Add GPUVertexLayout to graphics backends

Source/Engine/Graphics/Shaders/GPUVertexLayout.cpp

@@ -0,0 +1,103 @@
+// Copyright (c) 2012-2024 Wojciech Figat. All rights reserved.
+
+#include "GPUVertexLayout.h"
+#if GPU_ENABLE_ASSERTION_LOW_LAYERS
+#include "Engine/Core/Log.h"
+#endif
+#include "Engine/Core/Collections/Dictionary.h"
+#include "Engine/Graphics/GPUDevice.h"
+#if GPU_ENABLE_RESOURCE_NAMING
+#include "Engine/Scripting/Enums.h"
+#endif
+
+// VertexElement has been designed to be POD and memory-comparable for faster hashing and comparision.
+struct VertexElementRaw
+{
+    uint32 Words[2];
+};
+
+static_assert(sizeof(VertexElement) == sizeof(VertexElementRaw), "Incorrect size of the VertexElement!");
+
+namespace
+{
+    CriticalSection CacheLocker;
+    Dictionary<uint32, GPUVertexLayout*> LayoutCache;
+}
+
+String VertexElement::ToString() const
+{
+#if GPU_ENABLE_RESOURCE_NAMING
+    return String::Format(TEXT("{}, format {}, offset {}, per-instance {}, slot {}"), ScriptingEnum::ToString(Type), ScriptingEnum::ToString(Format), Offset, PerInstance, Slot);
+#else
+    return TEXT("VertexElement");
+#endif
+}
+
+bool VertexElement::operator==(const VertexElement& other) const
+{
+    auto thisRaw = (const VertexElementRaw*)this;
+    auto otherRaw = (const VertexElementRaw*)&other;
+    return thisRaw->Words[0] == otherRaw->Words[0] && thisRaw->Words[1] == otherRaw->Words[1];
+}
+
+uint32 GetHash(const VertexElement& key)
+{
+    auto keyRaw = (const VertexElementRaw*)&key;
+    uint32 hash = keyRaw->Words[0];
+    CombineHash(hash, keyRaw->Words[1]);
+    return hash;
+}
+
+GPUVertexLayout::GPUVertexLayout()
+    : GPUResource(SpawnParams(Guid::New(), TypeInitializer))
+{
+}
+
+GPUVertexLayout* GPUVertexLayout::Get(const Elements& elements)
+{
+    // Hash input layout
+    uint32 hash = 0;
+    for (const VertexElement& element : elements)
+    {
+        CombineHash(hash, GetHash(element));
+    }
+
+    // Lookup existing cache
+    CacheLocker.Lock();
+    GPUVertexLayout* result;
+    if (!LayoutCache.TryGet(hash, result))
+    {
+        result = GPUDevice::Instance->CreateVertexLayout(elements);
+        if (!result)
+        {
+#if GPU_ENABLE_ASSERTION_LOW_LAYERS
+            for (auto& e : elements)
+                LOG(Error, " {}", e.ToString());
+#endif
+            LOG(Error, "Failed to create vertex layout");
+            CacheLocker.Unlock();
+            return nullptr;
+        }
+        LayoutCache.Add(hash, result);
+    }
+#if GPU_ENABLE_ASSERTION_LOW_LAYERS
+    else if (result->GetElements() != elements)
+    {
+        for (auto& e : result->GetElements())
+            LOG(Error, " (a) {}", e.ToString());
+        for (auto& e : elements)
+            LOG(Error, " (b) {}", e.ToString());
+        LOG(Fatal, "Vertex layout cache collision for hash {}", hash);
+    }
+#endif
+    CacheLocker.Unlock();
+
+    return result;
+}
+
+void ClearVertexLayoutCache()
+{
+    for (const auto& e : LayoutCache)
+        Delete(e.Value);
+    LayoutCache.Clear();
+}