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anyrender_skia: add opt-in Skia Graphite backend for Metal (macOS/iOS) #103

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anyrender_skia: add opt-in Skia Graphite backend for Metal (macOS/iOS) #103

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b2d41ff
anyrender_skia: add opt-in Skia Graphite backend for Metal (macOS/iOS)
nicoburns Sep 29, 2026
ba464c2
anyrender_skia: add SkiaScenePainter::new_graphite
nicoburns Sep 29, 2026
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15 changes: 13 additions & 2 deletions crates/anyrender_skia/Cargo.toml
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Original file line number Diff line number Diff line change
Expand Up @@ -12,7 +12,13 @@ edition.workspace = true
pixels_window_renderer = ["dep:pixels_window_renderer"]
softbuffer_window_renderer = ["dep:softbuffer_window_renderer"]
log_frame_times = ["debug_timer/enable", "pixels_window_renderer?/log_frame_times", "softbuffer_window_renderer?/log_frame_times"]
vulkan = ["skia-safe/vulkan"]
vulkan = ["ganesh", "skia-safe?/vulkan"]
# GPU engines used by the window renderer on macOS/iOS (Linux/Windows always use Ganesh via OpenGL).
# rust-skia only publishes prebuilt binaries with one of these enabled: use
# `default-features = false, features = ["graphite"]` to use Graphite without building Skia from source.
ganesh = ["skia-safe?/ganesh"]
graphite = ["dep:skia-safe"]
default = ["ganesh"]

[dependencies]
anyrender = { workspace = true }
Expand All @@ -22,11 +28,12 @@ peniko = { workspace = true }
raw-window-handle = { workspace = true }
softbuffer_window_renderer = { workspace = true, optional = true }
pixels_window_renderer = { workspace = true, optional = true }
skia-safe = { version = "0.153.3", features = ["gl", "pdf"]}
skia-safe = { version = "0.153.3", features = ["pdf"] }
oaty = "0.2"
hashbrown = "0.17.0"

[target.'cfg(not(any(target_os = "macos", target_os = "ios")))'.dependencies]
skia-safe = { version = "0.153.3", features = ["gl"] }
glutin = { version = "0.32.3", features = ["default", "wgl", "egl"] }
gl = "0.14.0"
ash = "^0.38.0"
Expand All @@ -37,9 +44,13 @@ ash-window = "0.13.0"
skia-safe = { version = "0.153.3", features = ["textlayout"] }

[target.'cfg(target_os = "macos")'.dependencies]
# Optional so that the `graphite` feature only enables Skia's Graphite engine on Apple targets.
skia-safe = { version = "0.153.3", features = ["graphite"], optional = true }
objc2-app-kit = { version = "0.3.2", default-features = false, features = ["objc2-quartz-core", "NSView", "NSResponder"] }

[target.'cfg(target_os = "ios")'.dependencies]
# Optional so that the `graphite` feature only enables Skia's Graphite engine on Apple targets.
skia-safe = { version = "0.153.3", features = ["graphite"], optional = true }
objc2-ui-kit = { version = "0.3.2", default-features = false, features = ["objc2-quartz-core", "UIView", "UIResponder"] }

[target.'cfg(any(target_os = "macos", target_os = "ios"))'.dependencies]
Expand Down
16 changes: 8 additions & 8 deletions crates/anyrender_skia/src/image_renderer.rs
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Expand Up @@ -65,10 +65,10 @@ impl ImageRenderer for SkiaImageRenderer {
// Clear surface with transparent background to allow transparency in rendered images
surface.canvas().clear(Color::TRANSPARENT);

draw_fn(&mut SkiaScenePainter {
inner: surface.canvas(),
cache: &mut self.scene_cache,
});
draw_fn(&mut SkiaScenePainter::new(
surface.canvas(),
&mut self.scene_cache,
));
timer.record_time("render");

self.scene_cache.next_gen();
Expand All @@ -91,10 +91,10 @@ impl ImageRenderer for SkiaImageRenderer {
// Clear surface with transparent background to allow transparency in rendered images
surface.canvas().clear(Color::TRANSPARENT);

draw_fn(&mut SkiaScenePainter {
inner: surface.canvas(),
cache: &mut self.scene_cache,
});
draw_fn(&mut SkiaScenePainter::new(
surface.canvas(),
&mut self.scene_cache,
));
timer.record_time("render");

self.scene_cache.next_gen();
Expand Down
5 changes: 5 additions & 0 deletions crates/anyrender_skia/src/lib.rs
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Expand Up @@ -6,6 +6,11 @@ mod window_renderer;
mod cache;
#[cfg(any(target_os = "macos", target_os = "ios"))]
mod metal;
#[cfg(all(
any(target_os = "macos", target_os = "ios"),
not(any(feature = "ganesh", feature = "graphite"))
))]
compile_error!("anyrender_skia requires the `ganesh` or `graphite` feature on macOS/iOS");
#[cfg(not(any(target_os = "macos", target_os = "ios")))]
mod opengl;
#[cfg(feature = "vulkan")]
Expand Down
193 changes: 54 additions & 139 deletions crates/anyrender_skia/src/metal.rs
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Expand Up @@ -4,151 +4,66 @@ use objc2::{rc::Retained, runtime::ProtocolObject};
#[cfg(target_os = "macos")]
use objc2_app_kit::NSView;
use objc2_core_foundation::CGSize;
use objc2_metal::{MTLCommandBuffer, MTLCommandQueue, MTLCreateSystemDefaultDevice, MTLDevice};
use objc2_quartz_core::{CAMetalDrawable, CAMetalLayer};
use objc2_metal::MTLDevice;
use objc2_quartz_core::CAMetalLayer;
#[cfg(target_os = "ios")]
use objc2_ui_kit::UIView;
use skia_safe::{
ColorType, Surface,
gpu::{self, DirectContext, SurfaceOrigin, backend_render_targets, mtl},
scalar,
};

use crate::window_renderer::SkiaBackend;

pub struct MetalBackend {
pub metal_layer: Retained<CAMetalLayer>,
pub command_queue: Retained<ProtocolObject<dyn MTLCommandQueue>>,
pub skia: DirectContext,
prepared_drawable: Option<Retained<ProtocolObject<dyn objc2_metal::MTLDrawable>>>,
}

impl MetalBackend {
pub fn new(
window: Arc<dyn anyrender::WindowHandle>,
width: u32,
height: u32,
composite_alpha_mode: anyrender::CompositeAlphaMode,
) -> Self {
let device = MTLCreateSystemDefaultDevice().expect("no device found");

let metal_layer = {
let layer = CAMetalLayer::new();
layer.setDevice(Some(&device));
layer.setPixelFormat(objc2_metal::MTLPixelFormat::BGRA8Unorm);
layer.setOpaque(matches!(
composite_alpha_mode,
anyrender::CompositeAlphaMode::Opaque | anyrender::CompositeAlphaMode::Auto
));
layer.setPresentsWithTransaction(false);
// Disabling this option allows Skia's Blend Mode to work.
// More about: https://developer.apple.com/documentation/quartzcore/cametallayer/1478168-framebufferonly
layer.setFramebufferOnly(false);
layer.setDrawableSize(CGSize::new(width as f64, height as f64));

let view_ptr = match window.window_handle().unwrap().as_raw() {
#[cfg(target_os = "macos")]
raw_window_handle::RawWindowHandle::AppKit(appkit) => {
appkit.ns_view.as_ptr() as *mut NSView
}
#[cfg(target_os = "ios")]
raw_window_handle::RawWindowHandle::UiKit(uikit) => {
uikit.ui_view.as_ptr() as *mut UIView
}
_ => panic!("Wrong window handle type"),
};
let view = unsafe { view_ptr.as_ref().unwrap() };

#[cfg(target_os = "macos")]
{
view.setWantsLayer(true);
view.setLayer(Some(&layer.clone().into_super()));
}

#[cfg(target_os = "ios")]
{
// TODO: consider using raw-window-metal crate. It synchronises some properties
// from the parent UIView layer to the child metal layer when they change
layer.setFrame(view.layer().frame());
view.layer().addSublayer(&layer)
}

layer
};

let command_queue = device
.newCommandQueue()
.expect("unable to get command queue");

let backend = unsafe {
mtl::BackendContext::new(
Retained::as_ptr(&device) as mtl::Handle,
Retained::as_ptr(&command_queue) as mtl::Handle,
)
};

let skia_context = gpu::direct_contexts::make_metal(&backend, None).unwrap();

Self {
metal_layer,
command_queue,
skia: skia_context,
prepared_drawable: None,
#[cfg(feature = "ganesh")]
mod ganesh;
#[cfg(feature = "graphite")]
mod graphite;

#[cfg(feature = "ganesh")]
pub(crate) use ganesh::MetalBackend;
#[cfg(feature = "graphite")]
pub(crate) use graphite::MetalGraphiteBackend;

/// Creates a `CAMetalLayer` for `device` and attaches it to the window's view.
fn create_metal_layer(
device: &ProtocolObject<dyn MTLDevice>,
window: Arc<dyn anyrender::WindowHandle>,
width: u32,
height: u32,
composite_alpha_mode: anyrender::CompositeAlphaMode,
) -> Retained<CAMetalLayer> {
let layer = CAMetalLayer::new();
layer.setDevice(Some(device));
layer.setPixelFormat(objc2_metal::MTLPixelFormat::BGRA8Unorm);
layer.setOpaque(matches!(
composite_alpha_mode,
anyrender::CompositeAlphaMode::Opaque | anyrender::CompositeAlphaMode::Auto
));
layer.setPresentsWithTransaction(false);
// Disabling this option allows Skia's Blend Mode to work.
// More about: https://developer.apple.com/documentation/quartzcore/cametallayer/1478168-framebufferonly
layer.setFramebufferOnly(false);
layer.setDrawableSize(CGSize::new(width as f64, height as f64));

let view_ptr = match window.window_handle().unwrap().as_raw() {
#[cfg(target_os = "macos")]
raw_window_handle::RawWindowHandle::AppKit(appkit) => {
appkit.ns_view.as_ptr() as *mut NSView
}
#[cfg(target_os = "ios")]
raw_window_handle::RawWindowHandle::UiKit(uikit) => uikit.ui_view.as_ptr() as *mut UIView,
_ => panic!("Wrong window handle type"),
};
let view = unsafe { view_ptr.as_ref().unwrap() };

#[cfg(target_os = "macos")]
{
view.setWantsLayer(true);
view.setLayer(Some(&layer.clone().into_super()));
}
}

impl SkiaBackend for MetalBackend {
fn set_size(&mut self, width: u32, height: u32) {
self.metal_layer
.setDrawableSize(CGSize::new(width as f64, height as f64));
#[cfg(target_os = "ios")]
{
// TODO: consider using raw-window-metal crate. It synchronises some properties
// from the parent UIView layer to the child metal layer when they change
layer.setFrame(view.layer().frame());
view.layer().addSublayer(&layer)
}

fn prepare(&mut self) -> Option<Surface> {
let drawable = self.metal_layer.nextDrawable()?;

let (drawable_width, drawable_height) = {
let size = self.metal_layer.drawableSize();
(size.width as scalar, size.height as scalar)
};

let surface = {
let texture_info = unsafe {
mtl::TextureInfo::new(Retained::as_ptr(&drawable.texture()) as mtl::Handle)
};

let backend_render_target = backend_render_targets::make_mtl(
(drawable_width as i32, drawable_height as i32),
&texture_info,
);

gpu::surfaces::wrap_backend_render_target(
&mut self.skia,
&backend_render_target,
SurfaceOrigin::TopLeft,
ColorType::BGRA8888,
None,
None,
)
.unwrap()
};

self.prepared_drawable = Some((&drawable).into());

Some(surface)
}

fn flush(&mut self, surface: Surface) {
self.skia.flush_and_submit();
drop(surface);
let command_buffer = self
.command_queue
.commandBuffer()
.expect("unable to get command buffer");

// TODO: save drawable
let drawable = self.prepared_drawable.take().unwrap();
command_buffer.presentDrawable(&drawable);
command_buffer.commit();
}
layer
}
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