reorg linux-specific methods a bit

src/surface.rs

@@ -528,39 +528,6 @@ impl Surface {
             })
         }
     }
-
-    /// Returns a pointer to the `wl_buffer` containing this [`Surface`]s pixel data.
-    ///
-    /// This function will only succeed if the [`Display`] this [`Surface`] was created from is
-    /// using the Wayland backend. To check the VA-API backend type, use [`Display::display_api`].
-    ///
-    /// The returned pointer is valid while the [`Surface`] exists.
-    ///
-    /// [`Surface::sync`] should be called before using the `wl_buffer`, to ensure that all enqueued
-    /// operations have finished.
-    ///
-    /// **Note**: The underlying function, `vaGetSurfaceBufferWl`, is not implemented on Mesa/AMD,
-    /// so this will always return an error there.
-    ///
-    /// (also note that the `wl_buffer` type in the documentation is deliberately private; cast it
-    /// to the desired type to use it)
-    #[cfg(target_os = "linux")]
-    #[cfg_attr(docsrs, doc(cfg(target_os = "linux")))]
-    pub fn wayland_buffer(&self) -> Result<*mut crate::dlopen::wl_buffer> {
-        unsafe {
-            let mut wlbufferptr = MaybeUninit::uninit();
-            check(
-                "vaGetSurfaceBufferWl",
-                crate::dlopen::libva_wayland::get()?.vaGetSurfaceBufferWl(
-                    self.d.raw,
-                    self.id,
-                    0,
-                    wlbufferptr.as_mut_ptr(),
-                ),
-            )?;
-            Ok(wlbufferptr.assume_init())
-        }
-    }
 }
 
 impl Drop for Surface {

src/surface/drm.rs

@@ -1,11 +1,17 @@
 //! DRM PRIME surface export/import.
 //!
 //! This wraps some of the functionality in `va_drmcommon.h`.
+//!
+//! Also see [`Surface::export_prime`].
 
 use core::fmt;
 use std::{mem::MaybeUninit, os::fd::RawFd};
 
-use crate::{check, PixelFormat, Result};
+use crate::{
+    check,
+    dlopen::{libva_wayland, wl_buffer},
+    PixelFormat, Result,
+};
 
 use super::{ExportSurfaceFlags, Surface, SurfaceAttribMemoryType};
 
@@ -40,31 +46,52 @@ impl fmt::Debug for PrimeSurfaceDescriptor {
 }
 
 impl PrimeSurfaceDescriptor {
+    /// Returns the FourCC code of the overall PRIME surface (eg. [`PixelFormat::NV12`]).
     #[inline]
     pub fn fourcc(&self) -> PixelFormat {
         self.fourcc
     }
 
+    /// Returns the width of the exported surface in pixels.
     #[inline]
     pub fn width(&self) -> u32 {
         self.width
     }
 
+    /// Returns the height of the exported surface in pixels.
     #[inline]
     pub fn height(&self) -> u32 {
         self.height
     }
 
+    /// Returns the list of PRIME objects that make up the surface.
+    ///
+    /// There should be at least 1 object in here, but many multiplanar formats like
+    /// [`PixelFormat::NV12`] are represented as two separate objects.
     #[inline]
     pub fn objects(&self) -> &[PrimeObject] {
         &self.objects[..self.num_objects as usize]
     }
 
+    /// Returns the PRIME object at `index`.
+    ///
+    /// `index` is typically taken from [`PrimePlane::object_index`].
+    ///
+    /// # Panics
+    ///
+    /// This will panic if `index` is out of bounds.
     pub fn object(&self, index: u32) -> &PrimeObject {
         assert!(index < self.num_objects && index < 4);
         &self.objects[index as usize]
     }
 
+    /// Returns the list of PRIME layers making up the surface.
+    ///
+    /// If [`ExportSurfaceFlags::COMPOSED_LAYERS`] was used to export the [`Surface`], there will be
+    /// exactly one layer (potentially with multiple planes).
+    ///
+    /// If [`ExportSurfaceFlags::SEPARATE_LAYERS`] was used, each layer will contain a single plane,
+    /// and multi-planar formats will have multiple layers.
     #[inline]
     pub fn layers(&self) -> &[PrimeLayer] {
         &self.layers[..self.num_layers as usize]
@@ -188,6 +215,7 @@ impl PrimePlane {
     }
 }
 
+/// Linux-specific surface methods.
 impl Surface {
     /// Exports a surface as a set of DRM PRIME objects.
     ///
@@ -219,4 +247,36 @@ impl Surface {
             Ok(descriptor.assume_init())
         }
     }
+
+    /// Returns a pointer to the `wl_buffer` containing this [`Surface`]s pixel data.
+    ///
+    /// This function will only succeed if the [`Display`][crate::display::Display] this [`Surface`]
+    /// was created from is using the Wayland backend. To check the VA-API backend type, use
+    /// [`Display::display_api`][crate::display::Display::display_api].
+    ///
+    /// The returned pointer is valid while the [`Surface`] exists.
+    ///
+    /// [`Surface::sync`] should be called before using the `wl_buffer`, to ensure that all enqueued
+    /// operations have finished.
+    ///
+    /// **Note**: The underlying function, `vaGetSurfaceBufferWl`, is not implemented on Mesa/AMD,
+    /// so this will always return an error there.
+    ///
+    /// (also note that the `wl_buffer` type in the documentation is deliberately private; cast it
+    /// to the desired type to use it)
+    pub fn wayland_buffer(&self) -> Result<*mut wl_buffer> {
+        unsafe {
+            let mut wlbufferptr = MaybeUninit::uninit();
+            check(
+                "vaGetSurfaceBufferWl",
+                libva_wayland::get()?.vaGetSurfaceBufferWl(
+                    self.d.raw,
+                    self.id,
+                    0,
+                    wlbufferptr.as_mut_ptr(),
+                ),
+            )?;
+            Ok(wlbufferptr.assume_init())
+        }
+    }
 }