MoltenVK/MoltenVK/GPUObjects/MVKDescriptorSet.h - external/github.com/KhronosGroup/MoltenVK - Git at Google

 /*
  * MVKDescriptorSet.h
  *
  * Copyright (c) 2015-2020 The Brenwill Workshop Ltd. (http://www.brenwill.com)
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
  * You may obtain a copy of the License at
  *
  *     http://www.apache.org/licenses/LICENSE-2.0
  *
  * Unless required by applicable law or agreed to in writing, software
  * distributed under the License is distributed on an "AS IS" BASIS,
  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */

 #pragma once

 #include "MVKDescriptor.h"
 #include "MVKSmallVector.h"
 #include <unordered_set>
 #include <unordered_map>
 #include <vector>

 class MVKDescriptorPool;
 class MVKPipelineLayout;
 class MVKCommandEncoder;


 #pragma mark -
 #pragma mark MVKDescriptorSetLayout

 /** Represents a Vulkan descriptor set layout. */
 class MVKDescriptorSetLayout : public MVKVulkanAPIDeviceObject {

 public:

 	/** Returns the Vulkan type of this object. */
 	VkObjectType getVkObjectType() override { return VK_OBJECT_TYPE_DESCRIPTOR_SET_LAYOUT; }

 	/** Returns the debug report object type of this object. */
 	VkDebugReportObjectTypeEXT getVkDebugReportObjectType() override { return VK_DEBUG_REPORT_OBJECT_TYPE_DESCRIPTOR_SET_LAYOUT_EXT; }

 	/** Encodes this descriptor set layout and the specified descriptor set on the specified command encoder. */
 	void bindDescriptorSet(MVKCommandEncoder* cmdEncoder,
 						   MVKDescriptorSet* descSet,
 						   MVKShaderResourceBinding& dslMTLRezIdxOffsets,
 						   MVKArrayRef<uint32_t> dynamicOffsets,
 						   uint32_t& dynamicOffsetIndex);

 	/** Encodes this descriptor set layout and the specified descriptor updates on the specified command encoder immediately. */
 	void pushDescriptorSet(MVKCommandEncoder* cmdEncoder,
 						   MVKArrayRef<VkWriteDescriptorSet>& descriptorWrites,
 						   MVKShaderResourceBinding& dslMTLRezIdxOffsets);


 	/** Encodes this descriptor set layout and the updates from the given template on the specified command encoder immediately. */
 	void pushDescriptorSet(MVKCommandEncoder* cmdEncoder,
 						   MVKDescriptorUpdateTemplate* descUpdateTemplates,
 						   const void* pData,
 						   MVKShaderResourceBinding& dslMTLRezIdxOffsets);


 	/** Populates the specified shader converter context, at the specified DSL index. */
 	void populateShaderConverterContext(mvk::SPIRVToMSLConversionConfiguration& context,
                                         MVKShaderResourceBinding& dslMTLRezIdxOffsets,
                                         uint32_t dslIndex);

 	/** Returns true if this layout is for push descriptors only. */
 	bool isPushDescriptorLayout() const { return _isPushDescriptorLayout; }

 	MVKDescriptorSetLayout(MVKDevice* device, const VkDescriptorSetLayoutCreateInfo* pCreateInfo);

 protected:

 	friend class MVKDescriptorSetLayoutBinding;
 	friend class MVKPipelineLayout;
 	friend class MVKDescriptorSet;
 	friend class MVKDescriptorPool;

 	void propagateDebugName() override {}
 	inline uint32_t getDescriptorCount() { return _descriptorCount; }
 	inline uint32_t getDescriptorIndex(uint32_t binding, uint32_t elementIndex = 0) { return _bindingToDescriptorIndex[binding] + elementIndex; }
 	inline MVKDescriptorSetLayoutBinding* getBinding(uint32_t binding) { return &_bindings[_bindingToIndex[binding]]; }
 	const VkDescriptorBindingFlags* getBindingFlags(const VkDescriptorSetLayoutCreateInfo* pCreateInfo);

 	MVKSmallVector<MVKDescriptorSetLayoutBinding> _bindings;
 	std::unordered_map<uint32_t, uint32_t> _bindingToIndex;
 	std::unordered_map<uint32_t, uint32_t> _bindingToDescriptorIndex;
 	MVKShaderResourceBinding _mtlResourceCounts;
 	uint32_t _descriptorCount;
 	bool _isPushDescriptorLayout;
 };


 #pragma mark -
 #pragma mark MVKDescriptorSet

 /** Represents a Vulkan descriptor set. */
 class MVKDescriptorSet : public MVKVulkanAPIDeviceObject {

 public:

 	/** Returns the Vulkan type of this object. */
 	VkObjectType getVkObjectType() override { return VK_OBJECT_TYPE_DESCRIPTOR_SET; }

 	/** Returns the debug report object type of this object. */
 	VkDebugReportObjectTypeEXT getVkDebugReportObjectType() override { return VK_DEBUG_REPORT_OBJECT_TYPE_DESCRIPTOR_SET_EXT; }

 	/** Returns the descriptor type for the specified binding number. */
 	VkDescriptorType getDescriptorType(uint32_t binding);

 	/** Updates the resource bindings in this instance from the specified content. */
 	template<typename DescriptorAction>
 	void write(const DescriptorAction* pDescriptorAction, size_t stride, const void* pData);

 	/**
 	 * Reads the resource bindings defined in the specified content
 	 * from this instance into the specified collection of bindings.
 	 */
 	void read(const VkCopyDescriptorSet* pDescriptorCopies,
 			  VkDescriptorImageInfo* pImageInfo,
 			  VkDescriptorBufferInfo* pBufferInfo,
 			  VkBufferView* pTexelBufferView,
 			  VkWriteDescriptorSetInlineUniformBlockEXT* pInlineUniformBlock);

 	MVKDescriptorSet(MVKDescriptorSetLayout* layout,
 					 uint32_t variableDescriptorCount,
 					 MVKDescriptorPool* pool);

 	~MVKDescriptorSet() override;

 protected:
 	friend class MVKDescriptorSetLayoutBinding;
 	friend class MVKDescriptorPool;

 	void propagateDebugName() override {}
 	MVKDescriptor* getDescriptor(uint32_t binding, uint32_t elementIndex = 0);

 	MVKDescriptorSetLayout* _layout;
 	MVKDescriptorPool* _pool;
 	MVKSmallVector<MVKDescriptor*> _descriptors;
 	uint32_t _variableDescriptorCount;
 };


 #pragma mark -
 #pragma mark MVKDescriptorTypePreallocation

 /** Support class for MVKDescriptorPool that holds preallocated instances of a single concrete descriptor class. */
 template<class DescriptorClass>
 class MVKDescriptorTypePreallocation : public MVKBaseObject {

 public:

 	/** Returns the Vulkan API opaque object controlling this object. */
 	MVKVulkanAPIObject* getVulkanAPIObject() override { return nullptr; };

 	MVKDescriptorTypePreallocation(const VkDescriptorPoolCreateInfo* pCreateInfo,
 								   VkDescriptorType descriptorType);

 protected:
 	friend class MVKPreallocatedDescriptors;

 	VkResult allocateDescriptor(MVKDescriptor** pMVKDesc);
 	bool findDescriptor(uint32_t endIndex, MVKDescriptor** pMVKDesc);
 	void freeDescriptor(MVKDescriptor* mvkDesc);
 	void reset();

 	MVKSmallVector<DescriptorClass> _descriptors;
 	MVKSmallVector<bool> _availability;
 	uint32_t _nextAvailableIndex;
 	bool _supportAvailability;
 };


 #pragma mark -
 #pragma mark MVKPreallocatedDescriptors

 /** Support class for MVKDescriptorPool that holds preallocated instances of all concrete descriptor classes. */
 class MVKPreallocatedDescriptors : public MVKBaseObject {

 public:

 	/** Returns the Vulkan API opaque object controlling this object. */
 	MVKVulkanAPIObject* getVulkanAPIObject() override { return nullptr; };

 	MVKPreallocatedDescriptors(const VkDescriptorPoolCreateInfo* pCreateInfo);

 protected:
 	friend class MVKDescriptorPool;

 	VkResult allocateDescriptor(VkDescriptorType descriptorType, MVKDescriptor** pMVKDesc);
 	void freeDescriptor(MVKDescriptor* mvkDesc);
 	void reset();

 	MVKDescriptorTypePreallocation<MVKUniformBufferDescriptor> _uniformBufferDescriptors;
 	MVKDescriptorTypePreallocation<MVKStorageBufferDescriptor> _storageBufferDescriptors;
 	MVKDescriptorTypePreallocation<MVKUniformBufferDynamicDescriptor> _uniformBufferDynamicDescriptors;
 	MVKDescriptorTypePreallocation<MVKStorageBufferDynamicDescriptor> _storageBufferDynamicDescriptors;
 	MVKDescriptorTypePreallocation<MVKInlineUniformBlockDescriptor> _inlineUniformBlockDescriptors;
 	MVKDescriptorTypePreallocation<MVKSampledImageDescriptor> _sampledImageDescriptors;
 	MVKDescriptorTypePreallocation<MVKStorageImageDescriptor> _storageImageDescriptors;
 	MVKDescriptorTypePreallocation<MVKInputAttachmentDescriptor> _inputAttachmentDescriptors;
 	MVKDescriptorTypePreallocation<MVKSamplerDescriptor> _samplerDescriptors;
 	MVKDescriptorTypePreallocation<MVKCombinedImageSamplerDescriptor> _combinedImageSamplerDescriptors;
 	MVKDescriptorTypePreallocation<MVKUniformTexelBufferDescriptor> _uniformTexelBufferDescriptors;
 	MVKDescriptorTypePreallocation<MVKStorageTexelBufferDescriptor> _storageTexelBufferDescriptors;
 };


 #pragma mark -
 #pragma mark MVKDescriptorPool

 /** Represents a Vulkan descriptor pool. */
 class MVKDescriptorPool : public MVKVulkanAPIDeviceObject {

 public:

 	/** Returns the Vulkan type of this object. */
 	VkObjectType getVkObjectType() override { return VK_OBJECT_TYPE_DESCRIPTOR_POOL; }

 	/** Returns the debug report object type of this object. */
 	VkDebugReportObjectTypeEXT getVkDebugReportObjectType() override { return VK_DEBUG_REPORT_OBJECT_TYPE_DESCRIPTOR_POOL_EXT; }

 	/** Allocates descriptor sets. */
 	VkResult allocateDescriptorSets(const VkDescriptorSetAllocateInfo* pAllocateInfo,
 									VkDescriptorSet* pDescriptorSets);

 	/** Free's up the specified descriptor set. */
 	VkResult freeDescriptorSets(uint32_t count, const VkDescriptorSet* pDescriptorSets);

 	/** Destroys all currently allocated descriptor sets. */
 	VkResult reset(VkDescriptorPoolResetFlags flags);

 	MVKDescriptorPool(MVKDevice* device, const VkDescriptorPoolCreateInfo* pCreateInfo);

 	~MVKDescriptorPool() override;

 protected:
 	friend class MVKDescriptorSet;

 	void propagateDebugName() override {}
 	VkResult allocateDescriptorSet(MVKDescriptorSetLayout* mvkDSL, uint32_t variableDescriptorCount, VkDescriptorSet* pVKDS);
 	const uint32_t* getVariableDecriptorCounts(const VkDescriptorSetAllocateInfo* pAllocateInfo);
 	void freeDescriptorSet(MVKDescriptorSet* mvkDS);
 	VkResult allocateDescriptor(VkDescriptorType descriptorType, MVKDescriptor** pMVKDesc);
 	void freeDescriptor(MVKDescriptor* mvkDesc);

 	uint32_t _maxSets;
 	std::unordered_set<MVKDescriptorSet*> _allocatedSets;
 	MVKPreallocatedDescriptors* _preallocatedDescriptors;
 };


 #pragma mark -
 #pragma mark MVKDescriptorUpdateTemplate

 /** Represents a Vulkan descriptor update template. */
 class MVKDescriptorUpdateTemplate : public MVKVulkanAPIDeviceObject {

 public:

 	/** Returns the Vulkan type of this object. */
 	VkObjectType getVkObjectType() override { return VK_OBJECT_TYPE_DESCRIPTOR_UPDATE_TEMPLATE; }

 	/** Returns the debug report object type of this object. */
 	VkDebugReportObjectTypeEXT getVkDebugReportObjectType() override { return VK_DEBUG_REPORT_OBJECT_TYPE_DESCRIPTOR_UPDATE_TEMPLATE_EXT; }

 	/** Get the nth update template entry. */
 	const VkDescriptorUpdateTemplateEntryKHR* getEntry(uint32_t n) const;

 	/** Get the total number of entries. */
 	uint32_t getNumberOfEntries() const;

 	/** Get the type of this template. */
 	VkDescriptorUpdateTemplateTypeKHR getType() const;

 	/** Constructs an instance for the specified device. */
 	MVKDescriptorUpdateTemplate(MVKDevice* device, const VkDescriptorUpdateTemplateCreateInfoKHR* pCreateInfo);

 	/** Destructor. */
 	~MVKDescriptorUpdateTemplate() override = default;

 protected:
 	void propagateDebugName() override {}

 	VkDescriptorUpdateTemplateTypeKHR _type;
 	MVKSmallVector<VkDescriptorUpdateTemplateEntryKHR, 1> _entries;
 };

 #pragma mark -
 #pragma mark Support functions

 /** Updates the resource bindings in the descriptor sets inditified in the specified content. */
 void mvkUpdateDescriptorSets(uint32_t writeCount,
 							const VkWriteDescriptorSet* pDescriptorWrites,
 							uint32_t copyCount,
 							const VkCopyDescriptorSet* pDescriptorCopies);

 /** Updates the resource bindings in the given descriptor set from the specified template. */
 void mvkUpdateDescriptorSetWithTemplate(VkDescriptorSet descriptorSet,
 										VkDescriptorUpdateTemplateKHR updateTemplate,
 										const void* pData);

 /**
  * If the shader stage binding has a binding defined for the specified stage, populates
  * the context at the descriptor set binding from the shader stage resource binding.
  */
 void mvkPopulateShaderConverterContext(mvk::SPIRVToMSLConversionConfiguration& context,
 									   MVKShaderStageResourceBinding& ssRB,
 									   spv::ExecutionModel stage,
 									   uint32_t descriptorSetIndex,
 									   uint32_t bindingIndex,
 									   uint32_t count,
 									   MVKSampler* immutableSampler);
	/*
	* MVKDescriptorSet.h
	*
	* Copyright (c) 2015-2020 The Brenwill Workshop Ltd. (http://www.brenwill.com)
	*
	* Licensed under the Apache License, Version 2.0 (the "License");
	* you may not use this file except in compliance with the License.
	* You may obtain a copy of the License at
	*
	* http://www.apache.org/licenses/LICENSE-2.0
	*
	* Unless required by applicable law or agreed to in writing, software
	* distributed under the License is distributed on an "AS IS" BASIS,
	* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
	* See the License for the specific language governing permissions and
	* limitations under the License.
	*/

	#pragma once

	#include "MVKDescriptor.h"
	#include "MVKSmallVector.h"
	#include <unordered_set>
	#include <unordered_map>
	#include <vector>

	class MVKDescriptorPool;
	class MVKPipelineLayout;
	class MVKCommandEncoder;


	#pragma mark -
	#pragma mark MVKDescriptorSetLayout

	/** Represents a Vulkan descriptor set layout. */
	class MVKDescriptorSetLayout : public MVKVulkanAPIDeviceObject {

	public:

	/** Returns the Vulkan type of this object. */
	VkObjectType getVkObjectType() override { return VK_OBJECT_TYPE_DESCRIPTOR_SET_LAYOUT; }

	/** Returns the debug report object type of this object. */
	VkDebugReportObjectTypeEXT getVkDebugReportObjectType() override { return VK_DEBUG_REPORT_OBJECT_TYPE_DESCRIPTOR_SET_LAYOUT_EXT; }

	/** Encodes this descriptor set layout and the specified descriptor set on the specified command encoder. */
	void bindDescriptorSet(MVKCommandEncoder* cmdEncoder,
	MVKDescriptorSet* descSet,
	MVKShaderResourceBinding& dslMTLRezIdxOffsets,
	MVKArrayRef<uint32_t> dynamicOffsets,
	uint32_t& dynamicOffsetIndex);

	/** Encodes this descriptor set layout and the specified descriptor updates on the specified command encoder immediately. */
	void pushDescriptorSet(MVKCommandEncoder* cmdEncoder,
	MVKArrayRef<VkWriteDescriptorSet>& descriptorWrites,
	MVKShaderResourceBinding& dslMTLRezIdxOffsets);


	/** Encodes this descriptor set layout and the updates from the given template on the specified command encoder immediately. */
	void pushDescriptorSet(MVKCommandEncoder* cmdEncoder,
	MVKDescriptorUpdateTemplate* descUpdateTemplates,
	const void* pData,
	MVKShaderResourceBinding& dslMTLRezIdxOffsets);


	/** Populates the specified shader converter context, at the specified DSL index. */
	void populateShaderConverterContext(mvk::SPIRVToMSLConversionConfiguration& context,
	MVKShaderResourceBinding& dslMTLRezIdxOffsets,
	uint32_t dslIndex);

	/** Returns true if this layout is for push descriptors only. */
	bool isPushDescriptorLayout() const { return _isPushDescriptorLayout; }

	MVKDescriptorSetLayout(MVKDevice* device, const VkDescriptorSetLayoutCreateInfo* pCreateInfo);

	protected:

	friend class MVKDescriptorSetLayoutBinding;
	friend class MVKPipelineLayout;
	friend class MVKDescriptorSet;
	friend class MVKDescriptorPool;

	void propagateDebugName() override {}
	inline uint32_t getDescriptorCount() { return _descriptorCount; }
	inline uint32_t getDescriptorIndex(uint32_t binding, uint32_t elementIndex = 0) { return _bindingToDescriptorIndex[binding] + elementIndex; }
	inline MVKDescriptorSetLayoutBinding* getBinding(uint32_t binding) { return &_bindings[_bindingToIndex[binding]]; }
	const VkDescriptorBindingFlags* getBindingFlags(const VkDescriptorSetLayoutCreateInfo* pCreateInfo);

	MVKSmallVector<MVKDescriptorSetLayoutBinding> _bindings;
	std::unordered_map<uint32_t, uint32_t> _bindingToIndex;
	std::unordered_map<uint32_t, uint32_t> _bindingToDescriptorIndex;
	MVKShaderResourceBinding _mtlResourceCounts;
	uint32_t _descriptorCount;
	bool _isPushDescriptorLayout;
	};


	#pragma mark -
	#pragma mark MVKDescriptorSet

	/** Represents a Vulkan descriptor set. */
	class MVKDescriptorSet : public MVKVulkanAPIDeviceObject {

	public:

	/** Returns the Vulkan type of this object. */
	VkObjectType getVkObjectType() override { return VK_OBJECT_TYPE_DESCRIPTOR_SET; }

	/** Returns the debug report object type of this object. */
	VkDebugReportObjectTypeEXT getVkDebugReportObjectType() override { return VK_DEBUG_REPORT_OBJECT_TYPE_DESCRIPTOR_SET_EXT; }

	/** Returns the descriptor type for the specified binding number. */
	VkDescriptorType getDescriptorType(uint32_t binding);

	/** Updates the resource bindings in this instance from the specified content. */
	template<typename DescriptorAction>
	void write(const DescriptorAction* pDescriptorAction, size_t stride, const void* pData);

	/**
	* Reads the resource bindings defined in the specified content
	* from this instance into the specified collection of bindings.
	*/
	void read(const VkCopyDescriptorSet* pDescriptorCopies,
	VkDescriptorImageInfo* pImageInfo,
	VkDescriptorBufferInfo* pBufferInfo,
	VkBufferView* pTexelBufferView,
	VkWriteDescriptorSetInlineUniformBlockEXT* pInlineUniformBlock);

	MVKDescriptorSet(MVKDescriptorSetLayout* layout,
	uint32_t variableDescriptorCount,
	MVKDescriptorPool* pool);

	~MVKDescriptorSet() override;

	protected:
	friend class MVKDescriptorSetLayoutBinding;
	friend class MVKDescriptorPool;

	void propagateDebugName() override {}
	MVKDescriptor* getDescriptor(uint32_t binding, uint32_t elementIndex = 0);

	MVKDescriptorSetLayout* _layout;
	MVKDescriptorPool* _pool;
	MVKSmallVector<MVKDescriptor*> _descriptors;
	uint32_t _variableDescriptorCount;
	};


	#pragma mark -
	#pragma mark MVKDescriptorTypePreallocation

	/** Support class for MVKDescriptorPool that holds preallocated instances of a single concrete descriptor class. */
	template<class DescriptorClass>
	class MVKDescriptorTypePreallocation : public MVKBaseObject {

	public:

	/** Returns the Vulkan API opaque object controlling this object. */
	MVKVulkanAPIObject* getVulkanAPIObject() override { return nullptr; };

	MVKDescriptorTypePreallocation(const VkDescriptorPoolCreateInfo* pCreateInfo,
	VkDescriptorType descriptorType);

	protected:
	friend class MVKPreallocatedDescriptors;

	VkResult allocateDescriptor(MVKDescriptor** pMVKDesc);
	bool findDescriptor(uint32_t endIndex, MVKDescriptor** pMVKDesc);
	void freeDescriptor(MVKDescriptor* mvkDesc);
	void reset();

	MVKSmallVector<DescriptorClass> _descriptors;
	MVKSmallVector<bool> _availability;
	uint32_t _nextAvailableIndex;
	bool _supportAvailability;
	};


	#pragma mark -
	#pragma mark MVKPreallocatedDescriptors

	/** Support class for MVKDescriptorPool that holds preallocated instances of all concrete descriptor classes. */
	class MVKPreallocatedDescriptors : public MVKBaseObject {

	public:

	/** Returns the Vulkan API opaque object controlling this object. */
	MVKVulkanAPIObject* getVulkanAPIObject() override { return nullptr; };

	MVKPreallocatedDescriptors(const VkDescriptorPoolCreateInfo* pCreateInfo);

	protected:
	friend class MVKDescriptorPool;

	VkResult allocateDescriptor(VkDescriptorType descriptorType, MVKDescriptor** pMVKDesc);
	void freeDescriptor(MVKDescriptor* mvkDesc);
	void reset();

	MVKDescriptorTypePreallocation<MVKUniformBufferDescriptor> _uniformBufferDescriptors;
	MVKDescriptorTypePreallocation<MVKStorageBufferDescriptor> _storageBufferDescriptors;
	MVKDescriptorTypePreallocation<MVKUniformBufferDynamicDescriptor> _uniformBufferDynamicDescriptors;
	MVKDescriptorTypePreallocation<MVKStorageBufferDynamicDescriptor> _storageBufferDynamicDescriptors;
	MVKDescriptorTypePreallocation<MVKInlineUniformBlockDescriptor> _inlineUniformBlockDescriptors;
	MVKDescriptorTypePreallocation<MVKSampledImageDescriptor> _sampledImageDescriptors;
	MVKDescriptorTypePreallocation<MVKStorageImageDescriptor> _storageImageDescriptors;
	MVKDescriptorTypePreallocation<MVKInputAttachmentDescriptor> _inputAttachmentDescriptors;
	MVKDescriptorTypePreallocation<MVKSamplerDescriptor> _samplerDescriptors;
	MVKDescriptorTypePreallocation<MVKCombinedImageSamplerDescriptor> _combinedImageSamplerDescriptors;
	MVKDescriptorTypePreallocation<MVKUniformTexelBufferDescriptor> _uniformTexelBufferDescriptors;
	MVKDescriptorTypePreallocation<MVKStorageTexelBufferDescriptor> _storageTexelBufferDescriptors;
	};


	#pragma mark -
	#pragma mark MVKDescriptorPool

	/** Represents a Vulkan descriptor pool. */
	class MVKDescriptorPool : public MVKVulkanAPIDeviceObject {

	public:

	/** Returns the Vulkan type of this object. */
	VkObjectType getVkObjectType() override { return VK_OBJECT_TYPE_DESCRIPTOR_POOL; }

	/** Returns the debug report object type of this object. */
	VkDebugReportObjectTypeEXT getVkDebugReportObjectType() override { return VK_DEBUG_REPORT_OBJECT_TYPE_DESCRIPTOR_POOL_EXT; }

	/** Allocates descriptor sets. */
	VkResult allocateDescriptorSets(const VkDescriptorSetAllocateInfo* pAllocateInfo,
	VkDescriptorSet* pDescriptorSets);

	/** Free's up the specified descriptor set. */
	VkResult freeDescriptorSets(uint32_t count, const VkDescriptorSet* pDescriptorSets);

	/** Destroys all currently allocated descriptor sets. */
	VkResult reset(VkDescriptorPoolResetFlags flags);

	MVKDescriptorPool(MVKDevice* device, const VkDescriptorPoolCreateInfo* pCreateInfo);

	~MVKDescriptorPool() override;

	protected:
	friend class MVKDescriptorSet;

	void propagateDebugName() override {}
	VkResult allocateDescriptorSet(MVKDescriptorSetLayout* mvkDSL, uint32_t variableDescriptorCount, VkDescriptorSet* pVKDS);
	const uint32_t* getVariableDecriptorCounts(const VkDescriptorSetAllocateInfo* pAllocateInfo);
	void freeDescriptorSet(MVKDescriptorSet* mvkDS);
	VkResult allocateDescriptor(VkDescriptorType descriptorType, MVKDescriptor** pMVKDesc);
	void freeDescriptor(MVKDescriptor* mvkDesc);

	uint32_t _maxSets;
	std::unordered_set<MVKDescriptorSet*> _allocatedSets;
	MVKPreallocatedDescriptors* _preallocatedDescriptors;
	};


	#pragma mark -
	#pragma mark MVKDescriptorUpdateTemplate

	/** Represents a Vulkan descriptor update template. */
	class MVKDescriptorUpdateTemplate : public MVKVulkanAPIDeviceObject {

	public:

	/** Returns the Vulkan type of this object. */
	VkObjectType getVkObjectType() override { return VK_OBJECT_TYPE_DESCRIPTOR_UPDATE_TEMPLATE; }

	/** Returns the debug report object type of this object. */
	VkDebugReportObjectTypeEXT getVkDebugReportObjectType() override { return VK_DEBUG_REPORT_OBJECT_TYPE_DESCRIPTOR_UPDATE_TEMPLATE_EXT; }

	/** Get the nth update template entry. */
	const VkDescriptorUpdateTemplateEntryKHR* getEntry(uint32_t n) const;

	/** Get the total number of entries. */
	uint32_t getNumberOfEntries() const;

	/** Get the type of this template. */
	VkDescriptorUpdateTemplateTypeKHR getType() const;

	/** Constructs an instance for the specified device. */
	MVKDescriptorUpdateTemplate(MVKDevice* device, const VkDescriptorUpdateTemplateCreateInfoKHR* pCreateInfo);

	/** Destructor. */
	~MVKDescriptorUpdateTemplate() override = default;

	protected:
	void propagateDebugName() override {}

	VkDescriptorUpdateTemplateTypeKHR _type;
	MVKSmallVector<VkDescriptorUpdateTemplateEntryKHR, 1> _entries;
	};

	#pragma mark -
	#pragma mark Support functions

	/** Updates the resource bindings in the descriptor sets inditified in the specified content. */
	void mvkUpdateDescriptorSets(uint32_t writeCount,
	const VkWriteDescriptorSet* pDescriptorWrites,
	uint32_t copyCount,
	const VkCopyDescriptorSet* pDescriptorCopies);

	/** Updates the resource bindings in the given descriptor set from the specified template. */
	void mvkUpdateDescriptorSetWithTemplate(VkDescriptorSet descriptorSet,
	VkDescriptorUpdateTemplateKHR updateTemplate,
	const void* pData);

	/**
	* If the shader stage binding has a binding defined for the specified stage, populates
	* the context at the descriptor set binding from the shader stage resource binding.
	*/
	void mvkPopulateShaderConverterContext(mvk::SPIRVToMSLConversionConfiguration& context,
	MVKShaderStageResourceBinding& ssRB,
	spv::ExecutionModel stage,
	uint32_t descriptorSetIndex,
	uint32_t bindingIndex,
	uint32_t count,
	MVKSampler* immutableSampler);