Moved slv2 directory for consistency

git-svn-id: http://svn.drobilla.net/lad/slv2@165 a436a847-0d15-0410-975c-d299462d15a1

1 files changed, 321 insertions, 0 deletions

diff --git a/slv2/lv2.h b/slv2/lv2.h
new file mode 100644
index 0000000..e38e2ac
--- /dev/null
+++ b/slv2/lv2.h
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+/* LV2 - LADSPA (Linux Audio Developer's Simple Plugin API) Version 2.0
+ * *** PROVISIONAL ***
+ *
+ * Copyright (C) 2000-2002 Richard W.E. Furse, Paul Barton-Davis, Stefan
+ * Westerfeld
+ * Copyright (C) 2006 Steve Harris, Dave Robillard.
+ *
+ * This header is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU Lesser General Public License as published
+ * by the Free Software Foundation; either version 2.1 of the License,
+ * or (at your option) any later version.
+ *
+ * This header 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
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301
+ * USA.
+ */
+
+#ifndef LV2_H_INCLUDED
+#define LV2_H_INCLUDED
+
+#include <stdint.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+
+/* ************************************************************************* */
+
+
+/* Overview: 
+ *
+ * There are a large number of open source and free software synthesis
+ * packages in use or development at this time. This API ('LV2')
+ * attempts to give programmers the ability to write simple 'plugin'
+ * audio processors in C/C++ and link them dynamically ('plug') into
+ * a range of these packages ('hosts').  It should be possible for any
+ * host and any plugin to communicate completely through this interface.
+ *
+ * This API is deliberately as short and simple as possible.
+ * The information required to use a plugin is in a companion data
+ * (RDF) file.  The shared library portion of the API (defined in this
+ * header) does not contain enough information to make use of the plugin
+ * possible - the data file is mandatory.
+ *
+ * Plugins are expected to distinguish between control rate and audio
+ * rate data. Plugins have 'ports' that are inputs or outputs for audio
+ * or control data and each plugin is 'run' for a 'block' corresponding
+ * to a short time interval measured in samples. Audio rate data is
+ * communicated using arrays with one element per sample processed,
+ * allowing a block of audio to be processed by the plugin in a single
+ * pass. Control rate data is communicated using single values. Control
+ * rate data has a single value at the start of a call to the 'run()'
+ * function, and may be considered to remain this value for its duration.
+ * Thus the 'control rate' is determined by the block size, controlled
+ * by the host.  The plugin may assume that all its input and output
+ * ports have been connected to the relevant data location (see the
+ * 'connect_port()' function below) before it is asked to run.
+ *
+ * Plugins will reside in shared object files suitable for dynamic linking
+ * by dlopen() and family. The file will provide a number of 'plugin
+ * types' that can be used to instantiate actual plugins (sometimes known
+ * as 'plugin instances') that can be connected together to perform tasks.
+ *
+ * This API contains very limited error-handling.
+ */
+
+
+/* ************************************************************************* */
+
+    
+/** Plugin Handle.
+ *
+ * This plugin handle indicates a particular instance of the plugin
+ * concerned. It is valid to compare this to NULL (0 for C++) but
+ * otherwise the host MUST not attempt to interpret it. The plugin
+ * may use it to reference internal instance data. */
+typedef void * LV2_Handle;
+
+
+/* ************************************************************************* */
+
+
+/** Host feature.
+ * 
+ * These are passed to a plugin's instantiate method to represent a special
+ * feature the host has which the plugin may depend on.  This is to allow
+ * extensions to the LV2 specification without causing any breakage.  The base
+ * LV2 specification does not define any host features; hosts are not required
+ * to use this facility.
+ */
+typedef struct _LV2_Host_Feature {
+	/** A globally unique, case-sensitive identifier for this feature.
+	 *
+	 * This MUST be defined in the specification of any LV2 extension which
+	 * defines a host feature.
+	 */
+	const char * URI;
+
+	/** Pointer to arbitrary data.
+	 *
+	 * This is to allow hosts to pass data to a plugin (simple values, data
+	 * structures, function pointers, etc) as part of a 'feature'.  The LV2
+	 * specification makes no restrictions on the contents of this data.
+	 * The data here MUST be cleary defined by the LV2 extension which defines
+	 * this feature.
+	 * If no data is required, this may be set to NULL.
+	 */
+	void * data;
+} LV2_Host_Feature;
+
+
+/* ************************************************************************* */
+
+
+/** Descriptor for a Type of Plugin.
+ * 
+ * This structure is used to describe a plugin type. It provides a number
+ * of functions to instantiate it, link it to buffers and run it. */
+typedef struct _LV2_Descriptor { 
+
+  /** 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. */
+  const char * URI;
+
+  /** 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.
+   *
+   * BundlePath is a string of the path to the plugin's .lv2 bundle
+   * directory, it MUST not include the trailing /.
+   *
+   * HostFeatures is a NULL terminated array of the URIs of the LV2
+   * features that 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).
+   *
+   * 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,
+                            uint32_t                       SampleRate,
+                            const char *                   BundlePath,
+                            const LV2_Host_Feature**       HostFeatures);
+
+  /** 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 an array of void * (typically
+   * float *) for audio ports or a single void * value for control
+   * ports. Memory issues are managed by the host. The plugin must
+   * read/write the data at these locations every time run() is called
+   * and the data present at the time of this connection call MUST NOT
+   * be considered meaningful.
+   *
+   * 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.
+   *
+   * 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_PROPERTY_INPLACE_BROKEN (FIXME)).
+   * However, overlapped buffers or use of a single buffer for both
+   * audio and control data may result in unexpected behaviour. */
+  void (*connect_port)(LV2_Handle    Instance,
+                       uint32_t      Port,
+                       void *        DataLocation);
+
+  /** 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);
+
+  /** 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 property LV2_PROPERTY_HARD_RT_CAPABLE then
+   * there are various things that the plugin MUST NOT do within the run()
+   * function (see above). */
+  void (*run)(LV2_Handle    Instance,
+              uint32_t      SampleCount);
+
+  /** 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);
+
+  /** 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);
+
+} LV2_Descriptor;
+
+
+/* ****************************************************************** */
+
+
+/** Accessing a Plugin:
+ *
+ * The exact mechanism by which plugins are loaded is host-dependent,
+ * however all most hosts will need to know is the URI of the plugin they
+ * wish to load.  The environment variable LV2_PATH, if present, should
+ * contain a colon-separated path indicating directories (containing
+ * plugin bundle subdirectories) that should be searched (in order)
+ * for plugins.  It is expected that hosts will use a library to provide
+ * this functionality.
+ * 
+ * A plugin programmer must include a function called "lv2_descriptor"
+ * with the following function prototype within the shared object
+ * file. This function will have C-style linkage (if you are using
+ * C++ this is taken care of by the 'extern "C"' clause at the top of
+ * the file).
+ *
+ * A host will find the plugin shared object file by one means or another,
+ * find the lv2_descriptor() function, call it, and proceed from there.
+ *
+ * Plugin types are accessed by index (not ID) using values from 0
+ * upwards. Out of range indexes must result in this function returning
+ * NULL, so the plugin count can be determined by checking for the least
+ * index that results in NULL being returned.  Index has no meaning,
+ * hosts MUST NOT depend on it remaining constant (ie when serialising)
+ * in any way. */
+const LV2_Descriptor * lv2_descriptor(uint32_t Index);
+
+
+/** Datatype corresponding to the lv2_descriptor() function. */
+typedef const LV2_Descriptor * 
+(*LV2_Descriptor_Function)(uint32_t Index);
+
+
+/* ******************************************************************** */
+
+
+/* Put this (LV2_SYMBOL_EXPORT) before any functions that are to be loaded
+ * by the host as a symbol from the dynamic library.
+ */
+#ifdef WIN32
+#define LV2_SYMBOL_EXPORT __declspec(dllexport)
+#else
+#define LV2_SYMBOL_EXPORT
+#endif
+
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* LV2_H_INCLUDED */
+