Struct MPSImageHistogram 

pub struct MPSImageHistogram { /* private fields */ }

Available on crate features MPSCore and MPSImageHistogram and MPSKernel only.

The MPSImageHistogram computes the histogram of an image.

See also Apple’s documentation

Implementations

impl MPSImageHistogram

pub unsafe fn clipRectSource(&self) -> MTLRegion

Available on crate feature MPSImage only.

The source rectangle to use when reading data.

A MTLRegion that indicates which part of the source to read. If the clipRectSource does not lie completely within the source image, the intersection of the image bounds and clipRectSource will be used. The clipRectSource replaces the MPSUnaryImageKernel offset parameter for this filter. The latter is ignored. Default: MPSRectNoClip, use the entire source texture.

pub unsafe fn setClipRectSource(&self, clip_rect_source: MTLRegion)

Available on crate feature MPSImage only.

Setter for clipRectSource.

pub unsafe fn zeroHistogram(&self) -> bool

Available on crate feature MPSImage only.

Zero-initalize the histogram results

Indicates that the memory region in which the histogram results are to be written in the histogram buffer are to be zero-initialized or not. Default: YES.

pub unsafe fn setZeroHistogram(&self, zero_histogram: bool)

Available on crate feature MPSImage only.

Setter for zeroHistogram.

pub unsafe fn initWithCoder_device( this: Allocated<Self>, a_decoder: &NSCoder, device: &ProtocolObject<dyn MTLDevice>, ) -> Option<Retained<Self>>

Available on crate feature MPSImage only.

NSSecureCoding compatability

While the standard NSSecureCoding/NSCoding method -initWithCoder: should work, since the file can’t know which device your data is allocated on, we have to guess and may guess incorrectly. To avoid that problem, use initWithCoder:device instead.

Parameter aDecoder: The NSCoder subclass with your serialized MPSKernel

Parameter device: The MTLDevice on which to make the MPSKernel

Returns: A new MPSKernel object, or nil if failure.

Safety

a_decoder possibly has further requirements.

pub unsafe fn encodeToCommandBuffer_sourceTexture_histogram_histogramOffset( &self, command_buffer: &ProtocolObject<dyn MTLCommandBuffer>, source: &ProtocolObject<dyn MTLTexture>, histogram: &ProtocolObject<dyn MTLBuffer>, histogram_offset: NSUInteger, )

Available on crate feature MPSImage only.

Encode the filter to a command buffer using a MTLComputeCommandEncoder.

The filter will not begin to execute until after the command buffer has been enqueued and committed.

Parameter commandBuffer: A valid MTLCommandBuffer.

Parameter source: A valid MTLTexture containing the source image for the filter

Parameter histogram: A valid MTLBuffer to receive the histogram results.

Parameter histogramOffset: Byte offset into histogram buffer at which to write the histogram results. Must be a multiple of 32 bytes. The histogram results / channel are stored together. The number of channels for which histogram results are stored is determined by the number of channels in the image. If histogramInfo.histogramForAlpha is false and the source image is RGBA then only histogram results for RGB channels are stored.

The histogram results are stored in the histogram buffer as follows:

• histogram results for the R channel for all bins followed by
• histogram results for the G channel for all bins followed by
• histogram results for the B channel for all bins followed by
• histogram results for the A channel for all bins

Safety

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

pub unsafe fn histogramSizeForSourceFormat( &self, source_format: MTLPixelFormat, ) -> usize

Available on crate feature MPSImage only.

The amount of space in the output MTLBuffer the histogram will take up.

This convenience function calculates the minimum amount of space needed in the output histogram for the results. The MTLBuffer should be at least this length, longer if histogramOffset is non-zero.

Parameter sourceFormat: The MTLPixelFormat of the source image. This is the source parameter of -encodeToCommandBuffer: sourceTexture:histogram:histogramOffset

Returns: The number of bytes needed to store the result histograms.

impl MPSImageHistogram

Methods declared on superclass MPSKernel.

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

Available on crate feature MPSImage only.

Standard init with default properties per filter type

Parameter device: The device that the filter will be used on. May not be NULL.

Returns: a pointer to the newly initialized object. This will fail, returning nil if the device is not supported. Devices must be MTLFeatureSet_iOS_GPUFamily2_v1 or later.

pub unsafe fn initWithCoder( this: Allocated<Self>, a_decoder: &NSCoder, ) -> Option<Retained<Self>>

Available on crate feature MPSImage only.

Called by NSCoder to decode MPSKernels

This isn’t the right interface to decode a MPSKernel, but it is the one that NSCoder uses. To enable your NSCoder (e.g. NSKeyedUnarchiver) to set which device to use extend the object to adopt the MPSDeviceProvider protocol. Otherwise, the Metal system default device will be used.

Safety

a_decoder possibly has further requirements.

impl MPSImageHistogram

Methods declared on superclass NSObject.

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

Available on crate feature MPSImage only.

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

Available on crate feature MPSImage only.

Methods from Deref<Target = MPSKernel>

pub unsafe fn options(&self) -> MPSKernelOptions

Available on crate feature MPSCoreTypes only.

The set of options used to run the kernel. subsubsection_options

pub unsafe fn setOptions(&self, options: MPSKernelOptions)

Available on crate feature MPSCoreTypes only.

Setter for options.

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

The device on which the kernel will be used

pub unsafe fn label(&self) -> Option<Retained<NSString>>

A string to help identify this object.

pub unsafe fn setLabel(&self, label: Option<&NSString>)

Setter for label.

This is copied when set.

pub unsafe fn copyWithZone_device( &self, zone: *mut NSZone, device: Option<&ProtocolObject<dyn MTLDevice>>, ) -> Retained<Self>

Make a copy of this MPSKernel for a new device

-copyWithZone: will call this API to make a copy of the MPSKernel on the same device. This interface may also be called directly to make a copy of the MPSKernel on a new device. Typically, the same MPSKernels should not be used to encode kernels on multiple command buffers from multiple threads. Many MPSKernels have mutable properties that might be changed by the other thread while this one is trying to encode. If you need to use a MPSKernel from multiple threads make a copy of it for each additional thread using -copyWithZone: or -copyWithZone:device:

Parameter zone: The NSZone in which to allocate the object

Parameter device: The device for the new MPSKernel. If nil, then use self.device.

Returns: a pointer to a copy of this MPSKernel. This will fail, returning nil if the device is not supported. Devices must be MTLFeatureSet_iOS_GPUFamily2_v1 or later.

Safety

zone must be a valid pointer or null.

Methods from Deref<Target = NSObject>

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

Handle messages the object doesn’t recognize.

See Apple’s documentation for details.

Methods from Deref<Target = AnyObject>

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());

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.

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`
    }
}

Trait Implementations

impl AsRef<AnyObject> for MPSImageHistogram

Available on crate feature MPSImage only.

fn as_ref(&self) -> &AnyObject

Converts this type into a shared reference of the (usually inferred) input type.

impl AsRef<MPSImageHistogram> for MPSImageHistogram

Available on crate feature MPSImage only.

fn as_ref(&self) -> &Self

Converts this type into a shared reference of the (usually inferred) input type.

impl AsRef<MPSKernel> for MPSImageHistogram

Available on crate feature MPSImage only.

fn as_ref(&self) -> &MPSKernel

Converts this type into a shared reference of the (usually inferred) input type.

impl AsRef<NSObject> for MPSImageHistogram

Available on crate feature MPSImage only.

fn as_ref(&self) -> &NSObject

Converts this type into a shared reference of the (usually inferred) input type.

impl Borrow<AnyObject> for MPSImageHistogram

Available on crate feature MPSImage only.

fn borrow(&self) -> &AnyObject

Immutably borrows from an owned value.

impl Borrow<MPSKernel> for MPSImageHistogram

Available on crate feature MPSImage only.

fn borrow(&self) -> &MPSKernel

Immutably borrows from an owned value.

impl Borrow<NSObject> for MPSImageHistogram

Available on crate feature MPSImage only.

fn borrow(&self) -> &NSObject

Immutably borrows from an owned value.

impl ClassType for MPSImageHistogram

Available on crate feature MPSImage only.

const NAME: &'static str = "MPSImageHistogram"

The name of the Objective-C class that this type represents.

type Super = MPSKernel

The superclass of this class.

type ThreadKind = <<MPSImageHistogram as ClassType>::Super as ClassType>::ThreadKind

Whether the type can be used from any thread, or from only the main thread.

fn class() -> &'static AnyClass

Get a reference to the Objective-C class that this type represents.

fn as_super(&self) -> &Self::Super

Get an immutable reference to the superclass.

impl CopyingHelper for MPSImageHistogram

Available on crate feature MPSImage only.

type Result = MPSImageHistogram

The immutable counterpart of the type, or Self if the type has no immutable counterpart.

impl Debug for MPSImageHistogram

Available on crate feature MPSImage only.

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Deref for MPSImageHistogram

Available on crate feature MPSImage only.

type Target = MPSKernel

The resulting type after dereferencing.

fn deref(&self) -> &Self::Target

Dereferences the value.

impl Hash for MPSImageHistogram

Available on crate feature MPSImage only.

fn hash<H: Hasher>(&self, state: &mut H)

Feeds this value into the given Hasher.

fn hash_slice<H>(data: &[Self], state: &mut H)

where H: Hasher, Self: Sized,

Feeds a slice of this type into the given Hasher.

impl Message for MPSImageHistogram

Available on crate feature MPSImage only.

fn retain(&self) -> Retained<Self>

where Self: Sized,

Increment the reference count of the receiver.

impl NSCoding for MPSImageHistogram

Available on crate feature MPSImage only.

unsafe fn encodeWithCoder(&self, coder: &NSCoder)

where Self: Sized + Message,

Safety

unsafe fn initWithCoder( this: Allocated<Self>, coder: &NSCoder, ) -> Option<Retained<Self>>

where Self: Sized + Message,

Safety

impl NSCopying for MPSImageHistogram

Available on crate feature MPSImage only.

fn copy(&self) -> Retained<Self::Result>

where Self: Sized + Message + CopyingHelper,

Returns a new instance that’s a copy of the receiver.

unsafe fn copyWithZone(&self, zone: *mut NSZone) -> Retained<Self::Result>

where Self: Sized + Message + CopyingHelper,

Returns a new instance that’s a copy of the receiver.

impl NSObjectProtocol for MPSImageHistogram

Available on crate feature MPSImage only.

fn isEqual(&self, other: Option<&AnyObject>) -> bool

where Self: Sized + Message,

Check whether the object is equal to an arbitrary other object.

fn hash(&self) -> usize

where Self: Sized + Message,

An integer that can be used as a table address in a hash table structure.

fn isKindOfClass(&self, cls: &AnyClass) -> bool

where Self: Sized + Message,

Check if the object is an instance of the class, or one of its subclasses.

fn is_kind_of<T>(&self) -> bool

where T: ClassType, Self: Sized + Message,

👎Deprecated: use isKindOfClass directly, or cast your objects with AnyObject::downcast_ref

Check if the object is an instance of the class type, or one of its subclasses.

fn isMemberOfClass(&self, cls: &AnyClass) -> bool

where Self: Sized + Message,

Check if the object is an instance of a specific class, without checking subclasses.

fn respondsToSelector(&self, aSelector: Sel) -> bool

where Self: Sized + Message,

Check whether the object implements or inherits a method with the given selector.

fn conformsToProtocol(&self, aProtocol: &AnyProtocol) -> bool

where Self: Sized + Message,

Check whether the object conforms to a given protocol.

fn description(&self) -> Retained<NSObject>

where Self: Sized + Message,

A textual representation of the object.

fn debugDescription(&self) -> Retained<NSObject>

where Self: Sized + Message,

A textual representation of the object to use when debugging.

fn isProxy(&self) -> bool

where Self: Sized + Message,

Check whether the receiver is a subclass of the NSProxy root class instead of the usual NSObject.

fn retainCount(&self) -> usize

where Self: Sized + Message,

The reference count of the object.

impl NSSecureCoding for MPSImageHistogram

Available on crate feature MPSImage only.

fn supportsSecureCoding() -> bool

where Self: Sized + ClassType,

impl PartialEq for MPSImageHistogram

Available on crate feature MPSImage only.

fn eq(&self, other: &Self) -> bool

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl RefEncode for MPSImageHistogram

Available on crate feature MPSImage only.

const ENCODING_REF: Encoding = <MPSKernel as ::objc2::RefEncode>::ENCODING_REF

The Objective-C type-encoding for a reference of this type.

impl DowncastTarget for MPSImageHistogram

Available on crate feature MPSImage only.

impl Eq for MPSImageHistogram

Available on crate feature MPSImage only.