Struct SCNGeometrySource

Source

pub struct SCNGeometrySource { /* private fields */ }

Available on crate feature SCNGeometry only.

Expand description

A geometry source contains geometry data for a specific semantic. The data format is described by properties.

Implementations§

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impl SCNGeometrySource

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pub unsafe fn geometrySourceWithData_semantic_vectorCount_floatComponents_componentsPerVector_bytesPerComponent_dataOffset_dataStride( data: &NSData, semantic: &SCNGeometrySourceSemantic, vector_count: NSInteger, float_components: bool, components_per_vector: NSInteger, bytes_per_component: NSInteger, offset: NSInteger, stride: NSInteger, ) -> Retained<Self>

Creates and returns a geometry source from the given data and parameters.

Parameter data: The geometry data.

Parameter semantic: The semantic of the geometry source.

Parameter vectorCount: The number of geometry source vectors.

Parameter floatComponents: A flag that indicates if vector components are floating point values.

Parameter componentsPerVector: The number of scalar components in a vector.

Parameter bytesPerComponent: The number of bytes that represent a vector component.

Parameter offset: The offset from the beginning of the data. In bytes.

Parameter stride: The number of bytes from a vector to the next one in the data.

Source

pub unsafe fn geometrySourceWithVertices_count( vertices: NonNull<SCNVector3>, count: NSInteger, ) -> Retained<Self>

Available on crate features SceneKitTypes and objc2-core-foundation only.

Creates and returns a geometry source from vertices stored in a buffer of SCNVector3 values.

Parameter vertices: The buffer of vertices.

Parameter count: The number of vertices.

Input vertices are copied to an optimized data format. The actual format is described by the properties of the resulting instance.

§Safety

vertices must be a valid pointer.

Source

pub unsafe fn geometrySourceWithNormals_count( normals: NonNull<SCNVector3>, count: NSInteger, ) -> Retained<Self>

Available on crate features SceneKitTypes and objc2-core-foundation only.

Creates and returns a geometry source from normals stored in a buffer of SCNVector3 values.

Parameter normals: The buffer of normals.

Parameter count: The number of normals.

Input normals are copied to an optimized data format. The actual format is described by the properties of the resulting instance.

§Safety

normals must be a valid pointer.

Source

pub unsafe fn geometrySourceWithTextureCoordinates_count( texcoord: NonNull<CGPoint>, count: NSInteger, ) -> Retained<Self>

Available on crate feature objc2-core-foundation only.

Creates and returns a geometry source from texture coordinates stored in a buffer of CGPoint values.

Parameter texcoord: The buffer of texture coordinates.

Parameter count: The number of texture coordinate points.

Input texture coordinates are copied to an optimized data format. The actual format is described by the properties of the resulting instance.

§Safety

texcoord must be a valid pointer.

Source

pub unsafe fn geometrySourceWithBuffer_vertexFormat_semantic_vertexCount_dataOffset_dataStride( buffer: &ProtocolObject<dyn MTLBuffer>, vertex_format: MTLVertexFormat, semantic: &SCNGeometrySourceSemantic, vertex_count: NSInteger, offset: NSInteger, stride: NSInteger, ) -> Retained<Self>

Available on crate feature objc2-metal and non-watchOS only.

Creates and returns a geometry source from the given data and parameters.

Parameter buffer: A Metal buffer.

Parameter vertexFormat: The vertex format.

Parameter semantic: The semantic of the geometry source.

Parameter vertexCount: The number of vertex.

Parameter offset: The offset from the beginning of the data. In bytes.

Parameter stride: The number of bytes from a vector to the next one in the data.

Attempting to modify the Metal buffer outside the SCNSceneRenderer delegate callbacks is undefined. The typical usage it to modify the MTLBuffer within the willRenderScene callback, using a compute kernel or a vertex function in the user own command buffer. So something like:

(void)renderer:(id <SCNSceneRenderer

)aRenderer willRenderScene:(SCNScene *)scene atTime:(NSTimeInterval)time { // ask for a new command buffer id <MTLCommandBuffer myCommandBuffer = [aRenderer.commandQueue commandBuffer];

// get a compute command encoder id <MTLComputeCommandEncoder

myComputeCommandEncoder = [myCommandBuffer computeCommandEncoder];

// configure the compute command encoder’s pipeline state, buffer inputs etc… //…

// dispatch the [myComputeCommandEncoder dispatchThreadgroups:numberOfWorkingGroups threadsPerThreadgroup:numberOfThreads]; [myComputeCommandEncoder endEncoding];

[myCommandBuffer commit]; }

§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.

Source

pub unsafe fn data(&self) -> Retained<NSData>

The data for the geometry source

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pub unsafe fn semantic(&self) -> Retained<SCNGeometrySourceSemantic>

The semantic of the geometry source

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pub unsafe fn vectorCount(&self) -> NSInteger

The number of vectors in the data.

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pub unsafe fn floatComponents(&self) -> bool

A flag that indicates if vector components are floating point values.

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pub unsafe fn componentsPerVector(&self) -> NSInteger

The number of scalar components in each vector.

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pub unsafe fn bytesPerComponent(&self) -> NSInteger

The size of a vector component in bytes.

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pub unsafe fn dataOffset(&self) -> NSInteger

The offset from the beginning of the data. In bytes.

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pub unsafe fn dataStride(&self) -> NSInteger

The number of bytes from a vector to the next one in the data.

Source §

impl SCNGeometrySource

Methods declared on superclass NSObject.

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

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

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());

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`
    }
}