From b294ef47df0ae87c42fe8114987817fb28326f10 Mon Sep 17 00:00:00 2001
From: Mikko Rasa <tdb@tdb.fi>
Date: Mon, 27 Dec 2021 23:26:25 +0200
Subject: [PATCH] Make Buffer::AsyncTransfer default-constructible and
 move-assignable

---
 source/backends/opengl/buffer_backend.cpp |  4 ++--
 source/backends/vulkan/buffer_backend.cpp | 16 ++++++++--------
 source/core/buffer.cpp                    | 17 ++++++++++++++++-
 source/core/buffer.h                      |  4 +++-
 4 files changed, 29 insertions(+), 12 deletions(-)

diff --git a/source/backends/opengl/buffer_backend.cpp b/source/backends/opengl/buffer_backend.cpp
index c5954083..dc081b1c 100644
--- a/source/backends/opengl/buffer_backend.cpp
+++ b/source/backends/opengl/buffer_backend.cpp
@@ -135,12 +135,12 @@ void OpenGLBuffer::unbind_scratch()
 
 void Buffer::AsyncTransfer::allocate()
 {
-	dest_addr = buffer.map();
+	dest_addr = buffer->map();
 }
 
 void Buffer::AsyncTransfer::finalize()
 {
-	buffer.unmap();
+	buffer->unmap();
 }
 
 } // namespace GL
diff --git a/source/backends/vulkan/buffer_backend.cpp b/source/backends/vulkan/buffer_backend.cpp
index aaf41570..750c926b 100644
--- a/source/backends/vulkan/buffer_backend.cpp
+++ b/source/backends/vulkan/buffer_backend.cpp
@@ -110,15 +110,15 @@ void VulkanBuffer::set_vulkan_object_name() const
 
 void Buffer::AsyncTransfer::allocate()
 {
-	if(buffer.can_map())
-		dest_addr = static_cast<char *>(buffer.map())+offset;
+	if(buffer->can_map())
+		dest_addr = static_cast<char *>(buffer->map())+offset;
 	else
 	{
-		Buffer &buf = buffer;
+		Buffer &buf = *buffer;
 		size_t off = offset;
 		size_t sz = size;
 
-		dest_addr = buffer.device.get_transfer_queue().prepare_transfer(&buffer, false, size,
+		dest_addr = buf.device.get_transfer_queue().prepare_transfer(buffer, false, size,
 			[&buf, off, sz](){
 				buf.device.get_synchronizer().write_buffer(buf.handle, off, sz);
 			},
@@ -136,13 +136,13 @@ void Buffer::AsyncTransfer::allocate()
 
 void Buffer::AsyncTransfer::finalize()
 {
-	if(buffer.can_map())
+	if(buffer->can_map())
 	{
-		buffer.unmap();
-		buffer.device.get_synchronizer().write_buffer(buffer.handle, offset, size, true);
+		buffer->unmap();
+		buffer->device.get_synchronizer().write_buffer(buffer->handle, offset, size, true);
 	}
 	else
-		buffer.device.get_transfer_queue().finalize_transfer(dest_addr);
+		buffer->device.get_transfer_queue().finalize_transfer(dest_addr);
 }
 
 } // namespace GL
diff --git a/source/core/buffer.cpp b/source/core/buffer.cpp
index b6f2e44b..d5fc29d1 100644
--- a/source/core/buffer.cpp
+++ b/source/core/buffer.cpp
@@ -76,7 +76,7 @@ bool Buffer::unmap()
 
 
 Buffer::AsyncTransfer::AsyncTransfer(Buffer &b, size_t o, size_t s):
-	buffer(b),
+	buffer(&b),
 	offset(o),
 	size(s),
 	dest_addr(0)
@@ -93,6 +93,21 @@ Buffer::AsyncTransfer::AsyncTransfer(AsyncTransfer &&other):
 	other.dest_addr = 0;
 }
 
+Buffer::AsyncTransfer &Buffer::AsyncTransfer::operator=(AsyncTransfer &&other)
+{
+	if(dest_addr)
+		finalize();
+
+	buffer = other.buffer;
+	offset = other.offset;
+	size = other.size;
+	dest_addr = other.dest_addr;
+
+	other.dest_addr = 0;
+
+	return *this;
+}
+
 Buffer::AsyncTransfer::~AsyncTransfer()
 {
 	if(dest_addr)
diff --git a/source/core/buffer.h b/source/core/buffer.h
index 66eb8d41..9b129361 100644
--- a/source/core/buffer.h
+++ b/source/core/buffer.h
@@ -49,14 +49,16 @@ public:
 		friend class Buffer;
 
 	private:
-		Buffer &buffer;
+		Buffer *buffer = 0;
 		std::size_t offset = 0;
 		std::size_t size = 0;
 		void *dest_addr = 0;
 
 		AsyncTransfer(Buffer &, std::size_t, std::size_t);
 	public:
+		AsyncTransfer() = default;
 		AsyncTransfer(AsyncTransfer &&);
+		AsyncTransfer &operator=(AsyncTransfer &&);
 		~AsyncTransfer();
 
 	private:
-- 
2.43.0