Review comments

Author: LegNeato

blog/2024-12-29-rust-gpu-0.10.md

@@ -64,30 +64,32 @@ more control over the entire pipeline by letting them directly process batches o
 vertices and primitives in compute-like shaders. This allows for more efficient culling,
 level-of-detail calculations, and custom pipeline logic—all on the GPU.
 
-An example of a Rust GPU mesh shader that outputs points:
+An example of a Rust GPU mesh shader that outputs a triangle:
 
 ```
 use spirv_std::arch::set_mesh_outputs_ext;
-use spirv_std::glam::{UVec2, Vec4};
+use spirv_std::glam::{UVec3, Vec4};
 use spirv_std::spirv;
 
 #[spirv(mesh_ext(
     threads(1),
-    output_vertices = 1,
+    output_vertices = 3,
     output_primitives_ext = 1,
-    output_points
+    output_triangles_ext
 ))]
 pub fn main(
-    #[spirv(position)] positions: &mut [Vec4; 1],
-    #[spirv(primitive_point_indices_ext)] indices: &mut [u32; 1],
+    #[spirv(position)] positions: &mut [Vec4; 3],
+    #[spirv(primitive_triangle_indices_ext)] indices: &mut [UVec3; 1],
 ) {
     unsafe {
-        set_mesh_outputs_ext(1, 1);
+        set_mesh_outputs_ext(3, 1);
     }
 
     positions[0] = Vec4::new(-0.5, 0.5, 0.0, 1.0);
+    positions[1] = Vec4::new(0.5, 0.5, 0.0, 1.0);
+    positions[2] = Vec4::new(0.0, -0.5, 0.0, 1.0);
 
-    indices[0] = 0;
+    indices[0] = UVec3::new(0, 1, 2);
 }
 ```
 
@@ -110,39 +112,21 @@ pub fn main() {
 [@Firestar99](https://github.com/firestar99) also added support for subgroups via
 [subgroup intrinsics](https://github.com/Rust-GPU/rust-gpu/pull/14).
 
-[Subgroups](https://www.khronos.org/blog/vulkan-subgroup-tutorial) are small groups of
-threads within a workgroup that can share data and perform synchronized operations more
+[Subgroups](https://www.khronos.org/blog/vulkan-subgroup-tutorial) allow a group of
+threads of vendor-defined size to share data and perform synchronized operations more
 efficiently. For example, using subgroup intrinsics you can:
 
 - Perform reductions (e.g., sum, min, max) across threads in a subgroup.
 - Share intermediate results without relying on global memory, reducing latency.
 - Implement algorithms like prefix sums or parallel sorting more effectively.
 
-Here is a simple Rust GPU example to demonstrate subgroup reduction:
-
-```rust
-use glam::UVec3;
-use spirv_std::spirv;
-
-unsafe fn subgroup_i_add_reduce(value: u32) -> u32 {
-    spirv_std::arch::subgroup_i_add(value)
-}
-
-#[spirv(compute(threads(32, 1, 1)))]
-pub fn main(#[spirv(local_invocation_id)] local_invocation_id: UVec3) {
-    unsafe {
-        subgroup_i_add_reduce(local_invocation_id.x);
-    }
-}
-```
-
 ## Added `TypedBuffer`
 
 [@eddyb](https://github.com/eddyb) and [@Firestar99](https://github.com/firestar99)
 [introduced `TypedBuffer`](https://github.com/Rust-GPU/rust-gpu/pull/16), an explicit
 way to declare inputs and outputs as buffers. This enables declaring an "array of buffer
-descriptors containing something" as is common in [bindless
-textures](https://computergraphics.stackexchange.com/questions/10794/binding-vs-bindless).
+descriptors containing something" as is common in
+[bindless](https://computergraphics.stackexchange.com/questions/10794/binding-vs-bindless).
 
 Here is an example of using
 [`TypedBuffer`](https://rust-gpu.github.io/rust-gpu/api/spirv_std/struct.TypedBuffer.html)