Add the other CLAP metadata fields

plugins/diopser/src/lib.rs

@@ -412,6 +412,11 @@ fn unnormalize_automation_precision(normalized: f32) -> u32 {
 
 impl ClapPlugin for Diopser {
     const CLAP_ID: &'static str = "nl.robbertvanderhelm.diopser";
+    const CLAP_DESCRIPTION: &'static str = "A totally original phase rotation plugin";
+    const CLAP_KEYWORDS: &'static [&'static str] =
+        &["audio_effect", "mono", "stereo", "filter", "utility"];
+    const CLAP_MANUAL_URL: &'static str = Self::URL;
+    const CLAP_SUPPORT_URL: &'static str = Self::URL;
 }
 
 impl Vst3Plugin for Diopser {

plugins/examples/gain-gui/src/lib.rs

@@ -204,6 +204,10 @@ impl Plugin for Gain {
 
 impl ClapPlugin for Gain {
     const CLAP_ID: &'static str = "com.moist-plugins-gmbh.gain";
+    const CLAP_DESCRIPTION: &'static str = "A smoothed gain parameter example plugin";
+    const CLAP_KEYWORDS: &'static [&'static str] = &["audio_effect", "mono", "stereo", "tool"];
+    const CLAP_MANUAL_URL: &'static str = Self::URL;
+    const CLAP_SUPPORT_URL: &'static str = Self::URL;
 }
 
 impl Vst3Plugin for Gain {

plugins/examples/gain/src/lib.rs

@@ -131,6 +131,10 @@ impl Plugin for Gain {
 
 impl ClapPlugin for Gain {
     const CLAP_ID: &'static str = "com.moist-plugins-gmbh.gain";
+    const CLAP_DESCRIPTION: &'static str = "A smoothed gain parameter example plugin";
+    const CLAP_KEYWORDS: &'static [&'static str] = &["audio_effect", "mono", "stereo", "tool"];
+    const CLAP_MANUAL_URL: &'static str = Self::URL;
+    const CLAP_SUPPORT_URL: &'static str = Self::URL;
 }
 
 impl Vst3Plugin for Gain {

plugins/examples/sine/src/lib.rs

@@ -178,6 +178,10 @@ impl Plugin for Sine {
 
 impl ClapPlugin for Sine {
     const CLAP_ID: &'static str = "com.moist-plugins-gmbh.sine";
+    const CLAP_DESCRIPTION: &'static str = "An optionally MIDI controlled sine test tone";
+    const CLAP_KEYWORDS: &'static [&'static str] = &["instrument", "mono", "stereo", "utility"];
+    const CLAP_MANUAL_URL: &'static str = Self::URL;
+    const CLAP_SUPPORT_URL: &'static str = Self::URL;
 }
 
 impl Vst3Plugin for Sine {

src/plugin.rs

@@ -106,6 +106,20 @@ pub trait ClapPlugin: Plugin {
     /// A unique ID that identifies this particular plugin. This is usually in reverse domain name
     /// notation, e.g. `com.manufacturer.plugin-name`.
     const CLAP_ID: &'static str;
+    /// A short description for the plugin.
+    const CLAP_DESCRIPTION: &'static str;
+    /// Arbitrary keywords describing the plugin. See the CLAP specification for examples:
+    /// <https://github.com/free-audio/clap/blob/main/include/clap/plugin.h>.
+    //
+    // TODO: CLAP mentions that `win32-dpi-aware` is a special keyword that informs the host that
+    //       the plugin is DPI aware, can and should we have special handling for this?
+    const CLAP_KEYWORDS: &'static [&'static str];
+    /// A URL to the plugin's manual, CLAP does not specify what to do when there is none.
+    //
+    // TODO: CLAP does not specify this, can these manual fields be null pointers?
+    const CLAP_MANUAL_URL: &'static str;
+    /// A URL to the plugin's support page, CLAP does not specify what to do when there is none.
+    const CLAP_SUPPORT_URL: &'static str;
 }
 
 /// Provides auxiliary metadata needed for a VST3 plugin.