From d564baafed0863813a87d872f8663134e74228c8 Mon Sep 17 00:00:00 2001 From: David Robillard Date: Sun, 14 May 2023 20:03:30 -0400 Subject: Clean up documentation and remove junk files from install --- doc/c/world.rst | 157 -------------------------------------------------------- 1 file changed, 157 deletions(-) delete mode 100644 doc/c/world.rst (limited to 'doc/c/world.rst') diff --git a/doc/c/world.rst b/doc/c/world.rst deleted file mode 100644 index 8b71165..0000000 --- a/doc/c/world.rst +++ /dev/null @@ -1,157 +0,0 @@ -.. - Copyright 2020-2022 David Robillard - SPDX-License-Identifier: ISC - -.. default-domain:: c -.. highlight:: c - -##### -World -##### - -The world is the top-level object which represents an instance of Lilv. -It is used to discover and load LV2 data, -and stores an internal cache of loaded data for fast searching. - -An application typically has a single world, -which is constructed once on startup and used throughout the application's lifetime. - -************ -Construction -************ - -A world must be created before anything else. -A world is created with :func:`lilv_world_new`, for example: - -.. code-block:: c - - LilvWorld* world = lilv_world_new(); - -*************** -Setting Options -*************** - -Various options to control Lilv's behavior can be set with :func:`lilv_world_set_option`. -The currently supported options are :c:macro:`LILV_OPTION_FILTER_LANG`, -:c:macro:`LILV_OPTION_DYN_MANIFEST`, and :c:macro:`LILV_OPTION_LV2_PATH`. - -For example, to set the LV2 path to only load plugins bundled in the application: - -.. code-block:: c - - LilvNode* lv2_path = lilv_new_file_uri(world, NULL, "/myapp/lv2"); - - lilv_world_set_option(world, LILV_OPTION_LV2_PATH, lv2_path); - -************ -Loading Data -************ - -Before using anything, data must be loaded from disk. -All LV2 data (plugins, UIs, specifications, presets, and so on) is installed in `bundles`, -a standard directory format - -Discovering and Loading Bundles -=============================== - -Typical hosts will simply load all bundles in the standard LV2 locations on the system: - -.. code-block:: c - - lilv_world_load_all(world); - -This will discover all bundles on the system, -as well as load the required data defined in any discovered specifications. - -It is also possible to load a specific bundle: - -.. code-block:: c - - LilvNode* bundle_uri = lilv_new_file_uri(world, NULL, "/some/plugin.lv2"); - - lilv_world_load_bundle(world, bundle_uri); - -The LV2 specification itself is also installed in bundles, -so if you are not using :func:`lilv_world_load_all`, -it is necessary to manually load the discovered specification data: - -.. code-block:: c - - lilv_world_load_specifications(world); - lilv_world_load_plugin_classes(world); - -************* -Querying Data -************* - -The world contains a model of all the loaded data in memory which can be queried. - -Data Model -========== - -LV2 data is a set of "statements", -where a statement is a bit like a simple machine-readable sentence. -The "subject" and "object" are as in natural language, -and the "predicate" is like the verb, but more general. - -For example, we could make a statement about a plugin in english: - - MyOsc has the name "Super Oscillator" - -We can break this statement into 3 pieces like so: - -.. list-table:: - :header-rows: 1 - - * - Subject - - Predicate - - Object - * - MyOsc - - has the name - - "My Super Oscillator" - -Statements use URIs to identify things. -In this case, we assume that this plugin has the URI ``http://example.org/Osc``. -The LV2 specification defines that ``http://usefulinc.com/ns/doap#name`` is the property used to describe a plugin's name. -So, this statement is: - -.. list-table:: - :header-rows: 1 - - * - Subject - - Predicate - - Object - * - ``http://example.org/Osc`` - - ``http://usefulinc.com/ns/doap#name`` - - "My Oscillator" - -Finding Values -============== - -Based on this model, you can find all values that match a certain pattern. -Patterns are just statements, -but with ``NULL`` used as a wildcard that matches anything. -So, for example, you can get the name of a plugin using :func:`lilv_world_find_nodes`: - -.. code-block:: c - - LilvNode* plugin_uri = lilv_new_uri(world, "http://example.org/Osc"); - LilvNode* doap_name = lilv_new_uri(world, "http://usefulinc.com/ns/doap#name"); - - LilvNodes* values = lilv_world_find_nodes(world, plugin_uri, doap_name, NULL); - -Note that a set of values is returned, -because some properties may have several values. -When you are only interested in one value, -you can use the simpler :func:`lilv_world_get` instead: - -.. code-block:: c - - LilvNode* value = lilv_world_get(world, plugin_uri, doap_name, NULL); - -If you are only interested if a value exists at all, -use :func:`lilv_world_ask`: - -.. code-block:: c - - bool has_name = lilv_world_ask(world, plugin_uri, doap_name, NULL); -- cgit v1.2.1