Struct MPSVector

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pub struct MPSVector { /* private fields */ }

Available on crate feature MPSMatrix only.

Expand description

Dependencies: This depends on Metal.framework

A MPSVector object describes a 1-dimensional array of data and provides storage for its values. Some MPSMatrixKernel objects operate on MPSVector objects for convenience.

Implementations§

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impl MPSVector

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pub unsafe fn device(&self) -> Retained<ProtocolObject<dyn MTLDevice>>

Available on crate feature MPSCore only.

The device on which the MPSVector will be used.

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pub unsafe fn length(&self) -> NSUInteger

Available on crate feature MPSCore only.

The number of elements in the vector.

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pub unsafe fn vectors(&self) -> NSUInteger

Available on crate feature MPSCore only.

The number of vectors in the MPSVector.

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pub unsafe fn dataType(&self) -> MPSDataType

Available on crate features MPSCore and MPSCoreTypes only.

The type of the MPSVector data.

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pub unsafe fn vectorBytes(&self) -> NSUInteger

Available on crate feature MPSCore only.

The stride, in bytes, between corresponding elements of consecutive vectors.

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pub unsafe fn offset(&self) -> NSUInteger

Available on crate feature MPSCore only.

Byte-offset to the buffer where the vector data begins - see initWithBuffer:offset: descriptor: .

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pub unsafe fn data(&self) -> Retained<ProtocolObject<dyn MTLBuffer>>

Available on crate feature MPSCore only.

An MTLBuffer to store the data.

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pub unsafe fn initWithBuffer_descriptor( this: Allocated<Self>, buffer: &ProtocolObject<dyn MTLBuffer>, descriptor: &MPSVectorDescriptor, ) -> Retained<Self>

Available on crate feature MPSCore only.

Initialize a MPSVector object with a MTLBuffer.

Parameter buffer: The MTLBuffer object which contains the data to use for the MPSVector. May not be NULL.

Parameter descriptor: The MPSVectorDescriptor. May not be NULL.

Returns: A valid MPSVector object or nil, if failure.

This function returns a MPSVector object which uses the supplied MTLBuffer. The length, number of vectors, and stride between vectors are specified by the MPSVectorDescriptor object.

The provided MTLBuffer must have enough storage to hold

(descriptor.vectors-1) * descriptor.vectorBytes + descriptor.length * (element size) bytes.

§Safety

buffer may need to be synchronized.
buffer may be unretained, you must ensure it is kept alive while in use.
buffer contents should be of the correct type.

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pub unsafe fn initWithBuffer_offset_descriptor( this: Allocated<Self>, buffer: &ProtocolObject<dyn MTLBuffer>, offset: NSUInteger, descriptor: &MPSVectorDescriptor, ) -> Retained<Self>

Available on crate feature MPSCore only.

Initialize a MPSVector object with a MTLBuffer and an offset.

Parameter buffer: The MTLBuffer containing the data.

Parameter offset: The offset, in bytes, into the buffer at which data begins.

Parameter descriptor: The MPSVectorDescriptor.

§Safety

buffer may need to be synchronized.
buffer may be unretained, you must ensure it is kept alive while in use.
buffer contents should be of the correct type.

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pub unsafe fn initWithDevice_descriptor( this: Allocated<Self>, device: &ProtocolObject<dyn MTLDevice>, descriptor: &MPSVectorDescriptor, ) -> Retained<Self>

Available on crate feature MPSCore only.

Initialize a lazily backed MPSVector object with a descriptor

Parameter device: The device with which it will be used

Parameter descriptor: The shape and style of the matrix

Returns: A valid MPSVector object or nil

The vector object will be created, but the storage to hold the vector data will only be allocated when it is needed, typically when the data property is invoked. In conjunction with -resourceSize, this will allow you to estimate storage needs without actually creating the backing store for the vector.

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pub unsafe fn init(this: Allocated<Self>) -> Retained<Self>

Available on crate feature MPSCore only.

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pub unsafe fn synchronizeOnCommandBuffer( &self, command_buffer: &ProtocolObject<dyn MTLCommandBuffer>, )

Available on crate feature MPSCore only.

Flush the underlying MTLBuffer from the device’s caches, and invalidate any CPU caches if needed.

This will call [id <MTLBlitEncoder

synchronizeResource: ] on the vector’s MTLBuffer, if any. This is necessary for all MTLStorageModeManaged resources. For other resources, including temporary resources (these are all MTLStorageModePrivate), and buffers that have not yet been allocated, nothing is done. It is more efficient to use this method than to attempt to do this yourself with the data property.

Parameter commandBuffer: The commandbuffer on which to synchronize

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pub unsafe fn resourceSize(&self) -> NSUInteger

Available on crate feature MPSCore only.

Get the number of bytes used to allocate underyling MTLResources

This is the size of the backing store of underlying MTLResources. It does not include all storage used by the object, for example the storage used to hold the MPSVector instantiation and MTLBuffer is not included. It only measures the size of the allocation used to hold the vector data in the buffer. This value is subject to change between different devices and operating systems.

Except when -initWithBuffer:descriptor: is used, most MPSVectors are allocated without a backing store. The backing store is allocated lazily when it is needed, typically when the .texture property is called. Consequently, in most cases, it should be inexpensive to make a MPSMatrix to see how much memory it will need, and release it if it is too large.

This method may fail in certain circumstances, such as when the MPSMatrix is created with -initWithBuffer:descriptor:. In such cases, 0 will be returned.

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impl MPSVector

Methods declared on superclass NSObject.

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pub unsafe fn new() -> Retained<Self>

Available on crate feature MPSCore only.

Methods from Deref<Target = NSObject>§

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pub fn doesNotRecognizeSelector(&self, sel: Sel) -> !

Handle messages the object doesn’t recognize.

See Apple’s documentation for details.

Methods from Deref<Target = AnyObject>§

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pub fn class(&self) -> &'static AnyClass

Dynamically find the class of this object.

§Panics

May panic if the object is invalid (which may be the case for objects returned from unavailable init/new methods).

§Example

Check that an instance of NSObject has the precise class NSObject.

use objc2::ClassType;
use objc2::runtime::NSObject;

let obj = NSObject::new();
assert_eq!(obj.class(), NSObject::class());

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pub unsafe fn get_ivar<T>(&self, name: &str) -> &T
where T: Encode,

👎Deprecated: this is difficult to use correctly, use Ivar::load instead.

Use Ivar::load instead.

§Safety

The object must have an instance variable with the given name, and it must be of type T.

See Ivar::load_ptr for details surrounding this.

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pub fn downcast_ref<T>(&self) -> Option<&T>
where T: DowncastTarget,

Attempt to downcast the object to a class of type T.

This is the reference-variant. Use Retained::downcast if you want to convert a retained object to another type.

§Mutable classes

Some classes have immutable and mutable variants, such as NSString and NSMutableString.

When some Objective-C API signature says it gives you an immutable class, it generally expects you to not mutate that, even though it may technically be mutable “under the hood”.

So using this method to convert a NSString to a NSMutableString, while not unsound, is generally frowned upon unless you created the string yourself, or the API explicitly documents the string to be mutable.

See Apple’s documentation on mutability and on isKindOfClass: for more details.

§Generic classes

Objective-C generics are called “lightweight generics”, and that’s because they aren’t exposed in the runtime. This makes it impossible to safely downcast to generic collections, so this is disallowed by this method.

You can, however, safely downcast to generic collections where all the type-parameters are AnyObject.

§Panics

This works internally by calling isKindOfClass:. That means that the object must have the instance method of that name, and an exception will be thrown (if CoreFoundation is linked) or the process will abort if that is not the case. In the vast majority of cases, you don’t need to worry about this, since both root objects NSObject and NSProxy implement this method.

§Examples

Cast an NSString back and forth from NSObject.

use objc2::rc::Retained;
use objc2_foundation::{NSObject, NSString};

let obj: Retained<NSObject> = NSString::new().into_super();
let string = obj.downcast_ref::<NSString>().unwrap();
// Or with `downcast`, if we do not need the object afterwards
let string = obj.downcast::<NSString>().unwrap();

Try (and fail) to cast an NSObject to an NSString.

use objc2_foundation::{NSObject, NSString};

let obj = NSObject::new();
assert!(obj.downcast_ref::<NSString>().is_none());

Try to cast to an array of strings.

use objc2_foundation::{NSArray, NSObject, NSString};

let arr = NSArray::from_retained_slice(&[NSObject::new()]);
// This is invalid and doesn't type check.
let arr = arr.downcast_ref::<NSArray<NSString>>();

This fails to compile, since it would require enumerating over the array to ensure that each element is of the desired type, which is a performance pitfall.

Downcast when processing each element instead.

use objc2_foundation::{NSArray, NSObject, NSString};

let arr = NSArray::from_retained_slice(&[NSObject::new()]);

for elem in arr {
    if let Some(data) = elem.downcast_ref::<NSString>() {
        // handle `data`
    }
}