From 0c6d0de3ab90024ca6b02dd83bf0e64931ff47e2 Mon Sep 17 00:00:00 2001
From: Magnus Norddahl <dpjudas@users.noreply.github.com>
Date: Sat, 23 Mar 2019 14:58:37 +0100
Subject: [PATCH] - do not use persistent buffers for models as it is a limited
 resource where each consumes a vkDeviceMemory object

---
 src/rendering/vulkan/system/vk_buffers.cpp | 20 +++++++++++++++++---
 src/rendering/vulkan/system/vk_buffers.h   |  2 ++
 2 files changed, 19 insertions(+), 3 deletions(-)

diff --git a/src/rendering/vulkan/system/vk_buffers.cpp b/src/rendering/vulkan/system/vk_buffers.cpp
index 79d5af4f1..c5a3d780d 100644
--- a/src/rendering/vulkan/system/vk_buffers.cpp
+++ b/src/rendering/vulkan/system/vk_buffers.cpp
@@ -110,15 +110,29 @@ void VKBuffer::Unmap()
 
 void *VKBuffer::Lock(unsigned int size)
 {
-	SetData(size, nullptr, false);
-	if (!mPersistent)
+	if (!mBuffer)
+	{
+		// The model mesh loaders lock multiple non-persistent buffers at the same time. This is not allowed in vulkan.
+		// VkDeviceMemory can only be mapped once and multiple non-persistent buffers may come from the same device memory object.
+		mStaticUpload.Resize(size);
+		map = mStaticUpload.Data();
+	}
+	else if (!mPersistent)
+	{
 		map = mBuffer->Map(0, size);
+	}
 	return map;
 }
 
 void VKBuffer::Unlock()
 {
-	if (!mPersistent)
+	if (!mBuffer)
+	{
+		map = nullptr;
+		SetData(mStaticUpload.Size(), mStaticUpload.Data(), true);
+		mStaticUpload.Clear();
+	}
+	else if (!mPersistent)
 	{
 		mBuffer->Unmap();
 		map = nullptr;
diff --git a/src/rendering/vulkan/system/vk_buffers.h b/src/rendering/vulkan/system/vk_buffers.h
index 139924bc3..0477f1b68 100644
--- a/src/rendering/vulkan/system/vk_buffers.h
+++ b/src/rendering/vulkan/system/vk_buffers.h
@@ -2,6 +2,7 @@
 
 #include "hwrenderer/data/buffers.h"
 #include "vk_objects.h"
+#include "utility/tarray.h"
 
 #ifdef _MSC_VER
 // silence bogus warning C4250: 'VKVertexBuffer': inherits 'VKBuffer::VKBuffer::SetData' via dominance
@@ -28,6 +29,7 @@ public:
 	std::unique_ptr<VulkanBuffer> mBuffer;
 	std::unique_ptr<VulkanBuffer> mStaging;
 	bool mPersistent = false;
+	TArray<uint8_t> mStaticUpload;
 };
 
 class VKVertexBuffer : public IVertexBuffer, public VKBuffer