commit f25dded9e4b6fc1cc03a9371122449d20e1df4d6
parent fa2beac3d9b4242d01741635c4572b015251cd3f
Author: Alexandre Bique <bique.alexandre@gmail.com>
Date: Mon, 15 Jan 2024 14:02:02 +0100
Merge pull request #381 from baconpaul/ne-doc
Expand some note and note expression doc
Diffstat:
2 files changed, 22 insertions(+), 5 deletions(-)
diff --git a/ChangeLog.md b/ChangeLog.md
@@ -47,6 +47,8 @@ Note: we kept the last draft factory ID in order to not break plugins already us
## Documentation
* [events.h](include/clap/events.h): Clarify how "Port Channel Key NoteID" matching works
+* [events.h](include/clap/events.h): Clarify how `clap_event_note` fields map to MIDI, Host, etc...
+* [events.h](include/clap/events.h): Expand clap note expression documentation
* [plugin.h](include/clap/plugin.h): Style cleanup
* [params.h](include/clap/ext/params.h): Fix incorrect function name reference
* [latency.h](include/clap/ext/latency.h): Require the plugin to be activated to get the latency and clarify that the latency can only be fetched when the plugin is activated
diff --git a/include/clap/events.h b/include/clap/events.h
@@ -151,13 +151,28 @@ enum {
typedef struct clap_event_note {
clap_event_header_t header;
- int32_t note_id; // -1 if unspecified, otherwise >=0
- int16_t port_index;
- int16_t channel; // 0..15
- int16_t key; // 0..127
+ int32_t note_id; // host provided note id >= 0, or -1 if unspecified or wildcard
+ int16_t port_index; // port index from ext/note-ports; -1 for wildcard
+ int16_t channel; // 0..15, same as MIDI1 Channel Number, -1 for wildcard
+ int16_t key; // 0..127, same as MIDI1 Key Number (60==Middle C), -1 for wildcard
double velocity; // 0..1
} clap_event_note_t;
+// Note Expressions are well named modifications of a voice targeted to
+// voices using the same wildcard rules described above. Note Expressions are delivered
+// as sample accurate events and should be applied at the sample when received.
+//
+// Note expressions are a statement of value, not cumulative. A PAN event of 0 followed by 1
+// followed by 0.5 would pan hard left, hard right, and center. They are intended as
+// an offset from the non-note-expression voice default. A voice which had a volume of
+// -20db absent note expressions which received a +4db note expression would move the
+// voice to -16db.
+//
+// A plugin which receives a note expression at the same sample as a NOTE_ON event
+// should apply that expression to all generated samples. A plugin which receives
+// a note expression after a NOTE_ON event should initiate the voice with default
+// values and then apply the note expression when received. A plugin may make a choice
+// to smooth note expression streams.
enum {
// with 0 < x <= 4, plain = 20 * log(x)
CLAP_NOTE_EXPRESSION_VOLUME = 0,
@@ -165,7 +180,7 @@ enum {
// pan, 0 left, 0.5 center, 1 right
CLAP_NOTE_EXPRESSION_PAN = 1,
- // relative tuning in semitone, from -120 to +120
+ // relative tuning in semitone, from -120 to +120, in equal temperament
CLAP_NOTE_EXPRESSION_TUNING = 2,
// 0..1
