From ca5902c111be8aec2f7861d0282dcdd077276096 Mon Sep 17 00:00:00 2001
From: Ben Vanik <ben.vanik@gmail.com>
Date: Wed, 17 Feb 2016 19:43:42 -0800
Subject: [PATCH] Recreate swap chain on window resize.

---
 src/xenia/ui/vulkan/vulkan_context.cc    | 11 ++++
 src/xenia/ui/vulkan/vulkan_swap_chain.cc | 67 +++++++++++++++---------
 src/xenia/ui/vulkan/vulkan_swap_chain.h  |  8 +++
 3 files changed, 61 insertions(+), 25 deletions(-)

diff --git a/src/xenia/ui/vulkan/vulkan_context.cc b/src/xenia/ui/vulkan/vulkan_context.cc
index 5d82f4f46..9dd9c7d58 100644
--- a/src/xenia/ui/vulkan/vulkan_context.cc
+++ b/src/xenia/ui/vulkan/vulkan_context.cc
@@ -115,6 +115,17 @@ void VulkanContext::BeginSwap() {
   auto provider = static_cast<VulkanProvider*>(provider_);
   auto device = provider->device();
 
+  // If we have a window see if it's been resized since we last swapped.
+  // If it has been, we'll need to reinitialize the swap chain before we
+  // start touching it.
+  if (target_window_) {
+    if (target_window_->width() != swap_chain_->surface_width() ||
+        target_window_->height() != swap_chain_->surface_height()) {
+      // Resized!
+      swap_chain_->Reinitialize();
+    }
+  }
+
   // Acquire the next image and set it up for use.
   swap_chain_->Begin();
 
diff --git a/src/xenia/ui/vulkan/vulkan_swap_chain.cc b/src/xenia/ui/vulkan/vulkan_swap_chain.cc
index ec640d92f..cb088bb75 100644
--- a/src/xenia/ui/vulkan/vulkan_swap_chain.cc
+++ b/src/xenia/ui/vulkan/vulkan_swap_chain.cc
@@ -32,31 +32,7 @@ namespace vulkan {
 VulkanSwapChain::VulkanSwapChain(VulkanInstance* instance, VulkanDevice* device)
     : instance_(instance), device_(device) {}
 
-VulkanSwapChain::~VulkanSwapChain() {
-  for (auto& buffer : buffers_) {
-    DestroyBuffer(&buffer);
-  }
-  if (image_available_semaphore_) {
-    vkDestroySemaphore(*device_, image_available_semaphore_, nullptr);
-  }
-  if (render_pass_) {
-    vkDestroyRenderPass(*device_, render_pass_, nullptr);
-  }
-  if (render_cmd_buffer_) {
-    vkFreeCommandBuffers(*device_, cmd_pool_, 1, &render_cmd_buffer_);
-  }
-  if (cmd_pool_) {
-    vkDestroyCommandPool(*device_, cmd_pool_, nullptr);
-  }
-  // images_ doesn't need to be cleaned up as the swapchain does it implicitly.
-  if (handle) {
-    vkDestroySwapchainKHR(*device_, handle, nullptr);
-    handle = nullptr;
-  }
-  if (surface_) {
-    vkDestroySurfaceKHR(*instance_, surface_, nullptr);
-  }
-}
+VulkanSwapChain::~VulkanSwapChain() { Shutdown(); }
 
 bool VulkanSwapChain::Initialize(VkSurfaceKHR surface) {
   surface_ = surface;
@@ -338,6 +314,47 @@ void VulkanSwapChain::DestroyBuffer(Buffer* buffer) {
   buffer->image = nullptr;
 }
 
+bool VulkanSwapChain::Reinitialize() {
+  // Hacky, but stash the surface so we can reuse it.
+  auto surface = surface_;
+  surface_ = nullptr;
+  Shutdown();
+  return Initialize(surface);
+}
+
+void VulkanSwapChain::Shutdown() {
+  // TODO(benvanik): properly wait for a clean state.
+  for (auto& buffer : buffers_) {
+    DestroyBuffer(&buffer);
+  }
+  buffers_.clear();
+  if (image_available_semaphore_) {
+    vkDestroySemaphore(*device_, image_available_semaphore_, nullptr);
+    image_available_semaphore_ = nullptr;
+  }
+  if (render_pass_) {
+    vkDestroyRenderPass(*device_, render_pass_, nullptr);
+    render_pass_ = nullptr;
+  }
+  if (render_cmd_buffer_) {
+    vkFreeCommandBuffers(*device_, cmd_pool_, 1, &render_cmd_buffer_);
+    render_cmd_buffer_ = nullptr;
+  }
+  if (cmd_pool_) {
+    vkDestroyCommandPool(*device_, cmd_pool_, nullptr);
+    cmd_pool_ = nullptr;
+  }
+  // images_ doesn't need to be cleaned up as the swapchain does it implicitly.
+  if (handle) {
+    vkDestroySwapchainKHR(*device_, handle, nullptr);
+    handle = nullptr;
+  }
+  if (surface_) {
+    vkDestroySurfaceKHR(*instance_, surface_, nullptr);
+    surface_ = nullptr;
+  }
+}
+
 bool VulkanSwapChain::Begin() {
   // Get the index of the next available swapchain image.
   auto err =
diff --git a/src/xenia/ui/vulkan/vulkan_swap_chain.h b/src/xenia/ui/vulkan/vulkan_swap_chain.h
index 18bb26cee..1d1f578c3 100644
--- a/src/xenia/ui/vulkan/vulkan_swap_chain.h
+++ b/src/xenia/ui/vulkan/vulkan_swap_chain.h
@@ -41,7 +41,12 @@ class VulkanSwapChain {
   // Render command buffer, active inside the render pass from Begin to End.
   VkCommandBuffer render_cmd_buffer() const { return render_cmd_buffer_; }
 
+  // Initializes the swap chain with the given WSI surface.
   bool Initialize(VkSurfaceKHR surface);
+  // Reinitializes the swap chain with the initial surface.
+  // The surface will be retained but all other swap chain resources will be
+  // torn down and recreated with the new surface properties (size/etc).
+  bool Reinitialize();
 
   // Begins the swap operation, preparing state for rendering.
   bool Begin();
@@ -58,6 +63,9 @@ class VulkanSwapChain {
   bool InitializeBuffer(Buffer* buffer, VkImage target_image);
   void DestroyBuffer(Buffer* buffer);
 
+  // Safely releases all swap chain resources.
+  void Shutdown();
+
   VulkanInstance* instance_ = nullptr;
   VulkanDevice* device_ = nullptr;