Tell the UI that something interesting has happened at a plugin port.
What is "interesting" and how it is written to buffer is defined by
format, which has the same meaning as in LV2UI_Write_Function().
Format 0 is a special case for lv2:ControlPort, where this function
should be called when the port value changes (but not necessarily for
every change), buffer_size must be sizeof(float), and buffer
points to a single IEEE-754 float.
By default, the host should only call this function for lv2:ControlPort
inputs. However, the UI can request updates for other ports statically
with ui:portNotification or dynamicaly with ui:portSubscribe.
The UI MUST NOT retain any reference to buffer after this function
returns, it is only valid for the duration of the call.
This member may be NULL if the UI is not interested in any port events.
Tell the UI that something interesting has happened at a plugin port.
What is "interesting" and how it is written to buffer is defined by format, which has the same meaning as in LV2UI_Write_Function(). Format 0 is a special case for lv2:ControlPort, where this function should be called when the port value changes (but not necessarily for every change), buffer_size must be sizeof(float), and buffer points to a single IEEE-754 float.
By default, the host should only call this function for lv2:ControlPort inputs. However, the UI can request updates for other ports statically with ui:portNotification or dynamicaly with ui:portSubscribe.
The UI MUST NOT retain any reference to buffer after this function returns, it is only valid for the duration of the call.
This member may be NULL if the UI is not interested in any port events.