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

 /*
  * MVKDescriptorSet.h
  *
  * Copyright (c) 2015-2021 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 "MVKBitArray.h"
 #include <unordered_set>
 #include <unordered_map>
 #include <vector>

 class MVKDescriptorPool;
 class MVKPipelineLayout;
 class MVKCommandEncoder;
 class MVKResourcesCommandEncoderState;


 #pragma mark -
 #pragma mark MVKDescriptorSetLayout

 /**
  * Holds and manages the lifecycle of a MTLArgumentEncoder. The encoder can
  * only be set once, and copying this object results in an uninitialized
  * empty object, since mutex and MTLArgumentEncoder can/should not be copied.
  */
 struct MVKMTLArgumentEncoder {
 	std::mutex mtlArgumentEncodingLock;
 	NSUInteger mtlArgumentEncoderSize = 0;

 	id<MTLArgumentEncoder> getMTLArgumentEncoder() { return _mtlArgumentEncoder; }
 	void init(id<MTLArgumentEncoder> mtlArgEnc) {
 		if (_mtlArgumentEncoder) { return; }
 		_mtlArgumentEncoder = mtlArgEnc;		// takes ownership
 		mtlArgumentEncoderSize = mtlArgEnc.encodedLength;
 	}

 	MVKMTLArgumentEncoder(const MVKMTLArgumentEncoder& other) {}
 	MVKMTLArgumentEncoder& operator=(const MVKMTLArgumentEncoder& other) { return *this; }
 	MVKMTLArgumentEncoder() {}
 	~MVKMTLArgumentEncoder() { [_mtlArgumentEncoder release]; }

 private:
 	id<MTLArgumentEncoder> _mtlArgumentEncoder = nil;
 };

 /** 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,
 						   VkPipelineBindPoint pipelineBindPoint,
 						   uint32_t descSetIndex,
 						   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 conversion config, at the specified DSL index. */
 	void populateShaderConversionConfig(mvk::SPIRVToMSLConversionConfiguration& shaderConfig,
                                         MVKShaderResourceBinding& dslMTLRezIdxOffsets,
                                         uint32_t descSetIndex);

 	/**
 	 * Populates the bindings in this descriptor set layout used by the shader.
 	 * Returns false if the shader does not use the descriptor set at all.
 	 */
 	bool populateBindingUse(MVKBitArray& bindingUse,
 							mvk::SPIRVToMSLConversionConfiguration& context,
 							MVKShaderStage stage,
 							uint32_t descSetIndex);

 	/** Returns the number of bindings. */
 	uint32_t getBindingCount() { return (uint32_t)_bindings.size(); }

 	/** Returns the binding at the index in a descriptor set layout. */
 	MVKDescriptorSetLayoutBinding* getBindingAt(uint32_t index) { return &_bindings[index]; }

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

 	/** Returns true if this layout is using a Metal argument buffer. */
 	bool isUsingMetalArgumentBuffer()  { return isUsingMetalArgumentBuffers() && !isPushDescriptorLayout(); };

 	/** Returns the MTLArgumentEncoder for the descriptor set. */
 	MVKMTLArgumentEncoder& getMTLArgumentEncoder() { return _mtlArgumentEncoder; }

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

 protected:

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

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

 	MVKSmallVector<MVKDescriptorSetLayoutBinding> _bindings;
 	std::unordered_map<uint32_t, uint32_t> _bindingToIndex;
 	MVKMTLArgumentEncoder _mtlArgumentEncoder;
 	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 layout that defines this descriptor set. */
 	MVKDescriptorSetLayout* getLayout() { return _layout; }

 	/** 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);

 	/** Returns an MTLBuffer region allocation. */
     MVKMTLBufferAllocation* acquireMTLBufferRegion(NSUInteger length);
 	/**
 	 * Returns the Metal argument buffer to which resources are written,
 	 * or return nil if Metal argument buffers are not being used.
 	 */
 	id<MTLBuffer> getMetalArgumentBuffer();

 	/** Returns the offset into the Metal argument buffer to which resources are written. */
 	NSUInteger getMetalArgumentBufferOffset() { return _metalArgumentBufferOffset; }

 	/** Returns an array indicating the descriptors that have changed since the Metal argument buffer was last updated. */
 	MVKBitArray& getMetalArgumentBufferDirtyDescriptors() { return _metalArgumentBufferDirtyDescriptors; }

 	/** Returns the descriptor at an index. */
 	MVKDescriptor* getDescriptorAt(uint32_t descIndex) { return _descriptors[descIndex]; }

 	/** Returns the number of descriptors in this descriptor set. */
 	uint32_t getDescriptorCount() { return (uint32_t)_descriptors.size(); }

 	/** Returns the number of descriptors in this descriptor set that use dynamic offsets. */
 	uint32_t getDynamicOffsetDescriptorCount() { return _dynamicOffsetDescriptorCount; }

 	MVKDescriptorSet(MVKDescriptorPool* pool);

 protected:
 	friend class MVKDescriptorSetLayoutBinding;
 	friend class MVKDescriptorPool;

 	void propagateDebugName() override {}
 	MVKDescriptor* getDescriptor(uint32_t binding, uint32_t elementIndex = 0);
 	VkResult allocate(MVKDescriptorSetLayout* layout,
 					  uint32_t variableDescriptorCount,
 					  NSUInteger mtlArgBufferOffset);
 	void free(bool isPoolReset);

 	MVKDescriptorPool* _pool;
 	MVKDescriptorSetLayout* _layout;
 	MVKSmallVector<MVKDescriptor*> _descriptors;
 	MVKBitArray _metalArgumentBufferDirtyDescriptors;
 	NSUInteger _metalArgumentBufferOffset;
 	uint32_t _dynamicOffsetDescriptorCount;
 	uint32_t _variableDescriptorCount;
 };


 #pragma mark -
 #pragma mark MVKDescriptorTypePool

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

 public:

 	MVKVulkanAPIObject* getVulkanAPIObject() override { return nullptr; };

 	MVKDescriptorTypePool(size_t poolSize);

 protected:
 	friend class MVKDescriptorPool;

 	VkResult allocateDescriptor(MVKDescriptor** pMVKDesc, MVKDescriptorPool* pool);
 	void freeDescriptor(MVKDescriptor* mvkDesc, MVKDescriptorPool* pool);
 	void reset();

 	MVKSmallVector<DescriptorClass> _descriptors;
 	MVKBitArray _availability;
 };


 #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, bool poolDescriptors);

 	~MVKDescriptorPool() override;

 protected:
 	friend class MVKDescriptorSet;
 	template<class> friend class MVKDescriptorTypePool;

 	void propagateDebugName() override {}
 	const uint32_t* getVariableDecriptorCounts(const VkDescriptorSetAllocateInfo* pAllocateInfo);
 	VkResult allocateDescriptorSet(MVKDescriptorSetLayout* mvkDSL, uint32_t variableDescriptorCount, VkDescriptorSet* pVKDS);
 	void freeDescriptorSet(MVKDescriptorSet* mvkDS, bool isPoolReset);
 	VkResult allocateDescriptor(VkDescriptorType descriptorType, MVKDescriptor** pMVKDesc);
 	void freeDescriptor(MVKDescriptor* mvkDesc);
 	void initMetalArgumentBuffer(const VkDescriptorPoolCreateInfo* pCreateInfo);
 	NSUInteger getMetalArgumentBufferResourceStorageSize(NSUInteger bufferCount, NSUInteger textureCount, NSUInteger samplerCount);
 	MTLArgumentDescriptor* getMTLArgumentDescriptor(MTLDataType resourceType, NSUInteger argIndex, NSUInteger count);

 	MVKSmallVector<MVKDescriptorSet> _descriptorSets;
 	MVKBitArray _descriptorSetAvailablility;
 	id<MTLBuffer> _metalArgumentBuffer;
 	NSUInteger _nextMetalArgumentBufferOffset;
 	MVKMTLBufferAllocator _inlineBlockMTLBufferAllocator;

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


 #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 mvkPopulateShaderConversionConfig(mvk::SPIRVToMSLConversionConfiguration& shaderConfig,
 									   MVKShaderStageResourceBinding& ssRB,
 									   spv::ExecutionModel stage,
 									   uint32_t descriptorSetIndex,
 									   uint32_t bindingIndex,
 									   uint32_t count,
 									   MVKSampler* immutableSampler);
	/*
	* MVKDescriptorSet.h
	*
	* Copyright (c) 2015-2021 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 "MVKBitArray.h"
	#include <unordered_set>
	#include <unordered_map>
	#include <vector>

	class MVKDescriptorPool;
	class MVKPipelineLayout;
	class MVKCommandEncoder;
	class MVKResourcesCommandEncoderState;


	#pragma mark -
	#pragma mark MVKDescriptorSetLayout

	/**
	* Holds and manages the lifecycle of a MTLArgumentEncoder. The encoder can
	* only be set once, and copying this object results in an uninitialized
	* empty object, since mutex and MTLArgumentEncoder can/should not be copied.
	*/
	struct MVKMTLArgumentEncoder {
	std::mutex mtlArgumentEncodingLock;
	NSUInteger mtlArgumentEncoderSize = 0;

	id<MTLArgumentEncoder> getMTLArgumentEncoder() { return _mtlArgumentEncoder; }
	void init(id<MTLArgumentEncoder> mtlArgEnc) {
	if (_mtlArgumentEncoder) { return; }
	_mtlArgumentEncoder = mtlArgEnc; // takes ownership
	mtlArgumentEncoderSize = mtlArgEnc.encodedLength;
	}

	MVKMTLArgumentEncoder(const MVKMTLArgumentEncoder& other) {}
	MVKMTLArgumentEncoder& operator=(const MVKMTLArgumentEncoder& other) { return *this; }
	MVKMTLArgumentEncoder() {}
	~MVKMTLArgumentEncoder() { [_mtlArgumentEncoder release]; }

	private:
	id<MTLArgumentEncoder> _mtlArgumentEncoder = nil;
	};

	/** 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,
	VkPipelineBindPoint pipelineBindPoint,
	uint32_t descSetIndex,
	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 conversion config, at the specified DSL index. */
	void populateShaderConversionConfig(mvk::SPIRVToMSLConversionConfiguration& shaderConfig,
	MVKShaderResourceBinding& dslMTLRezIdxOffsets,
	uint32_t descSetIndex);

	/**
	* Populates the bindings in this descriptor set layout used by the shader.
	* Returns false if the shader does not use the descriptor set at all.
	*/
	bool populateBindingUse(MVKBitArray& bindingUse,
	mvk::SPIRVToMSLConversionConfiguration& context,
	MVKShaderStage stage,
	uint32_t descSetIndex);

	/** Returns the number of bindings. */
	uint32_t getBindingCount() { return (uint32_t)_bindings.size(); }

	/** Returns the binding at the index in a descriptor set layout. */
	MVKDescriptorSetLayoutBinding* getBindingAt(uint32_t index) { return &_bindings[index]; }

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

	/** Returns true if this layout is using a Metal argument buffer. */
	bool isUsingMetalArgumentBuffer() { return isUsingMetalArgumentBuffers() && !isPushDescriptorLayout(); };

	/** Returns the MTLArgumentEncoder for the descriptor set. */
	MVKMTLArgumentEncoder& getMTLArgumentEncoder() { return _mtlArgumentEncoder; }

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

	protected:

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

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

	MVKSmallVector<MVKDescriptorSetLayoutBinding> _bindings;
	std::unordered_map<uint32_t, uint32_t> _bindingToIndex;
	MVKMTLArgumentEncoder _mtlArgumentEncoder;
	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 layout that defines this descriptor set. */
	MVKDescriptorSetLayout* getLayout() { return _layout; }

	/** 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);

	/** Returns an MTLBuffer region allocation. */
	MVKMTLBufferAllocation* acquireMTLBufferRegion(NSUInteger length);
	/**
	* Returns the Metal argument buffer to which resources are written,
	* or return nil if Metal argument buffers are not being used.
	*/
	id<MTLBuffer> getMetalArgumentBuffer();

	/** Returns the offset into the Metal argument buffer to which resources are written. */
	NSUInteger getMetalArgumentBufferOffset() { return _metalArgumentBufferOffset; }

	/** Returns an array indicating the descriptors that have changed since the Metal argument buffer was last updated. */
	MVKBitArray& getMetalArgumentBufferDirtyDescriptors() { return _metalArgumentBufferDirtyDescriptors; }

	/** Returns the descriptor at an index. */
	MVKDescriptor* getDescriptorAt(uint32_t descIndex) { return _descriptors[descIndex]; }

	/** Returns the number of descriptors in this descriptor set. */
	uint32_t getDescriptorCount() { return (uint32_t)_descriptors.size(); }

	/** Returns the number of descriptors in this descriptor set that use dynamic offsets. */
	uint32_t getDynamicOffsetDescriptorCount() { return _dynamicOffsetDescriptorCount; }

	MVKDescriptorSet(MVKDescriptorPool* pool);

	protected:
	friend class MVKDescriptorSetLayoutBinding;
	friend class MVKDescriptorPool;

	void propagateDebugName() override {}
	MVKDescriptor* getDescriptor(uint32_t binding, uint32_t elementIndex = 0);
	VkResult allocate(MVKDescriptorSetLayout* layout,
	uint32_t variableDescriptorCount,
	NSUInteger mtlArgBufferOffset);
	void free(bool isPoolReset);

	MVKDescriptorPool* _pool;
	MVKDescriptorSetLayout* _layout;
	MVKSmallVector<MVKDescriptor*> _descriptors;
	MVKBitArray _metalArgumentBufferDirtyDescriptors;
	NSUInteger _metalArgumentBufferOffset;
	uint32_t _dynamicOffsetDescriptorCount;
	uint32_t _variableDescriptorCount;
	};


	#pragma mark -
	#pragma mark MVKDescriptorTypePool

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

	public:

	MVKVulkanAPIObject* getVulkanAPIObject() override { return nullptr; };

	MVKDescriptorTypePool(size_t poolSize);

	protected:
	friend class MVKDescriptorPool;

	VkResult allocateDescriptor(MVKDescriptor** pMVKDesc, MVKDescriptorPool* pool);
	void freeDescriptor(MVKDescriptor* mvkDesc, MVKDescriptorPool* pool);
	void reset();

	MVKSmallVector<DescriptorClass> _descriptors;
	MVKBitArray _availability;
	};


	#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, bool poolDescriptors);

	~MVKDescriptorPool() override;

	protected:
	friend class MVKDescriptorSet;
	template<class> friend class MVKDescriptorTypePool;

	void propagateDebugName() override {}
	const uint32_t* getVariableDecriptorCounts(const VkDescriptorSetAllocateInfo* pAllocateInfo);
	VkResult allocateDescriptorSet(MVKDescriptorSetLayout* mvkDSL, uint32_t variableDescriptorCount, VkDescriptorSet* pVKDS);
	void freeDescriptorSet(MVKDescriptorSet* mvkDS, bool isPoolReset);
	VkResult allocateDescriptor(VkDescriptorType descriptorType, MVKDescriptor** pMVKDesc);
	void freeDescriptor(MVKDescriptor* mvkDesc);
	void initMetalArgumentBuffer(const VkDescriptorPoolCreateInfo* pCreateInfo);
	NSUInteger getMetalArgumentBufferResourceStorageSize(NSUInteger bufferCount, NSUInteger textureCount, NSUInteger samplerCount);
	MTLArgumentDescriptor* getMTLArgumentDescriptor(MTLDataType resourceType, NSUInteger argIndex, NSUInteger count);

	MVKSmallVector<MVKDescriptorSet> _descriptorSets;
	MVKBitArray _descriptorSetAvailablility;
	id<MTLBuffer> _metalArgumentBuffer;
	NSUInteger _nextMetalArgumentBufferOffset;
	MVKMTLBufferAllocator _inlineBlockMTLBufferAllocator;

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


	#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 mvkPopulateShaderConversionConfig(mvk::SPIRVToMSLConversionConfiguration& shaderConfig,
	MVKShaderStageResourceBinding& ssRB,
	spv::ExecutionModel stage,
	uint32_t descriptorSetIndex,
	uint32_t bindingIndex,
	uint32_t count,
	MVKSampler* immutableSampler);