Adds legacy bda accessor, fixes fft accessor usage

Author: Fletterio

include/nbl/builtin/hlsl/bda/legacy_bda_accessor.hlsl

@@ -0,0 +1,103 @@
+// Copyright (C) 2018-2024 - DevSH Graphics Programming Sp. z O.O.
+// This file is part of the "Nabla Engine".
+// For conditions of distribution and use, see copyright notice in nabla.h
+
+// TODO: Remove all appearances of this class and refactor to use the real BDA once https://github.com/microsoft/DirectXShaderCompiler/issues/6541 is resolved
+//       Then, delete this file altogether.
+
+
+#ifndef _NBL_BUILTIN_HLSL_LEGACY_BDA_ACCESSOR_INCLUDED_
+#define _NBL_BUILTIN_HLSL_LEGACY_BDA_ACCESSOR_INCLUDED_
+
+#include "nbl/builtin/hlsl/glsl_compat/core.hlsl"
+#include "nbl/builtin/hlsl/bda/__ptr.hlsl"
+
+namespace nbl 
+{
+namespace hlsl
+{
+
+namespace impl {
+
+struct LegacyBdaAccessorBase
+{
+    // Note: Its a funny quirk of the SPIR-V Vulkan Env spec that `MemorySemanticsUniformMemoryMask` means SSBO as well :facepalm: (and probably BDA)
+	void workgroupExecutionAndMemoryBarrier() 
+	{
+		// we're only barriering the workgroup and trading memory within a workgroup
+		spirv::controlBarrier(spv::ScopeWorkgroup, spv::ScopeWorkgroup, spv::MemorySemanticsAcquireReleaseMask | spv::MemorySemanticsUniformMemoryMask);
+    }
+
+    void memoryBarrier() 
+	{
+		// By default it's device-wide access to the buffer
+		spirv::memoryBarrier(spv::ScopeDevice, spv::MemorySemanticsAcquireReleaseMask | spv::MemorySemanticsUniformMemoryMask);
+	}
+};
+
+} //namespace impl
+
+template<typename T>
+struct LegacyBdaAccessor : impl::LegacyBdaAccessorBase
+{
+    using type_t = T;
+    static LegacyBdaAccessor<T> create(const uint64_t address)
+    {
+        LegacyBdaAccessor<T> accessor;
+        accessor.address = address;
+        return accessor;
+    }
+
+    T get(const uint64_t index)
+    {
+        return vk::RawBufferLoad<T>(address + index * sizeof(T));
+    }
+
+    void get(const uint64_t index, NBL_REF_ARG(T) value)
+    {
+        value = vk::RawBufferLoad<T>(address + index * sizeof(T));
+    }
+
+    void set(const uint64_t index, const T value)
+    {
+        vk::RawBufferStore<T>(address + index * sizeof(T), value);
+    }
+
+    uint64_t address;
+};
+
+template<typename T>
+struct DoubleLegacyBdaAccessor : impl::LegacyBdaAccessorBase
+{
+    using type_t = T;
+    static DoubleLegacyBdaAccessor<T> create(const uint64_t inputAddress, const uint64_t outputAddress)
+    {
+        DoubleLegacyBdaAccessor<T> accessor;
+        accessor.inputAddress = inputAddress;
+        accessor.outputAddress = outputAddress;
+        return accessor;
+    }
+
+    T get(const uint64_t index)
+    {
+        return vk::RawBufferLoad<T>(inputAddress + index * sizeof(T));
+    }
+
+    void get(const uint64_t index, NBL_REF_ARG(T) value)
+    {
+        value = vk::RawBufferLoad<T>(inputAddress + index * sizeof(T));
+    }
+
+    void set(const uint64_t index, const T value)
+    {
+        vk::RawBufferStore<T>(outputAddress + index * sizeof(T), value);
+    }
+
+    uint64_t inputAddress, outputAddress;
+};
+
+
+}
+}
+
+#endif

include/nbl/builtin/hlsl/workgroup/fft.hlsl

@@ -276,6 +276,7 @@ struct FFT<K, false, Scalar, device_capabilities>
 
         // do K/2 small workgroup FFTs
         accessor_adaptors::Offset<Accessor> offsetAccessor;
+        offsetAccessor.accessor = accessor;
         [unroll]
         for (uint32_t k = 0; k < K; k += 2)
         {
@@ -297,6 +298,7 @@ struct FFT<K, true, Scalar, device_capabilities>
     {
         // do K/2 small workgroup FFTs
         accessor_adaptors::Offset<Accessor> offsetAccessor;
+        offsetAccessor.accessor = accessor;
         [unroll]
         for (uint32_t k = 0; k < K; k += 2)
         {

src/nbl/builtin/CMakeLists.txt

@@ -34,6 +34,7 @@ LIST_BUILTIN_RESOURCE(NBL_RESOURCES_TO_EMBED "glsl/barycentric/utils.glsl")
 LIST_BUILTIN_RESOURCE(NBL_RESOURCES_TO_EMBED "hlsl/bda/__ref.hlsl")
 LIST_BUILTIN_RESOURCE(NBL_RESOURCES_TO_EMBED "hlsl/bda/__ptr.hlsl")
 LIST_BUILTIN_RESOURCE(NBL_RESOURCES_TO_EMBED "hlsl/bda/bda_accessor.hlsl")
+LIST_BUILTIN_RESOURCE(NBL_RESOURCES_TO_EMBED "hlsl/bda/legacy_bda_accessor.hlsl")
 # bump mapping
 LIST_BUILTIN_RESOURCE(NBL_RESOURCES_TO_EMBED "glsl/bump_mapping/fragment.glsl") # TODO: rename to `frag.glsl`
 LIST_BUILTIN_RESOURCE(NBL_RESOURCES_TO_EMBED "glsl/bump_mapping/utils.glsl")