Fix up merge

Update signatures to match changes to backend trait, and add new types
and stub methods to complete mux abstraction.

piet-gpu-hal/src/macros.rs

@@ -25,6 +25,10 @@ macro_rules! mux_cfg {
     ( #[cfg(dx12)] $($tokens:tt)* ) => {
         #[cfg(target_os="windows")] $( $tokens )*
     };
+
+    ( #[cfg(mtl)] $($tokens:tt)* ) => {
+        #[cfg(target_os="macos")] $( $tokens )*
+    };
 }
 
 #[macro_export]
@@ -32,12 +36,15 @@ macro_rules! mux_enum {
     ( $(#[$outer:meta])* $v:vis enum $name:ident {
         Vk($vk:ty),
         Dx12($dx12:ty),
+        Mtl($mtl:ty),
     } ) => {
         $(#[$outer])* $v enum $name {
             #[cfg(not(target_os="macos"))]
             Vk($vk),
             #[cfg(target_os="windows")]
             Dx12($dx12),
+            #[cfg(target_os="macos")]
+            Mtl($mtl),
         }
 
         impl $name {
@@ -62,6 +69,17 @@ macro_rules! mux_enum {
                     }
                 }
             }
+
+            $crate::mux_cfg! {
+                #[cfg(mtl)]
+                #[allow(unused)]
+                fn mtl(&self) -> &$mtl {
+                    match self {
+                        $name::Mtl(x) => x,
+                        _ => panic!("downcast error")
+                    }
+                }
+            }
         }
     };
 }
@@ -73,6 +91,7 @@ macro_rules! mux_device_enum {
             pub enum $assoc_type {
                 Vk(<$crate::vulkan::VkDevice as $crate::Device>::$assoc_type),
                 Dx12(<$crate::dx12::Dx12Device as $crate::Device>::$assoc_type),
+                Mtl(<$crate::metal::MtlDevice as $crate::Device>::$assoc_type),
             }
         }
     }
@@ -83,22 +102,27 @@ macro_rules! mux_match {
     ( $e:expr ;
         $vkname:ident::Vk($vkvar:ident) => $vkblock: block
         $dx12name:ident::Dx12($dx12var:ident) => $dx12block: block
+        $mtlname:ident::Mtl($mtlvar:ident) => $mtlblock: block
     ) => {
         match $e {
             #[cfg(not(target_os="macos"))]
             $vkname::Vk($vkvar) => $vkblock
             #[cfg(target_os="windows")]
             $dx12name::Dx12($dx12var) => $dx12block
+            #[cfg(target_os="macos")]
+            $mtlname::Mtl($mtlvar) => $mtlblock
         }
     };
 
     ( $e:expr ;
         $vkname:ident::Vk($vkvar:ident) => $vkblock: expr,
         $dx12name:ident::Dx12($dx12var:ident) => $dx12block: expr,
+        $mtlname:ident::Mtl($mtlvar:ident) => $mtlblock: expr,
     ) => {
         $crate::mux_match! { $e;
             $vkname::Vk($vkvar) => { $vkblock }
             $dx12name::Dx12($dx12var) => { $dx12block }
+            $mtlname::Mtl($mtlvar) => { $mtlblock }
         }
     };
 }

piet-gpu-hal/src/metal.rs

@@ -14,17 +14,22 @@
 //
 // Also licensed under MIT license, at your choice.
 
-use crate::Error;
+use crate::{BufferUsage, Error};
 
-use bitflags::bitflags;
+pub struct MtlInstance;
 
-pub struct MetalInstance;
+pub struct MtlDevice {
-
-pub struct MetalDevice {
     device: metal::Device,
 }
 
-pub struct Buffer(metal::Buffer);
+pub struct MtlSurface;
+
+pub struct MtlSwapchain;
+
+pub struct Buffer {
+    buffer: metal::Buffer,
+    pub(crate) size: u64,
+}
 
 pub struct Image;
 
@@ -36,19 +41,6 @@ pub struct Fence;
 
 pub struct Semaphore;
 
-// This is the new direction of how I want this to go, and will
-// move it to crate level. It's very similar to wgpu's BufferUsage.
-bitflags! {
-    pub struct MemFlags: u32 {
-        const MAP_READ = 1;
-        const MAP_WRITE = 2;
-        const COPY_SRC = 4;
-        const COPY_DST = 8;
-        const STORAGE = 128;
-    }
-}
-
-
 pub struct CmdBuf;
 
 pub struct QueryPool;
@@ -57,29 +49,39 @@ pub struct PipelineBuilder;
 
 pub struct DescriptorSetBuilder;
 
-impl MetalInstance {
+impl MtlInstance {
-    pub fn new() -> MetalInstance {
+    pub fn new(
-        MetalInstance
+        window_handle: Option<&dyn raw_window_handle::HasRawWindowHandle>,
+    ) -> Result<(MtlInstance, Option<MtlSurface>), Error> {
+        Ok((MtlInstance, None))
     }
 
     // TODO might do some enumeration of devices
 
-    pub fn device(&self) -> Result<MetalDevice, Error> {
+    pub fn device(&self, surface: Option<&MtlSurface>) -> Result<MtlDevice, Error> {
         if let Some(device) = metal::Device::system_default() {
-            Ok(MetalDevice { device })
+            Ok(MtlDevice { device })
         } else {
             Err("can't create system default Metal device".into())
         }
     }
+
+    pub unsafe fn swapchain(
+        &self,
+        width: usize,
+        height: usize,
+        device: &MtlDevice,
+        surface: &MtlSurface,
+    ) -> Result<MtlSwapchain, Error> {
+        todo!()
+    }
 }
 
-impl crate::Device for MetalDevice {
+impl crate::Device for MtlDevice {
     type Buffer = Buffer;
 
     type Image = Image;
 
-    type MemFlags = MemFlags;
-
     type Pipeline = Pipeline;
 
     type DescriptorSet = DescriptorSet;
@@ -98,20 +100,22 @@ impl crate::Device for MetalDevice {
 
     type Sampler = ();
 
+    type ShaderSource = str;
+
     fn query_gpu_info(&self) -> crate::GpuInfo {
         todo!()
     }
 
-    fn create_buffer(&self, size: u64, mem_flags: Self::MemFlags) -> Result<Self::Buffer, Error> {
+    fn create_buffer(&self, size: u64, usage: BufferUsage) -> Result<Self::Buffer, Error> {
-        let options = if mem_flags.contains(MemFlags::MAP_READ) {
+        let options = if usage.contains(BufferUsage::MAP_READ) {
             metal::MTLResourceOptions::StorageModeShared | metal::MTLResourceOptions::CPUCacheModeDefaultCache
-        } else if mem_flags.contains(MemFlags::MAP_WRITE) {
+        } else if usage.contains(BufferUsage::MAP_WRITE) {
             metal::MTLResourceOptions::StorageModeShared | metal::MTLResourceOptions::CPUCacheModeWriteCombined
         } else {
             metal::MTLResourceOptions::StorageModePrivate
         };
         let buffer = self.device.new_buffer(size, options);
-        Ok(Buffer(buffer))
+        Ok(Buffer { buffer, size })
     }
 
     unsafe fn destroy_buffer(&self, buffer: &Self::Buffer) -> Result<(), Error> {
@@ -122,7 +126,6 @@ impl crate::Device for MetalDevice {
         &self,
         width: u32,
         height: u32,
-        mem_flags: Self::MemFlags,
     ) -> Result<Self::Image, Error> {
         todo!()
     }
@@ -151,46 +154,43 @@ impl crate::Device for MetalDevice {
         todo!()
     }
 
-    unsafe fn run_cmd_buf(
+    unsafe fn run_cmd_bufs(
         &self,
-        cmd_buf: &Self::CmdBuf,
+        cmd_bufs: &[&Self::CmdBuf],
-        wait_semaphores: &[Self::Semaphore],
+        wait_semaphores: &[&Self::Semaphore],
-        signal_semaphores: &[Self::Semaphore],
+        signal_semaphores: &[&Self::Semaphore],
         fence: Option<&Self::Fence>,
     ) -> Result<(), Error> {
         todo!()
     }
 
-    unsafe fn read_buffer<T: Sized>(
+    unsafe fn read_buffer(
         &self,
         buffer: &Self::Buffer,
-        result: &mut Vec<T>,
+        dst: *mut u8,
+        offset: u64,
+        size: u64,
     ) -> Result<(), Error> {
-        let contents_ptr = buffer.0.contents();
+        let contents_ptr = buffer.buffer.contents();
         if contents_ptr.is_null() {
             return Err("probably trying to read from private buffer".into());
         }
-        let len = buffer.0.length() as usize / std::mem::size_of::<T>();
+        std::ptr::copy_nonoverlapping((contents_ptr as *const u8).add(offset as usize), dst, size as usize);
-        if len > result.len() {
-            result.reserve(len - result.len());
-        }
-        std::ptr::copy_nonoverlapping(contents_ptr as *const T, result.as_mut_ptr(), len);
-        result.set_len(len);
         Ok(())
     }
 
-    unsafe fn write_buffer<T: Sized>(
+    unsafe fn write_buffer(
         &self,
-        buffer: &Self::Buffer,
+        buffer: &Buffer,
-        contents: &[T],
+        contents: *const u8,
+        offset: u64,
+        size: u64,
     ) -> Result<(), Error> {
-        let contents_ptr = buffer.0.contents();
+        let contents_ptr = buffer.buffer.contents();
         if contents_ptr.is_null() {
             return Err("probably trying to write to private buffer".into());
         }
-        let len = buffer.0.length() as usize / std::mem::size_of::<T>();
+        std::ptr::copy_nonoverlapping(contents, (contents_ptr as *mut u8).add(offset as usize), size as usize);
-        assert!(len >= contents.len());
-        std::ptr::copy_nonoverlapping(contents.as_ptr(), contents_ptr as *mut T, len);
         Ok(())
     }
 
@@ -202,11 +202,11 @@ impl crate::Device for MetalDevice {
         todo!()
     }
 
-    unsafe fn wait_and_reset(&self, fences: &[Self::Fence]) -> Result<(), Error> {
+    unsafe fn wait_and_reset(&self, fences: &[&Self::Fence]) -> Result<(), Error> {
         todo!()
     }
 
-    unsafe fn get_fence_status(&self, fence: Self::Fence) -> Result<bool, Error> {
+    unsafe fn get_fence_status(&self, fence: &Self::Fence) -> Result<bool, Error> {
         todo!()
     }
 
@@ -215,17 +215,7 @@ impl crate::Device for MetalDevice {
     }
 }
 
-impl crate::MemFlags for MemFlags {
+impl crate::CmdBuf<MtlDevice> for CmdBuf {
-    fn device_local() -> Self {
-        MemFlags::COPY_SRC | MemFlags::COPY_DST | MemFlags::STORAGE
-    }
-
-    fn host_coherent() -> Self {
-        MemFlags::device_local() | MemFlags::MAP_READ | MemFlags::MAP_WRITE
-    }
-}
-
-impl crate::CmdBuf<MetalDevice> for CmdBuf {
     unsafe fn begin(&mut self) {
         todo!()
     }
@@ -289,7 +279,7 @@ impl crate::CmdBuf<MetalDevice> for CmdBuf {
     }
 }
 
-impl crate::PipelineBuilder<MetalDevice> for PipelineBuilder {
+impl crate::PipelineBuilder<MtlDevice> for PipelineBuilder {
     fn add_buffers(&mut self, n_buffers: u32) {
         todo!()
     }
@@ -302,12 +292,12 @@ impl crate::PipelineBuilder<MetalDevice> for PipelineBuilder {
         todo!()
     }
 
-    unsafe fn create_compute_pipeline(self, device: &MetalDevice, code: &[u8]) -> Result<Pipeline, Error> {
+    unsafe fn create_compute_pipeline(self, device: &MtlDevice, code: &str) -> Result<Pipeline, Error> {
         todo!()
     }
 }
 
-impl crate::DescriptorSetBuilder<MetalDevice> for DescriptorSetBuilder {
+impl crate::DescriptorSetBuilder<MtlDevice> for DescriptorSetBuilder {
     fn add_buffers(&mut self, buffers: &[&Buffer]) {
         todo!()
     }
@@ -320,7 +310,25 @@ impl crate::DescriptorSetBuilder<MetalDevice> for DescriptorSetBuilder {
         todo!()
     }
 
-    unsafe fn build(self, device: &MetalDevice, pipeline: &Pipeline) -> Result<DescriptorSet, Error> {
+    unsafe fn build(self, device: &MtlDevice, pipeline: &Pipeline) -> Result<DescriptorSet, Error> {
         todo!()
     }
+}
+
+impl MtlSwapchain {
+    pub unsafe fn next(&mut self) -> Result<(usize, Semaphore), Error> {
+        todo!()
+    }
+
+    pub unsafe fn image(&self, idx: usize) -> Image {
+        todo!()
+    }
+
+    pub unsafe fn present(
+        &self,
+        image_idx: usize,
+        semaphores: &[&Semaphore],
+    ) -> Result<bool, Error> {
+        todo!()
+    }    
 }

piet-gpu-hal/src/mux.rs

@@ -26,6 +26,10 @@ mux_cfg! {
     #[cfg(dx12)]
     use crate::dx12;
 }
+mux_cfg! {
+    #[cfg(mtl)]
+    use crate::metal;
+}
 use crate::CmdBuf as CmdBufTrait;
 use crate::DescriptorSetBuilder as DescriptorSetBuilderTrait;
 use crate::Device as DeviceTrait;
@@ -37,6 +41,7 @@ mux_enum! {
     pub enum Instance {
         Vk(vulkan::VkInstance),
         Dx12(dx12::Dx12Instance),
+        Mtl(metal::MtlInstance),
     }
 }
 
@@ -45,6 +50,7 @@ mux_enum! {
     pub enum Device {
         Vk(vulkan::VkDevice),
         Dx12(dx12::Dx12Device),
+        Mtl(metal::MtlDevice),
     }
 }
 
@@ -53,6 +59,7 @@ mux_enum! {
     pub enum Surface {
         Vk(vulkan::VkSurface),
         Dx12(dx12::Dx12Surface),
+        Mtl(metal::MtlSurface),
     }
 }
 
@@ -61,6 +68,7 @@ mux_enum! {
     pub enum Swapchain {
         Vk(vulkan::VkSwapchain),
         Dx12(dx12::Dx12Swapchain),
+        Mtl(metal::MtlSwapchain),
     }
 }
 
@@ -78,8 +86,12 @@ mux_device_enum! { Sampler }
 
 /// The code for a shader, either as source or intermediate representation.
 pub enum ShaderCode<'a> {
+    /// SPIR-V (binary intermediate representation)
     Spv(&'a [u8]),
+    /// HLSL (source)
     Hlsl(&'a str),
+    /// Metal Shading Language (source)
+    Msl(&'a str),
 }
 
 impl Instance {
@@ -111,6 +123,15 @@ impl Instance {
                 }
             }
         }
+        mux_cfg! {
+            #[cfg(mtl)]
+            {
+                let result = metal::MtlInstance::new(window_handle);
+                if let Ok((instance, surface)) = result {
+                    return Ok((Instance::Mtl(instance), surface.map(Surface::Mtl)));
+                }
+            }
+        }
         // TODO plumb creation errors through.
         Err("No suitable instances found".into())
     }
@@ -124,6 +145,7 @@ impl Instance {
         mux_match! { self;
             Instance::Vk(i) => i.device(surface.map(Surface::vk)).map(Device::Vk),
             Instance::Dx12(i) => i.device(surface.map(Surface::dx12)).map(Device::Dx12),
+            Instance::Mtl(i) => i.device(surface.map(Surface::mtl)).map(Device::Mtl),
         }
     }
 
@@ -147,6 +169,9 @@ impl Instance {
             Instance::Dx12(i) => i
                 .swapchain(width, height, device.dx12(), surface.dx12())
                 .map(Swapchain::Dx12),
+            Instance::Mtl(i) => i
+                .swapchain(width, height, device.mtl(), surface.mtl())
+                .map(Swapchain::Mtl),
         }
     }
 }
@@ -159,6 +184,7 @@ impl Device {
         mux_match! { self;
             Device::Vk(d) => d.query_gpu_info(),
             Device::Dx12(d) => d.query_gpu_info(),
+            Device::Mtl(d) => d.query_gpu_info(),
         }
     }
 
@@ -166,6 +192,7 @@ impl Device {
         mux_match! { self;
             Device::Vk(d) => d.create_buffer(size, usage).map(Buffer::Vk),
             Device::Dx12(d) => d.create_buffer(size, usage).map(Buffer::Dx12),
+            Device::Mtl(d) => d.create_buffer(size, usage).map(Buffer::Mtl),
         }
     }
 
@@ -173,6 +200,7 @@ impl Device {
         mux_match! { self;
             Device::Vk(d) => d.destroy_buffer(buffer.vk()),
             Device::Dx12(d) => d.destroy_buffer(buffer.dx12()),
+            Device::Mtl(d) => d.destroy_buffer(buffer.mtl()),
         }
     }
 
@@ -180,6 +208,7 @@ impl Device {
         mux_match! { self;
             Device::Vk(d) => d.create_image2d(width, height).map(Image::Vk),
             Device::Dx12(d) => d.create_image2d(width, height).map(Image::Dx12),
+            Device::Mtl(d) => d.create_image2d(width, height).map(Image::Mtl),
         }
     }
 
@@ -187,6 +216,7 @@ impl Device {
         mux_match! { self;
             Device::Vk(d) => d.destroy_image(image.vk()),
             Device::Dx12(d) => d.destroy_image(image.dx12()),
+            Device::Mtl(d) => d.destroy_image(image.mtl()),
         }
     }
 
@@ -194,6 +224,7 @@ impl Device {
         mux_match! { self;
             Device::Vk(d) => d.create_fence(signaled).map(Fence::Vk),
             Device::Dx12(d) => d.create_fence(signaled).map(Fence::Dx12),
+            Device::Mtl(d) => d.create_fence(signaled).map(Fence::Mtl),
         }
     }
 
@@ -215,6 +246,14 @@ impl Device {
                     .collect::<SmallVec<[_; 4]>>();
                 d.wait_and_reset(&*fences)
             }
+            Device::Mtl(d) => {
+                let fences = fences
+                    .iter()
+                    .copied()
+                    .map(Fence::mtl)
+                    .collect::<SmallVec<[_; 4]>>();
+                d.wait_and_reset(&*fences)
+            }
         }
     }
 
@@ -222,6 +261,7 @@ impl Device {
         mux_match! { self;
             Device::Vk(d) => d.get_fence_status(fence.vk()),
             Device::Dx12(d) => d.get_fence_status(fence.dx12()),
+            Device::Mtl(d) => d.get_fence_status(fence.mtl()),
         }
     }
 
@@ -229,6 +269,7 @@ impl Device {
         mux_match! { self;
             Device::Vk(d) => d.create_semaphore().map(Semaphore::Vk),
             Device::Dx12(d) => d.create_semaphore().map(Semaphore::Dx12),
+            Device::Mtl(d) => d.create_semaphore().map(Semaphore::Mtl),
         }
     }
 
@@ -236,6 +277,7 @@ impl Device {
         mux_match! { self;
             Device::Vk(d) => PipelineBuilder::Vk(d.pipeline_builder()),
             Device::Dx12(d) => PipelineBuilder::Dx12(d.pipeline_builder()),
+            Device::Mtl(d) => PipelineBuilder::Mtl(d.pipeline_builder()),
         }
     }
 
@@ -243,6 +285,7 @@ impl Device {
         mux_match! { self;
             Device::Vk(d) => DescriptorSetBuilder::Vk(d.descriptor_set_builder()),
             Device::Dx12(d) => DescriptorSetBuilder::Dx12(d.descriptor_set_builder()),
+            Device::Mtl(d) => DescriptorSetBuilder::Mtl(d.descriptor_set_builder()),
         }
     }
 
@@ -250,6 +293,7 @@ impl Device {
         mux_match! { self;
             Device::Vk(d) => d.create_cmd_buf().map(CmdBuf::Vk),
             Device::Dx12(d) => d.create_cmd_buf().map(CmdBuf::Dx12),
+            Device::Mtl(d) => d.create_cmd_buf().map(CmdBuf::Mtl),
         }
     }
 
@@ -257,6 +301,7 @@ impl Device {
         mux_match! { self;
             Device::Vk(d) => d.create_query_pool(n_queries).map(QueryPool::Vk),
             Device::Dx12(d) => d.create_query_pool(n_queries).map(QueryPool::Dx12),
+            Device::Mtl(d) => d.create_query_pool(n_queries).map(QueryPool::Mtl),
         }
     }
 
@@ -264,6 +309,7 @@ impl Device {
         mux_match! { self;
             Device::Vk(d) => d.fetch_query_pool(pool.vk()),
             Device::Dx12(d) => d.fetch_query_pool(pool.dx12()),
+            Device::Mtl(d) => d.fetch_query_pool(pool.mtl()),
         }
     }
 
@@ -309,6 +355,23 @@ impl Device {
                     .collect::<SmallVec<[_; 4]>>(),
                 fence.map(Fence::dx12),
             ),
+            Device::Mtl(d) => d.run_cmd_bufs(
+                &cmd_bufs
+                    .iter()
+                    .map(|c| c.mtl())
+                    .collect::<SmallVec<[_; 4]>>(),
+                &wait_semaphores
+                    .iter()
+                    .copied()
+                    .map(Semaphore::mtl)
+                    .collect::<SmallVec<[_; 4]>>(),
+                &signal_semaphores
+                    .iter()
+                    .copied()
+                    .map(Semaphore::mtl)
+                    .collect::<SmallVec<[_; 4]>>(),
+                fence.map(Fence::mtl),
+            ),
         }
     }
 
@@ -322,6 +385,7 @@ impl Device {
         mux_match! { self;
             Device::Vk(d) => d.read_buffer(buffer.vk(), dst, offset, size),
             Device::Dx12(d) => d.read_buffer(buffer.dx12(), dst, offset, size),
+            Device::Mtl(d) => d.read_buffer(buffer.mtl(), dst, offset, size),
         }
     }
 
@@ -335,6 +399,7 @@ impl Device {
         mux_match! { self;
             Device::Vk(d) => d.write_buffer(buffer.vk(), contents, offset, size),
             Device::Dx12(d) => d.write_buffer(buffer.dx12(), contents, offset, size),
+            Device::Mtl(d) => d.write_buffer(buffer.mtl(), contents, offset, size),
         }
     }
 }
@@ -344,6 +409,7 @@ impl PipelineBuilder {
         mux_match! { self;
             PipelineBuilder::Vk(x) => x.add_buffers(n_buffers),
             PipelineBuilder::Dx12(x) => x.add_buffers(n_buffers),
+            PipelineBuilder::Mtl(x) => x.add_buffers(n_buffers),
         }
     }
 
@@ -351,6 +417,7 @@ impl PipelineBuilder {
         mux_match! { self;
             PipelineBuilder::Vk(x) => x.add_images(n_buffers),
             PipelineBuilder::Dx12(x) => x.add_images(n_buffers),
+            PipelineBuilder::Mtl(x) => x.add_images(n_buffers),
         }
     }
 
@@ -358,6 +425,7 @@ impl PipelineBuilder {
         mux_match! { self;
             PipelineBuilder::Vk(x) => x.add_textures(n_buffers),
             PipelineBuilder::Dx12(x) => x.add_textures(n_buffers),
+            PipelineBuilder::Mtl(x) => x.add_textures(n_buffers),
         }
     }
 
@@ -385,6 +453,15 @@ impl PipelineBuilder {
                 x.create_compute_pipeline(device.dx12(), shader_code)
                     .map(Pipeline::Dx12)
             }
+            PipelineBuilder::Mtl(x) => {
+                let shader_code = match code {
+                    ShaderCode::Msl(msl) => msl,
+                    // Panic or return "incompatible shader" error here?
+                    _ => panic!("Metal backend requires shader code in MSL format"),
+                };
+                x.create_compute_pipeline(device.mtl(), shader_code)
+                    .map(Pipeline::Mtl)
+            }
         }
     }
 }
@@ -406,6 +483,13 @@ impl DescriptorSetBuilder {
                     .map(Buffer::dx12)
                     .collect::<SmallVec<[_; 8]>>(),
             ),
+            DescriptorSetBuilder::Mtl(x) => x.add_buffers(
+                &buffers
+                    .iter()
+                    .copied()
+                    .map(Buffer::mtl)
+                    .collect::<SmallVec<[_; 8]>>(),
+            ),
         }
     }
 
@@ -425,6 +509,13 @@ impl DescriptorSetBuilder {
                     .map(Image::dx12)
                     .collect::<SmallVec<[_; 8]>>(),
             ),
+            DescriptorSetBuilder::Mtl(x) => x.add_images(
+                &images
+                    .iter()
+                    .copied()
+                    .map(Image::mtl)
+                    .collect::<SmallVec<[_; 8]>>(),
+            ),
         }
     }
 
@@ -444,6 +535,13 @@ impl DescriptorSetBuilder {
                     .map(Image::dx12)
                     .collect::<SmallVec<[_; 8]>>(),
             ),
+            DescriptorSetBuilder::Mtl(x) => x.add_textures(
+                &images
+                    .iter()
+                    .copied()
+                    .map(Image::mtl)
+                    .collect::<SmallVec<[_; 8]>>(),
+            ),
         }
     }
 
@@ -458,6 +556,9 @@ impl DescriptorSetBuilder {
             DescriptorSetBuilder::Dx12(x) => x
                 .build(device.dx12(), pipeline.dx12())
                 .map(DescriptorSet::Dx12),
+            DescriptorSetBuilder::Mtl(x) => x
+                .build(device.mtl(), pipeline.mtl())
+                .map(DescriptorSet::Mtl),
         }
     }
 }
@@ -467,6 +568,7 @@ impl CmdBuf {
         mux_match! { self;
             CmdBuf::Vk(c) => c.begin(),
             CmdBuf::Dx12(c) => c.begin(),
+            CmdBuf::Mtl(c) => c.begin(),
         }
     }
 
@@ -474,6 +576,7 @@ impl CmdBuf {
         mux_match! { self;
             CmdBuf::Vk(c) => c.finish(),
             CmdBuf::Dx12(c) => c.finish(),
+            CmdBuf::Mtl(c) => c.finish(),
         }
     }
 
@@ -486,6 +589,7 @@ impl CmdBuf {
         mux_match! { self;
             CmdBuf::Vk(c) => c.dispatch(pipeline.vk(), descriptor_set.vk(), size),
             CmdBuf::Dx12(c) => c.dispatch(pipeline.dx12(), descriptor_set.dx12(), size),
+            CmdBuf::Mtl(c) => c.dispatch(pipeline.mtl(), descriptor_set.mtl(), size),
         }
     }
 
@@ -493,6 +597,7 @@ impl CmdBuf {
         mux_match! { self;
             CmdBuf::Vk(c) => c.memory_barrier(),
             CmdBuf::Dx12(c) => c.memory_barrier(),
+            CmdBuf::Mtl(c) => c.memory_barrier(),
         }
     }
 
@@ -500,6 +605,7 @@ impl CmdBuf {
         mux_match! { self;
             CmdBuf::Vk(c) => c.host_barrier(),
             CmdBuf::Dx12(c) => c.host_barrier(),
+            CmdBuf::Mtl(c) => c.host_barrier(),
         }
     }
 
@@ -512,6 +618,7 @@ impl CmdBuf {
         mux_match! { self;
             CmdBuf::Vk(c) => c.image_barrier(image.vk(), src_layout, dst_layout),
             CmdBuf::Dx12(c) => c.image_barrier(image.dx12(), src_layout, dst_layout),
+            CmdBuf::Mtl(c) => c.image_barrier(image.mtl(), src_layout, dst_layout),
         }
     }
 
@@ -519,6 +626,7 @@ impl CmdBuf {
         mux_match! { self;
             CmdBuf::Vk(c) => c.clear_buffer(buffer.vk(), size),
             CmdBuf::Dx12(c) => c.clear_buffer(buffer.dx12(), size),
+            CmdBuf::Mtl(c) => c.clear_buffer(buffer.mtl(), size),
         }
     }
 
@@ -526,6 +634,7 @@ impl CmdBuf {
         mux_match! { self;
             CmdBuf::Vk(c) => c.copy_buffer(src.vk(), dst.vk()),
             CmdBuf::Dx12(c) => c.copy_buffer(src.dx12(), dst.dx12()),
+            CmdBuf::Mtl(c) => c.copy_buffer(src.mtl(), dst.mtl()),
         }
     }
 
@@ -533,6 +642,7 @@ impl CmdBuf {
         mux_match! { self;
             CmdBuf::Vk(c) => c.copy_image_to_buffer(src.vk(), dst.vk()),
             CmdBuf::Dx12(c) => c.copy_image_to_buffer(src.dx12(), dst.dx12()),
+            CmdBuf::Mtl(c) => c.copy_image_to_buffer(src.mtl(), dst.mtl()),
         }
     }
 
@@ -540,6 +650,7 @@ impl CmdBuf {
         mux_match! { self;
             CmdBuf::Vk(c) => c.copy_buffer_to_image(src.vk(), dst.vk()),
             CmdBuf::Dx12(c) => c.copy_buffer_to_image(src.dx12(), dst.dx12()),
+            CmdBuf::Mtl(c) => c.copy_buffer_to_image(src.mtl(), dst.mtl()),
         }
     }
 
@@ -547,6 +658,7 @@ impl CmdBuf {
         mux_match! { self;
             CmdBuf::Vk(c) => c.blit_image(src.vk(), dst.vk()),
             CmdBuf::Dx12(c) => c.blit_image(src.dx12(), dst.dx12()),
+            CmdBuf::Mtl(c) => c.blit_image(src.mtl(), dst.mtl()),
         }
     }
 
@@ -554,6 +666,7 @@ impl CmdBuf {
         mux_match! { self;
             CmdBuf::Vk(c) => c.reset_query_pool(pool.vk()),
             CmdBuf::Dx12(c) => c.reset_query_pool(pool.dx12()),
+            CmdBuf::Mtl(c) => c.reset_query_pool(pool.mtl()),
         }
     }
 
@@ -561,6 +674,7 @@ impl CmdBuf {
         mux_match! { self;
             CmdBuf::Vk(c) => c.write_timestamp(pool.vk(), query),
             CmdBuf::Dx12(c) => c.write_timestamp(pool.dx12(), query),
+            CmdBuf::Mtl(c) => c.write_timestamp(pool.mtl(), query),
         }
     }
 
@@ -568,6 +682,7 @@ impl CmdBuf {
         mux_match! { self;
             CmdBuf::Vk(c) => c.finish_timestamps(pool.vk()),
             CmdBuf::Dx12(c) => c.finish_timestamps(pool.dx12()),
+            CmdBuf::Mtl(c) => c.finish_timestamps(pool.mtl()),
         }
     }
 }
@@ -577,6 +692,7 @@ impl Buffer {
         mux_match! { self;
             Buffer::Vk(b) => b.size,
             Buffer::Dx12(b) => b.size,
+            Buffer::Mtl(b) => b.size,
         }
     }
 }
@@ -592,6 +708,10 @@ impl Swapchain {
                 let (idx, sem) = s.next()?;
                 Ok((idx, Semaphore::Dx12(sem)))
             }
+            Swapchain::Mtl(s) => {
+                let (idx, sem) = s.next()?;
+                Ok((idx, Semaphore::Mtl(sem)))
+            }
         }
     }
 
@@ -599,6 +719,7 @@ impl Swapchain {
         mux_match! { self;
             Swapchain::Vk(s) => Image::Vk(s.image(idx)),
             Swapchain::Dx12(s) => Image::Dx12(s.image(idx)),
+            Swapchain::Mtl(s) => Image::Mtl(s.image(idx)),
         }
     }
 
@@ -624,6 +745,14 @@ impl Swapchain {
                     .map(Semaphore::dx12)
                     .collect::<SmallVec<[_; 4]>>(),
             ),
+            Swapchain::Mtl(s) => s.present(
+                image_idx,
+                &semaphores
+                    .iter()
+                    .copied()
+                    .map(Semaphore::mtl)
+                    .collect::<SmallVec<[_; 4]>>(),
+            ),
         }
     }
 }