descriptor_heap.h

#pragma once

#include "d3d12_includes.h"

#include "util/string.h"
#include "util/weak_ptr.h"

#define BLOWBOX_DESCRIPTOR_ID_UNKNOWN ~(0u)

namespace blowbox
{
    //typedef unsigned int DescriptorId;

    class Device;

    class DescriptorHeap
    {
    public:
        DescriptorHeap();
        ~DescriptorHeap();

        void Create(const WString& name, D3D12_DESCRIPTOR_HEAP_TYPE heap_type, D3D12_DESCRIPTOR_HEAP_FLAGS flags = D3D12_DESCRIPTOR_HEAP_FLAG_SHADER_VISIBLE, UINT descriptor_count = 4096U);

        UINT CreateDepthStencilView(ID3D12Resource* dsv_buffer, D3D12_DEPTH_STENCIL_VIEW_DESC* desc);

        UINT CreateRenderTargetView(ID3D12Resource* rtv_buffer, D3D12_RENDER_TARGET_VIEW_DESC* desc);

        UINT CreateConstantBufferView(D3D12_CONSTANT_BUFFER_VIEW_DESC* desc);

        UINT CreateShaderResourceView(ID3D12Resource* srv_buffer, D3D12_SHADER_RESOURCE_VIEW_DESC* desc);

        UINT CreateUnorderedAccessView(ID3D12Resource* buffer, ID3D12Resource* counter_buffer, D3D12_UNORDERED_ACCESS_VIEW_DESC* desc);

        UINT CreateSampler(D3D12_SAMPLER_DESC* desc);

        D3D12_CPU_DESCRIPTOR_HANDLE GetCPUDescriptorById(UINT id);

        D3D12_GPU_DESCRIPTOR_HANDLE GetGPUDescriptorById(UINT id);

        ID3D12DescriptorHeap* Get() { return heap_; }

        const D3D12_DESCRIPTOR_HEAP_DESC& GetDesc() { return heap_desc_; }

        void Clear();

        UINT GetDescriptorSize() const { return descriptor_size_; }

        UINT GetDescriptorsAllocated() const { return current_allocations_; }

        UINT GetDescriptorHeapMaxAllocations() const { return heap_->GetDesc().NumDescriptors; }
    private:
        ID3D12DescriptorHeap* heap_;                
        D3D12_DESCRIPTOR_HEAP_DESC heap_desc_;      

        // @todo Make the descriptor heap use a pool strategy instead of linear strategy
        UINT current_allocations_;                  
        UINT descriptor_size_;                      
    };
}