From 0d63c7ee5f5a709a2a94505e0089e01913b67ee8 Mon Sep 17 00:00:00 2001
From: Jean Pierre Cimalando <jp-dev@inbox.ru>
Date: Thu, 29 Apr 2021 15:38:43 +0200
Subject: [PATCH] Add vst support for message<->update conversion

---
 plugins/vst/CMakeLists.txt      |  1 +
 plugins/vst/SfizzVstUpdates.cpp | 18 ++++++++++++-----
 plugins/vst/SfizzVstUpdates.h   | 36 +++++++++++++++++++++++++++------
 plugins/vst/SfizzVstUpdates.hpp | 30 +++++++++++++++++++++++++++
 4 files changed, 74 insertions(+), 11 deletions(-)
 create mode 100644 plugins/vst/SfizzVstUpdates.hpp

diff --git a/plugins/vst/CMakeLists.txt b/plugins/vst/CMakeLists.txt
index a92125ad..894975f4 100644
--- a/plugins/vst/CMakeLists.txt
+++ b/plugins/vst/CMakeLists.txt
@@ -33,6 +33,7 @@ add_library(sfizz-vst3-core STATIC EXCLUDE_FROM_ALL
     SfizzVstState.h
     SfizzVstParameters.h
     SfizzVstUpdates.h
+    SfizzVstUpdates.hpp
     SfizzVstUpdates.cpp
     SfizzVstIDs.h
     OrderedEventProcessor.h
diff --git a/plugins/vst/SfizzVstUpdates.cpp b/plugins/vst/SfizzVstUpdates.cpp
index 6ffcbea5..eac7a685 100644
--- a/plugins/vst/SfizzVstUpdates.cpp
+++ b/plugins/vst/SfizzVstUpdates.cpp
@@ -40,12 +40,20 @@ void QueuedUpdates::removeDependent(IDependent* dep)
 }
 
 ///
-OSCUpdate::OSCUpdate(const uint8* data, uint32 size)
+bool OSCUpdate::saveToAttributes(Vst::IAttributeList* attrs) const
 {
-    uint8* copy = new uint8[size];
-    std::copy_n(data, size, copy);
-    data_.reset(copy);
-    size_ = size;
+    return attrs->setBinary("Data", data(), size()) == kResultTrue;
+}
+
+bool OSCUpdate::loadFromAttributes(Vst::IAttributeList* attrs)
+{
+    const void* data;
+    uint32 size;
+    if (attrs->getBinary("Data", data, size) != kResultTrue)
+        return false;
+    const uint8* data8 = reinterpret_cast<const uint8*>(data);
+    data_.assign(data8, data8 + size);
+    return true;
 }
 
 ///
diff --git a/plugins/vst/SfizzVstUpdates.h b/plugins/vst/SfizzVstUpdates.h
index d39edcfd..23f8a529 100644
--- a/plugins/vst/SfizzVstUpdates.h
+++ b/plugins/vst/SfizzVstUpdates.h
@@ -6,14 +6,32 @@
 
 #pragma once
 #include "SfizzVstState.h"
+#include <public.sdk/source/vst/vstcomponentbase.h>
+#include <pluginterfaces/vst/ivstmessage.h>
 #include <base/source/fobject.h>
 #include <vector>
 #include <map>
 #include <string>
 #include <memory>
 #include <mutex>
+#include <cstring>
 #include <cstdint>
 
+/**
+ * @brief Update which is convertible with Vst::IMessage back and forth.
+ */
+template <class T> class IConvertibleToMessage {
+public:
+    virtual ~IConvertibleToMessage() {}
+
+    IPtr<Vst::IMessage> convertToMessage(Vst::ComponentBase* sender) const;
+    static IPtr<T> convertFromMessage(Vst::IMessage& message);
+
+protected:
+    virtual bool saveToAttributes(Vst::IAttributeList* attrs) const = 0;
+    virtual bool loadFromAttributes(Vst::IAttributeList* attrs) = 0;
+};
+
 /**
  * @brief Update which notifies a FIFO queue of one-time updates
  */
@@ -37,17 +55,21 @@ private:
 /**
  * @brief Update which notifies a single OSC message
  */
-class OSCUpdate : public Steinberg::FObject {
+class OSCUpdate : public Steinberg::FObject,
+                  public IConvertibleToMessage<OSCUpdate> {
 public:
-    OSCUpdate(const uint8* data, uint32 size);
-    const uint8* data() const noexcept { return data_.get(); }
-    uint32_t size() const noexcept { return size_; }
+    OSCUpdate() = default;
+    OSCUpdate(const uint8* data, uint32 size) : data_(data, data + size) {}
+    const uint8* data() const noexcept { return data_.data(); }
+    uint32_t size() const noexcept { return static_cast<uint32_t>(data_.size()); }
+
+    bool saveToAttributes(Vst::IAttributeList* attrs) const override;
+    bool loadFromAttributes(Vst::IAttributeList* attrs) override;
 
     OBJ_METHODS(OSCUpdate, FObject)
 
 private:
-    std::unique_ptr<uint8[]> data_;
-    uint32 size_ = 0;
+    std::vector<uint8> data_;
 };
 
 /**
@@ -163,3 +185,5 @@ private:
     SfizzPlayState state_ {};
     mutable std::mutex mutex_;
 };
+
+#include "SfizzVstUpdates.hpp"
diff --git a/plugins/vst/SfizzVstUpdates.hpp b/plugins/vst/SfizzVstUpdates.hpp
new file mode 100644
index 00000000..92f7557b
--- /dev/null
+++ b/plugins/vst/SfizzVstUpdates.hpp
@@ -0,0 +1,30 @@
+// SPDX-License-Identifier: BSD-2-Clause
+
+// This code is part of the sfizz library and is licensed under a BSD 2-clause
+// license. You should have receive a LICENSE.md file along with the code.
+// If not, contact the sfizz maintainers at https://github.com/sfztools/sfizz
+
+#pragma once
+#include "SfizzVstUpdates.h"
+
+template <class T>
+IPtr<Vst::IMessage> IConvertibleToMessage<T>::convertToMessage(Vst::ComponentBase* sender) const
+{
+    IPtr<Vst::IMessage> message = owned(sender->allocateMessage());
+    message->setMessageID(static_cast<const T*>(this)->isA());
+    if (!saveToAttributes(message->getAttributes()))
+        return nullptr;
+    return message;
+}
+
+template <class T>
+IPtr<T> IConvertibleToMessage<T>::convertFromMessage(Vst::IMessage& message)
+{
+    IPtr<T> object;
+    if (!strcmp(T::getFClassID(), message.getMessageID())) {
+        object = owned(new T);
+        if (!object->loadFromAttributes(message.getAttributes()))
+            object = nullptr;
+    }
+    return object;
+}