dtourolle
a8043e6827
With Skia drawing pre-rotated on wgpu's Vulkan swapchain, Android no longer needs to draw with Skia over OpenGL, which was the only reason the develop view read its frame back through memory (TD-1). So `unstable-wgpu-29` moves back to the common slint dependency. The android-activity backend then builds `SkiaRenderer::default_wgpu_29`, and `shared_gpu` loses its Android arm. The one wgpu device is handed to Slint through `BackendSelector::require_wgpu_29` on both platforms. `slint::android::init_with_event_listener` runs before `dr_ui::run`, so the selector reaches the Android adapter before its window exists. `renderer-femtovg-wgpu` stays desktop-only, since Android has no FemtoVG. The two `#[cfg(target_os = "android")]` readbacks in `develop::render` (the frame through `export_pixels` and the focus overlay through `read_overlay`) are gone. `read_overlay` stays for the tests that check what the overlay marks. Built for arm64 and release-signed. Not yet run on the tablet.
833 lines
33 KiB
Rust
833 lines
33 KiB
Rust
//! TRACES: NFR-PORT-2
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//! GPU device and compute for DarkRoom.
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//!
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//! It began as a spike proving one thing — that a compute shader can write a
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//! texture reaching the screen without a CPU round-trip (ARCH §6.1) — and the
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//! module doc said for eight releases that it held no pipeline and no masks.
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//! It holds both now, plus demosaic, detail, segmentation masks, two
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//! histograms and focus peaking. The zero-copy claim is still the one that
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//! matters, and since TD-1 was paid off it holds on Android too.
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//!
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//! Deliberately free of UI dependencies (ARCH §6.5a). The texture is handed
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//! out as a `wgpu::Texture`; who composites it is not this crate's concern.
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//!
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//! That independence is why [`GpuContext::new_shared`] hands back the raw
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//! instance and adapter rather than talking to a compositor itself: the
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//! compositor will only sample a texture that came from the device *it* draws
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//! with, so somebody has to make one device for both — but it does not have to
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//! be this crate, and this crate must not know who it is.
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use std::sync::Arc;
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use wgpu::util::DeviceExt;
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mod adjust;
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mod demosaic;
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mod detail;
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mod error;
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mod focus;
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mod histogram;
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mod mask;
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mod merge;
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mod raw_histogram;
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mod readback;
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mod segment;
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pub use adjust::AdjustPass;
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// The format the neighbourhood stage works in. Public because it is a promise
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// rather than an implementation detail: a detail pass is guaranteed linear,
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// unclipped, full internal precision (FR-DEV-2), and anyone reasoning about
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// VRAM at 24 MP needs to know what an intermediate costs.
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pub use demosaic::{DemosaicedImage, Demosaicer};
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pub use detail::INTERMEDIATE_FORMAT as DETAIL_INTERMEDIATE_FORMAT;
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pub use error::GpuError;
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pub use focus::{FocusPeakPass, FocusPeaking, PeakColour, PeakSensitivity};
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pub use merge::{Band, MergeFrame, MergeOutput, MergePass};
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// Renamed on the way out: `BINS` says enough inside `histogram`, and nothing
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// at all at a crate root shared with demosaic and segmentation.
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pub use histogram::{Histogram, HistogramPass, BINS as HISTOGRAM_BINS};
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pub use mask::{LabelField, MaskArray, MaskPass, SubjectMasks};
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// Renamed on the way out on the same terms as the display histogram's
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// constants above, and kept distinct from them because the two axes are
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// different quantities: one counts output code values, the other counts stops
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// below sensor saturation. A caller that confused them would draw a correct
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// plot against the wrong scale.
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pub use raw_histogram::{
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RawHistogram, RawHistogramPass, BINS as RAW_HISTOGRAM_BINS,
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BINS_PER_STOP as RAW_HISTOGRAM_BINS_PER_STOP, STOPS as RAW_HISTOGRAM_STOPS,
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};
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pub use segment::{SegmentOptions, SegmentPass, Segmentation};
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/// Owns the wgpu device and queue.
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///
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/// One device is shared by the compute pipeline and the UI, which is what
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/// allows compositing with no interop layer. Cloning is cheap and shares the
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/// same underlying device.
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#[derive(Clone)]
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pub struct GpuContext {
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pub device: Arc<wgpu::Device>,
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pub queue: Arc<wgpu::Queue>,
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adapter_info: wgpu::AdapterInfo,
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}
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/// TRACES: FR-DSP-1 | AC-8
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/// One device, opened so that a compositor can be made to share it.
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///
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/// The texture the adjust pass writes only reaches the screen without a copy
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/// if the compositor is drawing with the *same* `wgpu::Device` — two devices
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/// are two address spaces, and a texture from one is not a texture the other
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/// can sample. So the device cannot be an implementation detail of either
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/// side; it has to be made once and handed to both.
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///
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/// [`Self::ctx`] is what the compute passes want. The instance and adapter are
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/// what a compositor wants in order to adopt the same setup — Slint's
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/// `WGPUConfiguration::Manual` asks for all four pieces — and they are handed
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/// out raw rather than wrapped, because naming Slint here would put a UI
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/// dependency in the one crate that must not have one (ARCH §6.5a).
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pub struct SharedGpu {
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/// The context every compute pass in this crate runs on.
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pub ctx: GpuContext,
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/// The instance the compositor will create its window surface from.
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pub instance: wgpu::Instance,
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/// The adapter [`Self::ctx`]'s device came from.
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pub adapter: wgpu::Adapter,
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}
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/// TRACES: FR-DSP-1 | NFR-RES-4
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/// Which GPU to prefer, on a machine with more than one.
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///
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/// **Not obviously the fastest one**, which is why this is a choice rather
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/// than a constant. A discrete card wins on raw compute and loses on every
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/// byte that has to reach it: a 24 MP frame is ~96 MB of RGBA, and each
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/// upload and each export readback crosses PCIe. An integrated GPU shares
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/// memory with the CPU, so those transfers are not transfers. It also does not
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/// empty a laptop battery.
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///
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/// Which of those dominates depends on the work — a slider drag over a
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/// resident texture is compute-bound and favours the discrete card, while
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/// import, export and thumbnailing are transfer-heavy — so the honest thing is
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/// to let it be set rather than to assume.
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#[derive(Debug, Clone, Copy, PartialEq, Eq, Default)]
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pub enum AdapterPreference {
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/// The most capable GPU. What this has always done, and the default: it is
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/// the right answer for interactive editing, which is the frame budget
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/// that FR-DSP-3 actually measures.
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#[default]
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Performance,
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/// An integrated GPU where there is one — shared memory, no bus crossing,
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/// and far less power.
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Efficiency,
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}
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impl AdapterPreference {
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/// Read the override, defaulting to [`Performance`](Self::Performance).
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///
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/// An environment variable rather than a setting, *for now*: this belongs
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/// on the settings page beside the cache budget, and putting it there
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/// needs a control and a restart prompt, because the device is opened once
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/// at startup and shared with the compositor. The variable is what makes
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/// the choice testable and gives someone with a broken primary GPU a way
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/// out today.
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pub fn from_env() -> Self {
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match std::env::var("DARKROOM_GPU").as_deref() {
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Ok("integrated") | Ok("efficiency") | Ok("igpu") => Self::Efficiency,
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_ => Self::Performance,
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}
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}
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/// How much we want an adapter, lowest first.
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///
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/// A CPU adapter sorts last under both policies rather than being
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/// excluded: software rendering is a poor experience and a working one,
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/// and on a machine where every real GPU has failed it is the difference
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/// between a slow editor and no editor.
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fn rank(self, device_type: wgpu::DeviceType) -> u8 {
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use wgpu::DeviceType as D;
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match (self, device_type) {
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(_, D::Cpu) => 4,
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(Self::Performance, D::DiscreteGpu) => 0,
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(Self::Performance, D::IntegratedGpu) => 1,
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(Self::Efficiency, D::IntegratedGpu) => 0,
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(Self::Efficiency, D::DiscreteGpu) => 1,
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(_, D::VirtualGpu) => 2,
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(_, D::Other) => 3,
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}
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}
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}
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impl GpuContext {
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/// Create a headless context — no surface, no window.
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///
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/// Used by tests, by the examples, and by anything that only needs to
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/// compute. A context opened this way cannot be shared with a compositor:
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/// see [`Self::new_shared`] for that, and for why the difference matters.
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pub async fn new_headless() -> Result<Self, GpuError> {
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// GL is allowed alongside Vulkan here and nowhere else: a machine with
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// no Vulkan loader should still run the tests, and a headless context
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// never has to produce a window surface — which is precisely the thing
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// the GL backend cannot do from an instance opened without a display
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// handle.
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Self::open(wgpu::Backends::VULKAN | wgpu::Backends::GL)
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.await
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.map(|shared| shared.ctx)
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}
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/// TRACES: FR-DSP-1 | AC-8
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/// Open a device intended to be shared with the compositor.
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///
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/// Vulkan only, unlike [`Self::new_headless`]. The caller will hand the
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/// instance to a compositor that has to create a *window surface* from it,
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/// and wgpu's GL backend reaches its display through EGL at instance
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/// creation — an instance opened without a display handle, which is the
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/// only kind available before a window exists, cannot then produce a GL
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/// surface. Vulkan takes the window handle at surface creation instead, so
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/// it is the only backend this order of operations permits.
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///
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/// A machine with no Vulkan therefore gets no shared device, and the
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/// caller is expected to carry on without the develop path rather than
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/// refuse to start.
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pub async fn new_shared() -> Result<SharedGpu, GpuError> {
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// Vulkan on both targets (D1), and here it is not merely the
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// preference — see above.
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Self::open(wgpu::Backends::VULKAN).await
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}
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/// TRACES: FR-DSP-1 | NFR-R1
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/// Open a device, trying every adapter rather than only the best one.
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///
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/// # Why this is not `request_adapter`
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///
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/// `request_adapter` with `HighPerformance` returns *one* adapter and no
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/// second chance. That is the right answer on a healthy machine and the
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/// wrong one on a machine with a sick GPU, which is not a rare state:
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/// observed 2026-08-29 on a laptop whose discrete card had hit an NVRM
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/// assertion failure and a fullchip reset. The driver still advertised the
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/// adapter, `request_adapter` dutifully picked it as the highest
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/// performing, and the process died on it — while a working integrated GPU
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/// and a working external card sat unused in the same enumeration.
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///
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/// A photo editor that will not start because the *fastest* GPU is broken,
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/// on a machine holding two that are not, is worse than a slow one.
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///
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/// So: enumerate, order by how much we want each, and take the first that
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/// actually yields a device. The ordering reproduces what
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/// `HighPerformance` means — discrete, then integrated, then anything —
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/// so the healthy case picks exactly what it picked before and pays one
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/// extra enumeration for it.
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///
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/// # What this cannot do
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///
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/// A GPU sick enough to accept `request_device` and fail later is still
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/// fatal, because the failure arrives as a segfault inside the driver
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/// rather than as an error we could catch. This moves the boundary from
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/// "the preferred adapter is unusable" to "the preferred adapter is
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/// unusable *and* dishonest about it"; it does not remove it. Device loss
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/// after a successful open is a different problem with a different answer
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/// (ARCH §5.6).
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async fn open(backends: wgpu::Backends) -> Result<SharedGpu, GpuError> {
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// `new_without_display_handle` rather than a struct literal: the
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// descriptor carries a boxed display handle and so has no `Default`,
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// and there is no window yet to take one from in either case.
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let mut descriptor = wgpu::InstanceDescriptor::new_without_display_handle();
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descriptor.backends = backends;
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let instance = wgpu::Instance::new(descriptor);
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let mut adapters: Vec<wgpu::Adapter> = instance.enumerate_adapters(backends).await;
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if adapters.is_empty() {
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return Err(GpuError::NoAdapter);
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}
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let policy = AdapterPreference::from_env();
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adapters.sort_by_key(|a| policy.rank(a.get_info().device_type));
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// Kept so a total failure can say what it tried. "No suitable GPU
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// adapter found" on a machine with three of them sends the reader to
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// look for a driver that is installed and loaded.
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let mut refusals: Vec<String> = Vec::new();
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for adapter in adapters {
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let adapter_info = adapter.get_info();
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match Self::device_from(&adapter).await {
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Ok((device, queue)) => {
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log::info!(
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"gpu: {} ({:?}, {:?})",
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adapter_info.name,
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adapter_info.device_type,
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adapter_info.backend
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);
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if !refusals.is_empty() {
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// At `info`, not `debug`: the user is now running on
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// their second-choice GPU and any performance
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// complaint that follows begins here.
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log::info!(
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"gpu: fell back after {} unusable adapter(s): {}",
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refusals.len(),
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refusals.join("; ")
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);
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}
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return Ok(SharedGpu {
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ctx: Self {
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device: Arc::new(device),
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queue: Arc::new(queue),
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adapter_info,
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},
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instance,
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adapter,
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});
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}
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Err(e) => refusals.push(format!("{} ({e})", adapter_info.name)),
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}
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}
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Err(GpuError::DeviceRequest(format!(
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"every adapter refused a device: {}",
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refusals.join("; ")
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)))
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}
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/// TRACES: NFR-COMPAT-1
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/// Ask one adapter for a device, with the limits the pipeline needs.
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async fn device_from(adapter: &wgpu::Adapter) -> Result<(wgpu::Device, wgpu::Queue), GpuError> {
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adapter
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.request_device(&wgpu::DeviceDescriptor {
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label: Some("darkroom-device"),
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required_features: wgpu::Features::empty(),
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// Defaults, not `downlevel_defaults`: storage textures
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// in compute shaders are required, and the downlevel tier
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// does not guarantee them. This is effectively our GPU
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// floor (NFR-COMPAT-1).
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//
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// `using_resolution` raises only the texture-dimension limits,
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// to whatever this adapter actually offers. That matters once
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// a compositor shares this device: the default ceiling is
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// 8192, and a swapchain image for a large or scaled display
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// can exceed it — a limit we chose for our own compute passes
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// would otherwise silently cap somebody else's window.
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required_limits: wgpu::Limits::default().using_resolution(adapter.limits()),
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memory_hints: wgpu::MemoryHints::Performance,
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// Nothing behind a feature flag wgpu itself calls unstable —
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// the pipeline is ordinary compute and storage textures.
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experimental_features: wgpu::ExperimentalFeatures::disabled(),
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// The API trace, absorbed into the descriptor in wgpu 25 from
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// the second argument this call used to take.
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trace: wgpu::Trace::Off,
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})
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.await
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.map_err(|e| GpuError::DeviceRequest(e.to_string()))
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}
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/// Build a context from a device and queue owned by someone else — the
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/// path used when Slint has already created them.
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pub fn from_parts(
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device: Arc<wgpu::Device>,
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queue: Arc<wgpu::Queue>,
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adapter_info: wgpu::AdapterInfo,
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) -> Self {
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Self {
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device,
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queue,
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adapter_info,
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}
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}
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pub fn adapter_name(&self) -> &str {
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&self.adapter_info.name
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}
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pub fn backend(&self) -> wgpu::Backend {
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self.adapter_info.backend
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}
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/// TRACES: NFR-OPS-1
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/// The driver, as the adapter reported it, for a diagnostics bundle.
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/// Name and version in one string because wgpu splits them by backend
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/// and neither half means much without the other.
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pub fn driver(&self) -> String {
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let info = &self.adapter_info;
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match (info.driver.is_empty(), info.driver_info.is_empty()) {
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(true, true) => "unknown driver".to_string(),
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(false, true) => info.driver.clone(),
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(true, false) => info.driver_info.clone(),
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(false, false) => format!("{} {}", info.driver, info.driver_info),
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}
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}
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}
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#[repr(C)]
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#[derive(Copy, Clone, Debug, bytemuck::Pod, bytemuck::Zeroable)]
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struct Params {
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width: u32,
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height: u32,
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phase: f32,
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_pad: f32,
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}
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/// A compute pass writing into a storage texture.
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///
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/// Stands in for the develop pipeline in v0.1. What matters is the shape:
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/// compute writes a texture, the texture is handed to the compositor, and
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/// pixels never travel back through the CPU.
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/// TRACES: FR-DEV-4 | R4
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pub struct RenderTarget {
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ctx: GpuContext,
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texture: wgpu::Texture,
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view: wgpu::TextureView,
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pipeline: wgpu::ComputePipeline,
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bind_group_layout: wgpu::BindGroupLayout,
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bind_group: wgpu::BindGroup,
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params_buf: wgpu::Buffer,
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width: u32,
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height: u32,
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/// Reused staging buffer for the temporary readback path. Allocating one
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/// per frame is a significant cost at large window sizes.
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#[cfg(any(test, feature = "readback"))]
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readback_buf: std::cell::RefCell<Option<(wgpu::Buffer, u32)>>,
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}
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impl RenderTarget {
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pub const FORMAT: wgpu::TextureFormat = wgpu::TextureFormat::Rgba8Unorm;
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pub fn new(ctx: &GpuContext, width: u32, height: u32) -> Result<Self, GpuError> {
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let (width, height) = (width.max(1), height.max(1));
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let shader = ctx
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.device
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.create_shader_module(wgpu::ShaderModuleDescriptor {
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label: Some("gradient"),
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source: wgpu::ShaderSource::Wgsl(include_str!("shaders/gradient.wgsl").into()),
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});
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let bind_group_layout =
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ctx.device
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.create_bind_group_layout(&wgpu::BindGroupLayoutDescriptor {
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label: Some("render-target-bgl"),
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entries: &[
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wgpu::BindGroupLayoutEntry {
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binding: 0,
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visibility: wgpu::ShaderStages::COMPUTE,
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ty: wgpu::BindingType::StorageTexture {
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access: wgpu::StorageTextureAccess::WriteOnly,
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format: Self::FORMAT,
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view_dimension: wgpu::TextureViewDimension::D2,
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},
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count: None,
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},
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wgpu::BindGroupLayoutEntry {
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binding: 1,
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visibility: wgpu::ShaderStages::COMPUTE,
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ty: wgpu::BindingType::Buffer {
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ty: wgpu::BufferBindingType::Uniform,
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has_dynamic_offset: false,
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min_binding_size: None,
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},
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count: None,
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},
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],
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});
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let layout = ctx
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.device
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.create_pipeline_layout(&wgpu::PipelineLayoutDescriptor {
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label: Some("render-target-layout"),
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bind_group_layouts: &[Some(&bind_group_layout)],
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immediate_size: 0,
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});
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let pipeline = ctx
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.device
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.create_compute_pipeline(&wgpu::ComputePipelineDescriptor {
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label: Some("gradient-pipeline"),
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layout: Some(&layout),
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module: &shader,
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entry_point: Some("main"),
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compilation_options: Default::default(),
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cache: None,
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});
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let params_buf = ctx
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.device
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.create_buffer_init(&wgpu::util::BufferInitDescriptor {
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label: Some("params"),
|
|
contents: bytemuck::bytes_of(&Params {
|
|
width,
|
|
height,
|
|
phase: 0.0,
|
|
_pad: 0.0,
|
|
}),
|
|
usage: wgpu::BufferUsages::UNIFORM | wgpu::BufferUsages::COPY_DST,
|
|
});
|
|
|
|
let (texture, view) = Self::create_texture(ctx, width, height);
|
|
let bind_group = Self::create_bind_group(ctx, &bind_group_layout, &view, ¶ms_buf);
|
|
|
|
Ok(Self {
|
|
ctx: ctx.clone(),
|
|
texture,
|
|
view,
|
|
pipeline,
|
|
bind_group_layout,
|
|
bind_group,
|
|
params_buf,
|
|
width,
|
|
height,
|
|
#[cfg(any(test, feature = "readback"))]
|
|
readback_buf: std::cell::RefCell::new(None),
|
|
})
|
|
}
|
|
|
|
fn create_texture(
|
|
ctx: &GpuContext,
|
|
width: u32,
|
|
height: u32,
|
|
) -> (wgpu::Texture, wgpu::TextureView) {
|
|
let texture = ctx.device.create_texture(&wgpu::TextureDescriptor {
|
|
label: Some("render-target"),
|
|
size: wgpu::Extent3d {
|
|
width,
|
|
height,
|
|
depth_or_array_layers: 1,
|
|
},
|
|
mip_level_count: 1,
|
|
sample_count: 1,
|
|
dimension: wgpu::TextureDimension::D2,
|
|
format: Self::FORMAT,
|
|
// STORAGE_BINDING to write from compute; TEXTURE_BINDING so the
|
|
// compositor can sample it. COPY_SRC exists only for tests —
|
|
// production never reads this back (ARCH §6.1).
|
|
//
|
|
// RENDER_ATTACHMENT is not something this pass ever uses. It is
|
|
// there because Slint refuses to import a texture without it
|
|
// (`TextureImportError::InvalidUsage`), the compositor having to
|
|
// assume it may need to draw into what it was given. Declaring an
|
|
// unused capability costs an allocation flag and buys the whole
|
|
// zero-copy path, so it is a cheap price for AC-8.
|
|
usage: wgpu::TextureUsages::STORAGE_BINDING
|
|
| wgpu::TextureUsages::TEXTURE_BINDING
|
|
| wgpu::TextureUsages::RENDER_ATTACHMENT
|
|
| wgpu::TextureUsages::COPY_SRC,
|
|
view_formats: &[],
|
|
});
|
|
let view = texture.create_view(&Default::default());
|
|
(texture, view)
|
|
}
|
|
|
|
fn create_bind_group(
|
|
ctx: &GpuContext,
|
|
layout: &wgpu::BindGroupLayout,
|
|
view: &wgpu::TextureView,
|
|
params: &wgpu::Buffer,
|
|
) -> wgpu::BindGroup {
|
|
ctx.device.create_bind_group(&wgpu::BindGroupDescriptor {
|
|
label: Some("render-target-bg"),
|
|
layout,
|
|
entries: &[
|
|
wgpu::BindGroupEntry {
|
|
binding: 0,
|
|
resource: wgpu::BindingResource::TextureView(view),
|
|
},
|
|
wgpu::BindGroupEntry {
|
|
binding: 1,
|
|
resource: params.as_entire_binding(),
|
|
},
|
|
],
|
|
})
|
|
}
|
|
|
|
/// Resize, reallocating the texture. No-op when unchanged.
|
|
pub fn resize(&mut self, width: u32, height: u32) {
|
|
let (width, height) = (width.max(1), height.max(1));
|
|
if width == self.width && height == self.height {
|
|
return;
|
|
}
|
|
let (texture, view) = Self::create_texture(&self.ctx, width, height);
|
|
self.bind_group =
|
|
Self::create_bind_group(&self.ctx, &self.bind_group_layout, &view, &self.params_buf);
|
|
self.texture = texture;
|
|
self.view = view;
|
|
self.width = width;
|
|
self.height = height;
|
|
#[cfg(any(test, feature = "readback"))]
|
|
{
|
|
// Size changed, so the staging buffer no longer fits.
|
|
*self.readback_buf.borrow_mut() = None;
|
|
}
|
|
}
|
|
|
|
/// Run the compute pass. Results stay on the GPU.
|
|
pub fn render(&self, phase: f32) {
|
|
self.ctx.queue.write_buffer(
|
|
&self.params_buf,
|
|
0,
|
|
bytemuck::bytes_of(&Params {
|
|
width: self.width,
|
|
height: self.height,
|
|
phase,
|
|
_pad: 0.0,
|
|
}),
|
|
);
|
|
|
|
let mut enc = self
|
|
.ctx
|
|
.device
|
|
.create_command_encoder(&wgpu::CommandEncoderDescriptor {
|
|
label: Some("render-encoder"),
|
|
});
|
|
{
|
|
let mut pass = enc.begin_compute_pass(&wgpu::ComputePassDescriptor {
|
|
label: Some("gradient-pass"),
|
|
timestamp_writes: None,
|
|
});
|
|
pass.set_pipeline(&self.pipeline);
|
|
pass.set_bind_group(0, &self.bind_group, &[]);
|
|
// 8x8 workgroups, rounded up so edge pixels are covered.
|
|
pass.dispatch_workgroups(self.width.div_ceil(8), self.height.div_ceil(8), 1);
|
|
}
|
|
self.ctx.queue.submit(Some(enc.finish()));
|
|
}
|
|
|
|
pub fn texture(&self) -> &wgpu::Texture {
|
|
&self.texture
|
|
}
|
|
|
|
pub fn view(&self) -> &wgpu::TextureView {
|
|
&self.view
|
|
}
|
|
|
|
pub fn size(&self) -> (u32, u32) {
|
|
(self.width, self.height)
|
|
}
|
|
|
|
/// Read pixels back to the CPU.
|
|
///
|
|
/// **Tests only.** Production code must never call this — it is exactly
|
|
/// the round-trip ARCH §6.1 forbids, and AC-8 asserts it does not happen.
|
|
#[cfg(any(test, feature = "readback"))]
|
|
pub async fn read_pixels(&self) -> Result<Vec<u8>, GpuError> {
|
|
// Buffer rows must be aligned to COPY_BYTES_PER_ROW_ALIGNMENT (256).
|
|
let unpadded = self.width * 4;
|
|
let align = wgpu::COPY_BYTES_PER_ROW_ALIGNMENT;
|
|
let padded = unpadded.div_ceil(align) * align;
|
|
|
|
let needed = (padded * self.height) as u64;
|
|
let mut slot = self.readback_buf.borrow_mut();
|
|
if slot.as_ref().map(|(_, p)| *p) != Some(padded) {
|
|
*slot = Some((
|
|
self.ctx.device.create_buffer(&wgpu::BufferDescriptor {
|
|
label: Some("readback"),
|
|
size: needed,
|
|
usage: wgpu::BufferUsages::COPY_DST | wgpu::BufferUsages::MAP_READ,
|
|
mapped_at_creation: false,
|
|
}),
|
|
padded,
|
|
));
|
|
}
|
|
let buf = &slot.as_ref().unwrap().0;
|
|
|
|
let mut enc = self.ctx.device.create_command_encoder(&Default::default());
|
|
enc.copy_texture_to_buffer(
|
|
wgpu::TexelCopyTextureInfo {
|
|
texture: &self.texture,
|
|
mip_level: 0,
|
|
origin: wgpu::Origin3d::ZERO,
|
|
aspect: wgpu::TextureAspect::All,
|
|
},
|
|
wgpu::TexelCopyBufferInfo {
|
|
buffer: buf,
|
|
layout: wgpu::TexelCopyBufferLayout {
|
|
offset: 0,
|
|
bytes_per_row: Some(padded),
|
|
rows_per_image: Some(self.height),
|
|
},
|
|
},
|
|
wgpu::Extent3d {
|
|
width: self.width,
|
|
height: self.height,
|
|
depth_or_array_layers: 1,
|
|
},
|
|
);
|
|
self.ctx.queue.submit(Some(enc.finish()));
|
|
|
|
let slice = buf.slice(..);
|
|
let (tx, rx) = std::sync::mpsc::channel();
|
|
slice.map_async(wgpu::MapMode::Read, move |r| {
|
|
let _ = tx.send(r);
|
|
});
|
|
// Fallible since wgpu 26, and worth propagating rather than ignoring:
|
|
// the failure it reports is a lost device (NFR-R7), and without this
|
|
// the map callback below simply never arrives and the error surfaces
|
|
// as a timeout somewhere less informative.
|
|
self.ctx
|
|
.device
|
|
.poll(wgpu::PollType::wait_indefinitely())
|
|
.map_err(|e| GpuError::Readback(e.to_string()))?;
|
|
rx.recv()
|
|
.map_err(|e| GpuError::Readback(e.to_string()))?
|
|
.map_err(|e| GpuError::Readback(e.to_string()))?;
|
|
|
|
// Strip row padding.
|
|
let data = slice.get_mapped_range();
|
|
let mut out = Vec::with_capacity((unpadded * self.height) as usize);
|
|
for row in 0..self.height {
|
|
let start = (row * padded) as usize;
|
|
out.extend_from_slice(&data[start..start + unpadded as usize]);
|
|
}
|
|
drop(data);
|
|
buf.unmap();
|
|
Ok(out)
|
|
}
|
|
}
|
|
|
|
#[cfg(test)]
|
|
mod tests {
|
|
use super::*;
|
|
|
|
fn ctx() -> Option<GpuContext> {
|
|
// CI runners and headless machines may have no usable adapter. Skip
|
|
// rather than fail — the device-dependent assertions still run
|
|
// wherever a GPU exists.
|
|
match pollster::block_on(GpuContext::new_headless()) {
|
|
Ok(c) => Some(c),
|
|
Err(e) => {
|
|
eprintln!("skipping: no GPU adapter ({e})");
|
|
None
|
|
}
|
|
}
|
|
}
|
|
|
|
#[test]
|
|
fn compute_writes_the_texture() {
|
|
let Some(ctx) = ctx() else { return };
|
|
let rt = RenderTarget::new(&ctx, 64, 64).expect("render target");
|
|
rt.render(0.0);
|
|
|
|
let px = pollster::block_on(rt.read_pixels()).expect("readback");
|
|
assert_eq!(px.len(), 64 * 64 * 4);
|
|
|
|
// The shader writes opaque pixels everywhere; an all-zero buffer would
|
|
// mean the dispatch silently did nothing.
|
|
assert!(
|
|
px.chunks_exact(4).all(|p| p[3] == 255),
|
|
"every pixel should be opaque"
|
|
);
|
|
assert!(
|
|
px.iter().any(|&b| b != 0),
|
|
"texture should not be uniformly zero"
|
|
);
|
|
}
|
|
|
|
#[test]
|
|
fn phase_changes_output() {
|
|
let Some(ctx) = ctx() else { return };
|
|
let rt = RenderTarget::new(&ctx, 32, 32).expect("render target");
|
|
|
|
rt.render(0.0);
|
|
let a = pollster::block_on(rt.read_pixels()).expect("readback");
|
|
rt.render(std::f32::consts::PI);
|
|
let b = pollster::block_on(rt.read_pixels()).expect("readback");
|
|
|
|
assert_ne!(a, b, "moving the highlight should change the image");
|
|
}
|
|
|
|
#[test]
|
|
fn resize_reallocates() {
|
|
let Some(ctx) = ctx() else { return };
|
|
let mut rt = RenderTarget::new(&ctx, 16, 16).expect("render target");
|
|
assert_eq!(rt.size(), (16, 16));
|
|
|
|
rt.resize(48, 24);
|
|
assert_eq!(rt.size(), (48, 24));
|
|
|
|
rt.render(0.0);
|
|
let px = pollster::block_on(rt.read_pixels()).expect("readback");
|
|
assert_eq!(px.len(), 48 * 24 * 4);
|
|
}
|
|
|
|
#[test]
|
|
fn zero_size_is_clamped() {
|
|
let Some(ctx) = ctx() else { return };
|
|
// A minimised window reports zero; texture creation would panic.
|
|
let rt = RenderTarget::new(&ctx, 0, 0).expect("render target");
|
|
assert_eq!(rt.size(), (1, 1));
|
|
}
|
|
}
|
|
|
|
#[cfg(test)]
|
|
mod adapter_choice_tests {
|
|
//! Which GPU gets picked, and what happens when it will not open.
|
|
//!
|
|
//! These are about the *ordering*, which is pure — opening a device needs
|
|
//! hardware and is covered by every other test in this crate implicitly.
|
|
|
|
use super::*;
|
|
|
|
/// Only the two fields the ordering reads are set; the rest come from
|
|
/// `Default`, so a wgpu upgrade that adds another does not break this.
|
|
/// The order adapters would be tried in, named so a failure reads as the
|
|
/// hardware it stands for.
|
|
fn order(policy: AdapterPreference, mut gpus: Vec<(&str, wgpu::DeviceType)>) -> Vec<&str> {
|
|
gpus.sort_by_key(|(_, t)| policy.rank(*t));
|
|
gpus.into_iter().map(|(name, _)| name).collect()
|
|
}
|
|
|
|
fn a_laptop() -> Vec<(&'static str, wgpu::DeviceType)> {
|
|
vec![
|
|
("Iris Xe", wgpu::DeviceType::IntegratedGpu),
|
|
("RTX 3050", wgpu::DeviceType::DiscreteGpu),
|
|
("llvmpipe", wgpu::DeviceType::Cpu),
|
|
]
|
|
}
|
|
|
|
#[test]
|
|
fn performance_takes_the_discrete_card() {
|
|
// What this has always done, and what an interactive slider drag wants:
|
|
// the texture is already resident, so the work is compute and the bus
|
|
// does not come into it.
|
|
assert_eq!(
|
|
order(AdapterPreference::Performance, a_laptop()),
|
|
["RTX 3050", "Iris Xe", "llvmpipe"]
|
|
);
|
|
}
|
|
|
|
#[test]
|
|
fn efficiency_takes_the_integrated_one() {
|
|
// Shared memory, so a 96 MB frame upload is not a transfer, and a
|
|
// laptop battery that lasts. The discrete card stays as the fallback
|
|
// rather than being excluded.
|
|
assert_eq!(
|
|
order(AdapterPreference::Efficiency, a_laptop()),
|
|
["Iris Xe", "RTX 3050", "llvmpipe"]
|
|
);
|
|
}
|
|
|
|
#[test]
|
|
fn software_rendering_is_last_but_never_dropped() {
|
|
// On a machine where every real GPU has failed this is the difference
|
|
// between a slow editor and no editor.
|
|
for policy in [
|
|
AdapterPreference::Performance,
|
|
AdapterPreference::Efficiency,
|
|
] {
|
|
assert_eq!(
|
|
*order(policy, a_laptop()).last().unwrap(),
|
|
"llvmpipe",
|
|
"{policy:?}"
|
|
);
|
|
}
|
|
}
|
|
|
|
#[test]
|
|
fn a_machine_with_one_gpu_is_unaffected_by_the_policy() {
|
|
// The common case: no choice to make, and no behaviour to change.
|
|
let one = vec![("Iris Xe", wgpu::DeviceType::IntegratedGpu)];
|
|
assert_eq!(
|
|
order(AdapterPreference::Performance, one.clone()),
|
|
order(AdapterPreference::Efficiency, one)
|
|
);
|
|
}
|
|
|
|
#[test]
|
|
fn the_default_is_what_it_did_before() {
|
|
// Changing which GPU an existing user lands on is not something to do
|
|
// by accident.
|
|
assert_eq!(AdapterPreference::default(), AdapterPreference::Performance);
|
|
}
|
|
}
|