Struct MTLRasterizationRateMapDescriptor

Source

pub struct MTLRasterizationRateMapDescriptor { /* private fields */ }

Available on crate feature MTLRasterizationRate only.

Expand description

Describes a MTLRasterizationRateMap containing an arbitrary number of MTLRasterizationRateLayerDescriptor instances.

An MTLRasterizationRateMapDescriptor is compiled into an MTLRasterizationRateMap using MTLDevice.

Implementations§

Source §

impl MTLRasterizationRateMapDescriptor

Source

pub unsafe fn rasterizationRateMapDescriptorWithScreenSize( screen_size: MTLSize, ) -> Retained<MTLRasterizationRateMapDescriptor>

Available on crate feature MTLTypes only.

Convenience descriptor creation function without layers

Parameter screenSize: The dimensions, in screen space pixels, of the region where variable rasterization is applied. The depth component of MTLSize is ignored.

Returns: A descriptor containing no layers. Add or remove layers using setObject:atIndexedSubscript:.

§Safety

screenSize might not be bounds-checked.

Source

pub unsafe fn rasterizationRateMapDescriptorWithScreenSize_layer( screen_size: MTLSize, layer: &MTLRasterizationRateLayerDescriptor, ) -> Retained<MTLRasterizationRateMapDescriptor>

Available on crate feature MTLTypes only.

Convenience descriptor creation function for a single layer.

Parameter screenSize: The dimensions, in screen space pixels, of the region where variable rasterization is applied. The depth component of MTLSize is ignored.

Parameter layer: The single layer describing how the rasterization rate varies in screen space

Returns: A descriptor containing a single layer. Add or remove layers using setObject:atIndexedSubscript:.

§Safety

screenSize might not be bounds-checked.

Source

pub unsafe fn layerAtIndex( &self, layer_index: NSUInteger, ) -> Option<Retained<MTLRasterizationRateLayerDescriptor>>

Returns: The MTLRasterizationRateLayerDescriptor instance for the given layerIndex, or nil if no instance hasn’t been set for this index.

Use setLayer:atIndex: to add or set the layer. Identical to “layers[layerIndex]”.

§Safety

layerIndex might not be bounds-checked.

Source

pub unsafe fn setLayer_atIndex( &self, layer: Option<&MTLRasterizationRateLayerDescriptor>, layer_index: NSUInteger, )

Sets the MTLRasterizationRateLayerDescriptor instance for the given layerIndex.

The previous instance at the index, if any, will be overwritten. Set nil to an index to remove the layer at that index from the descriptor. Identical to “layers[layerIndex] = layer”.

§Safety

layerIndex might not be bounds-checked.

Source

pub fn layers(&self) -> Retained<MTLRasterizationRateLayerArray>

Returns: A modifiable array of layers

Accesses the layers currently stored in the descriptor. Syntactic sugar around “layerAtIndex:” and “setLayer:atIndex:”

Source

pub fn screenSize(&self) -> MTLSize

Available on crate feature MTLTypes only.

Returns: The dimensions, in screen space pixels, of the region where variable rasterization is applied.

The region always has its origin at [0, 0]. The depth component of MTLSize is ignored.

Source

pub unsafe fn setScreenSize(&self, screen_size: MTLSize)

Available on crate feature MTLTypes only.

Setter for screenSize.

§Safety

This might not be bounds-checked.

Source

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

A string to help identify this object.

The default value is nil.

Source

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

Setter for label.

This is copied when set.

Source

pub fn layerCount(&self) -> NSUInteger

Returns: The number of subsequent non-nil layer instances stored in the descriptor, starting at index 0.

This property is modified by setting new layer instances using setLayer:atIndex: or assigning to layers[X]

Source §

impl MTLRasterizationRateMapDescriptor

Methods declared on superclass NSObject.

Source

pub unsafe fn rasterizationRateMapDescriptorWithScreenSize_layerCount_layers( screen_size: MTLSize, layer_count: NSUInteger, layers: NonNull<NonNull<MTLRasterizationRateLayerDescriptor>>, ) -> Retained<MTLRasterizationRateMapDescriptor>

Available on crate feature MTLTypes only.

Convenience descriptor creation function for an arbitrary amount of layers stored in a C-array.

Parameter screenSize: The dimensions, in screen space pixels, of the region where variable rasterization is applied. The depth component of MTLSize is ignored.

Parameter layerCount: The number of layers in the descriptor.

Parameter layers: An array of pointers to layer descriptors. The array must contain layerCount non-null pointers to MTLRasterizationRateLayerDescriptor instances.

Returns: A descriptor containing all the specified layers. Add or remove layers using setObject:atIndexedSubscript:.

The function copies the array of pointers internally, the caller need not keep the array alive after creating the descriptor.

Methods from Deref<Target = NSObject>§

Source

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

Handle messages the object doesn’t recognize.

See Apple’s documentation for details.

Methods from Deref<Target = AnyObject>§

Source

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());

Source

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.

Source

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`
    }
}