librashader/librashader-runtime-d3d12/src/heap.rs
2023-02-01 02:08:50 -05:00

291 lines
9.7 KiB
Rust

use crate::error;
use std::cell::RefCell;
use std::marker::PhantomData;
use std::sync::Arc;
use windows::Win32::Graphics::Direct3D12::{ID3D12DescriptorHeap, ID3D12Device, D3D12_CPU_DESCRIPTOR_HANDLE, D3D12_DESCRIPTOR_HEAP_DESC, D3D12_DESCRIPTOR_HEAP_FLAG_NONE, D3D12_DESCRIPTOR_HEAP_FLAG_SHADER_VISIBLE, D3D12_DESCRIPTOR_HEAP_TYPE_CBV_SRV_UAV, D3D12_DESCRIPTOR_HEAP_TYPE_SAMPLER, D3D12_GPU_DESCRIPTOR_HANDLE, D3D12_DESCRIPTOR_HEAP_TYPE};
#[const_trait]
pub trait D3D12HeapType {
fn get_desc(size: usize) -> D3D12_DESCRIPTOR_HEAP_DESC;
}
pub trait D3D12ShaderVisibleHeapType: D3D12HeapType {}
#[derive(Clone)]
pub struct SamplerPaletteHeap;
#[derive(Clone)]
pub struct CpuStagingHeap;
#[derive(Clone)]
pub struct ResourceWorkHeap;
#[derive(Clone)]
pub struct SamplerWorkHeap;
impl const D3D12HeapType for SamplerPaletteHeap {
// sampler palettes just get set directly
fn get_desc(size: usize) -> D3D12_DESCRIPTOR_HEAP_DESC {
D3D12_DESCRIPTOR_HEAP_DESC {
Type: D3D12_DESCRIPTOR_HEAP_TYPE_SAMPLER,
NumDescriptors: size as u32,
Flags: D3D12_DESCRIPTOR_HEAP_FLAG_NONE,
NodeMask: 0,
}
}
}
impl const D3D12HeapType for CpuStagingHeap {
// Lut texture heaps are CPU only and get bound to the descriptor heap of the shader.
fn get_desc(size: usize) -> D3D12_DESCRIPTOR_HEAP_DESC {
D3D12_DESCRIPTOR_HEAP_DESC {
Type: D3D12_DESCRIPTOR_HEAP_TYPE_CBV_SRV_UAV,
NumDescriptors: size as u32,
Flags: D3D12_DESCRIPTOR_HEAP_FLAG_NONE,
NodeMask: 0,
}
}
}
impl D3D12ShaderVisibleHeapType for ResourceWorkHeap {}
impl const D3D12HeapType for ResourceWorkHeap {
// Lut texture heaps are CPU only and get bound to the descriptor heap of the shader.
fn get_desc(size: usize) -> D3D12_DESCRIPTOR_HEAP_DESC {
D3D12_DESCRIPTOR_HEAP_DESC {
Type: D3D12_DESCRIPTOR_HEAP_TYPE_CBV_SRV_UAV,
NumDescriptors: size as u32,
Flags: D3D12_DESCRIPTOR_HEAP_FLAG_SHADER_VISIBLE,
NodeMask: 0,
}
}
}
impl D3D12ShaderVisibleHeapType for SamplerWorkHeap {}
impl const D3D12HeapType for SamplerWorkHeap {
// Lut texture heaps are CPU only and get bound to the descriptor heap of the shader.
fn get_desc(size: usize) -> D3D12_DESCRIPTOR_HEAP_DESC {
D3D12_DESCRIPTOR_HEAP_DESC {
Type: D3D12_DESCRIPTOR_HEAP_TYPE_SAMPLER,
NumDescriptors: size as u32,
Flags: D3D12_DESCRIPTOR_HEAP_FLAG_SHADER_VISIBLE,
NodeMask: 0,
}
}
}
#[derive(Clone)]
pub struct D3D12DescriptorHeapSlot<T> {
cpu_handle: D3D12_CPU_DESCRIPTOR_HANDLE,
gpu_handle: Option<D3D12_GPU_DESCRIPTOR_HANDLE>,
heap: Arc<RefCell<D3D12DescriptorHeapInner>>,
slot: usize,
_pd: PhantomData<T>,
}
impl<T> D3D12DescriptorHeapSlot<T> {
/// Get the index of the resource within the heap.
pub fn index(&self) -> usize {
self.slot
}
}
impl<T> AsRef<D3D12_CPU_DESCRIPTOR_HANDLE> for D3D12DescriptorHeapSlot<T> {
fn as_ref(&self) -> &D3D12_CPU_DESCRIPTOR_HANDLE {
&self.cpu_handle
}
}
impl<T: D3D12ShaderVisibleHeapType> AsRef<D3D12_GPU_DESCRIPTOR_HANDLE>
for D3D12DescriptorHeapSlot<T>
{
fn as_ref(&self) -> &D3D12_GPU_DESCRIPTOR_HANDLE {
self.gpu_handle.as_ref().unwrap()
}
}
impl<T: D3D12ShaderVisibleHeapType> From<&D3D12DescriptorHeap<T>> for ID3D12DescriptorHeap {
fn from(value: &D3D12DescriptorHeap<T>) -> Self {
value.0.borrow().heap.clone()
}
}
#[derive(Debug)]
struct D3D12DescriptorHeapInner {
device: ID3D12Device,
heap: ID3D12DescriptorHeap,
ty: D3D12_DESCRIPTOR_HEAP_TYPE,
cpu_start: D3D12_CPU_DESCRIPTOR_HANDLE,
gpu_start: Option<D3D12_GPU_DESCRIPTOR_HANDLE>,
handle_size: usize,
start: usize,
num_descriptors: usize,
// Bit flag representation of available handles in the heap.
//
// 0 - Occupied
// 1 - free
// todo: actually use a bitset here.
map: Box<[bool]>,
}
pub struct D3D12DescriptorHeap<T>(Arc<RefCell<D3D12DescriptorHeapInner>>, PhantomData<T>);
impl<T: D3D12HeapType> D3D12DescriptorHeap<T> {
pub fn new(device: &ID3D12Device, size: usize) -> error::Result<D3D12DescriptorHeap<T>> {
let desc = T::get_desc(size);
unsafe { D3D12DescriptorHeap::new_with_desc(device, desc) }
}
}
impl<T> D3D12DescriptorHeap<T> {
pub unsafe fn new_with_desc(
device: &ID3D12Device,
desc: D3D12_DESCRIPTOR_HEAP_DESC,
) -> error::Result<D3D12DescriptorHeap<T>> {
unsafe {
let heap: ID3D12DescriptorHeap = device.CreateDescriptorHeap(&desc)?;
let cpu_start = heap.GetCPUDescriptorHandleForHeapStart();
let gpu_start = if (desc.Flags & D3D12_DESCRIPTOR_HEAP_FLAG_SHADER_VISIBLE).0 != 0 {
Some(heap.GetGPUDescriptorHandleForHeapStart())
} else {
None
};
Ok(D3D12DescriptorHeap(
Arc::new(RefCell::new(D3D12DescriptorHeapInner {
device: device.clone(),
heap,
ty: desc.Type,
cpu_start,
gpu_start,
handle_size: device.GetDescriptorHandleIncrementSize(desc.Type) as usize,
start: 0,
num_descriptors: desc.NumDescriptors as usize,
map: vec![false; desc.NumDescriptors as usize].into_boxed_slice(),
})),
PhantomData::default(),
))
}
}
/// suballocates this heap into equally sized chunks.
/// if there aren't enough descriptors, throws an error.
///
/// it is UB (programmer error) to call this if the descriptor heap already has
/// descriptors allocated for it.
///
/// size must also divide equally into the size of the heap.
pub unsafe fn suballocate(self, size: usize) -> Vec<D3D12DescriptorHeap<T>> {
// has to be called right after creation.
assert_eq!(Arc::strong_count(&self.0), 1,
"D3D12DescriptorHeap::suballocate can only be callled immediately after creation.");
let inner = Arc::try_unwrap(self.0)
.expect("[d3d12] undefined behaviour to suballocate a descriptor heap with live descriptors.")
.into_inner();
// number of suballocated heaps
let num_heaps = inner.num_descriptors / size;
let remainder = inner.num_descriptors % size;
assert_eq!(remainder, 0, "D3D12DescriptorHeap::suballocate \
must be called with a size that equally divides the number of descriptors");
let mut heaps = Vec::new();
let mut start = 0;
let root_cpu_ptr = inner.cpu_start.ptr;
let root_gpu_ptr = inner.gpu_start.map(|p| p.ptr);
for _ in 0..num_heaps {
let new_cpu_start = root_cpu_ptr + (start * inner.handle_size);
let new_gpu_start = root_gpu_ptr
.map(|r| D3D12_GPU_DESCRIPTOR_HANDLE {
ptr: r + (start as u64 * inner.handle_size as u64)
});
heaps.push(D3D12DescriptorHeapInner {
device: inner.device.clone(),
heap: inner.heap.clone(),
ty: inner.ty,
cpu_start: D3D12_CPU_DESCRIPTOR_HANDLE {
ptr: new_cpu_start
},
gpu_start: new_gpu_start,
handle_size: inner.handle_size,
start: 0,
num_descriptors: size,
map: vec![false; size].into_boxed_slice(),
});
start += size;
}
heaps.into_iter()
.map(|inner| D3D12DescriptorHeap(
Arc::new(RefCell::new(inner)),
PhantomData::default()))
.collect()
}
pub fn alloc_slot(&mut self) -> error::Result<D3D12DescriptorHeapSlot<T>> {
let mut handle = D3D12_CPU_DESCRIPTOR_HANDLE { ptr: 0 };
let mut inner = self.0.borrow_mut();
for i in inner.start..inner.num_descriptors {
if !inner.map[i] {
inner.map[i] = true;
handle.ptr = inner.cpu_start.ptr + (i * inner.handle_size);
inner.start = i + 1;
let gpu_handle = inner
.gpu_start
.map(|gpu_start| D3D12_GPU_DESCRIPTOR_HANDLE {
ptr: (handle.ptr as u64 - inner.cpu_start.ptr as u64) + gpu_start.ptr,
});
return Ok(D3D12DescriptorHeapSlot {
cpu_handle: handle,
slot: i,
heap: Arc::clone(&self.0),
gpu_handle,
_pd: Default::default(),
});
}
}
todo!("error need to fail");
}
pub fn copy_descriptors<const NUM_DESC: usize>(&mut self,
source: &[&D3D12_CPU_DESCRIPTOR_HANDLE; NUM_DESC])
-> error::Result<[D3D12DescriptorHeapSlot<T>; NUM_DESC]> {
let dest = array_init::try_array_init(|_| self.alloc_slot())?;
let inner = self.0.borrow_mut();
unsafe {
// unfortunately we can't guarantee that the source and dest descriptors are contiguous so...
for i in 0..NUM_DESC {
inner.device.CopyDescriptorsSimple(
1,
*dest[i].as_ref(),
*source[i],
inner.ty
);
}
}
Ok(dest)
}
}
impl<T> Drop for D3D12DescriptorHeapSlot<T> {
fn drop(&mut self) {
let mut inner = self.heap.borrow_mut();
inner.map[self.slot] = false;
if inner.start > self.slot {
inner.start = self.slot
}
}
}