Lepton's Vulkan driver has no external memory or sync fd extensions,
so the Steam Frame gets a native SteamOS build instead. Its backend is
the PC's: OpenXR creates Dawn's own Vulkan instance and device, and the
eyes are copied into the swapchain on Dawn's queue, with nothing shared
between devices.
- openxr_vulkan_win32 and Aurora's vulkan_win32_interop now compile on
desktop Linux. Dawn links statically there, so the bridge calls the
patched package's hooks directly, and exists only when the package's
aurora-dawn.json declares the Vulkan hook ABI (AuroraDawnProvider
turns AuroraVulkanAbi into AURORA_DAWN_VULKAN_HOOKS); a stock Dawn
keeps the stubs and VR falls back to the desktop.
- openxr_integration.cpp gains a Linux branch: XR_KHR_vulkan_enable2,
the timespec clock, refresh rate, performance level, the Frame
controllers and eye gaze; fragment density maps are requested on
Linux as on the Quest (fdm.cpp and gpu.cpp, AURORA_FDM=0/1 overrides).
- Controller motion uses XR_KHR_convert_timespec_time on any Linux.
- CMake: Vulkan headers are fetched for Linux OpenXR builds, the
headset option is MKW_HEADSET on Android and Linux, and Linux aarch64
builds take MKW_LINUX_CPU (cortex-x4 for the Steam Frame, else native).
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_019HBRGKTE1GnN2ah8gcZKr3
- Added SetRenderScale method to both D3D12 and Vulkan backends to adjust the render scale dynamically.
- Updated eye size calculations to reflect the new render scale in both backends.
- Implemented ResizeWritablePair method to handle resizing of swapchains based on the requested eye sizes.
- Modified BeginFrame methods to ensure swapchains are resized appropriately before rendering.
- Enhanced error handling to maintain current eye sizes when the requested sizes cannot be allocated.
- Added tests to validate render scale functionality, ensuring correct behavior when scaling up and down, including handling of refused sizes.
The panel was drawn into the eye images, so below a 1.00x OpenXR
resolution its 1440x1080 canvas was minified into a small eye region and
the text became hard to read. It is now submitted as a quad layer of its
own over the scene's projection or menu quad, which the compositor samples
directly at any render scale.
Each backend (D3D12, Windows Vulkan, Quest) makes the panel's swapchain
pair (plus two shared buffers on the Quest) the first time the panel
opens. While it is open, the frame hands Aurora one more stereo target
after the eyes, which the bridge fills with the panel texture or a
transparent image. The panel image follows the eyes' displayed/retained
pairing, so a cancelled frame never shows an unwritten panel. The quad
hangs where the pointer's hits are tested. Aurora leaves the panel out of
the eyes in layer mode, and a backend that cannot make the layer falls
back to drawing it into the eyes.
On the Quest, debug.wiicompiled.panel_layer 0 selects the old path at
run time. Measured there at a race start (render_scale 0.8), the layer
costs nothing while the panel is closed; while it is open, app GPU time is
10.5 ms against 9.7 ms drawn into the eyes, with unchanged frame rates.
The replay tests cover lazy creation, cancelled frames, closed and
unplaced panels, and render-first pacing on D3D12 and Windows Vulkan.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude