Add ResourceMemory::from_device_memory_unchecked (#2519)

vulkano/src/memory/mod.rs

@@ -146,11 +146,43 @@ impl ResourceMemory {
  unsafe { Self::new_dedicated_unchecked(Arc::new(device_memory)) }
  }
 
- #[cfg_attr(not(feature = "document_unchecked"), doc(hidden))]
+ /// Same as [`new_dedicated`], except that this allows creating aliasing resources.
+ ///
+ /// # Safety
+ ///
+ /// - Two resources must not alias each other, and if they do, you must ensure correct
+ /// synchronization yourself.
  pub unsafe fn new_dedicated_unchecked(device_memory: Arc<DeviceMemory>) -> Self {
+ let size = device_memory.allocation_size();
+
+ unsafe { Self::from_device_memory_unchecked(device_memory, 0, size) }
+ }
+
+ /// Creates a new `ResourceMemory` from the given portion of the given device memory block. You
+ /// may use this when you need to portion an existing memory block in a specific way. Note that
+ /// when you don't have this requirement of placing resources at specific offsets, you should
+ /// use a memory allocator instead.
+ ///
+ /// # Safety
+ ///
+ /// - Two resources must not alias each other (as returned by [`Buffer::memory_requirements`]
+ /// or [`Image::memory_requirements`]), and if they do, you must ensure correct
+ /// synchronization yourself.
+ ///
+ /// # Panics
+ ///
+ /// - Panics if `offset + size` is greater than `device_memory.allocation_size()`.
+ pub unsafe fn from_device_memory_unchecked(
+ device_memory: Arc<DeviceMemory>,
+ offset: DeviceSize,
+ size: DeviceSize,
+ ) -> Self {
+ assert!(offset <= device_memory.allocation_size());
+ assert!(size <= device_memory.allocation_size() - offset);
+
  ResourceMemory {
- offset: 0,
- size: device_memory.allocation_size(),
+ offset,
+ size,
  allocation_type: AllocationType::Unknown,
  allocation_handle: AllocationHandle::null(),
  suballocation_handle: None,