptor** slim_descriptors = 0;
+
+/* This is the data for a single instance of the plugin */
+typedef struct
+{
+	float* input;
+	float* maxrise;
+	float* maxfall;
+	float* reset;
+	float* output;
+	float srate;
+	float last_output;
+}
+SLim;
+
+/* Clean up after a plugin instance */
+static void cleanup (LV2_Handle instance)
+{
+	free(instance);
+}
+
+/* This is called when the hosts connects a port to a buffer */
+static void connect_port(LV2_Handle instance,
+                     uint32_t port, void* data)
+{
+	SLim* plugin = (SLim *)instance;
+
+	switch (port) {
+	case SLIM_INPUT:
+		plugin->input = data;
+		break;
+	case SLIM_MAXRISE:
+		plugin->maxrise = data;
+		break;
+	case SLIM_MAXFALL:
+		plugin->maxfall = data;
+		break;
+	case SLIM_OUTPUT:
+		plugin->output = data;
+		break;
+	}
+}
+
+/* The host uses this function to create an instance of a plugin */
+static LV2_Handle
+instantiate(const LV2_Descriptor*     descriptor,
+            double                    sample_rate,
+            const char*               bundle_path,
+            const LV2_Feature* const* features)
+{
+	SLim* plugin = (SLim*)calloc(1, sizeof(SLim));
+	plugin->srate = (float)sample_rate;
+	return (LV2_Handle)plugin;
+}
+
+/* This is called before the hosts starts to use the plugin instance */
+static void activate(LV2_Handle instance)
+{
+	SLim* plugin = (SLim*)instance;
+	plugin->last_output = 0;
+}
+
+/* The run function! */
+static void run(LV2_Handle instance, uint32_t sample_count)
+{
+	SLim* plugin = (SLim*)instance;
+
+	if (plugin->input && plugin->output) {
+		unsigned long i;
+		float maxrise, maxfall;
+		for (i = 0; i < sample_count; ++i) {
+
+			if (plugin->maxrise)
+				maxrise = plugin->maxrise[i];
+			else
+				maxrise = 0;
+
+			if (plugin->maxfall)
+				maxfall = plugin->maxfall[i];
+			else
+				maxfall = 0;
+
+			float maxinc = maxrise / plugin->srate;
+			float maxdec = maxfall / plugin->srate;
+			float increment = plugin->input[i] - plugin->last_output;
+			if (increment > maxinc)
+				increment = maxinc;
+			else if (increment < -maxdec)
+				increment = -maxdec;
+
+			plugin->output[i] = plugin->last_output + increment;
+			plugin->last_output = plugin->output[i];
+		}
+	}
+}
+
+static const LV2_Descriptor descriptor = {
+	"http://drobilla.net/plugins/omins/slew_limiter",
+	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;
+	}
+}
-- 
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