actually pass descriptor binding flags to Vulkan

Author: AnastaZIuk

include/nbl/asset/IDescriptorSetLayout.h

@@ -46,10 +46,10 @@ class IDescriptorSetLayout : public virtual core::IReferenceCounted  // TODO: tr
 		enum class E_CREATE_FLAGS : uint8_t
 		{
 			ECF_NONE = 0,
-			ECF_UPDATE_AFTER_BIND_BIT = 1u << 1,
-			ECF_UPDATE_UNUSED_WHILE_PENDING_BIT = 1u << 2,
-			ECF_PARTIALLY_BOUND_BIT = 1u << 3,
-			ECF_VARIABLE_DESCRIPTOR_COUNT_BIT = 1u << 4
+			ECF_UPDATE_AFTER_BIND_BIT = 1u << 0,
+			ECF_UPDATE_UNUSED_WHILE_PENDING_BIT = 1u << 1,
+			ECF_PARTIALLY_BOUND_BIT = 1u << 2,
+			ECF_VARIABLE_DESCRIPTOR_COUNT_BIT = 1u << 3
 		};
 
 		uint32_t binding;

include/nbl/video/CVulkanCommon.h

@@ -1027,6 +1027,16 @@ inline constexpr VkDescriptorType getVkDescriptorTypeFromDescriptorType(const as
     }
 }
 
+inline VkDescriptorBindingFlagBits getVkDescriptorBindingFlagsFrom(const core::bitflag<IGPUDescriptorSetLayout::SBinding::E_CREATE_FLAGS> flags)
+{
+    // Wait for C++23
+    //static_assert(std::to_underlying(IGPUDescriptorSetLayout::SBinding::E_CREATE_FLAGS::ECF_UPDATE_AFTER_BIND_BIT)==VK_DESCRIPTOR_BINDING_UPDATE_AFTER_BIND_BIT);
+    //static_assert(IGPUDescriptorSetLayout::SBinding::E_CREATE_FLAGS::ECF_UPDATE_AFTER_BIND_BIT==VK_DESCRIPTOR_BINDING_UPDATE_UNUSED_WHILE_PENDING_BIT);
+    //static_assert(IGPUDescriptorSetLayout::SBinding::E_CREATE_FLAGS::ECF_UPDATE_AFTER_BIND_BIT==VK_DESCRIPTOR_BINDING_PARTIALLY_BOUND_BIT);
+    //static_assert(IGPUDescriptorSetLayout::SBinding::E_CREATE_FLAGS::ECF_UPDATE_AFTER_BIND_BIT==VK_DESCRIPTOR_BINDING_VARIABLE_DESCRIPTOR_COUNT_BIT);
+    return static_cast<VkDescriptorBindingFlagBits>(flags.value);
+}
+
 inline IPhysicalDevice::E_DRIVER_ID getDriverIdFromVkDriverId(const VkDriverId in)
 {
     if(in == VK_DRIVER_ID_AMD_PROPRIETARY) return IPhysicalDevice::E_DRIVER_ID::EDI_AMD_PROPRIETARY;

include/nbl/video/ILogicalDevice.h

@@ -631,6 +631,7 @@ class NBL_API2 ILogicalDevice : public core::IReferenceCounted, public IDeviceMe
             {
                 if (layout)
                 {
+                    // TODO: when creating the layouts, cache if they have any update after bindingings, and patch `createInfo.flags` with that here
                     const auto setCount = setCounts ? *(setCountsIt):1u;
                     createInfo.maxSets += setCount;
                     for (uint32_t t=0; t<static_cast<uint32_t>(asset::IDescriptor::E_TYPE::ET_COUNT); ++t)

src/nbl/video/CVulkanLogicalDevice.cpp

@@ -539,9 +539,12 @@ core::smart_refctd_ptr<IGPUDescriptorSetLayout> CVulkanLogicalDevice::createDesc
 {
     std::vector<VkSampler> vk_samplers;
     std::vector<VkDescriptorSetLayoutBinding> vk_dsLayoutBindings;
+    std::vector<VkDescriptorBindingFlags> vk_bindingFlags;
     vk_samplers.reserve(maxSamplersCount); // Reserve to avoid resizing and pointer change while iterating 
     vk_dsLayoutBindings.reserve(bindings.size());
+    vk_bindingFlags.reserve(bindings.size());
 
+    bool updateAfterBindFound = false;
     for (const auto& binding : bindings)
     {
         auto& vkDescSetLayoutBinding = vk_dsLayoutBindings.emplace_back();
@@ -560,13 +563,22 @@ core::smart_refctd_ptr<IGPUDescriptorSetLayout> CVulkanLogicalDevice::createDesc
                 vk_samplers.push_back(static_cast<const CVulkanSampler*>(binding.immutableSamplers[i].get())->getInternalObject());
             vkDescSetLayoutBinding.pImmutableSamplers = vk_samplers.data()+samplerOffset;
         }
+
+        if (binding.createFlags.hasFlags(IGPUDescriptorSetLayout::SBinding::E_CREATE_FLAGS::ECF_UPDATE_AFTER_BIND_BIT))
+            updateAfterBindFound = true;
+        vk_bindingFlags.emplace_back() = getVkDescriptorBindingFlagsFrom(binding.createFlags);
     }
 
-    VkDescriptorSetLayoutCreateInfo vk_createInfo = { VK_STRUCTURE_TYPE_DESCRIPTOR_SET_LAYOUT_CREATE_INFO };
-    vk_createInfo.pNext = nullptr; // pNext of interest:  VkDescriptorSetLayoutBindingFlagsCreateInfo
-    vk_createInfo.flags = 0; // Todo(achal): I would need to create a IDescriptorSetLayout::SCreationParams for this
-    vk_createInfo.bindingCount = vk_dsLayoutBindings.size();
+    VkDescriptorSetLayoutBindingFlagsCreateInfo vk_bindingFlagsInfo = { VK_STRUCTURE_TYPE_DESCRIPTOR_SET_LAYOUT_BINDING_FLAGS_CREATE_INFO, nullptr };
+    VkDescriptorSetLayoutCreateInfo vk_createInfo = { VK_STRUCTURE_TYPE_DESCRIPTOR_SET_LAYOUT_CREATE_INFO, &vk_bindingFlagsInfo };
+    // Todo(achal): I would need to create a IDescriptorSetLayout::SCreationParams for this
+    // Answer: We don't actually support any extensions/features that would necessitate exposing any other flag than update_after_bind
+    vk_createInfo.flags = 0;
+    if (updateAfterBindFound)
+        vk_createInfo.flags |= VK_DESCRIPTOR_SET_LAYOUT_CREATE_UPDATE_AFTER_BIND_POOL_BIT;
+    vk_createInfo.bindingCount = vk_bindingFlagsInfo.bindingCount = vk_dsLayoutBindings.size();
     vk_createInfo.pBindings = vk_dsLayoutBindings.data();
+    vk_bindingFlagsInfo.pBindingFlags = vk_bindingFlags.data();
 
     VkDescriptorSetLayout vk_dsLayout;
     if (m_devf.vk.vkCreateDescriptorSetLayout(m_vkdev,&vk_createInfo,nullptr,&vk_dsLayout)==VK_SUCCESS)