java.lang.Object
- org.lwjgl.system.Pointer.Default
- - org.lwjgl.system.Struct
  - - org.lwjgl.vulkan.VkPhysicalDeviceMemoryProperties

All Implemented Interfaces:

java.lang.AutoCloseable, org.lwjgl.system.NativeResource, org.lwjgl.system.Pointer
```
public class VkPhysicalDeviceMemoryProperties
extends org.lwjgl.system.Struct
implements org.lwjgl.system.NativeResource
```
Structure specifying physical device memory properties.
Description

The VkPhysicalDeviceMemoryProperties structure describes a number of memory heaps as well as a number of memory types that can be used to access memory allocated in those heaps. Each heap describes a memory resource of a particular size, and each memory type describes a set of memory properties (e.g. host cached vs uncached) that can be used with a given memory heap. Allocations using a particular memory type will consume resources from the heap indicated by that memory type's heap index. More than one memory type may share each heap, and the heaps and memory types provide a mechanism to advertise an accurate size of the physical memory resources while allowing the memory to be used with a variety of different properties.

The number of memory heaps is given by memoryHeapCount and is less than or equal to MAX_MEMORY_HEAPS. Each heap is described by an element of the memoryHeaps array as a VkMemoryHeap structure. The number of memory types available across all memory heaps is given by memoryTypeCount and is less than or equal to MAX_MEMORY_TYPES. Each memory type is described by an element of the memoryTypes array as a VkMemoryType structure.

At least one heap must include MEMORY_HEAP_DEVICE_LOCAL_BIT in VkMemoryHeap::flags. If there are multiple heaps that all have similar performance characteristics, they may all include MEMORY_HEAP_DEVICE_LOCAL_BIT. In a unified memory architecture (UMA) system there is often only a single memory heap which is considered to be equally "local" to the host and to the device, and such an implementation must advertise the heap as device-local.

Each memory type returned by GetPhysicalDeviceMemoryProperties must have its propertyFlags set to one of the following values:
There must be at least one memory type with both the MEMORY_PROPERTY_HOST_VISIBLE_BIT and MEMORY_PROPERTY_HOST_COHERENT_BIT bits set in its propertyFlags. There must be at least one memory type with the MEMORY_PROPERTY_DEVICE_LOCAL_BIT bit set in its propertyFlags. If the deviceCoherentMemory feature is enabled, there must be at least one memory type with the MEMORY_PROPERTY_DEVICE_COHERENT_BIT_AMD bit set in its propertyFlags.

For each pair of elements X and Y returned in memoryTypes, X must be placed at a lower index position than Y if:
- either the set of bit flags returned in the propertyFlags member of X is a strict subset of the set of bit flags returned in the propertyFlags member of Y; or
- the propertyFlags members of X and Y are equal, and X belongs to a memory heap with greater performance (as determined in an implementation-specific manner) ; or
- or the propertyFlags members of X includes MEMORY_PROPERTY_DEVICE_COHERENT_BIT_AMD or MEMORY_PROPERTY_DEVICE_UNCACHED_BIT_AMD and Y does not
Note

There is no ordering requirement between X and Y elements for the case their propertyFlags members are not in a subset relation. That potentially allows more than one possible way to order the same set of memory types. Notice that the list of all allowed memory property flag combinations is written in a valid order. But if instead MEMORY_PROPERTY_DEVICE_LOCAL_BIT was before MEMORY_PROPERTY_HOST_VISIBLE_BIT | MEMORY_PROPERTY_HOST_COHERENT_BIT, the list would still be in a valid order.

There may be a performance penalty for using device coherent or uncached device memory types, and using these accidentally is undesirable. In order to avoid this, memory types with these properties always appear at the end of the list; but are subject to the same rules otherwise.

This ordering requirement enables applications to use a simple search loop to select the desired memory type along the lines of:
```
 // Find a memory in `memoryTypeBitsRequirement` that includes all of `requiredProperties`
 int32_t findProperties(const VkPhysicalDeviceMemoryProperties* pMemoryProperties,
                        uint32_t memoryTypeBitsRequirement,
                        VkMemoryPropertyFlags requiredProperties) {
     const uint32_t memoryCount = pMemoryProperties->memoryTypeCount;
     for (uint32_t memoryIndex = 0; memoryIndex < memoryCount; ++memoryIndex) {
         const uint32_t memoryTypeBits = (1 << memoryIndex);
         const bool isRequiredMemoryType = memoryTypeBitsRequirement & memoryTypeBits;
 
         const VkMemoryPropertyFlags properties =
             pMemoryProperties->memoryTypes[memoryIndex].propertyFlags;
         const bool hasRequiredProperties =
             (properties & requiredProperties) == requiredProperties;
 
         if (isRequiredMemoryType && hasRequiredProperties)
             return static_cast<int32_t>(memoryIndex);
     }
 
     // failed to find memory type
     return -1;
 }
 
 // Try to find an optimal memory type, or if it does not exist try fallback memory type
 // `device` is the VkDevice
 // `image` is the VkImage that requires memory to be bound
 // `memoryProperties` properties as returned by vkGetPhysicalDeviceMemoryProperties
 // `requiredProperties` are the property flags that must be present
 // `optimalProperties` are the property flags that are preferred by the application
 VkMemoryRequirements memoryRequirements;
 vkGetImageMemoryRequirements(device, image, &memoryRequirements);
 int32_t memoryType =
     findProperties(&memoryProperties, memoryRequirements.memoryTypeBits, optimalProperties);
 if (memoryType == -1) // not found; try fallback properties
     memoryType =
         findProperties(&memoryProperties, memoryRequirements.memoryTypeBits, requiredProperties);
```
See Also

VkMemoryHeap, VkMemoryType, VkPhysicalDeviceMemoryProperties2, GetPhysicalDeviceMemoryProperties

Member documentation
- memoryTypeCount – the number of valid elements in the memoryTypes array.
- memoryTypes[VK_MAX_MEMORY_TYPES] – an array of VkMemoryType structures describing the memory types that can be used to access memory allocated from the heaps specified by memoryHeaps.
- memoryHeapCount – the number of valid elements in the memoryHeaps array.
- memoryHeaps[VK_MAX_MEMORY_HEAPS] – an array of VkMemoryHeap structures describing the memory heaps from which memory can be allocated.
Layout
```
 struct VkPhysicalDeviceMemoryProperties {
     uint32_t memoryTypeCount;
     VkMemoryType memoryTypes[VK_MAX_MEMORY_TYPES];
     uint32_t memoryHeapCount;
     VkMemoryHeap memoryHeaps[VK_MAX_MEMORY_HEAPS];
 }
```

Nested Class Summary

Nested Classes
Modifier and Type Class Description

static class VkPhysicalDeviceMemoryProperties.Buffer
An array of VkPhysicalDeviceMemoryProperties structs.
- Nested classes/interfaces inherited from interface org.lwjgl.system.Pointer
  org.lwjgl.system.Pointer.Default

Field Summary

Fields
Modifier and Type	Field	Description
`static int`	`ALIGNOF`	The struct alignment in bytes.
`static int`	`MEMORYHEAPCOUNT MEMORYHEAPS MEMORYTYPECOUNT MEMORYTYPES`	The struct member offsets.
`static int`	`SIZEOF`	The struct size in bytes.

Fields inherited from interface org.lwjgl.system.Pointer
BITS32, BITS64, CLONG_SHIFT, CLONG_SIZE, POINTER_SHIFT, POINTER_SIZE

Constructor Summary

Constructors
Constructor	Description
`VkPhysicalDeviceMemoryProperties(java.nio.ByteBuffer container)`	Creates a `VkPhysicalDeviceMemoryProperties` instance at the current position of the specified `ByteBuffer` container.

Method Summary

All Methods Static Methods Instance Methods Concrete Methods
Modifier and Type	Method	Description
`static VkPhysicalDeviceMemoryProperties`	`calloc()`	Returns a new `VkPhysicalDeviceMemoryProperties` instance allocated with `memCalloc`.
`static VkPhysicalDeviceMemoryProperties.Buffer`	`calloc(int capacity)`	Returns a new `VkPhysicalDeviceMemoryProperties.Buffer` instance allocated with `memCalloc`.
`static VkPhysicalDeviceMemoryProperties`	`callocStack()`	Returns a new `VkPhysicalDeviceMemoryProperties` instance allocated on the thread-local `MemoryStack` and initializes all its bits to zero.
`static VkPhysicalDeviceMemoryProperties.Buffer`	`callocStack(int capacity)`	Returns a new `VkPhysicalDeviceMemoryProperties.Buffer` instance allocated on the thread-local `MemoryStack` and initializes all its bits to zero.
`static VkPhysicalDeviceMemoryProperties.Buffer`	`callocStack(int capacity, org.lwjgl.system.MemoryStack stack)`	Returns a new `VkPhysicalDeviceMemoryProperties.Buffer` instance allocated on the specified `MemoryStack` and initializes all its bits to zero.
`static VkPhysicalDeviceMemoryProperties`	`callocStack(org.lwjgl.system.MemoryStack stack)`	Returns a new `VkPhysicalDeviceMemoryProperties` instance allocated on the specified `MemoryStack` and initializes all its bits to zero.
`static VkPhysicalDeviceMemoryProperties`	`create()`	Returns a new `VkPhysicalDeviceMemoryProperties` instance allocated with `BufferUtils`.
`static VkPhysicalDeviceMemoryProperties.Buffer`	`create(int capacity)`	Returns a new `VkPhysicalDeviceMemoryProperties.Buffer` instance allocated with `BufferUtils`.
`static VkPhysicalDeviceMemoryProperties`	`create(long address)`	Returns a new `VkPhysicalDeviceMemoryProperties` instance for the specified memory address.
`static VkPhysicalDeviceMemoryProperties.Buffer`	`create(long address, int capacity)`	Create a `VkPhysicalDeviceMemoryProperties.Buffer` instance at the specified memory.
`static VkPhysicalDeviceMemoryProperties`	`createSafe(long address)`	Like `create`, but returns `null` if `address` is `NULL`.
`static VkPhysicalDeviceMemoryProperties.Buffer`	`createSafe(long address, int capacity)`	Like `create`, but returns `null` if `address` is `NULL`.
`static VkPhysicalDeviceMemoryProperties`	`malloc()`	Returns a new `VkPhysicalDeviceMemoryProperties` instance allocated with `memAlloc`.
`static VkPhysicalDeviceMemoryProperties.Buffer`	`malloc(int capacity)`	Returns a new `VkPhysicalDeviceMemoryProperties.Buffer` instance allocated with `memAlloc`.
`static VkPhysicalDeviceMemoryProperties`	`mallocStack()`	Returns a new `VkPhysicalDeviceMemoryProperties` instance allocated on the thread-local `MemoryStack`.
`static VkPhysicalDeviceMemoryProperties.Buffer`	`mallocStack(int capacity)`	Returns a new `VkPhysicalDeviceMemoryProperties.Buffer` instance allocated on the thread-local `MemoryStack`.
`static VkPhysicalDeviceMemoryProperties.Buffer`	`mallocStack(int capacity, org.lwjgl.system.MemoryStack stack)`	Returns a new `VkPhysicalDeviceMemoryProperties.Buffer` instance allocated on the specified `MemoryStack`.
`static VkPhysicalDeviceMemoryProperties`	`mallocStack(org.lwjgl.system.MemoryStack stack)`	Returns a new `VkPhysicalDeviceMemoryProperties` instance allocated on the specified `MemoryStack`.
`int`	`memoryHeapCount()`	Returns the value of the `memoryHeapCount` field.
`VkMemoryHeap.Buffer`	`memoryHeaps()`	Returns a `VkMemoryHeap`.Buffer view of the `memoryHeaps` field.
`VkMemoryHeap`	`memoryHeaps(int index)`	Returns a `VkMemoryHeap` view of the struct at the specified index of the `memoryHeaps` field.
`int`	`memoryTypeCount()`	Returns the value of the `memoryTypeCount` field.
`VkMemoryType.Buffer`	`memoryTypes()`	Returns a `VkMemoryType`.Buffer view of the `memoryTypes` field.
`VkMemoryType`	`memoryTypes(int index)`	Returns a `VkMemoryType` view of the struct at the specified index of the `memoryTypes` field.
`static int`	`nmemoryHeapCount(long struct)`	Unsafe version of `memoryHeapCount()`.
`static VkMemoryHeap.Buffer`	`nmemoryHeaps(long struct)`	Unsafe version of `memoryHeaps()`.
`static VkMemoryHeap`	`nmemoryHeaps(long struct, int index)`	Unsafe version of `memoryHeaps`.
`static int`	`nmemoryTypeCount(long struct)`	Unsafe version of `memoryTypeCount()`.
`static VkMemoryType.Buffer`	`nmemoryTypes(long struct)`	Unsafe version of `memoryTypes()`.
`static VkMemoryType`	`nmemoryTypes(long struct, int index)`	Unsafe version of `memoryTypes`.
`int`	`sizeof()`

Methods inherited from interface org.lwjgl.system.NativeResource
close, free

Methods inherited from class java.lang.Object
getClass, notify, notifyAll, wait, wait, wait

Methods inherited from class org.lwjgl.system.Pointer.Default
address, equals, hashCode, toString

Methods inherited from class org.lwjgl.system.Struct
clear, free, isNull

- Field Detail
  - SIZEOF
    
    The struct size in bytes.
  - ALIGNOF
    
    The struct alignment in bytes.
  - MEMORYTYPECOUNT, MEMORYTYPES, MEMORYHEAPCOUNT, MEMORYHEAPS
    
    The struct member offsets.
- Constructor Detail
  - VkPhysicalDeviceMemoryProperties
```
public VkPhysicalDeviceMemoryProperties(java.nio.ByteBuffer container)
```
    Creates a VkPhysicalDeviceMemoryProperties instance at the current position of the specified ByteBuffer container. Changes to the buffer's content will be visible to the struct instance and vice versa.
    The created instance holds a strong reference to the container object.
- Method Detail
  - sizeof
```
public int sizeof()
```
    Specified by:
    
    sizeof in class org.lwjgl.system.Struct
  - memoryTypeCount
```
public int memoryTypeCount()
```
    Returns the value of the memoryTypeCount field.
  - memoryTypes
```
public VkMemoryType.Buffer memoryTypes()
```
    Returns a VkMemoryType.Buffer view of the memoryTypes field.
  - memoryTypes
```
public VkMemoryType memoryTypes(int index)
```
    Returns a VkMemoryType view of the struct at the specified index of the memoryTypes field.
  - memoryHeapCount
```
public int memoryHeapCount()
```
    Returns the value of the memoryHeapCount field.
  - memoryHeaps
```
public VkMemoryHeap.Buffer memoryHeaps()
```
    Returns a VkMemoryHeap.Buffer view of the memoryHeaps field.
  - memoryHeaps
```
public VkMemoryHeap memoryHeaps(int index)
```
    Returns a VkMemoryHeap view of the struct at the specified index of the memoryHeaps field.
  - malloc
```
public static VkPhysicalDeviceMemoryProperties malloc()
```
    Returns a new VkPhysicalDeviceMemoryProperties instance allocated with memAlloc. The instance must be explicitly freed.
  - calloc
```
public static VkPhysicalDeviceMemoryProperties calloc()
```
    Returns a new VkPhysicalDeviceMemoryProperties instance allocated with memCalloc. The instance must be explicitly freed.
  - create
```
public static VkPhysicalDeviceMemoryProperties create()
```
    Returns a new VkPhysicalDeviceMemoryProperties instance allocated with BufferUtils.
  - create
```
public static VkPhysicalDeviceMemoryProperties create(long address)
```
    Returns a new VkPhysicalDeviceMemoryProperties instance for the specified memory address.
  - createSafe
```
@Nullable
public static VkPhysicalDeviceMemoryProperties createSafe(long address)
```
    Like create, but returns null if address is NULL.
  - malloc
```
public static VkPhysicalDeviceMemoryProperties.Buffer malloc(int capacity)
```
    Returns a new VkPhysicalDeviceMemoryProperties.Buffer instance allocated with memAlloc. The instance must be explicitly freed.
    
    Parameters:
    
    capacity - the buffer capacity
  - calloc
```
public static VkPhysicalDeviceMemoryProperties.Buffer calloc(int capacity)
```
    Returns a new VkPhysicalDeviceMemoryProperties.Buffer instance allocated with memCalloc. The instance must be explicitly freed.
    
    Parameters:
    
    capacity - the buffer capacity
  - create
```
public static VkPhysicalDeviceMemoryProperties.Buffer create(int capacity)
```
    Returns a new VkPhysicalDeviceMemoryProperties.Buffer instance allocated with BufferUtils.
    
    Parameters:
    
    capacity - the buffer capacity
  - create
```
public static VkPhysicalDeviceMemoryProperties.Buffer create(long address,
                                                             int capacity)
```
    Create a VkPhysicalDeviceMemoryProperties.Buffer instance at the specified memory.
    
    Parameters:
    
    address - the memory address
    
    capacity - the buffer capacity
  - createSafe
```
@Nullable
public static VkPhysicalDeviceMemoryProperties.Buffer createSafe(long address,
                                                                 int capacity)
```
    Like create, but returns null if address is NULL.
  - mallocStack
```
public static VkPhysicalDeviceMemoryProperties mallocStack()
```
    Returns a new VkPhysicalDeviceMemoryProperties instance allocated on the thread-local MemoryStack.
  - callocStack
```
public static VkPhysicalDeviceMemoryProperties callocStack()
```
    Returns a new VkPhysicalDeviceMemoryProperties instance allocated on the thread-local MemoryStack and initializes all its bits to zero.
  - mallocStack
```
public static VkPhysicalDeviceMemoryProperties mallocStack(org.lwjgl.system.MemoryStack stack)
```
    Returns a new VkPhysicalDeviceMemoryProperties instance allocated on the specified MemoryStack.
    
    Parameters:
    
    stack - the stack from which to allocate
  - callocStack
```
public static VkPhysicalDeviceMemoryProperties callocStack(org.lwjgl.system.MemoryStack stack)
```
    Returns a new VkPhysicalDeviceMemoryProperties instance allocated on the specified MemoryStack and initializes all its bits to zero.
    
    Parameters:
    
    stack - the stack from which to allocate
  - mallocStack
```
public static VkPhysicalDeviceMemoryProperties.Buffer mallocStack(int capacity)
```
    Returns a new VkPhysicalDeviceMemoryProperties.Buffer instance allocated on the thread-local MemoryStack.
    
    Parameters:
    
    capacity - the buffer capacity
  - callocStack
```
public static VkPhysicalDeviceMemoryProperties.Buffer callocStack(int capacity)
```
    Returns a new VkPhysicalDeviceMemoryProperties.Buffer instance allocated on the thread-local MemoryStack and initializes all its bits to zero.
    
    Parameters:
    
    capacity - the buffer capacity
  - mallocStack
```
public static VkPhysicalDeviceMemoryProperties.Buffer mallocStack(int capacity,
                                                                  org.lwjgl.system.MemoryStack stack)
```
    Returns a new VkPhysicalDeviceMemoryProperties.Buffer instance allocated on the specified MemoryStack.
    
    Parameters:
    
    stack - the stack from which to allocate
    
    capacity - the buffer capacity
  - callocStack
```
public static VkPhysicalDeviceMemoryProperties.Buffer callocStack(int capacity,
                                                                  org.lwjgl.system.MemoryStack stack)
```
    Returns a new VkPhysicalDeviceMemoryProperties.Buffer instance allocated on the specified MemoryStack and initializes all its bits to zero.
    
    Parameters:
    
    stack - the stack from which to allocate
    
    capacity - the buffer capacity
  - nmemoryTypeCount
```
public static int nmemoryTypeCount(long struct)
```
    Unsafe version of memoryTypeCount().
  - nmemoryTypes
```
public static VkMemoryType.Buffer nmemoryTypes(long struct)
```
    Unsafe version of memoryTypes().
  - nmemoryTypes
```
public static VkMemoryType nmemoryTypes(long struct,
                                        int index)
```
    Unsafe version of memoryTypes.
  - nmemoryHeapCount
```
public static int nmemoryHeapCount(long struct)
```
    Unsafe version of memoryHeapCount().
  - nmemoryHeaps
```
public static VkMemoryHeap.Buffer nmemoryHeaps(long struct)
```
    Unsafe version of memoryHeaps().
  - nmemoryHeaps
```
public static VkMemoryHeap nmemoryHeaps(long struct,
                                        int index)
```
    Unsafe version of memoryHeaps.

Class VkPhysicalDeviceMemoryProperties

Description

Note

See Also

Member documentation

Layout

Nested Class Summary

Nested classes/interfaces inherited from interface org.lwjgl.system.Pointer

Field Summary

Fields inherited from interface org.lwjgl.system.Pointer

Constructor Summary

Method Summary

Methods inherited from interface org.lwjgl.system.NativeResource

Methods inherited from class java.lang.Object

Methods inherited from class org.lwjgl.system.Pointer.Default

Methods inherited from class org.lwjgl.system.Struct

Field Detail

SIZEOF

ALIGNOF

MEMORYTYPECOUNT, MEMORYTYPES, MEMORYHEAPCOUNT, MEMORYHEAPS

Constructor Detail

VkPhysicalDeviceMemoryProperties

Method Detail

sizeof

memoryTypeCount

memoryTypes

memoryTypes

memoryHeapCount

memoryHeaps

memoryHeaps

malloc

calloc

create

create

createSafe

malloc

calloc

create

create

createSafe

mallocStack

callocStack

mallocStack

callocStack

mallocStack

callocStack

mallocStack

callocStack

nmemoryTypeCount

nmemoryTypes

nmemoryTypes

nmemoryHeapCount

nmemoryHeaps

nmemoryHeaps