/// <summary>
/// Creates a new <see cref="ID3D12DescriptorHandleAllocator"/> instance with the specified parameters.
/// </summary>
/// <param name="device">The <see cref="ID3D12Device"/> instance to use.</param>
public ID3D12DescriptorHandleAllocator(ID3D12Device *device)
{
this.d3D12DescriptorHeap = device->CreateDescriptorHeap(DescriptorsPerHeap, isShaderVisible: true);
this.d3D12DescriptorHeapNonShaderVisible = device->CreateDescriptorHeap(DescriptorsPerHeap, isShaderVisible: false);
this.d3D12DescriptorHandlePairs = GC.AllocateUninitializedArray <ID3D12ResourceDescriptorHandles>((int)DescriptorsPerHeap);
this.head = 0;
this.tail = 0;
this.size = (int)DescriptorsPerHeap;
D3D12_CPU_DESCRIPTOR_HANDLE d3D12CpuDescriptorHandleStart = this.d3D12DescriptorHeap.Get()->GetCPUDescriptorHandleForHeapStart();
D3D12_GPU_DESCRIPTOR_HANDLE d3D12GpuDescriptorHandleStart = this.d3D12DescriptorHeap.Get()->GetGPUDescriptorHandleForHeapStart();
D3D12_CPU_DESCRIPTOR_HANDLE d3D12CpuDescriptorHandleNonShaderVisibleStart = this.d3D12DescriptorHeapNonShaderVisible.Get()->GetCPUDescriptorHandleForHeapStart();
uint descriptorIncrementSize = device->GetDescriptorHandleIncrementSize(D3D12_DESCRIPTOR_HEAP_TYPE_CBV_SRV_UAV);
for (int i = 0; i < this.d3D12DescriptorHandlePairs.Length; i++)
{
D3D12_CPU_DESCRIPTOR_HANDLE.InitOffsetted(out D3D12_CPU_DESCRIPTOR_HANDLE d3D12CpuDescriptorHandle, in d3D12CpuDescriptorHandleStart, i, descriptorIncrementSize);
D3D12_GPU_DESCRIPTOR_HANDLE.InitOffsetted(out D3D12_GPU_DESCRIPTOR_HANDLE d3D12GpuDescriptorHandle, in d3D12GpuDescriptorHandleStart, i, descriptorIncrementSize);
D3D12_CPU_DESCRIPTOR_HANDLE.InitOffsetted(out D3D12_CPU_DESCRIPTOR_HANDLE d3D12CpuDescriptorHandleNonShaderVisible, in d3D12CpuDescriptorHandleNonShaderVisibleStart, i, descriptorIncrementSize);
this.d3D12DescriptorHandlePairs[i] = new ID3D12ResourceDescriptorHandles(
d3D12CpuDescriptorHandle,
d3D12GpuDescriptorHandle,
d3D12CpuDescriptorHandleNonShaderVisible);
}
}
/// <summary>
/// Reads the contents of a <see cref="Buffer{T}"/> instance in a given range and returns an array.
/// </summary>
/// <typeparam name="T">The type of items stored on the buffer.</typeparam>
/// <param name="source">The input <see cref="Buffer{T}"/> instance to read data from.</param>
/// <param name="offset">The offset to start reading data from.</param>
/// <param name="count">The number of items to read.</param>
/// <returns>A <typeparamref name="T"/> array with the contents of the specified range from the current buffer.</returns>
public static T[] ToArray <T>(this Buffer <T> source, int offset, int count)
where T : unmanaged
{
Guard.IsGreaterThanOrEqualTo(count, 0, nameof(count));
T[] data = GC.AllocateUninitializedArray <T>(count);
source.CopyTo(data.AsSpan(), offset);
return(data);
}