Answer event queries within the Wine VST host

meson.build

@@ -44,6 +44,6 @@ executable(
   ],
   native : false,
   include_directories : include_dir,
-  dependencies : [],
   link_args : []
+  dependencies : [msgpack_dep],
 )

src/common/communication.h

@@ -1,6 +1,7 @@
 #pragma once
 
 #include <cinttypes>
+#include <iostream>
 #include <msgpack.hpp>
 #include <optional>
 
@@ -49,14 +50,14 @@ struct EventResult {
  *
  * @relates read_object
  */
-template <typename Stream, typename T>
+template <typename T, typename Stream>
 inline void write_object(Stream& stream, const T& object) {
     // TODO: Reuse buffers
     msgpack::sbuffer buffer;
     msgpack::pack(buffer, object);
 
     stream << buffer.size();
-    stream << buffer.data();
+    stream.write(buffer.data(), buffer.size());
     stream.flush();
 }
 
@@ -66,11 +67,12 @@ inline void write_object(Stream& stream, const T& object) {
  available.
  *
  * @param stream The stream to read from.
+ * @throw msgpack::type_error If the conversion to an object was not successful.
  *
  * @relates write_object
  */
-template <typename Stream>
+template <typename T, typename Stream>
-inline EventResult read_object(Stream& stream) {
+inline T read_object(Stream& stream) {
     size_t message_length;
     stream >> message_length;
 

src/plugin/bridge.cpp

@@ -15,7 +15,7 @@
 namespace bp = boost::process;
 namespace fs = boost::filesystem;
 
-constexpr auto yabridge_wine_host_name = "yabridge-host.exeTODO";
+constexpr auto yabridge_wine_host_name = "yabridge-host.exe";
 
 fs::path find_wine_vst_host();
 
@@ -38,15 +38,6 @@ intptr_t Bridge::dispatch(AEffect* /*plugin*/,
                           intptr_t value,
                           void* result,
                           float option) {
-    Event event{opcode, parameter, value, option};
-    write_object(vst_stdin, event);
-
-    EventResult response = read_object(vst_stdout);
-    if (response.result) {
-        std::copy(response.result->begin(), response.result->end(),
-                  static_cast<char*>(result));
-    }
-
     // Some events need some extra handling
     // TODO: Handle other things such as GUI itneraction
     switch (opcode) {
@@ -64,6 +55,15 @@ intptr_t Bridge::dispatch(AEffect* /*plugin*/,
             break;
     }
 
+    Event event{opcode, parameter, value, option};
+    write_object(vst_stdin, event);
+
+    auto response = read_object<EventResult>(vst_stdout);
+    if (response.result) {
+        std::copy(response.result->begin(), response.result->end(),
+                  static_cast<char*>(result));
+    }
+
     return response.return_value;
 }
 
@@ -109,7 +109,7 @@ fs::path find_wine_vst_host() {
     // Bosot will return an empty path if the file could not be found in the
     // search path
     fs::path vst_host_path = bp::search_path(yabridge_wine_host_name);
-    if (fs::is_empty(vst_host_path)) {
+    if (vst_host_path == "") {
         throw std::runtime_error("Could not locate '" +
                                  std::string(yabridge_wine_host_name) + "'");
     }

src/wine-host/native-includes.h

@@ -0,0 +1,26 @@
+#pragma once
+
+// Libraries like Boost and msgpack think we're compiling on Windows or using a
+// MSVC toolchain. This will cause them to make assumptions about the way
+// certain types are defined, which headers are available and which features to
+// disable (i.e. POSIX specific features). The only way around this I could
+// think of was to just temporarily undefine the macros these libraries use to
+// detect it's running under a WIN32 environment. If anyone knows a better way
+// to do this, please let me know!
+
+#pragma push_macro("WIN32")
+#pragma push_macro("_WIN32")
+#pragma push_macro("__WIN32__")
+#pragma push_macro("_WIN64")
+
+#undef WIN32
+#undef _WIN32
+#undef __WIN32__
+#undef _WIN64
+
+#include <msgpack.hpp>
+
+#pragma pop_macro("WIN32")
+#pragma pop_macro("_WIN32")
+#pragma pop_macro("__WIN32__")
+#pragma pop_macro("_WIN64")

src/wine-host/vst-host.cpp

@@ -1,7 +1,28 @@
-// TODO: Do something useful here!
+#include <vestige/aeffect.h>
 
 #include <iostream>
 
+#include "native-includes.h"
+
+// `native-includes.h` has to be included before any other files as otherwise we
+// might get the wrong version of certain libraries
+#include "../common/communication.h"
+
 int main() {
-    std::cout << "Hello, world!" << std::endl;
+    // TODO: The program should terminate automatically when stdin gets closed
+
+    // TODO: Remove debug
+    while (true) {
+        auto event = read_object<Event>(std::cin);
+
+        EventResult response;
+        if (event.opcode == effGetEffectName) {
+            response.return_value = 1;
+            response.result = "Hello, world!";
+        } else {
+            response.return_value = 0;
+        }
+
+        write_object(std::cout, response);
+    }
 }