The renderer was effectively single-buffered despite allocating
triple-buffered infrastructure: Render() ended with an unconditional
vkQueueWaitIdle, and a single (presentComplete, renderComplete)
semaphore pair with zero fences was shared for the Window's lifetime.
Rework the pacing model so up to numFrames frames overlap:
- Per-swapchain-image VkFence, signaled by the submit and waited+reset
before that image's command buffer / descriptor-heap slot is
re-recorded. Keyed by acquired image index (drawCmdBuffers, the heap
slots, and the swapchain images are all image-indexed — see
WriteSwapchainDescriptors). Created signaled so first use passes.
- Per-image render-finished (present) semaphore: the presentation engine
holds it until the image is re-acquired, so per-image is the only safe
key (per-CPU-frame trips VUID-vkQueueSubmit-pSignalSemaphores-00067).
- Per-CPU-frame acquire semaphores (image index unknown until acquire
returns), sized numFrames+1: in-flight depth is bounded by the
per-image fences, so numFrames+1 distinct acquire semaphores guarantee
the reused one has no pending op (VUID-vkAcquireNextImageKHR-01779).
- Drop the steady-state vkQueueWaitIdle; keep it on resize / OUT_OF_DATE
/ teardown.
Add tests/FrameLoopSync: drives the real frame loop against a live
Wayland compositor for 60 frames (>> in-flight slots) and asserts the
CPU frame counter advanced, the swapchain rotated across multiple
images, and the validation layer stayed silent — the load-bearing check,
since the old single-pair design only avoided being an active race
because the wait-idle masked it.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Window::onMouseScroll now fires on every backend and speaks one unit:
signed whole detents packed in the uint32 payload, +1 = wheel down
(DOM deltaY sign).
- Wayland: implement the previously-stubbed PointerListenerHandleAxis —
vertical axis only, wl_fixed_to_double / 15 (libinput's units-per-
detent), sub-detent remainder accumulated and reset on pointer leave.
- Win32: add the missing WM_MOUSEWHEEL case — -GET_WHEEL_DELTA_WPARAM /
WHEEL_DELTA with a remainder accumulator for free-spinning wheels.
- DOM: dom-env.js normalizes WheelEvent.deltaY per deltaMode (100px /
3 lines / 1 page per detent) with the same remainder scheme, so wasm
delivers the identical unit instead of raw browser-specific deltas.
- Document the contract on Window::onMouseScroll.
- tests/MouseScroll: compositor-free regression test driving the
Wayland axis handler directly.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Two Vulkan validation errors fired on startup of every native (Vulkan)
example, reported in #5:
1. vkCreateDevice enabledLayerCount != 0. Device layers are deprecated
and ignored since Vulkan 1.0; passing them is a spec violation
(VUID-VkDeviceCreateInfo-enabledLayerCount-12384). The device-layer
enumeration/match block in Device::Initialize is removed and
enabledLayerCount is pinned to 0 — layers are enabled at the instance
only.
2. vkQueueSubmit layout transition on a presentable image that "has not
been acquired". StartInit() and RecreateSwapchainAndImages() eagerly
transitioned every swapchain image UNDEFINED -> PRESENT_SRC_KHR before
any vkAcquireNextImageKHR, which the spec forbids (a presentable image
may only be touched after acquire). Those pre-transitions are removed.
Each image's first layout transition now happens lazily in Render(),
after acquire, from UNDEFINED; subsequent frames transition from
PRESENT_SRC_KHR. A per-image `imageInitialised` flag (reset in
CreateSwapchain) selects the correct oldLayout.
Verified under sway (headless, GPU renderer) + VK_LAYER_KHRONOS_validation:
the original code reproduces both errors on HelloUI; the fixed build emits
zero validation messages across initial render and swapchain recreation.
Resolves#5
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
