path: root/lv2/lv2plug.in/ns/lv2core/lv2core.ttl
diff options
authorDavid Robillard <d@drobilla.net>2012-03-23 22:30:30 +0000
committerDavid Robillard <d@drobilla.net>2012-03-23 22:30:30 +0000
commit70d225871dbb58d770150abcc4b9e7907fabb19d (patch)
tree9be561fa27422846f526b34a3687986353927560 /lv2/lv2plug.in/ns/lv2core/lv2core.ttl
parent643622798f3f77eec64c30a9e0e6844ad9ebd8f4 (diff)
Add lv2:Parameter and better document the concept.
Diffstat (limited to 'lv2/lv2plug.in/ns/lv2core/lv2core.ttl')
1 files changed, 35 insertions, 15 deletions
diff --git a/lv2/lv2plug.in/ns/lv2core/lv2core.ttl b/lv2/lv2plug.in/ns/lv2core/lv2core.ttl
index 57f4fc8..7d0e729 100644
--- a/lv2/lv2plug.in/ns/lv2core/lv2core.ttl
+++ b/lv2/lv2plug.in/ns/lv2core/lv2core.ttl
@@ -449,32 +449,52 @@ port identification. The plugin author may change the values of this
property without changing the Plugin URI.
""" .
+ a rdfs:Class ;
+ rdfs:subClassOf rdf:Property ;
+ lv2:documentation """
+<p>A <q>parameter</q> of a plugin. A parameter is simply a recognized
+property, identified by URI. Parameters are abstract in the sense that they
+may be controlled by several methods. The simplest is with an
+lv2:ControlPort, which can be associated with a parameter using
+lv2:isParameter. Other methods, such as setting dynamic parameters via
+messages, are possible but not defined in this specification. The concept of a
+parameter is deliberately separate from any particular code mechanism, so that
+a parameter can be defined once and used in several contexts.</p>
+<p>Parameters are <em>meaningful</em> controls which allow hosts to act
+intelligently. For example, if a plugin has a foo:volume parameter, and the
+host understands it, the host knows how to automatically control the volume of
+that plugin.</p>
+<p>Any existing property can be used as a parameter, an LV2 specific definition
+is not required.</p>
+""" .
lv2:hasParameter a rdf:Property , owl:ObjectProperty ;
- rdfs:domain lv2:Resource ;
- rdfs:range rdf:Property ;
+ rdfs:range lv2:Parameter ;
rdfs:label "has parameter" ;
lv2:documentation """
-<p>Indicates that a plugin or other resource has a certain <q>parameter</q>. A
-parameter is simply a recognized property, i.e. a URI predicate and any type of
-object. Parameters may be associated with a control port or controlled using
-another mechanism. Parameter values may be part of an instance's state.</p>
+<p>Indicates that a specific parameter is supported. This predicate is to
+advertise that a plugin supports a parameter in some way other than a port
+value, such as a message interface. It is not necessary use for control port
+parameters, simply use lv2:isParameter on the port for that.</p>
-<p>Any property URI can be used as a parameter, no LV2 specific definition is
-required. Existing vocabularies SHOULD be used whenever possible.</p>
+<p>This property may be used to indicate any resource has a parameter, it is
+not restricted to plugins.</p>
""" .
lv2:isParameter a rdf:Property , owl:ObjectProperty ;
rdfs:domain lv2:Port ;
- rdfs:range rdf:Property ;
- rdfs:label "relation" ;
+ rdfs:range lv2:Parameter ;
+ rdfs:label "is parameter" ;
lv2:documentation """
<p>Indicates that a port contains the value of a plugin parameter.</p>
-<p>For example, if a port lv2:isParameter foo:volume, then the value of that
-port represents the foo:volume of the plugin instance. Associating a port with
-a well-defined parameter gives the port's value meaning. This allows it to be
-handled specially by the host and integrate with other property-based
-mechanisms (e.g. messages or plugin state).</p>
+<p>For example, if a port lv2:isParameter foo:gain, then the value of that port
+represents the foo:gain of the plugin instance. Associating a port with a
+well-defined parameter gives the port's value meaning, which allows the host
+to use the port more intelligently.</p>
<p>For a given parameter, plugins SHOULD have at most one port per direction
(lv2:InputPort or lv2:OutputPort).</p> """ .