fix(dx12): Handle multi-planar formats in texture copy operations

CHANGELOG.md

@@ -132,6 +132,7 @@ By @beholdnec in [#8505](https://github.com/gfx-rs/wgpu/pull/8505).
     };
   ```
   By @AdrianEddy in [#9496](https://github.com/gfx-rs/wgpu/pull/9496).
+- Extend `copy_texture_to_texture` to allow copying a single plane of a multi-planar source (NV12, P010) into a single-plane destination of the matching format (e.g. NV12 `Plane0` → `R8Unorm`, NV12 `Plane1` → `Rg8Unorm`). `copy_size` is interpreted in plane texels, not luma texels. By @AdrianEddy in [#9551](https://github.com/gfx-rs/wgpu/pull/9551).
 
 #### Metal
 
@@ -148,6 +149,7 @@ By @beholdnec in [#8505](https://github.com/gfx-rs/wgpu/pull/8505).
 
 - Added support for mesh shaders in naga's HLSL writer, completing DX12 support for mesh shaders. By @inner-daemons in [#8752](https://github.com/gfx-rs/wgpu/pull/8752).
 - Added `dx12::Queue::add_wait_fence` / `add_signal_fence` (and matching `remove_*` companions). They stage `ID3D12CommandQueue::Wait` / `Signal` calls on the next `Queue::submit`. The wait calls are issued before the submit's `ExecuteCommandLists`, the signal calls after wgpu's own `Signal(signal_fence, signal_value)`. Cross-API interop crates use this to GPU-side gate / publish wgpu submits against foreign-API fences. By @AdrianEddy in [#9463](https://github.com/gfx-rs/wgpu/pull/9463).
+- Added `dx12::Texture::with_plane_slice` so cross-API importers can wrap one plane of a multi-plane DXGI resource (e.g. `DXGI_FORMAT_NV12`) as a single-plane wgpu texture. Construct two wgpu textures from the same `ID3D12Resource`, one per plane, with the matching single-plane `TextureFormat` (`R8Unorm` / `Rg8Unorm`, `R16Unorm` / `Rg16Unorm`). Views and copies derived from the wrapper target the correct `PlaneSlice` instead of defaulting to plane 0. Also fixes `map_texture_format_for_copy` panicking on `(planar_format, single_plane_aspect)` during buffer<->texture transfers, and `TextureView::subresource_index` previously being hard-coded to plane 0. By @AdrianEddy in [#9551](https://github.com/gfx-rs/wgpu/pull/9551).
 
 #### Vulkan
 

tests/tests/wgpu-gpu/planar_texture/mod.rs

@@ -11,6 +11,7 @@ pub fn all_tests(tests: &mut Vec<GpuTestInitializer>) {
         NV12_TEXTURE_RENDERING,
         NV12_TEXTURE_COPYING,
         P010_TEXTURE_COPYING,
+        NV12_PLANE_TO_SINGLE_PLANE_COPY,
     ]);
 }
 
@@ -387,6 +388,200 @@ static NV12_TEXTURE_COPYING: GpuTestConfiguration = GpuTestConfiguration::new()
         ctx.queue.submit([command_encoder.finish()]);
     });
 
+/// Ensures that copying a single plane of an NV12 source into a matching
+/// single-plane destination (Plane0 → R8Unorm, Plane1 → Rg8Unorm) round-trips
+/// byte-for-byte. Exercises the planar→single-plane copy-compatibility
+/// extension in `copy_texture_to_texture`.
+#[gpu_test]
+static NV12_PLANE_TO_SINGLE_PLANE_COPY: GpuTestConfiguration = GpuTestConfiguration::new()
+    .parameters(TestParameters::default().features(wgpu::Features::TEXTURE_FORMAT_NV12))
+    .run_async(|ctx| async move {
+        // Width chosen so that bytes-per-row is 256-aligned for both planes:
+        //   luma   R8Unorm:  256 px * 1 byte/px = 256
+        //   chroma Rg8Unorm: 128 px * 2 byte/px = 256
+        const WIDTH: u32 = 256;
+        const HEIGHT: u32 = 256;
+        let luma_size = wgpu::Extent3d {
+            width: WIDTH,
+            height: HEIGHT,
+            depth_or_array_layers: 1,
+        };
+        let chroma_size = wgpu::Extent3d {
+            width: WIDTH / 2,
+            height: HEIGHT / 2,
+            depth_or_array_layers: 1,
+        };
+
+        let nv12 = ctx.device.create_texture(&wgpu::TextureDescriptor {
+            label: Some("nv12 src"),
+            dimension: wgpu::TextureDimension::D2,
+            size: luma_size,
+            format: wgpu::TextureFormat::NV12,
+            usage: wgpu::TextureUsages::COPY_SRC | wgpu::TextureUsages::COPY_DST,
+            mip_level_count: 1,
+            sample_count: 1,
+            view_formats: &[],
+        });
+
+        // Distinct patterns per plane so a swap or plane-0-fallback would fail
+        // the assertion at the end.
+        let luma_bytes: Vec<u8> = (0..(WIDTH * HEIGHT) as usize).map(|i| i as u8).collect();
+        let chroma_bytes: Vec<u8> = (0..(WIDTH / 2 * HEIGHT / 2 * 2) as usize)
+            .map(|i| (i ^ 0xA5) as u8)
+            .collect();
+
+        ctx.queue.write_texture(
+            wgpu::TexelCopyTextureInfo {
+                texture: &nv12,
+                mip_level: 0,
+                origin: wgpu::Origin3d::ZERO,
+                aspect: wgpu::TextureAspect::Plane0,
+            },
+            &luma_bytes,
+            wgpu::TexelCopyBufferLayout {
+                offset: 0,
+                bytes_per_row: Some(WIDTH),
+                rows_per_image: Some(HEIGHT),
+            },
+            luma_size,
+        );
+        ctx.queue.write_texture(
+            wgpu::TexelCopyTextureInfo {
+                texture: &nv12,
+                mip_level: 0,
+                origin: wgpu::Origin3d::ZERO,
+                aspect: wgpu::TextureAspect::Plane1,
+            },
+            &chroma_bytes,
+            wgpu::TexelCopyBufferLayout {
+                offset: 0,
+                bytes_per_row: Some(WIDTH / 2 * 2),
+                rows_per_image: Some(HEIGHT / 2),
+            },
+            chroma_size,
+        );
+
+        let r8 = ctx.device.create_texture(&wgpu::TextureDescriptor {
+            label: Some("r8 dst"),
+            dimension: wgpu::TextureDimension::D2,
+            size: luma_size,
+            format: wgpu::TextureFormat::R8Unorm,
+            usage: wgpu::TextureUsages::COPY_DST | wgpu::TextureUsages::COPY_SRC,
+            mip_level_count: 1,
+            sample_count: 1,
+            view_formats: &[],
+        });
+        let rg8 = ctx.device.create_texture(&wgpu::TextureDescriptor {
+            label: Some("rg8 dst"),
+            dimension: wgpu::TextureDimension::D2,
+            size: chroma_size,
+            format: wgpu::TextureFormat::Rg8Unorm,
+            usage: wgpu::TextureUsages::COPY_DST | wgpu::TextureUsages::COPY_SRC,
+            mip_level_count: 1,
+            sample_count: 1,
+            view_formats: &[],
+        });
+
+        let r8_readback = ctx.device.create_buffer(&wgpu::BufferDescriptor {
+            label: None,
+            size: luma_bytes.len() as u64,
+            usage: wgpu::BufferUsages::MAP_READ | wgpu::BufferUsages::COPY_DST,
+            mapped_at_creation: false,
+        });
+        let rg8_readback = ctx.device.create_buffer(&wgpu::BufferDescriptor {
+            label: None,
+            size: chroma_bytes.len() as u64,
+            usage: wgpu::BufferUsages::MAP_READ | wgpu::BufferUsages::COPY_DST,
+            mapped_at_creation: false,
+        });
+
+        let mut encoder = ctx
+            .device
+            .create_command_encoder(&wgpu::CommandEncoderDescriptor::default());
+
+        // The path under test.
+        encoder.copy_texture_to_texture(
+            wgpu::TexelCopyTextureInfo {
+                texture: &nv12,
+                mip_level: 0,
+                origin: wgpu::Origin3d::ZERO,
+                aspect: wgpu::TextureAspect::Plane0,
+            },
+            wgpu::TexelCopyTextureInfo {
+                texture: &r8,
+                mip_level: 0,
+                origin: wgpu::Origin3d::ZERO,
+                aspect: wgpu::TextureAspect::All,
+            },
+            luma_size,
+        );
+        encoder.copy_texture_to_texture(
+            wgpu::TexelCopyTextureInfo {
+                texture: &nv12,
+                mip_level: 0,
+                origin: wgpu::Origin3d::ZERO,
+                aspect: wgpu::TextureAspect::Plane1,
+            },
+            wgpu::TexelCopyTextureInfo {
+                texture: &rg8,
+                mip_level: 0,
+                origin: wgpu::Origin3d::ZERO,
+                aspect: wgpu::TextureAspect::All,
+            },
+            chroma_size,
+        );
+
+        encoder.copy_texture_to_buffer(
+            wgpu::TexelCopyTextureInfo {
+                texture: &r8,
+                mip_level: 0,
+                origin: wgpu::Origin3d::ZERO,
+                aspect: wgpu::TextureAspect::All,
+            },
+            wgpu::TexelCopyBufferInfo {
+                buffer: &r8_readback,
+                layout: wgpu::TexelCopyBufferLayout {
+                    offset: 0,
+                    bytes_per_row: Some(WIDTH),
+                    rows_per_image: Some(HEIGHT),
+                },
+            },
+            luma_size,
+        );
+        encoder.copy_texture_to_buffer(
+            wgpu::TexelCopyTextureInfo {
+                texture: &rg8,
+                mip_level: 0,
+                origin: wgpu::Origin3d::ZERO,
+                aspect: wgpu::TextureAspect::All,
+            },
+            wgpu::TexelCopyBufferInfo {
+                buffer: &rg8_readback,
+                layout: wgpu::TexelCopyBufferLayout {
+                    offset: 0,
+                    bytes_per_row: Some(WIDTH / 2 * 2),
+                    rows_per_image: Some(HEIGHT / 2),
+                },
+            },
+            chroma_size,
+        );
+
+        ctx.queue.submit([encoder.finish()]);
+
+        let r8_slice = r8_readback.slice(..);
+        r8_slice.map_async(wgpu::MapMode::Read, |_| ());
+        let rg8_slice = rg8_readback.slice(..);
+        rg8_slice.map_async(wgpu::MapMode::Read, |_| ());
+        ctx.async_poll(wgpu::PollType::wait_indefinitely())
+            .await
+            .unwrap();
+
+        let r8_data: Vec<u8> = r8_slice.get_mapped_range().unwrap().to_vec();
+        let rg8_data: Vec<u8> = rg8_slice.get_mapped_range().unwrap().to_vec();
+        assert_eq!(r8_data, luma_bytes, "luma plane mismatch");
+        assert_eq!(rg8_data, chroma_bytes, "chroma plane mismatch");
+    });
+
 /// Ensures that copying P010 texture to P010 texture works as expected
 #[gpu_test]
 static P010_TEXTURE_COPYING: GpuTestConfiguration = GpuTestConfiguration::new()

wgpu-core/src/command/transfer.rs

@@ -1373,9 +1373,23 @@ pub(super) fn copy_texture_to_texture(
     dst_texture.same_device(state.device)?;
 
     // src and dst texture format must be copy-compatible
-    // https://gpuweb.github.io/gpuweb/#copy-compatible
-    if src_texture.desc.format.remove_srgb_suffix() != dst_texture.desc.format.remove_srgb_suffix()
-    {
+    // (https://gpuweb.github.io/gpuweb/#copy-compatible), with an
+    // extension allowing one plane of a planar source to be copied
+    // into a single-plane destination of the matching format
+    // (e.g. NV12 Plane0 -> R8Unorm, NV12 Plane1 -> Rg8Unorm).
+    //
+    // When taking this path, `copy_size` and `source.origin` are
+    // interpreted in *plane* texels, not luma texels: copying NV12
+    // Plane1 into an Rg8Unorm of size (W/2, H/2) requires
+    // `copy_size = (W/2, H/2)`. The plane-extent check further down
+    // enforces this against the subsampled plane extent, so a caller
+    // passing luma-sized values gets a source-side error pointing at
+    // the actual mistake rather than an opaque destination overrun.
+    let src_fmt_no_srgb = src_texture.desc.format.remove_srgb_suffix();
+    let dst_fmt_no_srgb = dst_texture.desc.format.remove_srgb_suffix();
+    let planar_split_ok = src_fmt_no_srgb.is_multi_planar_format()
+        && src_fmt_no_srgb.aspect_specific_format(source.aspect) == Some(dst_fmt_no_srgb);
+    if src_fmt_no_srgb != dst_fmt_no_srgb && !planar_split_ok {
         return Err(TransferError::TextureFormatsNotCopyCompatible {
             src_format: src_texture.desc.format,
             dst_format: dst_texture.desc.format,
@@ -1392,6 +1406,45 @@ pub(super) fn copy_texture_to_texture(
         copy_size,
     )?;
 
+    // For planar -> single-plane copies, re-check the source extent
+    // in plane coordinates. `validate_texture_copy_range` above used
+    // the full luma extent of the planar source, so it does not
+    // catch a caller treating `copy_size` / `origin` as luma-sized
+    // when targeting a subsampled plane (NV12/P010 plane 1).
+    if planar_split_ok {
+        // `planar_split_ok` implies `aspect_specific_format(source.aspect)`
+        // returned `Some`, which is only true for `Plane{0,1,2}`.
+        let plane = source.aspect.to_plane().expect("planar_split_ok aspect");
+        let plane_extent = src_texture
+            .desc
+            .compute_render_extent(source.mip_level, Some(plane));
+        let check = |dimension, start: u32, size: u32, plane_size: u32| {
+            if start > plane_size || plane_size - start < size {
+                Err(TransferError::TextureOverrun {
+                    start_offset: start,
+                    end_offset: start.wrapping_add(size),
+                    texture_size: plane_size,
+                    dimension,
+                    side: CopySide::Source,
+                })
+            } else {
+                Ok(())
+            }
+        };
+        check(
+            TextureErrorDimension::X,
+            source.origin.x,
+            copy_size.width,
+            plane_extent.width,
+        )?;
+        check(
+            TextureErrorDimension::Y,
+            source.origin.y,
+            copy_size.height,
+            plane_extent.height,
+        )?;
+    }
+
     if Arc::as_ptr(src_texture) == Arc::as_ptr(dst_texture) {
         validate_copy_within_same_texture(
             source,
@@ -1405,7 +1458,8 @@ pub(super) fn copy_texture_to_texture(
     let (dst_range, dst_tex_base) = extract_texture_selector(destination, copy_size, dst_texture)?;
     let src_texture_aspects = hal::FormatAspects::from(src_texture.desc.format);
     let dst_texture_aspects = hal::FormatAspects::from(dst_texture.desc.format);
-    if src_tex_base.aspect != src_texture_aspects {
+    // `planar_split_ok` already constrains `source.aspect` to a single plane.
+    if src_tex_base.aspect != src_texture_aspects && !planar_split_ok {
         return Err(TransferError::CopySrcMissingAspects.into());
     }
     if dst_tex_base.aspect != dst_texture_aspects {

wgpu-hal/src/auxil/dxgi/conv.rs

@@ -175,6 +175,12 @@ pub fn map_texture_format_for_copy(
             crate::FormatAspects::STENCIL,
         ) => Dxgi::Common::DXGI_FORMAT_R8_UINT,
 
+        // `CopyTextureRegion` on a plane subresource wants the
+        // single-plane DXGI format, not the planar one.
+        (format, aspects) if format.is_multi_planar_format() && aspects.is_one() => {
+            map_texture_format(format.aspect_specific_format(aspects.map())?)
+        }
+
         (format, crate::FormatAspects::COLOR) => map_texture_format(format),
 
         _ => return None,

wgpu-hal/src/dx12/device.rs

@@ -477,6 +477,7 @@ impl super::Device {
                 suballocation::AllocationType::Texture,
                 format.theoretical_memory_footprint(size),
             ),
+            plane_slice_override: None,
         }
     }
 
@@ -598,6 +599,7 @@ impl crate::Device for super::Device {
             mip_level_count: desc.mip_level_count,
             sample_count: desc.sample_count,
             allocation,
+            plane_slice_override: None,
         })
     }
 
@@ -629,7 +631,7 @@ impl crate::Device for super::Device {
             subresource_index: texture.calc_subresource(
                 desc.range.base_mip_level,
                 desc.range.base_array_layer,
-                0,
+                view_desc.plane_slice(),
             ),
             mip_slice: desc.range.base_mip_level,
             handle_srv: if desc.usage.intersects(wgt::TextureUses::RESOURCE) {