From f53f6829f0fb2c8ce905eed87a2452217342a4af Mon Sep 17 00:00:00 2001
From: Robbert van der Helm <mail@robbertvanderhelm.nl>
Date: Tue, 15 Mar 2022 22:08:29 +0100
Subject: [PATCH] Implement the CLAP event filter extension

---
 src/wrapper/clap/wrapper.rs | 39 +++++++++++++++++++++++++++++++------
 1 file changed, 33 insertions(+), 6 deletions(-)

diff --git a/src/wrapper/clap/wrapper.rs b/src/wrapper/clap/wrapper.rs
index b8e2d3b4..0f17f657 100644
--- a/src/wrapper/clap/wrapper.rs
+++ b/src/wrapper/clap/wrapper.rs
@@ -6,10 +6,10 @@ use atomic_float::AtomicF32;
 use atomic_refcell::{AtomicRefCell, AtomicRefMut};
 use clap_sys::events::{
     clap_event_header, clap_event_note, clap_event_param_gesture, clap_event_param_value,
-    clap_input_events, clap_output_events, CLAP_CORE_EVENT_SPACE_ID, CLAP_EVENT_IS_LIVE,
-    CLAP_EVENT_MIDI, CLAP_EVENT_NOTE_EXPRESSION, CLAP_EVENT_NOTE_OFF, CLAP_EVENT_NOTE_ON,
-    CLAP_EVENT_PARAM_GESTURE_BEGIN, CLAP_EVENT_PARAM_GESTURE_END, CLAP_EVENT_PARAM_VALUE,
-    CLAP_TRANSPORT_HAS_BEATS_TIMELINE, CLAP_TRANSPORT_HAS_SECONDS_TIMELINE,
+    clap_event_type, clap_input_events, clap_output_events, CLAP_CORE_EVENT_SPACE_ID,
+    CLAP_EVENT_IS_LIVE, CLAP_EVENT_MIDI, CLAP_EVENT_NOTE_EXPRESSION, CLAP_EVENT_NOTE_OFF,
+    CLAP_EVENT_NOTE_ON, CLAP_EVENT_PARAM_GESTURE_BEGIN, CLAP_EVENT_PARAM_GESTURE_END,
+    CLAP_EVENT_PARAM_VALUE, CLAP_TRANSPORT_HAS_BEATS_TIMELINE, CLAP_TRANSPORT_HAS_SECONDS_TIMELINE,
     CLAP_TRANSPORT_HAS_TEMPO, CLAP_TRANSPORT_HAS_TIME_SIGNATURE, CLAP_TRANSPORT_IS_LOOP_ACTIVE,
     CLAP_TRANSPORT_IS_PLAYING, CLAP_TRANSPORT_IS_RECORDING, CLAP_TRANSPORT_IS_WITHIN_PRE_ROLL,
 };
@@ -20,6 +20,7 @@ use clap_sys::ext::audio_ports::{
 use clap_sys::ext::audio_ports_config::{
     clap_audio_ports_config, clap_plugin_audio_ports_config, CLAP_EXT_AUDIO_PORTS_CONFIG,
 };
+use clap_sys::ext::event_filter::{clap_plugin_event_filter, CLAP_EXT_EVENT_FILTER};
 use clap_sys::ext::gui::{
     clap_plugin_gui, clap_window, CLAP_EXT_GUI, CLAP_WINDOW_API_COCOA, CLAP_WINDOW_API_WIN32,
     CLAP_WINDOW_API_X11,
@@ -148,6 +149,8 @@ pub struct Wrapper<P: ClapPlugin> {
 
     clap_plugin_audio_ports: clap_plugin_audio_ports,
 
+    clap_plugin_event_filter: clap_plugin_event_filter,
+
     clap_plugin_gui: clap_plugin_gui,
 
     clap_plugin_latency: clap_plugin_latency,
@@ -365,6 +368,10 @@ impl<P: ClapPlugin> Wrapper<P> {
                 get: Self::ext_audio_ports_get,
             },
 
+            clap_plugin_event_filter: clap_plugin_event_filter {
+                accepts: Self::ext_event_filter_accepts,
+            },
+
             clap_plugin_gui: clap_plugin_gui {
                 is_api_supported: Self::ext_gui_is_api_supported,
                 create: Self::ext_gui_create,
@@ -754,7 +761,6 @@ impl<P: ClapPlugin> Wrapper<P> {
     ) -> bool {
         let raw_event = &*event;
         match (raw_event.space_id, raw_event.type_) {
-            // TODO: Implement the event filter
             (CLAP_CORE_EVENT_SPACE_ID, CLAP_EVENT_PARAM_VALUE) => {
                 let event = &*(event as *const clap_event_param_value);
                 self.update_plain_value_by_hash(
@@ -1166,12 +1172,14 @@ impl<P: ClapPlugin> Wrapper<P> {
         let id = CStr::from_ptr(id);
 
         // TODO: Implement:
-        //       - event_filter
+        //       - note ports
         //       - tail
         if id == CStr::from_ptr(CLAP_EXT_AUDIO_PORTS_CONFIG) {
             &wrapper.clap_plugin_audio_ports_config as *const _ as *const c_void
         } else if id == CStr::from_ptr(CLAP_EXT_AUDIO_PORTS) {
             &wrapper.clap_plugin_audio_ports as *const _ as *const c_void
+        } else if id == CStr::from_ptr(CLAP_EXT_EVENT_FILTER) {
+            &wrapper.clap_plugin_event_filter as *const _ as *const c_void
         } else if id == CStr::from_ptr(CLAP_EXT_GUI) && wrapper.editor.is_some() {
             // Only report that we support this extension if the plugin has an editor
             &wrapper.clap_plugin_gui as *const _ as *const c_void
@@ -1374,6 +1382,25 @@ impl<P: ClapPlugin> Wrapper<P> {
         }
     }
 
+    unsafe extern "C" fn ext_event_filter_accepts(
+        _plugin: *const clap_plugin,
+        space_id: u16,
+        event_type: clap_event_type,
+    ) -> bool {
+        match (space_id, event_type) {
+            (CLAP_CORE_EVENT_SPACE_ID, CLAP_EVENT_PARAM_VALUE) => true,
+            (CLAP_CORE_EVENT_SPACE_ID, CLAP_EVENT_NOTE_ON)
+            | (CLAP_CORE_EVENT_SPACE_ID, CLAP_EVENT_NOTE_OFF)
+            | (CLAP_CORE_EVENT_SPACE_ID, CLAP_EVENT_NOTE_EXPRESSION)
+            | (CLAP_CORE_EVENT_SPACE_ID, CLAP_EVENT_MIDI)
+                if P::ACCEPTS_MIDI =>
+            {
+                true
+            }
+            _ => false,
+        }
+    }
+
     unsafe extern "C" fn ext_gui_is_api_supported(
         _plugin: *const clap_plugin,
         api: *const c_char,