10 unstable releases (3 breaking)
0.4.2 | May 20, 2024 |
---|---|
0.4.1 | May 14, 2024 |
0.4.0 | Feb 28, 2024 |
0.3.0 | Feb 7, 2024 |
0.1.3 | Jan 5, 2024 |
#117 in #derive-debug
22 downloads per month
Used in 3 crates
(via crabslab)
21KB
430 lines
What
crabslab
is a slab implementation focused on marshalling data between CPUs and GPUs.
But Why?
It's hard to get data onto GPUs in the form you expect.
To marshall your data correctly you must know about the alignment and sizes of the underlying representation of your data. This will often surprise you!
Working with a slab on the other hand, only requires that your types can be written into an array and read from an array.
Opinion
Working with shaders is much easier using a slab.
Shader code can be written in Rust with rust-gpu
,
which will enable you to use this crate on both CPU and GPU code.
rust-gpu
This crate was made to work with rust-gpu
.
Specifically, with this crate it is possible to pack your types into a buffer on the CPU
and then read your types from the slab on the GPU (in Rust).
Other no-std platforms
Even though this crate was written with rust-gpu
in mind, it should work in other no-std
contexts.
And How
The idea is simple - crabslab
helps you manage a heap of contiguous u32
s (roughly in the form of Vec<u32>
).
Types implement the trait SlabItem
which writes the type into an index of the slab as contiguous u32
s and also
reads them out symmetrically.
crabslab
includes:
- a few traits:
Slab
GrowableSlab
SlabItem
- a derive macro for
SlabItem
for your types - a few new structs for working with slabs
Id
Array
Offset
- a helper struct
CpuSlab
which wraps anything implementingGrowableSlab
- feature for deriving
SlabItem
forglam
types
Example
use crabslab::{CpuSlab, Slab, GrowableSlab, SlabItem, Id};
use glam::{Vec3, Vec4};
#[derive(Debug, Default, SlabItem, PartialEq)]
struct Light {
direction: Vec3,
color: Vec4,
inner_cutoff: f32,
outer_cutoff: f32,
is_on: bool
}
impl Light {
fn standard() -> Self {
Light {
direction: Vec3::NEG_Z, // pointing down
color: Vec4::ONE, // white
inner_cutoff: 0.5,
outer_cutoff: 2.6,
is_on: true
}
}
}
fn cpu_code() -> (Id<Light>, Vec<u32>) {
let light = Light::standard();
// Create a new slab on the CPU-side.
// Using CpuSlab make `append` unambiguous, as `Vec` has its own `append` function.
let mut slab = CpuSlab::new(vec![]);
let id = slab.append(&light);
(id, slab.into_inner())
}
fn shader_code(light_id: Id<Light>, slab: &[u32]) {
let light = slab.read(light_id);
assert_eq!(Light::standard(), light);
}
let (light_id, slab) = cpu_code();
// marshalling your data depends on which GPU library you are using...
shader_code(light_id, &slab);
Dependencies
~260–700KB
~17K SLoC