gallery/vendor/i-slint-renderer-skia/wgpu_29_surface/dx12.rs
Greg Pomerantz 93b27d724b Root-cause and fix the Mali scroll jank; strip jank-hunt instrumentation
The 19-26 ms mid-scroll stalls (Mali-only, fixed content offsets) were
the Skia renderer's final synchronous GrDirectContext::flush() blocking
the UI thread on Mali driver back-pressure — proven by per-stage
timestamps in the vendored renderer (stall frames: flush 19-24 ms,
walk 1-3 ms, 1 binding re-eval, image imports 0.1 ms each).

- vendor/i-slint-renderer-skia (pinned 1.18.1, [patch.crates-io]):
  remove that one flush. Redundant on the wgpu backend: the surface
  already calls flush_and_submit before queue.present, same Vulkan
  queue, in-order. Phone: 0 stalls across 4 runs (max 3.6-7.4 ms vs
  the 8.3 ms budget), display verified clean.
- docs/BUGS/slint-skia-final-flush-jank.md: full evidence, prior art
  (slint-ui/slint#12030 closest), open question for a future
  upstream filing (not filed yet).
- Profiling also retired the O(n)-walk theory: Slint 1.18 prunes the
  item walk to ~133-152 items; the windowed Flickable built on that
  theory was already reverted (ListView is smooth with the fix).
- Strip all jank-hunt instrumentation: FR/SCR/TICK/APLYD/STG logging,
  stg markers, .gallery_* file knobs, jsamp thread sampler,
  DbgScroll programmatic scroll, nblog perf-file mirroring.
  Also fixes the 'launches into unstoppable fast scroll' bug: a
  leftover .gallery_cmd was re-read on every launch (file never
  deleted) and overrode user swipes — the hook is gone.
- Keep: nblog (logd backpressure is real), zero-dimension decode
  guards, keep-alive (default-off).
- HANDOFF: replace stale windowed-Flickable section with the actual
  root cause/fix; 15 unit tests pass.

Verified on phone (aarch64, 8580 photos) and emulator (x86_64).
2026-10-28 18:23:50 -04:00

177 lines
6.6 KiB
Rust

// Copyright © SixtyFPS GmbH <info@slint.dev>
// SPDX-License-Identifier: GPL-3.0-only OR LicenseRef-Slint-Royalty-free-2.0 OR LicenseRef-Slint-Software-3.0
use windows::Win32::Graphics::Direct3D12::{D3D12_RESOURCE_STATE_PRESENT, ID3D12Resource};
use windows::Win32::Graphics::Dxgi::Common::DXGI_STANDARD_MULTISAMPLE_QUALITY_PATTERN;
use windows::Win32::Graphics::Dxgi::Common::{
DXGI_FORMAT_B8G8R8A8_UNORM, DXGI_FORMAT_R8G8B8A8_UNORM, DXGI_FORMAT_R8G8B8A8_UNORM_SRGB,
};
use wgpu_29 as wgpu;
/// # Safety
/// `resource` must be a valid D3D12 resource for the lifetime of the returned Surface.
unsafe fn wrap_dx12_texture(
width: i32,
height: i32,
gr_context: &mut skia_safe::gpu::DirectContext,
resource: ID3D12Resource,
dxgi_format: windows::Win32::Graphics::Dxgi::Common::DXGI_FORMAT,
color_type: skia_safe::ColorType,
color_space: skia_safe::ColorSpace,
) -> Option<skia_safe::Surface> {
let texture_info = skia_safe::gpu::d3d::TextureResourceInfo {
resource,
alloc: None,
resource_state: D3D12_RESOURCE_STATE_PRESENT,
format: dxgi_format,
sample_count: 1,
level_count: 1,
sample_quality_pattern: DXGI_STANDARD_MULTISAMPLE_QUALITY_PATTERN,
protected: skia_safe::gpu::Protected::No,
};
let backend_render_target =
skia_safe::gpu::backend_render_targets::make_d3d((width, height), &texture_info);
skia_safe::gpu::surfaces::wrap_backend_render_target(
gr_context,
&backend_render_target,
skia_safe::gpu::SurfaceOrigin::TopLeft,
color_type,
color_space,
None,
)
}
/// # Safety
/// The caller must ensure `texture` was created by a DX12-backed wgpu device and remains
/// valid for the lifetime of the returned `skia_safe::Surface`.
pub unsafe fn make_dx12_surface(
gr_context: &mut skia_safe::gpu::DirectContext,
texture: &wgpu::Texture,
) -> Option<skia_safe::Surface> {
// SAFETY: texture is borrowed for the duration of this call; the D3D12 resource is
// ref-counted (COM) and cloned into Skia's internal BackendRenderTarget via wrap_dx12_texture.
unsafe {
let dx12_texture = texture.as_hal::<wgpu::wgc::api::Dx12>()?;
let resource = windows_core::Interface::from_raw(windows_core::Interface::into_raw(
dx12_texture.raw_resource().clone(),
));
let size = texture.size();
let (dxgi_format, color_type) = match texture.format() {
wgpu::TextureFormat::Rgba8Unorm => {
(DXGI_FORMAT_R8G8B8A8_UNORM, skia_safe::ColorType::RGBA8888)
}
wgpu::TextureFormat::Rgba8UnormSrgb => {
(DXGI_FORMAT_R8G8B8A8_UNORM_SRGB, skia_safe::ColorType::SRGBA8888)
}
wgpu::TextureFormat::Bgra8Unorm => {
(DXGI_FORMAT_B8G8R8A8_UNORM, skia_safe::ColorType::BGRA8888)
}
_ => return None,
};
wrap_dx12_texture(
size.width as i32,
size.height as i32,
gr_context,
resource,
dxgi_format,
color_type,
super::attachment_color_space(texture),
)
}
}
#[cfg_attr(not(feature = "unstable-wgpu-29"), allow(dead_code))]
#[allow(non_snake_case)]
pub unsafe fn import_dx12_texture(
canvas: &skia_safe::Canvas,
texture: wgpu::Texture,
) -> Option<skia_safe::Image> {
unsafe {
let color_space = super::sampled_texture_color_space(&texture);
let dx12_texture = texture.as_hal::<wgpu::wgc::api::Dx12>();
let resource: ID3D12Resource = windows_core::Interface::from_raw(
windows_core::Interface::into_raw(dx12_texture.unwrap().raw_resource().clone()),
);
let dxgi_texture_format = resource.GetDesc().Format;
let color_type = match dxgi_texture_format {
DXGI_FORMAT_R8G8B8A8_UNORM => skia_safe::ColorType::RGBA8888,
DXGI_FORMAT_R8G8B8A8_UNORM_SRGB => skia_safe::ColorType::SRGBA8888,
DXGI_FORMAT_B8G8R8A8_UNORM => skia_safe::ColorType::BGRA8888,
_ => return None,
};
let texture_info = skia_safe::gpu::d3d::TextureResourceInfo {
resource,
alloc: None,
resource_state: D3D12_RESOURCE_STATE_PRESENT,
format: dxgi_texture_format,
sample_count: 1,
level_count: 1,
sample_quality_pattern: DXGI_STANDARD_MULTISAMPLE_QUALITY_PATTERN,
protected: skia_safe::gpu::Protected::No,
};
let size = texture.size();
let backend_texture = skia_safe::gpu::backend_textures::make_d3d(
(size.width as i32, size.height as i32),
&texture_info,
"slint_imported_wgpu_texture",
);
Some(
skia_safe::image::Image::from_texture(
canvas.recording_context().as_mut().unwrap(),
&backend_texture,
skia_safe::gpu::SurfaceOrigin::TopLeft,
color_type,
skia_safe::AlphaType::Unpremul,
color_space,
)
.unwrap(),
)
}
}
pub unsafe fn make_dx12_context(
adapter: &wgpu::Adapter,
_device: &wgpu::Device,
queue: &wgpu::Queue,
) -> Option<skia_safe::gpu::DirectContext> {
let backend = unsafe {
let maybe_dx12_queue = queue.as_hal::<wgpu::wgc::api::Dx12>();
let dx12_adapter = adapter.as_hal::<wgpu::wgc::api::Dx12>().unwrap();
maybe_dx12_queue.map(|dx12_queue| {
let dx12_queue_raw = dx12_queue.as_raw();
let mut dx12_device_old: Option<windows::Win32::Graphics::Direct3D12::ID3D12Device> =
None;
dx12_queue_raw.GetDevice(&mut dx12_device_old as _).unwrap();
let dx12_device_old = dx12_device_old.unwrap();
let dx12_device = windows_core::Interface::from_raw(windows_core::Interface::into_raw(
dx12_device_old,
));
let idxgiadapter_3: windows::Win32::Graphics::Dxgi::IDXGIAdapter3 =
dx12_adapter.as_raw().clone().into();
skia_safe::gpu::d3d::BackendContext {
adapter: windows_core::Interface::from_raw(windows_core::Interface::into_raw(
idxgiadapter_3,
)),
device: dx12_device,
queue: windows_core::Interface::from_raw(windows_core::Interface::into_raw(
dx12_queue_raw.clone(),
)),
memory_allocator: None,
protected_context: skia_safe::gpu::Protected::No,
}
})
};
unsafe { skia_safe::gpu::direct_contexts::make_d3d(&backend.unwrap(), None) }
}