New input/output plugin architecture. New LV2 plugin.

1 files changed, 306 insertions, 0 deletions

diff --git a/lv2/lv2.cc b/lv2/lv2.cc
new file mode 100644
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+++ b/lv2/lv2.cc
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+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/***************************************************************************
+ *            lv2.cc
+ *
+ *  Wed Jul 13 13:50:33 CEST 2011
+ *  Copyright 2011 Bent Bisballe Nyeng
+ *  deva@aasimon.org
+ ****************************************************************************/
+
+/*
+ *  This file is part of DrumGizmo.
+ *
+ *  DrumGizmo 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.
+ *
+ *  DrumGizmo 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 DrumGizmo; if not, write to the Free Software
+ *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA.
+ */
+#include <lv2/lv2plug.in/ns/lv2core/lv2.h>
+
+#include <stdlib.h>
+
+#include <drumgizmo.h>
+
+#include "input_lv2.h"
+#include "output_lv2.h"
+
+#define MIDI_EVENT_URI "http://lv2plug.in/ns/ext/midi#MidiEvent"
+
+typedef struct {
+  InputLV2 *in;
+  OutputLV2 *out;
+  DrumGizmo *dg;
+  sample_t *buffer;
+  size_t buffer_size;
+} DGLV2;
+
+/** A globally unique, case-sensitive identifier for this plugin type.
+ *
+ * All plugins with the same URI MUST be compatible in terms of 'port
+ * signature', meaning they have the same number of ports, same port
+ * shortnames, and roughly the same functionality.  URIs should
+ * probably contain a version number (or similar) for this reason.
+ *
+ * Rationale:  When serializing session/patch/etc files, hosts MUST
+ * refer to a loaded plugin by the plugin URI only.  In the future
+ * loading a plugin with this URI MUST yield a plugin with the
+ * same ports (etc) which is 100% compatible. */
+#define DRUMGIZMO_URI "http://drumgizmo.org/lv2"
+
+/** Function pointer that instantiates a plugin.
+ *
+ * A handle is returned indicating the new plugin instance. The
+ * instantiation function accepts a sample rate as a parameter as well
+ * as the plugin descriptor from which this instantiate function was
+ * found. This function must return NULL if instantiation fails.
+ *
+ * bundle_path is a string of the path to the LV2 bundle which contains
+ * this plugin binary.  It MUST include the trailing directory separator
+ * (e.g. '/') so that BundlePath + filename gives the path to a file
+ * in the bundle.
+ *
+ * features is a NULL terminated array of LV2_Feature structs which
+ * represent the features the host supports. Plugins may refuse to
+ * instantiate if required features are not found here (however hosts
+ * SHOULD NOT use this as a discovery mechanism, instead reading the
+ * data file before attempting to instantiate the plugin).  This array
+ * must always exist; if a host has no features, it MUST pass a single
+ * element array containing NULL (to simplify plugins).
+ *
+ * Note that instance initialisation should generally occur in
+ * activate() rather than here.  If a host calls instantiate, it MUST
+ * call cleanup() at some point in the future. */
+LV2_Handle instantiate(const struct _LV2_Descriptor *descriptor,
+                       double sample_rate,
+                       const char *bundle_path,
+                       const LV2_Feature *const *features)
+{
+  DGLV2 *dglv2 = new DGLV2;
+
+  dglv2->in = new InputLV2();
+  dglv2->out = new OutputLV2();
+
+  dglv2->buffer = NULL;
+  dglv2->buffer_size = 0;
+
+  dglv2->dg = new DrumGizmo(dglv2->out, dglv2->in);
+  dglv2->dg->loadkit("/home/deva/docs/c/drumgizmo/kits/test/test.xml");
+  dglv2->dg->init(true);
+
+  return (LV2_Handle)dglv2;
+}
+
+/** Function pointer that connects a port on a plugin instance to a memory
+ * location where the block of data for the port will be read/written.
+ *
+ * The data location is expected to be of the type defined in the
+ * plugin's data file (e.g. an array of float for an lv2:AudioPort).
+ * Memory issues are managed by the host. The plugin must read/write
+ * the data at these locations every time run() is called, data
+ * present at the time of this connection call MUST NOT be
+ * considered meaningful. 
+ *
+ * The host MUST NOT try to connect a data buffer to a port index 
+ * that is not defined in the RDF data for the plugin. If it does, 
+ * the plugin's behaviour is undefined.
+ *
+ * connect_port() may be called more than once for a plugin instance
+ * to allow the host to change the buffers that the plugin is reading
+ * or writing. These calls may be made before or after activate()
+ * or deactivate() calls.  Note that there may be realtime constraints
+ * on connect_port (see lv2:hardRTCapable in lv2.ttl).
+ *
+ * connect_port() MUST be called at least once for each port before
+ * run() is called.  The plugin must pay careful attention to the block
+ * size passed to the run function as the block allocated may only just
+ * be large enough to contain the block of data (typically samples), and
+ * is not guaranteed to be constant.
+ *
+ * Plugin writers should be aware that the host may elect to use the
+ * same buffer for more than one port and even use the same buffer for
+ * both input and output (see lv2:inPlaceBroken in lv2.ttl).
+ * However, overlapped buffers or use of a single buffer for both
+ * audio and control data may result in unexpected behaviour.
+ *
+ * If the plugin has the feature lv2:hardRTCapable then there are 
+ * various things that the plugin MUST NOT do within the connect_port()
+ * function (see lv2.ttl). */
+void connect_port(LV2_Handle instance,
+                  uint32_t port,
+                  void *data_location)
+{
+  DGLV2 *dglv2 = (DGLV2 *)instance;
+
+  if(port == 0) {// MIDI in
+    dglv2->in->eventPort = (LV2_Event_Buffer*)data_location;
+  } else {// Audio Port
+    if(port - 1 < NUM_OUTPUTS)
+      dglv2->out->outputPort[port - 1] = (sample_t*)data_location;
+  }
+}
+
+/** Function pointer that initialises a plugin instance and activates
+ * it for use.
+ * 
+ * This is separated from instantiate() to aid real-time support and so
+ * that hosts can reinitialise a plugin instance by calling deactivate()
+ * and then activate(). In this case the plugin instance must reset all
+ * state information dependent on the history of the plugin instance
+ * except for any data locations provided by connect_port(). If there
+ * is nothing for activate() to do then the plugin writer may provide
+ * a NULL rather than an empty function.
+ *
+ * When present, hosts MUST call this function once before run()
+ * is called for the first time. This call SHOULD be made as close
+ * to the run() call as possible and indicates to real-time plugins
+ * that they are now live, however plugins MUST NOT rely on a prompt
+ * call to run() after activate().  activate() may not be called again
+ * unless deactivate() is called first (after which activate() may be
+ * called again, followed by deactivate, etc. etc.).  If a host calls
+ * activate, it MUST call deactivate at some point in the future.
+ *
+ * Note that connect_port() may be called before or after a call to
+ * activate(). */
+void activate(LV2_Handle instance)
+{
+  DGLV2 *dglv2 = (DGLV2 *)instance;
+  //dglv2->dg->run();
+  (void)dglv2;
+}
+
+/** Function pointer that runs a plugin instance for a block.
+ *
+ * Two parameters are required: the first is a handle to the particular
+ * instance to be run and the second indicates the block size (in
+ * samples) for which the plugin instance may run.
+ *
+ * Note that if an activate() function exists then it must be called
+ * before run(). If deactivate() is called for a plugin instance then
+ * the plugin instance may not be reused until activate() has been
+ * called again.
+ *
+ * If the plugin has the feature lv2:hardRTCapable then there are 
+ * various things that the plugin MUST NOT do within the run()
+ * function (see lv2.ttl). */
+void run(LV2_Handle instance,
+         uint32_t sample_count)
+{
+  static size_t pos = 0;
+  DGLV2 *dglv2 = (DGLV2 *)instance;
+
+  if(dglv2->buffer_size != sample_count) {
+    if(dglv2->buffer) free(dglv2->buffer);
+    dglv2->buffer_size = sample_count;
+    dglv2->buffer = (sample_t*)malloc(sizeof(sample_t) * dglv2->buffer_size);
+  }
+
+  dglv2->dg->run(pos, dglv2->buffer, dglv2->buffer_size);
+
+  pos += sample_count;
+}
+
+/** This is the counterpart to activate() (see above). If there is
+ * nothing for deactivate() to do then the plugin writer may provide
+ * a NULL rather than an empty function.
+ *
+ * Hosts must deactivate all activated units after they have been run()
+ * for the last time. This call SHOULD be made as close to the last
+ * run() call as possible and indicates to real-time plugins that
+ * they are no longer live, however plugins MUST NOT rely on prompt
+ * deactivation. Note that connect_port() may be called before or
+ * after a call to deactivate().
+ *
+ * Note that deactivation is not similar to pausing as the plugin
+ * instance will be reinitialised when activate() is called to reuse it.
+ * Hosts MUST NOT call deactivate() unless activate() was previously
+ * called. */
+void deactivate(LV2_Handle instance)
+{
+  DGLV2 *dglv2 = (DGLV2 *)instance;
+  dglv2->dg->stop();
+}
+
+/** This is the counterpart to instantiate() (see above).  Once an instance
+ * of a plugin has been finished with it can be deleted using this
+ * function. The instance handle passed ceases to be valid after
+ * this call.
+ * 
+ * If activate() was called for a plugin instance then a corresponding
+ * call to deactivate() MUST be made before cleanup() is called.
+ * Hosts MUST NOT call cleanup() unless instantiate() was previously
+ * called. */
+void cleanup(LV2_Handle instance)
+{
+  DGLV2 *dglv2 = (DGLV2 *)instance;
+  delete dglv2->dg;
+  delete dglv2->in;
+  delete dglv2->out;
+}
+
+/** Function pointer that can be used to return additional instance data for
+ * a plugin defined by some extenion (e.g. a struct containing additional
+ * function pointers).
+ *
+ * The actual type and meaning of the returned object MUST be specified 
+ * precisely by the extension if it defines any extra data.  If a particular
+ * extension does not define extra instance data, this function MUST return
+ * NULL for that extension's URI.  If a plugin does not support any
+ * extensions that define extra instance data, this function pointer may be
+ * set to NULL rather than providing an empty function.
+ * 
+ * The only parameter is the URI of the extension. The plugin MUST return
+ * NULL if it does not support the extension, but hosts SHOULD NOT use this
+ * as a discovery method (e.g. hosts should only call this function for
+ * extensions known to be supported by the plugin from the data file).
+ *
+ * The host is never responsible for freeing the returned value.
+ * 
+ * NOTE: This function should return a struct (likely containing function
+ * pointers) and NOT a direct function pointer.  Standard C and C++ do not
+ * allow type casts from void* to a function pointer type.  To provide
+ * additional functions a struct should be returned containing the extra
+ * function pointers (which is valid standard code, and a much better idea
+ * for extensibility anyway). */
+const void* extension_data(const char *uri)
+{
+  return NULL;
+}
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+static const LV2_Descriptor descriptor = {
+	DRUMGIZMO_URI,
+	instantiate,
+	connect_port,
+  activate,
+	run,
+  deactivate,
+	cleanup,
+	extension_data
+};
+
+LV2_SYMBOL_EXPORT
+const LV2_Descriptor* lv2_descriptor(uint32_t index)
+{
+	switch (index) {
+	case 0:
+		return &descriptor;
+	default:
+		return NULL;
+	}
+}
+
+#ifdef __cplusplus
+}
+#endif