objc2_metal/
slice.rs

1#![allow(unused_imports)]
2#![allow(clippy::missing_safety_doc)]
3use core::ptr::NonNull;
4
5use crate::*;
6
7#[allow(dead_code)]
8fn slice_to_ptr_count<T>(slice: &[T]) -> (NonNull<T>, usize) {
9    let ptr: *const T = slice.as_ptr();
10    let ptr: *mut T = ptr as *mut T;
11    // SAFETY: Slice pointers are always non-null
12    let ptr = unsafe { NonNull::new_unchecked(ptr) };
13    (ptr, slice.len())
14}
15
16#[cfg(all(feature = "MTLRenderCommandEncoder", feature = "MTLCommandEncoder"))]
17pub trait MTLRenderCommandEncoderSliceExt: MTLRenderCommandEncoder + objc2::Message {
18    // TODO: Safety
19    unsafe fn setViewports(&self, viewports: &[MTLViewport]);
20}
21
22#[cfg(all(feature = "MTLRenderCommandEncoder", feature = "MTLCommandEncoder"))]
23impl<P: MTLRenderCommandEncoder + objc2::Message> MTLRenderCommandEncoderSliceExt for P {
24    unsafe fn setViewports(&self, viewports: &[MTLViewport]) {
25        let (ptr, count) = slice_to_ptr_count(viewports);
26        unsafe { self.setViewports_count(ptr, count) }
27    }
28}
29
30// TODO: Many more methods take `(NonNull<Foo>, NSUInteger)` that can be
31// turned into `&[Foo]`.