Reverse engineer IO related opcodes

src/common/vst24.h

@@ -0,0 +1,40 @@
+// yabridge: a Wine VST bridge
+// Copyright (C) 2020  Robbert van der Helm
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program.  If not, see <https://www.gnu.org/licenses/>.
+
+#pragma once
+
+// This file contains important opcodes and structs missing from
+// `vestige/aeffectx.h`
+
+// Glanced from https://www.kvraudio.com/forum/viewtopic.php?p=2744675#p2744675.
+// These opcodes are used to retrieve names and specific properties for a
+// plugin's inputs and outputs, if the plugin supports this. The index parameter
+// is used to specify the index of the channel being queried, and the plugin
+// gets passed an empty struct to describe the input/output through the data
+// parameter. Finally the plugin returns a string containing the input or output
+// name.
+constexpr int effGetInputProperties = 33;
+constexpr int effGetOutputProperties = 34;
+
+/**
+ * The struct that's being passed through the data parameter during the
+ * `effGetInputProperties` and `effGetOutputProperties` opcodes. Reverse
+ * engineered by attaching gdb to Bitwig. The actual fields are missing but for
+ * this application we don't need them.
+ */
+struct VstIOProperties {
+    char data[128];
+};