Added Android Meta Quest Support

runtime/include/vr/openxr_vulkan.h

@@ -0,0 +1,78 @@
+// SPDX-License-Identifier: GPL-3.0-or-later
+
+#pragma once
+
+#if defined(MKW_ENABLE_OPENXR) && defined(__ANDROID__)
+
+#include "vr/openxr_backend.h"
+#include "vr/openxr_runtime.h"
+
+#include <cstdint>
+#include <memory>
+#include <string>
+
+namespace mkw::vr {
+
+struct OpenXRVulkanGraphicsRequirements {
+    // XR_MAKE_VERSION-encoded bounds reported by xrGetVulkanGraphicsRequirements2KHR.
+    XrVersion min_api_version = 0;
+    XrVersion max_api_version = 0;
+    // Which binding extension was negotiated: XR_KHR_vulkan_enable2 when the
+    // runtime offers it, otherwise the original XR_KHR_vulkan_enable.
+    bool uses_enable2 = false;
+};
+
+// Two-device Dawn/OpenXR Vulkan backend for Android (Meta Quest).
+//
+// Method surface and threading rules are identical to OpenXRD3D12Backend so the
+// pacing thread in openxr_integration.cpp is shared. The difference is behind
+// BindAurora: instead of binding Dawn's device to the session, this backend
+// creates its own VkInstance/VkDevice through the OpenXR runtime, owns a small
+// ring of AHardwareBuffers per eye, and hands them to Aurora's Vulkan stereo
+// bridge (aurora/vulkan_interop.h). When Aurora reports a completed copy, the
+// backend copies the buffer into the acquired XrSwapchain image on the
+// session's queue, so the compositor sees ordinary same-queue rendering.
+//
+// QueryGraphicsRequirements() runs after OpenXRRuntime::Initialize() and before
+// aurora_initialize(); BindAurora() runs afterwards, while Aurora's frame worker
+// is idle. Everything from BeginFrame() through FinishFrame() belongs to one XR
+// pacing thread; the Aurora callback only records a small copy on this
+// backend's private queue and publishes a token.
+class OpenXRVulkanBackend final {
+public:
+    explicit OpenXRVulkanBackend(OpenXRLogCallback logger = {});
+    ~OpenXRVulkanBackend();
+
+    OpenXRVulkanBackend(const OpenXRVulkanBackend&) = delete;
+    OpenXRVulkanBackend& operator=(const OpenXRVulkanBackend&) = delete;
+    OpenXRVulkanBackend(OpenXRVulkanBackend&&) = delete;
+    OpenXRVulkanBackend& operator=(OpenXRVulkanBackend&&) = delete;
+
+    bool QueryGraphicsRequirements(OpenXRRuntime& runtime);
+    bool BindAurora(OpenXRRuntime& runtime);
+
+    OpenXRBeginStatus BeginFrame(const OpenXRPresentation& presentation, OpenXRBackendFrame& frame);
+    OpenXRSubmissionStatus WaitForSubmission(const OpenXRBackendFrame& frame,
+                                             uint32_t timeout_ms = UINT32_MAX);
+    bool TryCancelPendingFrame(OpenXRBackendFrame& frame);
+    bool RepeatFrame(const OpenXRBackendFrame& frame);
+    bool FinishFrame(OpenXRBackendFrame& frame, bool submit_layer);
+
+    // Drains this backend's own queue before tearing down. Returns false only
+    // when the private device could not be waited on, in which case the caller
+    // retains the backend and runtime for the process lifetime.
+    bool Shutdown();
+
+    bool IsBound() const;
+    const OpenXRVulkanGraphicsRequirements& 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(__ANDROID__)