[LAD] More proposed LV2 addition/extension stuff

[Krzysztof Foltman]

Steve Harris wrote:
> You're right, we never defined the lv2:binary predicate.
>   
While you're adding stuff to lv2core, you might as well consider adding 
some of those (+/- any discussions that arise and probably rewrite in 
proper English), or perhaps I should move some of them into separate 
extension(s):

:trigger a :PortProperty ;
    rdfs:label "Trigger" ;
    rdfs:comment """
Indicates that the data item should be considered a Boolean value 
corresponding to the specific event that was detected (control output 
ports) or is to be triggered (control input ports). For input ports, the 
port needs to be reset to false by the host (any value less or equal 
than 0) after run() function is called.
""" .

(Boolean? discrete? based on if :integer or :toggle is present? a 
feature that says :trigger that is supported? use special labeled events 
instead?)

:supportsStrictBounds a :Feature
    rdfs:label   "Supports strict bounds" ;
    rdfs:comment """
Indicates use of host support for :hasStrictBounds port property. A 
plugin that specifies it as optional feature can omit value clamping for 
:hasStrictBounds ports, if the feature is supported by the host. When 
specified as required feature, it indicates that the plugin does not do 
any clamping for input ports that have a :hasStrictBounds property.
""" .

:hasStrictBounds a :PortProperty ;
    rdfs:label "Has strict bounds" ;
    rdfs:comment """
For hosts supporting the :supportsStrictBounds, it indicates that the 
value of the port should never exceed port's minimum and maximum control 
points. For input ports, it moves the responsibility for limiting the 
range of values to host, if it supports :supportsStrictBounds. For 
output ports, it indicates that values within specified range are to be 
expected, and breaking that should be considered by the host as error in 
plugin implementation.
""" .

These probably belong somewhere else, but I'll post them anyway:

:expensive a :PortProperty ;
    rdfs:label "Changes trigger expensive calculation" ;
    rdfs:comment """
Input ports only. Indicates that any changes to the port value may 
trigger expensive background calculation (eg. regenerate some lookup 
tables in background thread). Any value changes may have not have 
immediate effect at all, or may cause silence or diminished-quality 
version of the output data to be produced until background processing is 
finished. Ports having that property are typically not well suited for 
connection to outputs of other plugins, and should not be offered as 
connection targets or for automation by default.
""" .

:causesArtifacts a :PortProperty ;
    rdfs:label "May cause audio artifacts when changed" ;
    rdfs:comment """
Input ports only. Indicates that any changes to the port value may 
produce slight artifacts to produced audio signals (zipper noise and 
other results of signal discontinuities). Connecting ports of this type 
to continuous signals is not recommended, and when presenting a list of 
automation targets, those ports may be marked as artifact-producing.
""" .

:continuousCV a :PortProperty ;
    rdfs:label "Carries a smooth modulation signal" ;
    rdfs:comment """
Indicates that the port carries a "smooth" modulation signal. Control 
input ports of this type are well-suited for being connected to sources 
of smooth signals (knobs with smoothing, modulation rate oscillators, 
output ports with continuousCV type etc). Typically, a plugin with this 
type of ports will implement appropriate smoothing to avoid audio artifacts.
""" .

:discreteCV a :PortProperty ;
    rdfs:label "Carries a discrete modulation signal" ;
    rdfs:comment """
Indicates that the port carries a "discrete" modulation signal. Input 
ports of this type are well-suited for being connected to sources of 
discrete signals (switches, buttons, classifiers, event detectors etc.). 
May be combined with :trigger property.
""" .

Some of the above come up in #lad from time to time, but I don't think 
anybody tried to convert those raw ideas into .ttl before, so I decided 
to do it instead.

Krzysztof