From 707967ac1dbfaa2594001325c8e7be1dd149fad8 Mon Sep 17 00:00:00 2001
From: Philip Rebohle <philip.rebohle@tu-dortmund.de>
Date: Fri, 18 May 2018 16:46:34 +0200
Subject: [PATCH] [vr] Add OpenVR loader

Provides methods to query required Vulkan instance and device extensions.
---
 src/dxvk/dxvk_openvr.cpp | 87 ++++++++++++++++++++++++++++++++++++++++
 src/dxvk/dxvk_openvr.h   | 48 ++++++++++++++++++++++
 src/dxvk/meson.build     |  1 +
 3 files changed, 136 insertions(+)
 create mode 100644 src/dxvk/dxvk_openvr.cpp
 create mode 100644 src/dxvk/dxvk_openvr.h

diff --git a/src/dxvk/dxvk_openvr.cpp b/src/dxvk/dxvk_openvr.cpp
new file mode 100644
index 00000000..73812839
--- /dev/null
+++ b/src/dxvk/dxvk_openvr.cpp
@@ -0,0 +1,87 @@
+#include "dxvk_openvr.h"
+
+#include <openvr/openvr.hpp>
+
+namespace dxvk {
+  
+  VrInstance::VrInstance()
+  : m_compositor(getCompositor()) {
+    
+  }
+  
+  
+  VrInstance::~VrInstance() {
+    
+  }
+  
+  
+  vk::NameSet VrInstance::queryInstanceExtensions() const {
+    if (m_compositor != nullptr) {
+      uint32_t len = m_compositor->GetVulkanInstanceExtensionsRequired(nullptr, 0);
+      std::vector<char> extensionList(len);
+      len = m_compositor->GetVulkanInstanceExtensionsRequired(extensionList.data(), len);
+      return parseExtensionList(std::string(extensionList.data(), len));
+    } return vk::NameSet();
+  }
+  
+  
+  vk::NameSet VrInstance::queryDeviceExtensions(VkPhysicalDevice adapter) const {
+    if (m_compositor != nullptr) {
+      uint32_t len = m_compositor->GetVulkanDeviceExtensionsRequired(adapter, nullptr, 0);
+      std::vector<char> extensionList(len);
+      len = m_compositor->GetVulkanDeviceExtensionsRequired(adapter, extensionList.data(), len);
+      return parseExtensionList(std::string(extensionList.data(), len));
+    } return vk::NameSet();
+  }
+  
+  
+  vk::NameSet VrInstance::parseExtensionList(const std::string& str) {
+    vk::NameSet result;
+    
+    std::stringstream strstream(str);
+    std::string       section;
+    
+    while (std::getline(strstream, section, ' '))
+      result.add(section);
+    
+    return result;
+  }
+  
+  
+  vr::IVRCompositor* VrInstance::getCompositor() {
+    using GetGenericInterfaceProc = 
+      void* VR_CALLTYPE (*)(const char*, vr::EVRInitError*);
+    
+    // Locate the OpenVR DLL if loaded by the process
+    HMODULE ovrApi = ::GetModuleHandle("openvr_api.dll");
+    
+    if (ovrApi == nullptr) {
+      Logger::warn("OpenVR: Failed to locate module");
+      return nullptr;
+    }
+    
+    // Load method used to retrieve the IVRCompositor interface
+    auto vrGetGenericInterface = reinterpret_cast<GetGenericInterfaceProc>(
+      ::GetProcAddress(ovrApi, "VR_GetGenericInterface"));
+    
+    if (vrGetGenericInterface == nullptr) {
+      Logger::warn("OpenVR: VR_GetGenericInterface not found");
+      return nullptr;
+    }
+    
+    // Retrieve the compositor interface
+    vr::EVRInitError error = vr::VRInitError_None;
+    
+    auto compositor = reinterpret_cast<vr::IVRCompositor*>(
+      vrGetGenericInterface(vr::IVRCompositor_Version, &error));
+    
+    if (error != vr::VRInitError_None) {
+      Logger::warn(str::format("OpenVR: Failed to retrieve ", vr::IVRCompositor_Version));
+      return nullptr;
+    }
+    
+    Logger::warn("OpenVR: Compositor interface found");
+    return compositor;
+  }
+  
+}
\ No newline at end of file
diff --git a/src/dxvk/dxvk_openvr.h b/src/dxvk/dxvk_openvr.h
new file mode 100644
index 00000000..acb61f81
--- /dev/null
+++ b/src/dxvk/dxvk_openvr.h
@@ -0,0 +1,48 @@
+#pragma once
+
+#include "dxvk_include.h"
+
+namespace vr {
+  class IVRCompositor;
+}
+
+namespace dxvk {
+  
+  /**
+   * \brief OpenVR instance
+   * 
+   * Loads Initializes OpenVR to provide
+   * access to Vulkan extension queries.
+   */
+  class VrInstance {
+    
+  public:
+    
+    VrInstance();
+    ~VrInstance();
+    
+    /**
+     * \brief Queries required instance extensions
+     * \returns Set of required instance extensions
+     */
+    vk::NameSet queryInstanceExtensions() const;
+    
+    /**
+     * \brief Queries required device extensions
+     * 
+     * \param [in] adapter The Vulkan device to query
+     * \returns Set of required device extensions
+     */
+    vk::NameSet queryDeviceExtensions(VkPhysicalDevice adapter) const;
+    
+  private:
+    
+    vr::IVRCompositor* m_compositor = nullptr;
+    
+    static vk::NameSet parseExtensionList(const std::string& str);
+    
+    static vr::IVRCompositor* getCompositor();
+    
+  };
+  
+}
\ No newline at end of file
diff --git a/src/dxvk/meson.build b/src/dxvk/meson.build
index 1c563df9..02bf5cf9 100644
--- a/src/dxvk/meson.build
+++ b/src/dxvk/meson.build
@@ -42,6 +42,7 @@ dxvk_src = files([
   'dxvk_memory.cpp',
   'dxvk_meta_clear.cpp',
   'dxvk_meta_resolve.cpp',
+  'dxvk_openvr.cpp',
   'dxvk_pipecache.cpp',
   'dxvk_pipecompiler.cpp',
   'dxvk_pipelayout.cpp',