Add support for programmable samplers in shaders

Source/Engine/GraphicsDevice/DirectX/DX12/GPUSamplerDX12.h

@@ -0,0 +1,32 @@
+// Copyright (c) 2012-2021 Wojciech Figat. All rights reserved.
+
+#pragma once
+
+#include "Engine/Graphics/Textures/GPUSampler.h"
+#include "GPUDeviceDX12.h"
+
+#if GRAPHICS_API_DIRECTX12
+
+/// <summary>
+/// Sampler object for DirectX 12 backend.
+/// </summary>
+class GPUSamplerDX12 : public GPUResourceDX12<GPUSampler>
+{
+public:
+
+    GPUSamplerDX12(GPUDeviceDX12* device)
+        : GPUResourceDX12<GPUSampler>(device, StringView::Empty)
+    {
+    }
+
+    DescriptorHeapWithSlotsDX12::Slot Slot;
+    D3D12_CPU_DESCRIPTOR_HANDLE HandleCPU;
+
+protected:
+
+    // [GPUSampler]
+    bool OnInit() override;
+    void OnReleaseGPU() override;
+};
+
+#endif