// Copyright (C) 2009-2019, Panagiotis Christopoulos Charitos and contributors.
// All rights reserved.
// Code licensed under the BSD License.
// http://www.anki3d.org/LICENSE

#include <anki/gr/vulkan/DescriptorSet.h>
#include <anki/gr/Buffer.h>
#include <anki/gr/vulkan/BufferImpl.h>
#include <anki/util/List.h>
#include <anki/util/HashMap.h>
#include <anki/core/Trace.h>
#include <algorithm>

namespace anki
{

/// Descriptor set internal class.
class DS : public IntrusiveListEnabled<DS>
{
public:
	VkDescriptorSet m_handle = {};
	U64 m_lastFrameUsed = MAX_U64;
	U64 m_hash;
};

/// Per thread allocator.
class alignas(ANKI_CACHE_LINE_SIZE) DSThreadAllocator : public NonCopyable
{
public:
	const DSLayoutCacheEntry* m_layoutEntry; ///< Know your father.

	ThreadId m_tid;
	DynamicArray<VkDescriptorPool> m_pools;
	U32 m_lastPoolDSCount = 0;
	U32 m_lastPoolFreeDSCount = 0;

	IntrusiveList<DS> m_list; ///< At the left of the list are the least used sets.
	HashMap<U64, DS*> m_hashmap;

	DSThreadAllocator(const DSLayoutCacheEntry* layout, ThreadId tid)
		: m_layoutEntry(layout)
		, m_tid(tid)
	{
		ANKI_ASSERT(m_layoutEntry);
	}

	~DSThreadAllocator();

	ANKI_USE_RESULT Error init();
	ANKI_USE_RESULT Error createNewPool();

	ANKI_USE_RESULT Error getOrCreateSet(
		U64 hash, const Array<AnyBinding, MAX_BINDINGS_PER_DESCRIPTOR_SET>& bindings, const DS*& out)
	{
		out = tryFindSet(hash);
		if(out == nullptr)
		{
			ANKI_CHECK(newSet(hash, bindings, out));
		}

		return Error::NONE;
	}

private:
	ANKI_USE_RESULT const DS* tryFindSet(U64 hash);
	ANKI_USE_RESULT Error newSet(
		U64 hash, const Array<AnyBinding, MAX_BINDINGS_PER_DESCRIPTOR_SET>& bindings, const DS*& out);
	void writeSet(const Array<AnyBinding, MAX_BINDINGS_PER_DESCRIPTOR_SET>& bindings, const DS& set);
};

/// Cache entry. It's built around a specific descriptor set layout.
class DSLayoutCacheEntry
{
public:
	DescriptorSetFactory* m_factory;

	U64 m_hash = 0; ///< Layout hash.
	VkDescriptorSetLayout m_layoutHandle = {};
	BitSet<MAX_BINDINGS_PER_DESCRIPTOR_SET, U8> m_activeBindings = {false};
	Array<DescriptorType, MAX_BINDINGS_PER_DESCRIPTOR_SET> m_bindingType = {};
	U32 m_minBinding = MAX_U32;
	U32 m_maxBinding = 0;

	// Cache the create info
	Array<VkDescriptorPoolSize, U(DescriptorType::COUNT)> m_poolSizesCreateInf = {};
	VkDescriptorPoolCreateInfo m_poolCreateInf = {};

	DynamicArray<DSThreadAllocator*> m_threadAllocs;
	SpinLock m_threadAllocsMtx;

	DSLayoutCacheEntry(DescriptorSetFactory* factory)
		: m_factory(factory)
	{
	}

	~DSLayoutCacheEntry();

	ANKI_USE_RESULT Error init(const DescriptorBinding* bindings, U bindingCount, U64 hash);

	ANKI_USE_RESULT Error getOrCreateThreadAllocator(ThreadId tid, DSThreadAllocator*& alloc);
};

DSThreadAllocator::~DSThreadAllocator()
{
	auto alloc = m_layoutEntry->m_factory->m_alloc;

	while(!m_list.isEmpty())
	{
		DS* ds = &m_list.getFront();
		m_list.popFront();

		alloc.deleteInstance(ds);
	}

	for(VkDescriptorPool pool : m_pools)
	{
		vkDestroyDescriptorPool(m_layoutEntry->m_factory->m_dev, pool, nullptr);
	}
	m_pools.destroy(alloc);

	m_hashmap.destroy(alloc);
}

Error DSThreadAllocator::init()
{
	ANKI_CHECK(createNewPool());
	return Error::NONE;
}

Error DSThreadAllocator::createNewPool()
{
	m_lastPoolDSCount =
		(m_lastPoolDSCount != 0) ? (m_lastPoolDSCount * DESCRIPTOR_POOL_SIZE_SCALE) : DESCRIPTOR_POOL_INITIAL_SIZE;
	m_lastPoolFreeDSCount = m_lastPoolDSCount;

	// Set the create info
	Array<VkDescriptorPoolSize, U(DescriptorType::COUNT)> poolSizes;
	memcpy(&poolSizes[0],
		&m_layoutEntry->m_poolSizesCreateInf[0],
		sizeof(poolSizes[0]) * m_layoutEntry->m_poolCreateInf.poolSizeCount);

	for(U i = 0; i < m_layoutEntry->m_poolCreateInf.poolSizeCount; ++i)
	{
		poolSizes[i].descriptorCount *= m_lastPoolDSCount;
		ANKI_ASSERT(poolSizes[i].descriptorCount > 0);
	}

	VkDescriptorPoolCreateInfo ci = m_layoutEntry->m_poolCreateInf;
	ci.pPoolSizes = &poolSizes[0];
	ci.maxSets = m_lastPoolDSCount;

	// Create
	VkDescriptorPool pool;
	ANKI_VK_CHECK(vkCreateDescriptorPool(m_layoutEntry->m_factory->m_dev, &ci, nullptr, &pool));
	ANKI_TRACE_INC_COUNTER(VK_DESCRIPTOR_POOL_CREATE, 1);

	// Push back
	m_pools.resize(m_layoutEntry->m_factory->m_alloc, m_pools.getSize() + 1);
	m_pools[m_pools.getSize() - 1] = pool;

	return Error::NONE;
}

const DS* DSThreadAllocator::tryFindSet(U64 hash)
{
	ANKI_ASSERT(hash > 0);

	auto it = m_hashmap.find(hash);
	if(it == m_hashmap.getEnd())
	{
		return nullptr;
	}
	else
	{
		DS* ds = *it;

		// Remove from the list and place at the end of the list
		m_list.erase(ds);
		m_list.pushBack(ds);
		ds->m_lastFrameUsed = m_layoutEntry->m_factory->m_frameCount;

		return ds;
	}
}

Error DSThreadAllocator::newSet(
	U64 hash, const Array<AnyBinding, MAX_BINDINGS_PER_DESCRIPTOR_SET>& bindings, const DS*& out_)
{
	DS* out = nullptr;

	// First try to see if there are unused to recycle
	const U64 crntFrame = m_layoutEntry->m_factory->m_frameCount;
	auto it = m_list.getBegin();
	const auto end = m_list.getEnd();
	while(it != end)
	{
		DS* set = &(*it);
		U64 frameDiff = crntFrame - set->m_lastFrameUsed;
		if(frameDiff > DESCRIPTOR_FRAME_BUFFERING)
		{
			// Found something, recycle
			auto it2 = m_hashmap.find(set->m_hash);
			ANKI_ASSERT(it2 != m_hashmap.getEnd());
			m_hashmap.erase(m_layoutEntry->m_factory->m_alloc, it2);
			m_list.erase(set);

			m_list.pushBack(set);
			m_hashmap.emplace(m_layoutEntry->m_factory->m_alloc, hash, set);

			out = set;
			break;
		}
		++it;
	}

	if(out == nullptr)
	{
		// Need to allocate one

		if(m_lastPoolFreeDSCount == 0)
		{
			// Can't allocate one from the current pool, create new
			ANKI_CHECK(createNewPool());
		}

		--m_lastPoolFreeDSCount;

		VkDescriptorSetAllocateInfo ci = {};
		ci.sType = VK_STRUCTURE_TYPE_DESCRIPTOR_SET_ALLOCATE_INFO;
		ci.descriptorPool = m_pools.getBack();
		ci.pSetLayouts = &m_layoutEntry->m_layoutHandle;
		ci.descriptorSetCount = 1;

		VkDescriptorSet handle;
		VkResult rez = vkAllocateDescriptorSets(m_layoutEntry->m_factory->m_dev, &ci, &handle);
		(void)rez;
		ANKI_ASSERT(rez == VK_SUCCESS && "That allocation can't fail");
		ANKI_TRACE_INC_COUNTER(VK_DESCRIPTOR_SET_CREATE, 1);

		out = m_layoutEntry->m_factory->m_alloc.newInstance<DS>();
		out->m_handle = handle;

		m_hashmap.emplace(m_layoutEntry->m_factory->m_alloc, hash, out);
		m_list.pushBack(out);
	}

	ANKI_ASSERT(out);
	out->m_lastFrameUsed = crntFrame;
	out->m_hash = hash;

	// Finally, write it
	writeSet(bindings, *out);

	out_ = out;
	return Error::NONE;
}

void DSThreadAllocator::writeSet(const Array<AnyBinding, MAX_BINDINGS_PER_DESCRIPTOR_SET>& bindings, const DS& set)
{
	Array<VkWriteDescriptorSet, MAX_BINDINGS_PER_DESCRIPTOR_SET> writes;
	U writeCount = 0;

	Array<VkDescriptorImageInfo, MAX_BINDINGS_PER_DESCRIPTOR_SET> tex;
	U texCount = 0;
	Array<VkDescriptorBufferInfo, MAX_BINDINGS_PER_DESCRIPTOR_SET> buff;
	U buffCount = 0;

	VkWriteDescriptorSet writeTemplate = {};
	writeTemplate.sType = VK_STRUCTURE_TYPE_WRITE_DESCRIPTOR_SET;
	writeTemplate.pNext = nullptr;
	writeTemplate.dstSet = set.m_handle;
	writeTemplate.descriptorCount = 1;

	for(U i = m_layoutEntry->m_minBinding; i <= m_layoutEntry->m_maxBinding; ++i)
	{
		if(m_layoutEntry->m_activeBindings.get(i))
		{
			const AnyBinding& b = bindings[i];

			VkWriteDescriptorSet& w = writes[writeCount++];
			w = writeTemplate;
			w.dstBinding = i;
			w.descriptorType = convertDescriptorType(b.m_type);

			switch(b.m_type)
			{
			case DescriptorType::COMBINED_TEXTURE_SAMPLER:
				tex[texCount].sampler = b.m_texAndSampler.m_sampler->getHandle();
				tex[texCount].imageView = b.m_texAndSampler.m_texView->m_handle;
				tex[texCount].imageLayout = b.m_texAndSampler.m_layout;

				w.pImageInfo = &tex[texCount];

				++texCount;
				break;
			case DescriptorType::TEXTURE:
				tex[texCount].sampler = VK_NULL_HANDLE;
				tex[texCount].imageView = b.m_tex.m_texView->m_handle;
				tex[texCount].imageLayout = b.m_tex.m_layout;

				w.pImageInfo = &tex[texCount];

				++texCount;
				break;
			case DescriptorType::SAMPLER:
				tex[texCount].sampler = b.m_sampler.m_sampler->getHandle();
				tex[texCount].imageView = VK_NULL_HANDLE;
				tex[texCount].imageLayout = VK_IMAGE_LAYOUT_UNDEFINED;

				w.pImageInfo = &tex[texCount];

				++texCount;
				break;
			case DescriptorType::UNIFORM_BUFFER:
			case DescriptorType::STORAGE_BUFFER:
				buff[buffCount].buffer = b.m_buff.m_buff->getHandle();
				buff[buffCount].offset = 0;
				buff[buffCount].range = (b.m_buff.m_range == MAX_PTR_SIZE) ? VK_WHOLE_SIZE : b.m_buff.m_range;

				w.pBufferInfo = &buff[buffCount];

				++buffCount;
				break;
			case DescriptorType::IMAGE:
				tex[texCount].sampler = VK_NULL_HANDLE;
				tex[texCount].imageView = b.m_image.m_texView->m_handle;
				tex[texCount].imageLayout = VK_IMAGE_LAYOUT_GENERAL;

				w.pImageInfo = &tex[texCount];

				++texCount;
				break;
			default:
				ANKI_ASSERT(0);
			}
		}
	}

	vkUpdateDescriptorSets(m_layoutEntry->m_factory->m_dev, writeCount, &writes[0], 0, nullptr);
}

DSLayoutCacheEntry::~DSLayoutCacheEntry()
{
	auto alloc = m_factory->m_alloc;

	for(DSThreadAllocator* a : m_threadAllocs)
	{
		alloc.deleteInstance(a);
	}

	m_threadAllocs.destroy(alloc);

	if(m_layoutHandle)
	{
		vkDestroyDescriptorSetLayout(m_factory->m_dev, m_layoutHandle, nullptr);
	}
}

Error DSLayoutCacheEntry::init(const DescriptorBinding* bindings, U bindingCount, U64 hash)
{
	ANKI_ASSERT(bindings);
	ANKI_ASSERT(hash > 0);

	m_hash = hash;

	// Create the VK layout
	Array<VkDescriptorSetLayoutBinding, MAX_BINDINGS_PER_DESCRIPTOR_SET> vkBindings;
	VkDescriptorSetLayoutCreateInfo ci = {};
	ci.sType = VK_STRUCTURE_TYPE_DESCRIPTOR_SET_LAYOUT_CREATE_INFO;

	for(U i = 0; i < bindingCount; ++i)
	{
		VkDescriptorSetLayoutBinding& vk = vkBindings[i];
		const DescriptorBinding& ak = bindings[i];

		vk.binding = ak.m_binding;
		vk.descriptorCount = 1;
		vk.descriptorType = convertDescriptorType(ak.m_type);
		vk.pImmutableSamplers = nullptr;
		vk.stageFlags = convertShaderTypeBit(ak.m_stageMask);

		ANKI_ASSERT(m_activeBindings.get(ak.m_binding) == false);
		m_activeBindings.set(ak.m_binding);
		m_bindingType[ak.m_binding] = ak.m_type;
		m_minBinding = min<U32>(m_minBinding, ak.m_binding);
		m_maxBinding = max<U32>(m_maxBinding, ak.m_binding);
	}

	ci.bindingCount = bindingCount;
	ci.pBindings = &vkBindings[0];

	ANKI_VK_CHECK(vkCreateDescriptorSetLayout(m_factory->m_dev, &ci, nullptr, &m_layoutHandle));

	// Create the pool info
	U poolSizeCount = 0;
	for(U i = 0; i < bindingCount; ++i)
	{
		U j;
		for(j = 0; j < poolSizeCount; ++j)
		{
			if(m_poolSizesCreateInf[j].type == convertDescriptorType(bindings[i].m_type))
			{
				++m_poolSizesCreateInf[j].descriptorCount;
				break;
			}
		}

		if(j == poolSizeCount)
		{
			m_poolSizesCreateInf[poolSizeCount].type = convertDescriptorType(bindings[i].m_type);
			m_poolSizesCreateInf[poolSizeCount].descriptorCount = 1;
			++poolSizeCount;
		}
	}

	if(poolSizeCount == 0)
	{
		// If the poolSizeCount it means that the DS layout has 0 descriptors. Since the pool sizes can't be zero put
		// something in them
		m_poolSizesCreateInf[0].type = VK_DESCRIPTOR_TYPE_STORAGE_IMAGE;
		m_poolSizesCreateInf[0].descriptorCount = 1;
		++poolSizeCount;
	}

	ANKI_ASSERT(poolSizeCount > 0);

	m_poolCreateInf.sType = VK_STRUCTURE_TYPE_DESCRIPTOR_POOL_CREATE_INFO;
	m_poolCreateInf.poolSizeCount = poolSizeCount;

	return Error::NONE;
}

Error DSLayoutCacheEntry::getOrCreateThreadAllocator(ThreadId tid, DSThreadAllocator*& alloc)
{
	alloc = nullptr;

	LockGuard<SpinLock> lock(m_threadAllocsMtx);

	class Comp
	{
	public:
		Bool operator()(const DSThreadAllocator* a, ThreadId tid) const
		{
			return a->m_tid < tid;
		}

		Bool operator()(ThreadId tid, const DSThreadAllocator* a) const
		{
			return tid < a->m_tid;
		}
	};

	// Find using binary search
	auto it = binarySearch(m_threadAllocs.getBegin(), m_threadAllocs.getEnd(), tid, Comp());

	if(it != m_threadAllocs.getEnd())
	{
		ANKI_ASSERT((*it)->m_tid == tid);
		alloc = *it;
	}
	else
	{
		// Need to create one

		alloc = m_factory->m_alloc.newInstance<DSThreadAllocator>(this, tid);
		ANKI_CHECK(alloc->init());

		m_threadAllocs.resize(m_factory->m_alloc, m_threadAllocs.getSize() + 1);
		m_threadAllocs[m_threadAllocs.getSize() - 1] = alloc;

		// Sort for fast find
		std::sort(m_threadAllocs.getBegin(),
			m_threadAllocs.getEnd(),
			[](const DSThreadAllocator* a, const DSThreadAllocator* b) { return a->m_tid < b->m_tid; });
	}

	ANKI_ASSERT(alloc);
	return Error::NONE;
}

void DescriptorSetState::flush(
	Bool& stateDirty, U64& hash, Array<U32, MAX_BINDINGS_PER_DESCRIPTOR_SET>& dynamicOffsets, U& dynamicOffsetCount)
{
	dynamicOffsetCount = 0;

	// Get cache entry
	ANKI_ASSERT(m_layout.m_entry);
	const DSLayoutCacheEntry& entry = *m_layout.m_entry;

	// Early out if nothing happened
	if(!m_anyBindingDirty && !m_layoutDirty)
	{
		stateDirty = false;
		return;
	}

	Bool dynamicOffsetsDirty = false;

	// Compute the hash
	Array<U64, MAX_BINDINGS_PER_DESCRIPTOR_SET * 2 * 2> toHash;
	U toHashCount = 0;

	const U minBinding = entry.m_minBinding;
	const U maxBinding = entry.m_maxBinding;
	for(U i = minBinding; i <= maxBinding; ++i)
	{
		if(entry.m_activeBindings.get(i))
		{
			toHash[toHashCount++] = m_bindings[i].m_uuids[0];

			switch(entry.m_bindingType[i])
			{
			case DescriptorType::COMBINED_TEXTURE_SAMPLER:
				ANKI_ASSERT(
					m_bindings[i].m_type == DescriptorType::COMBINED_TEXTURE_SAMPLER && "Have bound the wrong type");
				toHash[toHashCount++] = m_bindings[i].m_uuids[1];
				toHash[toHashCount++] = U64(m_bindings[i].m_texAndSampler.m_layout);
				break;
			case DescriptorType::TEXTURE:
				ANKI_ASSERT(m_bindings[i].m_type == DescriptorType::TEXTURE && "Have bound the wrong type");
				toHash[toHashCount] = U64(m_bindings[i].m_tex.m_layout);
				break;
			case DescriptorType::SAMPLER:
				ANKI_ASSERT(m_bindings[i].m_type == DescriptorType::SAMPLER && "Have bound the wrong type");
				break;
			case DescriptorType::UNIFORM_BUFFER:
				ANKI_ASSERT(m_bindings[i].m_type == DescriptorType::UNIFORM_BUFFER && "Have bound the wrong type");
				toHash[toHashCount++] = m_bindings[i].m_buff.m_range;
				dynamicOffsets[dynamicOffsetCount++] = m_bindings[i].m_buff.m_offset;
				dynamicOffsetsDirty = dynamicOffsetsDirty || m_dynamicOffsetDirty.get(i);
				break;
			case DescriptorType::STORAGE_BUFFER:
				ANKI_ASSERT(m_bindings[i].m_type == DescriptorType::STORAGE_BUFFER && "Have bound the wrong type");
				toHash[toHashCount++] = m_bindings[i].m_buff.m_range;
				dynamicOffsets[dynamicOffsetCount++] = m_bindings[i].m_buff.m_offset;
				dynamicOffsetsDirty = dynamicOffsetsDirty || m_dynamicOffsetDirty.get(i);
				break;
			case DescriptorType::IMAGE:
				ANKI_ASSERT(m_bindings[i].m_type == DescriptorType::IMAGE && "Have bound the wrong type");
				break;
			default:
				ANKI_ASSERT(0);
			}
		}
	}

	hash = (toHashCount == 1) ? toHash[0] : computeHash(&toHash[0], toHashCount * sizeof(U64));

	if(hash != m_lastHash || dynamicOffsetsDirty || m_layoutDirty)
	{
		m_lastHash = hash;
		stateDirty = true;
	}
	else
	{
		stateDirty = false;
	}

	m_anyBindingDirty = false;
	m_layoutDirty = false;
	m_dynamicOffsetDirty.unsetAll();
}

DescriptorSetFactory::~DescriptorSetFactory()
{
}

void DescriptorSetFactory::init(const GrAllocator<U8>& alloc, VkDevice dev)
{
	m_alloc = alloc;
	m_dev = dev;
}

void DescriptorSetFactory::destroy()
{
	for(DSLayoutCacheEntry* l : m_caches)
	{
		m_alloc.deleteInstance(l);
	}

	m_caches.destroy(m_alloc);
}

Error DescriptorSetFactory::newDescriptorSetLayout(const DescriptorSetLayoutInitInfo& init, DescriptorSetLayout& layout)
{
	// Compute the hash for the layout
	Array<DescriptorBinding, MAX_BINDINGS_PER_DESCRIPTOR_SET> bindings;
	U bindingCount = init.m_bindings.getSize();
	U64 hash;

	if(init.m_bindings.getSize() > 0)
	{
		memcpy(&bindings[0], &init.m_bindings[0], init.m_bindings.getSizeInBytes());
		std::sort(&bindings[0],
			&bindings[0] + bindingCount,
			[](const DescriptorBinding& a, const DescriptorBinding& b) { return a.m_binding < b.m_binding; });

		hash = computeHash(&bindings[0], init.m_bindings.getSizeInBytes());
		ANKI_ASSERT(hash != 1);
	}
	else
	{
		hash = 1;
	}

	// Find or create the cache entry
	LockGuard<SpinLock> lock(m_cachesMtx);

	DSLayoutCacheEntry* cache = nullptr;
	U count = 0;
	for(DSLayoutCacheEntry* it : m_caches)
	{
		if(it->m_hash == hash)
		{
			cache = it;
			break;
		}
		++count;
	}

	if(cache == nullptr)
	{
		cache = m_alloc.newInstance<DSLayoutCacheEntry>(this);
		ANKI_CHECK(cache->init(&bindings[0], bindingCount, hash));

		m_caches.resize(m_alloc, m_caches.getSize() + 1);
		m_caches[m_caches.getSize() - 1] = cache;
	}

	// Set the layout
	layout.m_handle = cache->m_layoutHandle;
	layout.m_entry = cache;

	return Error::NONE;
}

Error DescriptorSetFactory::newDescriptorSet(ThreadId tid,
	DescriptorSetState& state,
	DescriptorSet& set,
	Bool& dirty,
	Array<U32, MAX_BINDINGS_PER_DESCRIPTOR_SET>& dynamicOffsets,
	U& dynamicOffsetCount)
{
	ANKI_TRACE_SCOPED_EVENT(VK_DESCRIPTOR_SET_GET_OR_CREATE);

	U64 hash;
	state.flush(dirty, hash, dynamicOffsets, dynamicOffsetCount);

	if(!dirty)
	{
		return Error::NONE;
	}

	DescriptorSetLayout layout = state.m_layout;
	DSLayoutCacheEntry& entry = *layout.m_entry;

	// Get thread allocator
	DSThreadAllocator* alloc;
	ANKI_CHECK(entry.getOrCreateThreadAllocator(tid, alloc));

	// Finally, allocate
	const DS* s;
	ANKI_CHECK(alloc->getOrCreateSet(hash, state.m_bindings, s));
	set.m_handle = s->m_handle;
	ANKI_ASSERT(set.m_handle != VK_NULL_HANDLE);

	return Error::NONE;
}

BindlessDescriptorSet::~BindlessDescriptorSet()
{
	ANKI_ASSERT(m_dset == VK_NULL_HANDLE);
	ANKI_ASSERT(m_layout == VK_NULL_HANDLE);
	ANKI_ASSERT(m_pool == VK_NULL_HANDLE);
}

Error BindlessDescriptorSet::init(const GrAllocator<U8>& alloc, VkDevice dev)
{
	ANKI_ASSERT(dev);
	m_alloc = alloc;
	m_dev = dev;

	// Create the layout
	{
		Array<VkDescriptorSetLayoutBinding, 2> bindings = {};
		bindings[0].binding = 0;
		bindings[0].stageFlags = VK_SHADER_STAGE_ALL;
		bindings[0].descriptorCount = MAX_BINDLESS_TEXTURES;
		bindings[0].descriptorType = VK_DESCRIPTOR_TYPE_SAMPLED_IMAGE;
		bindings[1].binding = 1;
		bindings[1].stageFlags = VK_SHADER_STAGE_ALL;
		bindings[1].descriptorCount = MAX_BINDLESS_IMAGES;
		bindings[1].descriptorType = VK_DESCRIPTOR_TYPE_STORAGE_IMAGE;

		Array<VkDescriptorBindingFlagsEXT, 2> bindingFlags = {};
		bindingFlags[0] = VK_DESCRIPTOR_BINDING_UPDATE_AFTER_BIND_BIT_EXT
						  | VK_DESCRIPTOR_BINDING_UPDATE_UNUSED_WHILE_PENDING_BIT_EXT
						  | VK_DESCRIPTOR_BINDING_PARTIALLY_BOUND_BIT_EXT;
		bindingFlags[1] = bindingFlags[0];

		VkDescriptorSetLayoutBindingFlagsCreateInfoEXT extraInfos = {};
		extraInfos.sType = VK_STRUCTURE_TYPE_DESCRIPTOR_SET_LAYOUT_BINDING_FLAGS_CREATE_INFO_EXT;
		extraInfos.bindingCount = bindingFlags.getSize();
		extraInfos.pBindingFlags = &bindingFlags[0];

		VkDescriptorSetLayoutCreateInfo ci = {};
		ci.sType = VK_STRUCTURE_TYPE_DESCRIPTOR_SET_LAYOUT_CREATE_INFO;
		ci.flags = VK_DESCRIPTOR_SET_LAYOUT_CREATE_UPDATE_AFTER_BIND_POOL_BIT_EXT;
		ci.bindingCount = bindings.getSize();
		ci.pBindings = &bindings[0];
		ci.pNext = &extraInfos;

		ANKI_VK_CHECK(vkCreateDescriptorSetLayout(m_dev, &ci, nullptr, &m_layout));
	}

	// Create the pool
	{
		Array<VkDescriptorPoolSize, 2> sizes = {};
		sizes[0].type = VK_DESCRIPTOR_TYPE_SAMPLED_IMAGE;
		sizes[0].descriptorCount = MAX_BINDLESS_TEXTURES;
		sizes[1].type = VK_DESCRIPTOR_TYPE_STORAGE_IMAGE;
		sizes[1].descriptorCount = MAX_BINDLESS_IMAGES;

		VkDescriptorPoolCreateInfo ci = {};
		ci.sType = VK_STRUCTURE_TYPE_DESCRIPTOR_POOL_CREATE_INFO;
		ci.maxSets = 1;
		ci.poolSizeCount = sizes.getSize();
		ci.pPoolSizes = &sizes[0];
		ci.flags = VK_DESCRIPTOR_POOL_CREATE_UPDATE_AFTER_BIND_BIT_EXT;

		ANKI_VK_CHECK(vkCreateDescriptorPool(m_dev, &ci, nullptr, &m_pool));
	}

	// Create the descriptor set
	{
		VkDescriptorSetAllocateInfo ci = {};
		ci.sType = VK_STRUCTURE_TYPE_DESCRIPTOR_SET_ALLOCATE_INFO;
		ci.descriptorPool = m_pool;
		ci.descriptorSetCount = 1;
		ci.pSetLayouts = &m_layout;

		ANKI_VK_CHECK(vkAllocateDescriptorSets(m_dev, &ci, &m_dset));
	}

	// Init the free arrays
	{
		m_freeTexIndices.create(m_alloc, MAX_BINDLESS_TEXTURES);
		m_freeTexIndexCount = m_freeTexIndices.getSize();

		for(U i = 0; i < m_freeTexIndices.getSize(); ++i)
		{
			m_freeTexIndices[i] = m_freeTexIndices.getSize() - i - 1;
		}

		m_freeImgIndices.create(m_alloc, MAX_BINDLESS_IMAGES);
		m_freeImgIndexCount = m_freeImgIndices.getSize();

		for(U i = 0; i < m_freeImgIndices.getSize(); ++i)
		{
			m_freeImgIndices[i] = m_freeImgIndices.getSize() - i - 1;
		}
	}

	return Error::NONE;
}

void BindlessDescriptorSet::destroy()
{
	if(m_pool)
	{
		vkDestroyDescriptorPool(m_dev, m_pool, nullptr);
		m_pool = VK_NULL_HANDLE;
		m_dset = VK_NULL_HANDLE;
	}

	if(m_layout)
	{
		vkDestroyDescriptorSetLayout(m_dev, m_layout, nullptr);
		m_layout = VK_NULL_HANDLE;
	}

	m_freeImgIndices.destroy(m_alloc);
	m_freeTexIndices.destroy(m_alloc);
}

U32 BindlessDescriptorSet::bindTexture(const VkImageView view, const VkImageLayout layout)
{
	ANKI_ASSERT(view);
	LockGuard<Mutex> lock(m_mtx);
	ANKI_ASSERT(m_freeTexIndexCount > 0 && "Out of indices");

	// Get the index
	--m_freeTexIndexCount;
	const U idx = m_freeTexIndices[m_freeTexIndexCount];
	ANKI_ASSERT(idx < MAX_BINDLESS_TEXTURES);

	// Update the set
	VkDescriptorImageInfo imageInf = {};
	imageInf.imageView = view;
	imageInf.imageLayout = layout;

	VkWriteDescriptorSet write = {};
	write.sType = VK_STRUCTURE_TYPE_WRITE_DESCRIPTOR_SET;
	write.pNext = nullptr;
	write.dstSet = m_dset;
	write.descriptorCount = 1;
	write.descriptorType = VK_DESCRIPTOR_TYPE_SAMPLED_IMAGE;
	write.dstArrayElement = idx;
	write.pImageInfo = &imageInf;

	vkUpdateDescriptorSets(m_dev, 1, &write, 0, nullptr);

	return idx;
}

U32 BindlessDescriptorSet::bindImage(const VkImageView view)
{
	ANKI_ASSERT(view);
	LockGuard<Mutex> lock(m_mtx);
	ANKI_ASSERT(m_freeImgIndexCount > 0 && "Out of indices");

	// Get the index
	--m_freeImgIndexCount;
	const U idx = m_freeImgIndices[m_freeImgIndexCount];
	ANKI_ASSERT(idx < MAX_BINDLESS_IMAGES);

	// Update the set
	VkDescriptorImageInfo imageInf = {};
	imageInf.imageView = view;
	imageInf.imageLayout = VK_IMAGE_LAYOUT_GENERAL; // Storage images are always in general.

	VkWriteDescriptorSet write = {};
	write.sType = VK_STRUCTURE_TYPE_WRITE_DESCRIPTOR_SET;
	write.pNext = nullptr;
	write.dstSet = m_dset;
	write.descriptorCount = 1;
	write.descriptorType = VK_DESCRIPTOR_TYPE_STORAGE_IMAGE;
	write.dstArrayElement = idx;
	write.pImageInfo = &imageInf;

	vkUpdateDescriptorSets(m_dev, 1, &write, 0, nullptr);

	return idx;
}

void BindlessDescriptorSet::unbindCommon(U32 idx, DynamicArray<U16>& freeIndices, U16& freeIndexCount)
{
	ANKI_ASSERT(idx < freeIndices.getSize());

	LockGuard<Mutex> lock(m_mtx);
	ANKI_ASSERT(freeIndexCount < freeIndices.getSize());

	freeIndices[freeIndexCount] = idx;
	++freeIndexCount;

	// Sort the free indices to minimize fragmentation
	std::sort(&freeIndices[0], &freeIndices[0] + freeIndexCount, std::greater<U16>());

	// Make sure there are no duplicates
	for(U i = 1; i < freeIndexCount; ++i)
	{
		ANKI_ASSERT(freeIndices[i] != freeIndices[i - 1]);
	}
}

Error BindlessDescriptorSet::initDeviceFeatures(
	VkPhysicalDevice pdev, VkPhysicalDeviceDescriptorIndexingFeaturesEXT& indexingFeatures)
{
	indexingFeatures = {};
	indexingFeatures.sType = VK_STRUCTURE_TYPE_PHYSICAL_DEVICE_DESCRIPTOR_INDEXING_FEATURES_EXT;

	VkPhysicalDeviceFeatures2 features = {};
	features.sType = VK_STRUCTURE_TYPE_PHYSICAL_DEVICE_FEATURES_2;
	features.pNext = &indexingFeatures;

	vkGetPhysicalDeviceFeatures2(pdev, &features);

	if(!indexingFeatures.descriptorBindingSampledImageUpdateAfterBind
		|| !indexingFeatures.descriptorBindingStorageImageUpdateAfterBind)
	{
		ANKI_VK_LOGE("Update descriptors after bind is not supported by the device");
		return Error::FUNCTION_FAILED;
	}

	if(!indexingFeatures.descriptorBindingUpdateUnusedWhilePending)
	{
		ANKI_VK_LOGE("Update descriptors while cmd buffer is pending is not supported by the device");
		return Error::FUNCTION_FAILED;
	}

	return Error::NONE;
}

} // end namespace anki