// Copyright 2018 The SwiftShader Authors. All Rights Reserved.
//
// 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.

#include "VkDescriptorSetLayout.hpp"

#include "VkDescriptorSet.hpp"
#include "VkSampler.hpp"
#include "VkImageView.hpp"
#include "VkBuffer.hpp"
#include "VkBufferView.hpp"
#include "System/Types.hpp"

#include <algorithm>
#include <cstring>

namespace
{

static bool UsesImmutableSamplers(const VkDescriptorSetLayoutBinding& binding)
{
	return (((binding.descriptorType == VK_DESCRIPTOR_TYPE_SAMPLER) ||
	        (binding.descriptorType == VK_DESCRIPTOR_TYPE_COMBINED_IMAGE_SAMPLER)) &&
	        (binding.pImmutableSamplers != nullptr));
}

}

namespace vk
{

DescriptorSetLayout::DescriptorSetLayout(const VkDescriptorSetLayoutCreateInfo* pCreateInfo, void* mem) :
	flags(pCreateInfo->flags), bindingCount(pCreateInfo->bindingCount), bindings(reinterpret_cast<VkDescriptorSetLayoutBinding*>(mem))
{
	uint8_t* hostMemory = static_cast<uint8_t*>(mem) + bindingCount * sizeof(VkDescriptorSetLayoutBinding);
	bindingOffsets = reinterpret_cast<size_t*>(hostMemory);
	hostMemory += bindingCount * sizeof(size_t);

	size_t offset = 0;
	for(uint32_t i = 0; i < bindingCount; i++)
	{
		bindings[i] = pCreateInfo->pBindings[i];
		if(UsesImmutableSamplers(bindings[i]))
		{
			size_t immutableSamplersSize = bindings[i].descriptorCount * sizeof(VkSampler);
			bindings[i].pImmutableSamplers = reinterpret_cast<const VkSampler*>(hostMemory);
			hostMemory += immutableSamplersSize;
			memcpy(const_cast<VkSampler*>(bindings[i].pImmutableSamplers),
			       pCreateInfo->pBindings[i].pImmutableSamplers,
			       immutableSamplersSize);
		}
		else
		{
			bindings[i].pImmutableSamplers = nullptr;
		}
		bindingOffsets[i] = offset;
		offset += bindings[i].descriptorCount * GetDescriptorSize(bindings[i].descriptorType);
	}
	ASSERT_MSG(offset == getDescriptorSetDataSize(), "offset: %d, size: %d", int(offset), int(getDescriptorSetDataSize()));
}

void DescriptorSetLayout::destroy(const VkAllocationCallbacks* pAllocator)
{
	vk::deallocate(bindings, pAllocator); // This allocation also contains pImmutableSamplers
}

size_t DescriptorSetLayout::ComputeRequiredAllocationSize(const VkDescriptorSetLayoutCreateInfo* pCreateInfo)
{
	size_t allocationSize = pCreateInfo->bindingCount * (sizeof(VkDescriptorSetLayoutBinding) + sizeof(size_t));

	for(uint32_t i = 0; i < pCreateInfo->bindingCount; i++)
	{
		if(UsesImmutableSamplers(pCreateInfo->pBindings[i]))
		{
			allocationSize += pCreateInfo->pBindings[i].descriptorCount * sizeof(VkSampler);
		}
	}

	return allocationSize;
}

size_t DescriptorSetLayout::GetDescriptorSize(VkDescriptorType type)
{
	switch(type)
	{
	case VK_DESCRIPTOR_TYPE_SAMPLER:
	case VK_DESCRIPTOR_TYPE_COMBINED_IMAGE_SAMPLER:
	case VK_DESCRIPTOR_TYPE_SAMPLED_IMAGE:
	case VK_DESCRIPTOR_TYPE_UNIFORM_TEXEL_BUFFER:
		return sizeof(SampledImageDescriptor);
	case VK_DESCRIPTOR_TYPE_STORAGE_IMAGE:
	case VK_DESCRIPTOR_TYPE_STORAGE_TEXEL_BUFFER:
	case VK_DESCRIPTOR_TYPE_INPUT_ATTACHMENT:
		return sizeof(StorageImageDescriptor);
	case VK_DESCRIPTOR_TYPE_UNIFORM_BUFFER:
	case VK_DESCRIPTOR_TYPE_STORAGE_BUFFER:
	case VK_DESCRIPTOR_TYPE_UNIFORM_BUFFER_DYNAMIC:
	case VK_DESCRIPTOR_TYPE_STORAGE_BUFFER_DYNAMIC:
		return sizeof(BufferDescriptor);
	default:
		UNIMPLEMENTED("Unsupported Descriptor Type");
		return 0;
	}
}

size_t DescriptorSetLayout::getDescriptorSetAllocationSize() const
{
	// vk::DescriptorSet has a layout member field.
	return sw::align<alignof(DescriptorSet)>(OFFSET(DescriptorSet, data) + getDescriptorSetDataSize());
}

size_t DescriptorSetLayout::getDescriptorSetDataSize() const
{
	size_t size = 0;
	for(uint32_t i = 0; i < bindingCount; i++)
	{
		size += bindings[i].descriptorCount * GetDescriptorSize(bindings[i].descriptorType);
	}

	return size;
}

uint32_t DescriptorSetLayout::getBindingIndex(uint32_t binding) const
{
	for(uint32_t i = 0; i < bindingCount; i++)
	{
		if(binding == bindings[i].binding)
		{
			return i;
		}
	}

	DABORT("Invalid DescriptorSetLayout binding: %d", int(binding));
	return 0;
}

void DescriptorSetLayout::initialize(VkDescriptorSet vkDescriptorSet)
{
	// Use a pointer to this descriptor set layout as the descriptor set's header
	DescriptorSet* descriptorSet = vk::Cast(vkDescriptorSet);
	descriptorSet->header.layout = this;
	uint8_t* mem = descriptorSet->data;

	for(uint32_t i = 0; i < bindingCount; i++)
	{
		size_t typeSize = GetDescriptorSize(bindings[i].descriptorType);
		if(UsesImmutableSamplers(bindings[i]))
		{
			for(uint32_t j = 0; j < bindings[i].descriptorCount; j++)
			{
				SampledImageDescriptor* imageSamplerDescriptor = reinterpret_cast<SampledImageDescriptor*>(mem);
				imageSamplerDescriptor->updateSampler(vk::Cast(bindings[i].pImmutableSamplers[j]));
				mem += typeSize;
			}
		}
		else
		{
			mem += bindings[i].descriptorCount * typeSize;
		}
	}
}

size_t DescriptorSetLayout::getBindingCount() const
{
	return bindingCount;
}

bool DescriptorSetLayout::hasBinding(uint32_t binding) const
{
	for(uint32_t i = 0; i < bindingCount; i++)
	{
		if(binding == bindings[i].binding)
		{
			return true;
		}
	}
	return false;
}

size_t DescriptorSetLayout::getBindingStride(uint32_t binding) const
{
	uint32_t index = getBindingIndex(binding);
	return GetDescriptorSize(bindings[index].descriptorType);
}

size_t DescriptorSetLayout::getBindingOffset(uint32_t binding, size_t arrayElement) const
{
	uint32_t index = getBindingIndex(binding);
	auto typeSize = GetDescriptorSize(bindings[index].descriptorType);
	return bindingOffsets[index] + OFFSET(DescriptorSet, data[0]) + (typeSize * arrayElement);
}

bool DescriptorSetLayout::isDynamic(VkDescriptorType type)
{
	return type == VK_DESCRIPTOR_TYPE_UNIFORM_BUFFER_DYNAMIC ||
		   type == VK_DESCRIPTOR_TYPE_STORAGE_BUFFER_DYNAMIC;
}

bool DescriptorSetLayout::isBindingDynamic(uint32_t binding) const
{
	uint32_t index = getBindingIndex(binding);
	return isDynamic(bindings[index].descriptorType);
}

uint32_t DescriptorSetLayout::getDynamicDescriptorCount() const
{
	uint32_t count = 0;
	for (size_t i = 0; i < bindingCount; i++)
	{
		if (isDynamic(bindings[i].descriptorType))
		{
			count += bindings[i].descriptorCount;
		}
	}
	return count;
}

uint32_t DescriptorSetLayout::getDynamicDescriptorOffset(uint32_t binding) const
{
	uint32_t n = getBindingIndex(binding);
	ASSERT(isDynamic(bindings[n].descriptorType));

	uint32_t index = 0;
	for (uint32_t i = 0; i < n; i++)
	{
		if (isDynamic(bindings[i].descriptorType))
		{
			index += bindings[i].descriptorCount;
		}
	}
	return index;
}

VkDescriptorSetLayoutBinding const & DescriptorSetLayout::getBindingLayout(uint32_t binding) const
{
	uint32_t index = getBindingIndex(binding);
	return bindings[index];
}

uint8_t* DescriptorSetLayout::getOffsetPointer(DescriptorSet *descriptorSet, uint32_t binding, uint32_t arrayElement, uint32_t count, size_t* typeSize) const
{
	uint32_t index = getBindingIndex(binding);
	*typeSize = GetDescriptorSize(bindings[index].descriptorType);
	size_t byteOffset = bindingOffsets[index] + (*typeSize * arrayElement);
	ASSERT(((*typeSize * count) + byteOffset) <= getDescriptorSetDataSize()); // Make sure the operation will not go out of bounds
	return &descriptorSet->data[byteOffset];
}

void SampledImageDescriptor::updateSampler(const vk::Sampler *sampler)
{
	if(sampler)
	{
		memcpy(&this->sampler, sampler, sizeof(this->sampler));
	}
	else
	{
		// Descriptor ID's start at 1, allowing to detect descriptor update
		// bugs by checking for 0. Also avoid reading random values.
		memset(&this->sampler, 0, sizeof(this->sampler));
	}
}

void DescriptorSetLayout::WriteDescriptorSet(DescriptorSet *dstSet, VkDescriptorUpdateTemplateEntry const &entry, char const *src)
{
	DescriptorSetLayout* dstLayout = dstSet->header.layout;
	auto &binding = dstLayout->bindings[dstLayout->getBindingIndex(entry.dstBinding)];
	ASSERT(dstLayout);
	ASSERT(binding.descriptorType == entry.descriptorType);

	size_t typeSize = 0;
	uint8_t* memToWrite = dstLayout->getOffsetPointer(dstSet, entry.dstBinding, entry.dstArrayElement, entry.descriptorCount, &typeSize);

	ASSERT(reinterpret_cast<intptr_t>(memToWrite) % 16 == 0);  // Each descriptor must be 16-byte aligned.

	if (entry.descriptorType == VK_DESCRIPTOR_TYPE_SAMPLER)
	{
		SampledImageDescriptor *imageSampler = reinterpret_cast<SampledImageDescriptor*>(memToWrite);

		for(uint32_t i = 0; i < entry.descriptorCount; i++)
		{
			auto update = reinterpret_cast<VkDescriptorImageInfo const *>(src + entry.offset + entry.stride * i);
			// "All consecutive bindings updated via a single VkWriteDescriptorSet structure, except those with a
			//  descriptorCount of zero, must all either use immutable samplers or must all not use immutable samplers."
			if (!binding.pImmutableSamplers)
			{
				imageSampler[i].updateSampler(vk::Cast(update->sampler));
			}
		}
	}
	else if (entry.descriptorType == VK_DESCRIPTOR_TYPE_UNIFORM_TEXEL_BUFFER)
	{
		SampledImageDescriptor *imageSampler = reinterpret_cast<SampledImageDescriptor*>(memToWrite);

		for (uint32_t i = 0; i < entry.descriptorCount; i++)
		{
			auto update = reinterpret_cast<VkBufferView const *>(src + entry.offset + entry.stride * i);
			auto bufferView = Cast(*update);

			imageSampler[i].type = VK_IMAGE_VIEW_TYPE_1D;
			imageSampler[i].imageViewId = bufferView->id;
			imageSampler[i].swizzle = { VK_COMPONENT_SWIZZLE_R, VK_COMPONENT_SWIZZLE_G, VK_COMPONENT_SWIZZLE_B, VK_COMPONENT_SWIZZLE_A };
			imageSampler[i].format = bufferView->getFormat();

			auto numElements = bufferView->getElementCount();
			imageSampler[i].extent = { numElements, 1, 1 };
			imageSampler[i].arrayLayers = 1;
			imageSampler[i].mipLevels = 1;
			imageSampler[i].sampleCount = 1;
			imageSampler[i].texture.widthWidthHeightHeight = sw::vector(numElements, numElements, 1, 1);
			imageSampler[i].texture.width = sw::replicate(numElements);
			imageSampler[i].texture.height = sw::replicate(1);
			imageSampler[i].texture.depth = sw::replicate(1);

			sw::Mipmap &mipmap = imageSampler[i].texture.mipmap[0];
			mipmap.buffer[0] = bufferView->getPointer();
			mipmap.width[0] = mipmap.width[1] = mipmap.width[2] = mipmap.width[3] = numElements;
			mipmap.height[0] = mipmap.height[1] = mipmap.height[2] = mipmap.height[3] = 1;
			mipmap.depth[0] = mipmap.depth[1] = mipmap.depth[2] = mipmap.depth[3] = 1;
			mipmap.pitchP.x = mipmap.pitchP.y = mipmap.pitchP.z = mipmap.pitchP.w = numElements;
			mipmap.sliceP.x = mipmap.sliceP.y = mipmap.sliceP.z = mipmap.sliceP.w = 0;
			mipmap.onePitchP[0] = mipmap.onePitchP[2] = 1;
			mipmap.onePitchP[1] = mipmap.onePitchP[3] = static_cast<short>(numElements);
		}
	}
	else if (entry.descriptorType == VK_DESCRIPTOR_TYPE_COMBINED_IMAGE_SAMPLER ||
	         entry.descriptorType == VK_DESCRIPTOR_TYPE_SAMPLED_IMAGE)
	{
		SampledImageDescriptor *imageSampler = reinterpret_cast<SampledImageDescriptor*>(memToWrite);

		for(uint32_t i = 0; i < entry.descriptorCount; i++)
		{
			auto update = reinterpret_cast<VkDescriptorImageInfo const *>(src + entry.offset + entry.stride * i);

			vk::ImageView *imageView = vk::Cast(update->imageView);
			Format format = imageView->getFormat(ImageView::SAMPLING);

			sw::Texture *texture = &imageSampler[i].texture;

			// "All consecutive bindings updated via a single VkWriteDescriptorSet structure, except those with a
			//  descriptorCount of zero, must all either use immutable samplers or must all not use immutable samplers."
			if(!binding.pImmutableSamplers)
			{
				imageSampler[i].updateSampler(vk::Cast(update->sampler));
			}

			imageSampler[i].imageViewId = imageView->id;
			imageSampler[i].extent = imageView->getMipLevelExtent(0);
			imageSampler[i].arrayLayers = imageView->getSubresourceRange().layerCount;
			imageSampler[i].mipLevels = imageView->getSubresourceRange().levelCount;
			imageSampler[i].sampleCount = imageView->getSampleCount();
			imageSampler[i].type = imageView->getType();
			imageSampler[i].swizzle = imageView->getComponentMapping();
			imageSampler[i].format = format;

			auto &subresourceRange = imageView->getSubresourceRange();

			for(int mipmapLevel = 0; mipmapLevel < sw::MIPMAP_LEVELS; mipmapLevel++)
			{
				int level = sw::clamp(mipmapLevel, 0, (int)subresourceRange.levelCount - 1);  // Level within the image view

				VkImageAspectFlagBits aspect = VK_IMAGE_ASPECT_COLOR_BIT;
				sw::Mipmap &mipmap = texture->mipmap[mipmapLevel];

				if(imageView->getType() == VK_IMAGE_VIEW_TYPE_CUBE)
				{
					for(int face = 0; face < 6; face++)
					{
						// Obtain the pointer to the corner of the level including the border, for seamless sampling.
						// This is taken into account in the sampling routine, which can't handle negative texel coordinates.
						VkOffset3D offset = {-1, -1, 0};

						// TODO(b/129523279): Implement as 6 consecutive layers instead of separate pointers.
						mipmap.buffer[face] = imageView->getOffsetPointer(offset, aspect, level, face, ImageView::SAMPLING);
					}
				}
				else
				{
					VkOffset3D offset = {0, 0, 0};
					mipmap.buffer[0] = imageView->getOffsetPointer(offset, aspect, level, 0, ImageView::SAMPLING);
				}

				VkExtent3D extent = imageView->getMipLevelExtent(level);

				int width = extent.width;
				int height = extent.height;
				int layers = imageView->getSubresourceRange().layerCount;  // TODO(b/129523279): Untangle depth vs layers throughout the sampler
				int depth = layers > 1 ? layers : extent.depth;
				int pitchP = imageView->rowPitchBytes(aspect, level, ImageView::SAMPLING) / format.bytes();
				int sliceP = (layers > 1 ? imageView->layerPitchBytes(aspect, ImageView::SAMPLING) : imageView->slicePitchBytes(aspect, level, ImageView::SAMPLING)) / format.bytes();

				WriteTextureLevelInfo(texture, mipmapLevel, width, height, depth, pitchP, sliceP);
			}
		}
	}
	else if (entry.descriptorType == VK_DESCRIPTOR_TYPE_STORAGE_IMAGE ||
			 entry.descriptorType == VK_DESCRIPTOR_TYPE_INPUT_ATTACHMENT)
	{
		auto descriptor = reinterpret_cast<StorageImageDescriptor *>(memToWrite);
		for(uint32_t i = 0; i < entry.descriptorCount; i++)
		{
			auto update = reinterpret_cast<VkDescriptorImageInfo const *>(src + entry.offset + entry.stride * i);
			auto imageView = Cast(update->imageView);
			descriptor[i].ptr = imageView->getOffsetPointer({0, 0, 0}, VK_IMAGE_ASPECT_COLOR_BIT, 0, 0);
			descriptor[i].extent = imageView->getMipLevelExtent(0);
			descriptor[i].rowPitchBytes = imageView->rowPitchBytes(VK_IMAGE_ASPECT_COLOR_BIT, 0);
			descriptor[i].samplePitchBytes = imageView->getSubresourceRange().layerCount > 1
											 ? imageView->layerPitchBytes(VK_IMAGE_ASPECT_COLOR_BIT)
											 : imageView->slicePitchBytes(VK_IMAGE_ASPECT_COLOR_BIT, 0);
			descriptor[i].slicePitchBytes = descriptor[i].samplePitchBytes * imageView->getSampleCount();
			descriptor[i].arrayLayers = imageView->getSubresourceRange().layerCount;
			descriptor[i].sampleCount = imageView->getSampleCount();
			descriptor[i].sizeInBytes = imageView->getImageSizeInBytes();

			if (imageView->getFormat().isStencil())
			{
				descriptor[i].stencilPtr = imageView->getOffsetPointer({0, 0, 0}, VK_IMAGE_ASPECT_STENCIL_BIT, 0, 0);
				descriptor[i].stencilRowPitchBytes = imageView->rowPitchBytes(VK_IMAGE_ASPECT_STENCIL_BIT, 0);
				descriptor[i].stencilSamplePitchBytes = imageView->getSubresourceRange().layerCount > 1
												 ? imageView->layerPitchBytes(VK_IMAGE_ASPECT_STENCIL_BIT)
												 : imageView->slicePitchBytes(VK_IMAGE_ASPECT_STENCIL_BIT, 0);
				descriptor[i].stencilSlicePitchBytes = descriptor[i].stencilSamplePitchBytes * imageView->getSampleCount();
			}
		}
	}
	else if (entry.descriptorType == VK_DESCRIPTOR_TYPE_STORAGE_TEXEL_BUFFER)
	{
		auto descriptor = reinterpret_cast<StorageImageDescriptor *>(memToWrite);
		for (uint32_t i = 0; i < entry.descriptorCount; i++)
		{
			auto update = reinterpret_cast<VkBufferView const *>(src + entry.offset + entry.stride * i);
			auto bufferView = Cast(*update);
			descriptor[i].ptr = bufferView->getPointer();
			descriptor[i].extent = {bufferView->getElementCount(), 1, 1};
			descriptor[i].rowPitchBytes = 0;
			descriptor[i].slicePitchBytes = 0;
			descriptor[i].samplePitchBytes = 0;
			descriptor[i].arrayLayers = 1;
			descriptor[i].sampleCount = 1;
			descriptor[i].sizeInBytes = bufferView->getRangeInBytes();
		}
	}
	else if (entry.descriptorType == VK_DESCRIPTOR_TYPE_UNIFORM_BUFFER ||
			 entry.descriptorType == VK_DESCRIPTOR_TYPE_UNIFORM_BUFFER_DYNAMIC ||
			 entry.descriptorType == VK_DESCRIPTOR_TYPE_STORAGE_BUFFER ||
			 entry.descriptorType == VK_DESCRIPTOR_TYPE_STORAGE_BUFFER_DYNAMIC)
	{
		auto descriptor = reinterpret_cast<BufferDescriptor *>(memToWrite);
		for (uint32_t i = 0; i < entry.descriptorCount; i++)
		{
			auto update = reinterpret_cast<VkDescriptorBufferInfo const *>(src + entry.offset + entry.stride * i);
			auto buffer = Cast(update->buffer);
			descriptor[i].ptr = buffer->getOffsetPointer(update->offset);
			descriptor[i].sizeInBytes = (update->range == VK_WHOLE_SIZE) ? buffer->getSize() - update->offset : update->range;
			descriptor[i].robustnessSize = buffer->getSize() - update->offset;
		}
	}
}

void DescriptorSetLayout::WriteTextureLevelInfo(sw::Texture *texture, int level, int width, int height, int depth, int pitchP, int sliceP)
{
	if(level == 0)
	{
		texture->widthWidthHeightHeight[0] = width;
		texture->widthWidthHeightHeight[1] = width;
		texture->widthWidthHeightHeight[2] = height;
		texture->widthWidthHeightHeight[3] = height;

		texture->width[0] = width;
		texture->width[1] = width;
		texture->width[2] = width;
		texture->width[3] = width;

		texture->height[0] = height;
		texture->height[1] = height;
		texture->height[2] = height;
		texture->height[3] = height;

		texture->depth[0] = depth;
		texture->depth[1] = depth;
		texture->depth[2] = depth;
		texture->depth[3] = depth;
	}

	sw::Mipmap &mipmap = texture->mipmap[level];

	short halfTexelU = 0x8000 / width;
	short halfTexelV = 0x8000 / height;
	short halfTexelW = 0x8000 / depth;

	mipmap.uHalf[0] = halfTexelU;
	mipmap.uHalf[1] = halfTexelU;
	mipmap.uHalf[2] = halfTexelU;
	mipmap.uHalf[3] = halfTexelU;

	mipmap.vHalf[0] = halfTexelV;
	mipmap.vHalf[1] = halfTexelV;
	mipmap.vHalf[2] = halfTexelV;
	mipmap.vHalf[3] = halfTexelV;

	mipmap.wHalf[0] = halfTexelW;
	mipmap.wHalf[1] = halfTexelW;
	mipmap.wHalf[2] = halfTexelW;
	mipmap.wHalf[3] = halfTexelW;

	mipmap.width[0] = width;
	mipmap.width[1] = width;
	mipmap.width[2] = width;
	mipmap.width[3] = width;

	mipmap.height[0] = height;
	mipmap.height[1] = height;
	mipmap.height[2] = height;
	mipmap.height[3] = height;

	mipmap.depth[0] = depth;
	mipmap.depth[1] = depth;
	mipmap.depth[2] = depth;
	mipmap.depth[3] = depth;

	mipmap.onePitchP[0] = 1;
	mipmap.onePitchP[1] = pitchP;
	mipmap.onePitchP[2] = 1;
	mipmap.onePitchP[3] = pitchP;

	mipmap.pitchP[0] = pitchP;
	mipmap.pitchP[1] = pitchP;
	mipmap.pitchP[2] = pitchP;
	mipmap.pitchP[3] = pitchP;

	mipmap.sliceP[0] = sliceP;
	mipmap.sliceP[1] = sliceP;
	mipmap.sliceP[2] = sliceP;
	mipmap.sliceP[3] = sliceP;
}

void DescriptorSetLayout::WriteDescriptorSet(const VkWriteDescriptorSet& writeDescriptorSet)
{
	DescriptorSet* dstSet = vk::Cast(writeDescriptorSet.dstSet);
	VkDescriptorUpdateTemplateEntry e;
	e.descriptorType = writeDescriptorSet.descriptorType;
	e.dstBinding = writeDescriptorSet.dstBinding;
	e.dstArrayElement = writeDescriptorSet.dstArrayElement;
	e.descriptorCount = writeDescriptorSet.descriptorCount;
	e.offset = 0;
	void const *ptr = nullptr;
	switch (writeDescriptorSet.descriptorType)
	{
	case VK_DESCRIPTOR_TYPE_STORAGE_TEXEL_BUFFER:
	case VK_DESCRIPTOR_TYPE_UNIFORM_TEXEL_BUFFER:
		ptr = writeDescriptorSet.pTexelBufferView;
		e.stride = sizeof(VkBufferView);
		break;

	case VK_DESCRIPTOR_TYPE_SAMPLER:
	case VK_DESCRIPTOR_TYPE_COMBINED_IMAGE_SAMPLER:
	case VK_DESCRIPTOR_TYPE_SAMPLED_IMAGE:
	case VK_DESCRIPTOR_TYPE_INPUT_ATTACHMENT:
	case VK_DESCRIPTOR_TYPE_STORAGE_IMAGE:
		ptr = writeDescriptorSet.pImageInfo;
		e.stride = sizeof(VkDescriptorImageInfo);
		break;

	case VK_DESCRIPTOR_TYPE_UNIFORM_BUFFER:
	case VK_DESCRIPTOR_TYPE_STORAGE_BUFFER:
	case VK_DESCRIPTOR_TYPE_UNIFORM_BUFFER_DYNAMIC:
	case VK_DESCRIPTOR_TYPE_STORAGE_BUFFER_DYNAMIC:
		ptr = writeDescriptorSet.pBufferInfo;
		e.stride = sizeof(VkDescriptorBufferInfo);
		break;

	default:
		UNIMPLEMENTED("descriptor type %u", writeDescriptorSet.descriptorType);
	}

	WriteDescriptorSet(dstSet, e, reinterpret_cast<char const *>(ptr));
}

void DescriptorSetLayout::CopyDescriptorSet(const VkCopyDescriptorSet& descriptorCopies)
{
	DescriptorSet* srcSet = vk::Cast(descriptorCopies.srcSet);
	DescriptorSetLayout* srcLayout = srcSet->header.layout;
	ASSERT(srcLayout);

	DescriptorSet* dstSet = vk::Cast(descriptorCopies.dstSet);
	DescriptorSetLayout* dstLayout = dstSet->header.layout;
	ASSERT(dstLayout);

	size_t srcTypeSize = 0;
	uint8_t* memToRead = srcLayout->getOffsetPointer(srcSet, descriptorCopies.srcBinding, descriptorCopies.srcArrayElement, descriptorCopies.descriptorCount, &srcTypeSize);

	size_t dstTypeSize = 0;
	uint8_t* memToWrite = dstLayout->getOffsetPointer(dstSet, descriptorCopies.dstBinding, descriptorCopies.dstArrayElement, descriptorCopies.descriptorCount, &dstTypeSize);

	ASSERT(srcTypeSize == dstTypeSize);
	size_t writeSize = dstTypeSize * descriptorCopies.descriptorCount;
	memcpy(memToWrite, memToRead, writeSize);
}

} // namespace vk