Added Vulkan PC OpenXR Support

runtime/include/vr/openxr_vulkan_win32.h

@@ -0,0 +1,109 @@
+// SPDX-License-Identifier: GPL-3.0-or-later
+
+#pragma once
+
+#if defined(MKW_ENABLE_OPENXR) && defined(_WIN32)
+
+#include "vr/openxr_backend.h"
+#include "vr/openxr_runtime.h"
+
+#include <array>
+#include <cstdint>
+#include <memory>
+#include <string>
+
+namespace mkw::vr {
+
+// Shared frame vocabulary for the Windows pacing and replay paths.
+using OpenXRWindowsVulkanFrameMode = OpenXRFrameMode;
+using OpenXRWindowsVulkanBeginStatus = OpenXRBeginStatus;
+using OpenXRWindowsVulkanSubmissionStatus = OpenXRSubmissionStatus;
+using OpenXRWindowsVulkanPresentation = OpenXRPresentation;
+using OpenXRWindowsVulkanFrame = OpenXRBackendFrame;
+
+struct OpenXRWindowsVulkanGraphicsRequirements {
+    XrVersion min_api_version = 0;
+    XrVersion max_api_version = 0;
+};
+
+// Same-device Dawn/OpenXR Vulkan backend.
+//
+// Startup is deliberately split in two. QueryGraphicsRequirements() runs
+// after OpenXRRuntime::Initialize() but before aurora_initialize(), allowing
+// OpenXR to create Dawn's Vulkan instance/device and select the physical GPU.
+// BindAurora() runs afterwards and checks the device before creating a session.
+//
+// All methods from BeginFrame() through FinishFrame(), plus PollEvents on the
+// associated OpenXRRuntime, belong to one XR pacing thread. Aurora's frame
+// worker never calls OpenXR: its post-submit callback only publishes a token
+// that WaitForSubmission() consumes. This is the synchronization boundary
+// required by the asynchronous sealed-frame renderer.
+class OpenXRWindowsVulkanBackend final {
+public:
+    explicit OpenXRWindowsVulkanBackend(OpenXRLogCallback logger = {});
+    ~OpenXRWindowsVulkanBackend();
+
+    OpenXRWindowsVulkanBackend(const OpenXRWindowsVulkanBackend&) = delete;
+    OpenXRWindowsVulkanBackend& operator=(const OpenXRWindowsVulkanBackend&) = delete;
+    OpenXRWindowsVulkanBackend(OpenXRWindowsVulkanBackend&&) = delete;
+    OpenXRWindowsVulkanBackend& operator=(OpenXRWindowsVulkanBackend&&) = delete;
+
+    bool QueryGraphicsRequirements(OpenXRRuntime& runtime);
+    bool BindAurora(OpenXRRuntime& runtime);
+
+    OpenXRWindowsVulkanBeginStatus BeginFrame(const OpenXRWindowsVulkanPresentation& presentation,
+                                      OpenXRWindowsVulkanFrame& frame);
+
+    // timeout_ms == UINT32_MAX waits until Aurora publishes this token or
+    // Shutdown() interrupts the wait. A timeout does not release XR images;
+    // the caller may keep pacing with RepeatFrame while Aurora still owns them.
+    OpenXRWindowsVulkanSubmissionStatus WaitForSubmission(const OpenXRWindowsVulkanFrame& frame,
+                                                  uint32_t timeout_ms = UINT32_MAX);
+
+    // Withdraws this token only if Aurora has not encoded it. On success no GPU
+    // command can reference the acquired images, and FinishFrame(frame, false)
+    // is required to release them and close the compositor frame.
+    bool TryCancelPendingFrame(OpenXRWindowsVulkanFrame& frame);
+
+    // Ends the current compositor cycle with the last completed layer and starts
+    // another, without releasing or changing Aurora's pending images/render token.
+    // The original render poses remain attached to the pending and retained images.
+    bool RepeatFrame(const OpenXRWindowsVulkanFrame& frame);
+
+    // Releases acquired images and calls xrEndFrame. submit_layer must only be
+    // true after WaitForSubmission returned Success. Immersive frames submit
+    // XrCompositionLayerProjection; virtual-screen frames submit an
+    // XrCompositionLayerQuad using the single mono target, placed as the
+    // presentation's quad_anchored/quad_pose describe. If no new usable layer is
+    // available, resubmits the retained layer using the current display time.
+    bool FinishFrame(OpenXRWindowsVulkanFrame& frame, bool submit_layer);
+
+    // Render-first path when interpolation is off. Aurora renders into acquired
+    // non-retained XR images while no compositor frame is open. BeginFrameForPacket
+    // accepts only a completed packet; CopyRenderedEyes verifies the already queued
+    // bridge copy. FinishFrame releases the images and submits their original poses.
+    OpenXRBeginStatus PreparePacket(const OpenXRPresentation& presentation, OpenXRBackendFrame& packet);
+    bool TryCancelPendingPacket(OpenXRBackendFrame& packet);
+    OpenXRBeginStatus BeginFrameForPacket(const OpenXRBackendFrame& packet, OpenXRBackendFrame& frame);
+    OpenXRSubmissionStatus CopyRenderedEyes(const OpenXRBackendFrame& frame);
+    OpenXRBeginStatus KeepAliveCycle();
+
+    // Call on the XR owner thread after Aurora's worker is idle and before
+    // aurora_shutdown(). Safe to repeat. False means a submitted Vulkan command
+    // could not be fenced; the caller must retain this backend and its runtime
+    // for the process lifetime instead of destroying possibly live resources.
+    bool Shutdown();
+
+    bool IsBound() const;
+    const OpenXRWindowsVulkanGraphicsRequirements& GraphicsRequirements() const;
+    int64_t SwapchainFormat() const;
+    const std::string& LastError() const;
+
+private:
+    class Impl;
+    std::unique_ptr<Impl> m_impl;
+};
+
+} // namespace mkw::vr
+
+#endif // defined(MKW_ENABLE_OPENXR) && defined(_WIN32)