🤘 metal: Migrate to objc2 architecture with objc2-metal bindings

.github/workflows/ci.yml

@@ -69,15 +69,6 @@ jobs:
         uses: dtolnay/rust-toolchain@nightly
       - name: Generate lockfile with minimal dependency versions
         run: cargo +nightly generate-lockfile -Zminimal-versions
-      - name: Bump `libc 0.1` version to `0.2` via `malloc_buf 0.0.6`
-        if: ${{ runner.os == 'macOS' }}
-        run: |
-          # The 7-year-unmaintained malloc_buf (depended on via metal-rs->objc)
-          # only allows using libc 0.2 since the 0.0.6 release, which is necessary
-          # since the libc 0.1 range no longer compiles.  Fortunately objc which
-          # is also unmaintained for 4 years depends on malloc_buf >=0.0,<0.1.0,
-          # allowing the 0.0.6 release to be used (but not the 1.0.0 release).
-          cargo update -p malloc_buf --precise 0.0.6
       - name: Cargo clippy with minimal-versions
         run: cargo +stable clippy --workspace --features ${{ matrix.features }} --no-default-features -- -D warnings
 

Cargo.toml

@@ -33,8 +33,18 @@ ash = { version = "0.38", optional = true, default-features = false, features =
 egui = { version = ">=0.24, <=0.27", optional = true, default-features = false }
 egui_extras = { version = ">=0.24, <=0.27", optional = true, default-features = false }
 
-[target.'cfg(any(target_os = "macos", target_os = "ios"))'.dependencies]
-metal = { version = "0.29.0", default-features = false, features = ["link", "dispatch"], optional = true }
+[target.'cfg(target_vendor = "apple")'.dependencies]
+objc2 = { version = "0.5.2", default-features = false, optional = true }
+objc2-foundation = { version = "0.2", default-features = false, optional = true }
+objc2-metal = { version = "0.2.1", default-features = false, features = [
+    "MTLAccelerationStructure",
+    "MTLBuffer",
+    "MTLDevice",
+    "MTLHeap",
+    "MTLResource",
+    "MTLTexture",
+    "std",
+], optional = true }
 
 [target.'cfg(windows)'.dependencies]
 # Only needed for public-winapi interop helpers
@@ -65,6 +75,11 @@ features = [
     "Win32_Graphics_Dxgi_Common",
 ]
 
+[target.'cfg(target_vendor = "apple")'.dev-dependencies]
+objc2-metal = { version = "0.2.1", default-features = false, features = [
+    "MTLPixelFormat",
+] }
+
 [[example]]
 name = "vulkan-buffer"
 required-features = ["vulkan", "ash/loaded"]
@@ -85,8 +100,8 @@ required-features = ["metal"]
 visualizer = ["dep:egui", "dep:egui_extras"]
 vulkan = ["dep:ash"]
 d3d12 = ["dep:windows"]
-metal = ["dep:metal"]
+metal = ["dep:objc2", "dep:objc2-metal", "dep:objc2-foundation"]
 # Expose helper functionality for winapi types to interface with gpu-allocator, which is primarily windows-rs driven
 public-winapi = ["dep:winapi"]
 
-default = ["d3d12", "vulkan"]
+default = ["d3d12", "vulkan", "metal"]

README.md

@@ -134,7 +134,7 @@ allocator.free(allocation).unwrap();
 
 ```rust
 use gpu_allocator::metal::*;
-
+use objc2_metal as metal;
 let mut allocator = Allocator::new(&AllocatorCreateDesc {
     device: device.clone(),
     debug_settings: Default::default(),
@@ -146,12 +146,12 @@ let mut allocator = Allocator::new(&AllocatorCreateDesc {
 ```rust
 use gpu_allocator::metal::*;
 use gpu_allocator::MemoryLocation;
-
+use objc2_metal as metal;
 let allocation_desc = AllocationCreateDesc::buffer(
     &device,
     "Example allocation",
     512, // size in bytes
-    gpu_allocator::MemoryLocation::GpuOnly,
+    MemoryLocation::GpuOnly,
 );
 let allocation = allocator.allocate(&allocation_desc).unwrap();
 let resource = allocation.make_buffer().unwrap();

examples/metal-buffer.rs

@@ -1,12 +1,20 @@
-use std::sync::Arc;
-
 use gpu_allocator::metal::{AllocationCreateDesc, Allocator, AllocatorCreateDesc};
 use log::info;
+use metal::MTLDevice as _;
+use objc2::rc::Id;
+use objc2_foundation::NSArray;
+use objc2_metal as metal;
 
 fn main() {
     env_logger::Builder::from_env(env_logger::Env::default().default_filter_or("trace")).init();
 
-    let device = Arc::new(metal::Device::system_default().unwrap());
+    // Allow the innards of objc2-metal to link the static function below:
+    // https://docs.rs/objc2-metal/0.2.2/objc2_metal/index.html
+    #[link(name = "CoreGraphics", kind = "framework")]
+    extern "C" {}
+
+    let device =
+        unsafe { Id::from_raw(metal::MTLCreateSystemDefaultDevice()) }.expect("No MTLDevice found");
 
     // Setting up the allocator
     let mut allocator = Allocator::new(&AllocatorCreateDesc {
@@ -60,11 +68,11 @@ fn main() {
 
     // Test allocating texture
     {
-        let texture_desc = metal::TextureDescriptor::new();
-        texture_desc.set_pixel_format(metal::MTLPixelFormat::RGBA8Unorm);
-        texture_desc.set_width(64);
-        texture_desc.set_height(64);
-        texture_desc.set_storage_mode(metal::MTLStorageMode::Private);
+        let texture_desc = unsafe { metal::MTLTextureDescriptor::new() };
+        texture_desc.setPixelFormat(metal::MTLPixelFormat::RGBA8Unorm);
+        unsafe { texture_desc.setWidth(64) };
+        unsafe { texture_desc.setHeight(64) };
+        texture_desc.setStorageMode(metal::MTLStorageMode::Private);
         let allocation_desc =
             AllocationCreateDesc::texture(&device, "Test allocation (Texture)", &texture_desc);
         let allocation = allocator.allocate(&allocation_desc).unwrap();
@@ -75,14 +83,14 @@ fn main() {
 
     // Test allocating acceleration structure
     {
-        let empty_array = metal::Array::from_slice(&[]);
-        let acc_desc = metal::PrimitiveAccelerationStructureDescriptor::descriptor();
-        acc_desc.set_geometry_descriptors(empty_array);
-        let sizes = device.acceleration_structure_sizes_with_descriptor(&acc_desc);
+        let empty_array = NSArray::from_slice(&[]);
+        let acc_desc = metal::MTLPrimitiveAccelerationStructureDescriptor::descriptor();
+        acc_desc.setGeometryDescriptors(Some(&empty_array));
+        let sizes = device.accelerationStructureSizesWithDescriptor(&acc_desc);
         let allocation_desc = AllocationCreateDesc::acceleration_structure_with_size(
             &device,
             "Test allocation (Acceleration structure)",
-            sizes.acceleration_structure_size,
+            sizes.accelerationStructureSize as u64,
             gpu_allocator::MemoryLocation::GpuOnly,
         );
         let allocation = allocator.allocate(&allocation_desc).unwrap();

src/d3d12/mod.rs

@@ -1,4 +1,10 @@
-use std::{backtrace::Backtrace, fmt, sync::Arc};
+use std::{
+    backtrace::Backtrace,
+    fmt,
+    // TODO: Remove when bumping MSRV to 1.80
+    mem::size_of_val,
+    sync::Arc,
+};
 
 use log::{debug, warn, Level};
 use windows::Win32::{
@@ -628,7 +634,7 @@ impl Allocator {
             device.CheckFeatureSupport(
                 D3D12_FEATURE_D3D12_OPTIONS,
                 <*mut D3D12_FEATURE_DATA_D3D12_OPTIONS>::cast(&mut options),
-                std::mem::size_of_val(&options) as u32,
+                size_of_val(&options) as u32,
             )
         }
         .map_err(|e| {

src/lib.rs

@@ -161,10 +161,11 @@
 //! ```no_run
 //! # #[cfg(feature = "metal")]
 //! # fn main() {
-//! # use std::sync::Arc;
 //! use gpu_allocator::metal::*;
-//!
-//! # let device = Arc::new(metal::Device::system_default().unwrap());
+//! # use objc2::rc::Id;
+//! use objc2_metal as metal;
+//! # let device = unsafe { metal::MTLCreateSystemDefaultDevice() };
+//! # let device = unsafe { Id::from_raw(device) }.expect("No MTLDevice found");
 //! let mut allocator = Allocator::new(&AllocatorCreateDesc {
 //!     device: device.clone(),
 //!     debug_settings: Default::default(),
@@ -179,22 +180,23 @@
 //! ```no_run
 //! # #[cfg(feature = "metal")]
 //! # fn main() {
-//! # use std::sync::Arc;
 //! use gpu_allocator::metal::*;
 //! use gpu_allocator::MemoryLocation;
-//! # let device = Arc::new(metal::Device::system_default().unwrap());
+//! # use objc2::rc::Id;
+//! use objc2_metal as metal;
+//! # let device = unsafe { metal::MTLCreateSystemDefaultDevice() };
+//! # let device = unsafe { Id::from_raw(device) }.expect("No MTLDevice found");
 //! # let mut allocator = Allocator::new(&AllocatorCreateDesc {
 //! #     device: device.clone(),
 //! #     debug_settings: Default::default(),
 //! #     allocation_sizes: Default::default(),
 //! # })
 //! # .unwrap();
-//!
 //! let allocation_desc = AllocationCreateDesc::buffer(
 //!     &device,
 //!     "Example allocation",
 //!     512, // size in bytes
-//!     gpu_allocator::MemoryLocation::GpuOnly,
+//!     MemoryLocation::GpuOnly,
 //! );
 //! let allocation = allocator.allocate(&allocation_desc).unwrap();
 //! let resource = allocation.make_buffer().unwrap();
@@ -206,6 +208,7 @@
 //! # #[cfg(not(feature = "metal"))]
 //! # fn main() {}
 //! ```
+#![deny(clippy::unimplemented, clippy::unwrap_used, clippy::ok_expect)]
 
 mod result;
 pub use result::*;
@@ -223,7 +226,7 @@ pub mod vulkan;
 #[cfg(all(windows, feature = "d3d12"))]
 pub mod d3d12;
 
-#[cfg(all(any(target_os = "macos", target_os = "ios"), feature = "metal"))]
+#[cfg(all(target_vendor = "apple", feature = "metal"))]
 pub mod metal;
 
 #[derive(Clone, Copy, Debug, PartialEq, Eq, Hash)]