Add not_output() to ParameterInfo

If not set, use the CLAP_PARAM_REQUIRES_PROCESS flag

Author: ilmai

plinth-plugin/src/formats/clap/extensions/params.rs

@@ -1,6 +1,6 @@
 use std::{ffi::{c_char, CStr}, marker::PhantomData, sync::atomic::Ordering};
 
-use clap_sys::{events::{clap_input_events, clap_output_events}, ext::params::{clap_param_info, clap_plugin_params, CLAP_PARAM_IS_AUTOMATABLE, CLAP_PARAM_IS_BYPASS, CLAP_PARAM_IS_HIDDEN, CLAP_PARAM_IS_MODULATABLE, CLAP_PARAM_IS_STEPPED}, id::clap_id, plugin::clap_plugin};
+use clap_sys::{events::{clap_input_events, clap_output_events}, ext::params::{CLAP_PARAM_IS_AUTOMATABLE, CLAP_PARAM_IS_BYPASS, CLAP_PARAM_IS_HIDDEN, CLAP_PARAM_IS_MODULATABLE, CLAP_PARAM_IS_STEPPED, CLAP_PARAM_REQUIRES_PROCESS, clap_param_info, clap_plugin_params}, id::clap_id, plugin::clap_plugin};
 
 use crate::{clap::{event::EventIterator, parameters::{map_parameter_value_from_clap, map_parameter_value_to_clap}, plugin_instance::PluginInstance, ClapPlugin}, processor::Processor, string::copy_str_to_char8, Parameters};
 
@@ -52,6 +52,9 @@ impl<P: ClapPlugin> Params<P> {
             if parameter_info.is_bypass() {
                 clap_param_info.flags |= CLAP_PARAM_IS_BYPASS;
             }
+            if parameter_info.is_output() {
+                clap_param_info.flags |= CLAP_PARAM_REQUIRES_PROCESS;
+            }
             if parameter_info.visible() {
                 clap_param_info.flags |= CLAP_PARAM_IS_AUTOMATABLE | CLAP_PARAM_IS_MODULATABLE
             } else {

plinth-plugin/src/parameters/info.rs

@@ -10,6 +10,7 @@ pub struct ParameterInfo {
     default_normalized_value: ParameterValue,
     steps: usize,
     is_bypass: bool,
+    is_output: bool,
     visible: bool,
 }
 
@@ -22,6 +23,7 @@ impl ParameterInfo {
             default_normalized_value: Default::default(),
             steps: 0,
             is_bypass: false,
+            is_output: true,
             visible: true,
         }
     }
@@ -46,6 +48,14 @@ impl ParameterInfo {
         self
     }
 
+    /// By default, parameters are assumed to affect plugin output
+    /// Calling this function will mark the parameter as not affecting the output,
+    /// which might improve performance
+    pub fn not_output(mut self) -> Self {
+        self.is_output = false;
+        self
+    }
+
     pub fn hidden(mut self) -> Self {
         self.visible = false;
         self
@@ -75,6 +85,10 @@ impl ParameterInfo {
         self.is_bypass
     }
 
+    pub fn is_output(&self) -> bool {
+        self.is_output
+    }
+
     pub fn visible(&self) -> bool {
         self.visible
     }