src/Pipeline/SpirvShaderSampling.cpp - SwiftShader - Git at Google

 // Copyright 2019 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 "SpirvShader.hpp"

 #include "SamplerCore.hpp"  // TODO: Figure out what's needed.
 #include "Device/Config.hpp"
 #include "System/Debug.hpp"
 #include "System/Math.hpp"
 #include "Vulkan/VkDescriptorSetLayout.hpp"
 #include "Vulkan/VkDevice.hpp"
 #include "Vulkan/VkImageView.hpp"
 #include "Vulkan/VkSampler.hpp"

 #include <spirv/unified1/spirv.hpp>

 #include <climits>
 #include <mutex>

 namespace sw {

 SpirvShader::ImageSampler *SpirvShader::getImageSampler(uint32_t inst, vk::SampledImageDescriptor const *imageDescriptor, const vk::Sampler *sampler)
 {
 	ImageInstruction instruction(inst);
 	const auto samplerId = sampler ? sampler->id : 0;
 	ASSERT(imageDescriptor->imageViewId != 0 && (samplerId != 0 || instruction.samplerMethod == Fetch));
 	ASSERT(imageDescriptor->device);

 	vk::Device::SamplingRoutineCache::Key key = { inst, imageDescriptor->imageViewId, samplerId };

 	vk::Device::SamplingRoutineCache *cache = imageDescriptor->device->getSamplingRoutineCache();

 	auto createSamplingRoutine = [&](const vk::Device::SamplingRoutineCache::Key &key) {
 		auto type = imageDescriptor->type;

 		Sampler samplerState = {};
 		samplerState.textureType = type;
 		samplerState.textureFormat = imageDescriptor->format;

 		samplerState.addressingModeU = convertAddressingMode(0, sampler, type);
 		samplerState.addressingModeV = convertAddressingMode(1, sampler, type);
 		samplerState.addressingModeW = convertAddressingMode(2, sampler, type);
 		samplerState.addressingModeY = convertAddressingMode(3, sampler, type);

 		samplerState.mipmapFilter = convertMipmapMode(sampler);
 		samplerState.swizzle = imageDescriptor->swizzle;
 		samplerState.gatherComponent = instruction.gatherComponent;
 		samplerState.largeTexture = (imageDescriptor->extent.width > SHRT_MAX) ||
 		                            (imageDescriptor->extent.height > SHRT_MAX) ||
 		                            (imageDescriptor->extent.depth > SHRT_MAX);

 		if(sampler)
 		{
 			samplerState.textureFilter = (instruction.samplerMethod == Gather) ? FILTER_GATHER : convertFilterMode(sampler);
 			samplerState.border = sampler->borderColor;

 			samplerState.mipmapFilter = convertMipmapMode(sampler);
 			samplerState.highPrecisionFiltering = (sampler->filteringPrecision == VK_SAMPLER_FILTERING_PRECISION_MODE_HIGH_GOOGLE);

 			samplerState.compareEnable = (sampler->compareEnable != VK_FALSE);
 			samplerState.compareOp = sampler->compareOp;
 			samplerState.unnormalizedCoordinates = (sampler->unnormalizedCoordinates != VK_FALSE);

 			samplerState.ycbcrModel = sampler->ycbcrModel;
 			samplerState.studioSwing = sampler->studioSwing;
 			samplerState.swappedChroma = sampler->swappedChroma;

 			samplerState.mipLodBias = sampler->mipLodBias;
 			samplerState.maxAnisotropy = sampler->maxAnisotropy;
 			samplerState.minLod = sampler->minLod;
 			samplerState.maxLod = sampler->maxLod;
 		}

 		return emitSamplerRoutine(instruction, samplerState);
 	};

 	auto routine = cache->getOrCreate(key, createSamplingRoutine);

 	return (ImageSampler *)(routine->getEntry());
 }

 std::shared_ptr<rr::Routine> SpirvShader::emitSamplerRoutine(ImageInstruction instruction, const Sampler &samplerState)
 {
 	// TODO(b/129523279): Hold a separate mutex lock for the sampler being built.
 	rr::Function<Void(Pointer<Byte>, Pointer<SIMD::Float>, Pointer<SIMD::Float>, Pointer<Byte>)> function;
 	{
 		Pointer<Byte> texture = function.Arg<0>();
 		Pointer<SIMD::Float> in = function.Arg<1>();
 		Pointer<SIMD::Float> out = function.Arg<2>();
 		Pointer<Byte> constants = function.Arg<3>();

 		SIMD::Float uvw[4] = { 0, 0, 0, 0 };
 		SIMD::Float q = 0;
 		SIMD::Float lodOrBias = 0;  // Explicit level-of-detail, or bias added to the implicit level-of-detail (depending on samplerMethod).
 		Vector4f dsx = { 0, 0, 0, 0 };
 		Vector4f dsy = { 0, 0, 0, 0 };
 		Vector4f offset = { 0, 0, 0, 0 };
 		SIMD::Int sampleId = 0;
 		SamplerFunction samplerFunction = instruction.getSamplerFunction();

 		uint32_t i = 0;
 		for(; i < instruction.coordinates; i++)
 		{
 			uvw[i] = in[i];
 		}

 		if(instruction.isDref())
 		{
 			q = in[i];
 			i++;
 		}

 		// TODO(b/134669567): Currently 1D textures are treated as 2D by setting the second coordinate to 0.
 		// Implement optimized 1D sampling.
 		if(samplerState.textureType == VK_IMAGE_VIEW_TYPE_1D)
 		{
 			uvw[1] = SIMD::Float(0);
 		}
 		else if(samplerState.textureType == VK_IMAGE_VIEW_TYPE_1D_ARRAY)
 		{
 			uvw[1] = SIMD::Float(0);
 			uvw[2] = in[1];  // Move 1D layer coordinate to 2D layer coordinate index.
 		}

 		if(instruction.samplerMethod == Lod || instruction.samplerMethod == Bias || instruction.samplerMethod == Fetch)
 		{
 			lodOrBias = in[i];
 			i++;
 		}
 		else if(instruction.samplerMethod == Grad)
 		{
 			for(uint32_t j = 0; j < instruction.grad; j++, i++)
 			{
 				dsx[j] = in[i];
 			}

 			for(uint32_t j = 0; j < instruction.grad; j++, i++)
 			{
 				dsy[j] = in[i];
 			}
 		}

 		for(uint32_t j = 0; j < instruction.offset; j++, i++)
 		{
 			offset[j] = in[i];
 		}

 		if(instruction.sample)
 		{
 			sampleId = As<SIMD::Int>(in[i]);
 		}

 		SamplerCore s(constants, samplerState);

 		// For explicit-lod instructions the LOD can be different per SIMD lane. SamplerCore currently assumes
 		// a single LOD per four elements, so we sample the image again for each LOD separately.
 		if(samplerFunction.method == Lod || samplerFunction.method == Grad)  // TODO(b/133868964): Also handle divergent Bias and Fetch with Lod.
 		{
 			auto lod = Pointer<Float>(&lodOrBias);

 			For(Int i = 0, i < SIMD::Width, i++)
 			{
 				SIMD::Float dPdx;
 				SIMD::Float dPdy;

 				dPdx.x = Pointer<Float>(&dsx.x)[i];
 				dPdx.y = Pointer<Float>(&dsx.y)[i];
 				dPdx.z = Pointer<Float>(&dsx.z)[i];

 				dPdy.x = Pointer<Float>(&dsy.x)[i];
 				dPdy.y = Pointer<Float>(&dsy.y)[i];
 				dPdy.z = Pointer<Float>(&dsy.z)[i];

 				// 1D textures are treated as 2D texture with second coordinate 0, so we also need to zero out the second grad component. TODO(b/134669567)
 				if(samplerState.textureType == VK_IMAGE_VIEW_TYPE_1D || samplerState.textureType == VK_IMAGE_VIEW_TYPE_1D_ARRAY)
 				{
 					dPdx.y = Float(0.0f);
 					dPdy.y = Float(0.0f);
 				}

 				Vector4f sample = s.sampleTexture(texture, uvw, q, lod[i], dPdx, dPdy, offset, sampleId, samplerFunction);

 				Pointer<Float> rgba = out;
 				rgba[0 * SIMD::Width + i] = Pointer<Float>(&sample.x)[i];
 				rgba[1 * SIMD::Width + i] = Pointer<Float>(&sample.y)[i];
 				rgba[2 * SIMD::Width + i] = Pointer<Float>(&sample.z)[i];
 				rgba[3 * SIMD::Width + i] = Pointer<Float>(&sample.w)[i];
 			}
 		}
 		else
 		{
 			Vector4f sample = s.sampleTexture(texture, uvw, q, lodOrBias.x, (dsx.x), (dsy.x), offset, sampleId, samplerFunction);

 			Pointer<SIMD::Float> rgba = out;
 			rgba[0] = sample.x;
 			rgba[1] = sample.y;
 			rgba[2] = sample.z;
 			rgba[3] = sample.w;
 		}
 	}

 	return function("sampler");
 }

 sw::FilterType SpirvShader::convertFilterMode(const vk::Sampler *sampler)
 {
 	if(sampler->anisotropyEnable != VK_FALSE)
 	{
 		return FILTER_ANISOTROPIC;
 	}

 	switch(sampler->magFilter)
 	{
 		case VK_FILTER_NEAREST:
 			switch(sampler->minFilter)
 			{
 				case VK_FILTER_NEAREST: return FILTER_POINT;
 				case VK_FILTER_LINEAR: return FILTER_MIN_LINEAR_MAG_POINT;
 				default:
 					UNSUPPORTED("minFilter %d", sampler->minFilter);
 					return FILTER_POINT;
 			}
 			break;
 		case VK_FILTER_LINEAR:
 			switch(sampler->minFilter)
 			{
 				case VK_FILTER_NEAREST: return FILTER_MIN_POINT_MAG_LINEAR;
 				case VK_FILTER_LINEAR: return FILTER_LINEAR;
 				default:
 					UNSUPPORTED("minFilter %d", sampler->minFilter);
 					return FILTER_POINT;
 			}
 			break;
 		default:
 			break;
 	}

 	UNSUPPORTED("magFilter %d", sampler->magFilter);
 	return FILTER_POINT;
 }

 sw::MipmapType SpirvShader::convertMipmapMode(const vk::Sampler *sampler)
 {
 	if(!sampler)
 	{
 		return MIPMAP_POINT;  // Samplerless operations (OpImageFetch) can take an integer Lod operand.
 	}

 	if(sampler->ycbcrModel != VK_SAMPLER_YCBCR_MODEL_CONVERSION_RGB_IDENTITY)
 	{
 		// TODO(b/151263485): Check image view level count instead.
 		return MIPMAP_NONE;
 	}

 	switch(sampler->mipmapMode)
 	{
 		case VK_SAMPLER_MIPMAP_MODE_NEAREST: return MIPMAP_POINT;
 		case VK_SAMPLER_MIPMAP_MODE_LINEAR: return MIPMAP_LINEAR;
 		default:
 			UNSUPPORTED("mipmapMode %d", sampler->mipmapMode);
 			return MIPMAP_POINT;
 	}
 }

 sw::AddressingMode SpirvShader::convertAddressingMode(int coordinateIndex, const vk::Sampler *sampler, VkImageViewType imageViewType)
 {
 	switch(imageViewType)
 	{
 		case VK_IMAGE_VIEW_TYPE_CUBE_ARRAY:
 			if(coordinateIndex == 3)
 			{
 				return ADDRESSING_LAYER;
 			}
 			// Fall through to CUBE case:
 		case VK_IMAGE_VIEW_TYPE_CUBE:
 			if(coordinateIndex <= 1)  // Cube faces themselves are addressed as 2D images.
 			{
 				// Vulkan 1.1 spec:
 				// "Cube images ignore the wrap modes specified in the sampler. Instead, if VK_FILTER_NEAREST is used within a mip level then
 				//  VK_SAMPLER_ADDRESS_MODE_CLAMP_TO_EDGE is used, and if VK_FILTER_LINEAR is used within a mip level then sampling at the edges
 				//  is performed as described earlier in the Cube map edge handling section."
 				// This corresponds with our 'SEAMLESS' addressing mode.
 				return ADDRESSING_SEAMLESS;
 			}
 			else if(coordinateIndex == 2)
 			{
 				// The cube face is an index into array layers.
 				return ADDRESSING_CUBEFACE;
 			}
 			else
 			{
 				return ADDRESSING_UNUSED;
 			}
 			break;

 		case VK_IMAGE_VIEW_TYPE_1D:  // Treated as 2D texture with second coordinate 0. TODO(b/134669567)
 			if(coordinateIndex == 1)
 			{
 				return ADDRESSING_WRAP;
 			}
 			else if(coordinateIndex >= 2)
 			{
 				return ADDRESSING_UNUSED;
 			}
 			break;

 		case VK_IMAGE_VIEW_TYPE_3D:
 			if(coordinateIndex >= 3)
 			{
 				return ADDRESSING_UNUSED;
 			}
 			break;

 		case VK_IMAGE_VIEW_TYPE_1D_ARRAY:  // Treated as 2D texture with second coordinate 0. TODO(b/134669567)
 			if(coordinateIndex == 1)
 			{
 				return ADDRESSING_WRAP;
 			}
 			// Fall through to 2D_ARRAY case:
 		case VK_IMAGE_VIEW_TYPE_2D_ARRAY:
 			if(coordinateIndex == 2)
 			{
 				return ADDRESSING_LAYER;
 			}
 			else if(coordinateIndex >= 3)
 			{
 				return ADDRESSING_UNUSED;
 			}
 			// Fall through to 2D case:
 		case VK_IMAGE_VIEW_TYPE_2D:
 			if(coordinateIndex >= 2)
 			{
 				return ADDRESSING_UNUSED;
 			}
 			break;

 		default:
 			UNSUPPORTED("imageViewType %d", imageViewType);
 			return ADDRESSING_WRAP;
 	}

 	if(!sampler)
 	{
 		// OpImageFetch does not take a sampler descriptor, but still needs a valid,
 		// arbitrary addressing mode that prevents out-of-bounds accesses:
 		// "The value returned by a read of an invalid texel is undefined, unless that
 		//  read operation is from a buffer resource and the robustBufferAccess feature
 		//  is enabled. In that case, an invalid texel is replaced as described by the
 		//  robustBufferAccess feature." - Vulkan 1.1

 		return ADDRESSING_WRAP;
 	}

 	VkSamplerAddressMode addressMode = VK_SAMPLER_ADDRESS_MODE_REPEAT;
 	switch(coordinateIndex)
 	{
 		case 0: addressMode = sampler->addressModeU; break;
 		case 1: addressMode = sampler->addressModeV; break;
 		case 2: addressMode = sampler->addressModeW; break;
 		default: UNSUPPORTED("coordinateIndex: %d", coordinateIndex);
 	}

 	switch(addressMode)
 	{
 		case VK_SAMPLER_ADDRESS_MODE_REPEAT: return ADDRESSING_WRAP;
 		case VK_SAMPLER_ADDRESS_MODE_MIRRORED_REPEAT: return ADDRESSING_MIRROR;
 		case VK_SAMPLER_ADDRESS_MODE_CLAMP_TO_EDGE: return ADDRESSING_CLAMP;
 		case VK_SAMPLER_ADDRESS_MODE_CLAMP_TO_BORDER: return ADDRESSING_BORDER;
 		case VK_SAMPLER_ADDRESS_MODE_MIRROR_CLAMP_TO_EDGE: return ADDRESSING_MIRRORONCE;
 		default:
 			UNSUPPORTED("addressMode %d", addressMode);
 			return ADDRESSING_WRAP;
 	}
 }

 }  // namespace sw
	// Copyright 2019 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 "SpirvShader.hpp"

	#include "SamplerCore.hpp" // TODO: Figure out what's needed.
	#include "Device/Config.hpp"
	#include "System/Debug.hpp"
	#include "System/Math.hpp"
	#include "Vulkan/VkDescriptorSetLayout.hpp"
	#include "Vulkan/VkDevice.hpp"
	#include "Vulkan/VkImageView.hpp"
	#include "Vulkan/VkSampler.hpp"

	#include <spirv/unified1/spirv.hpp>

	#include <climits>
	#include <mutex>

	namespace sw {

	SpirvShader::ImageSampler SpirvShader::getImageSampler(uint32_t inst, vk::SampledImageDescriptor const imageDescriptor, const vk::Sampler *sampler)
	{
	ImageInstruction instruction(inst);
	const auto samplerId = sampler ? sampler->id : 0;
	ASSERT(imageDescriptor->imageViewId != 0 && (samplerId != 0 \|\| instruction.samplerMethod == Fetch));
	ASSERT(imageDescriptor->device);

	vk::Device::SamplingRoutineCache::Key key = { inst, imageDescriptor->imageViewId, samplerId };

	vk::Device::SamplingRoutineCache *cache = imageDescriptor->device->getSamplingRoutineCache();

	auto createSamplingRoutine = [&](const vk::Device::SamplingRoutineCache::Key &key) {
	auto type = imageDescriptor->type;

	Sampler samplerState = {};
	samplerState.textureType = type;
	samplerState.textureFormat = imageDescriptor->format;

	samplerState.addressingModeU = convertAddressingMode(0, sampler, type);
	samplerState.addressingModeV = convertAddressingMode(1, sampler, type);
	samplerState.addressingModeW = convertAddressingMode(2, sampler, type);
	samplerState.addressingModeY = convertAddressingMode(3, sampler, type);

	samplerState.mipmapFilter = convertMipmapMode(sampler);
	samplerState.swizzle = imageDescriptor->swizzle;
	samplerState.gatherComponent = instruction.gatherComponent;
	samplerState.largeTexture = (imageDescriptor->extent.width > SHRT_MAX) \|\|
	(imageDescriptor->extent.height > SHRT_MAX) \|\|
	(imageDescriptor->extent.depth > SHRT_MAX);

	if(sampler)
	{
	samplerState.textureFilter = (instruction.samplerMethod == Gather) ? FILTER_GATHER : convertFilterMode(sampler);
	samplerState.border = sampler->borderColor;

	samplerState.mipmapFilter = convertMipmapMode(sampler);
	samplerState.highPrecisionFiltering = (sampler->filteringPrecision == VK_SAMPLER_FILTERING_PRECISION_MODE_HIGH_GOOGLE);

	samplerState.compareEnable = (sampler->compareEnable != VK_FALSE);
	samplerState.compareOp = sampler->compareOp;
	samplerState.unnormalizedCoordinates = (sampler->unnormalizedCoordinates != VK_FALSE);

	samplerState.ycbcrModel = sampler->ycbcrModel;
	samplerState.studioSwing = sampler->studioSwing;
	samplerState.swappedChroma = sampler->swappedChroma;

	samplerState.mipLodBias = sampler->mipLodBias;
	samplerState.maxAnisotropy = sampler->maxAnisotropy;
	samplerState.minLod = sampler->minLod;
	samplerState.maxLod = sampler->maxLod;
	}

	return emitSamplerRoutine(instruction, samplerState);
	};

	auto routine = cache->getOrCreate(key, createSamplingRoutine);

	return (ImageSampler *)(routine->getEntry());
	}

	std::shared_ptr<rr::Routine> SpirvShader::emitSamplerRoutine(ImageInstruction instruction, const Sampler &samplerState)
	{
	// TODO(b/129523279): Hold a separate mutex lock for the sampler being built.
	rr::Function<Void(Pointer<Byte>, Pointer<SIMD::Float>, Pointer<SIMD::Float>, Pointer<Byte>)> function;
	{
	Pointer<Byte> texture = function.Arg<0>();
	Pointer<SIMD::Float> in = function.Arg<1>();
	Pointer<SIMD::Float> out = function.Arg<2>();
	Pointer<Byte> constants = function.Arg<3>();

	SIMD::Float uvw[4] = { 0, 0, 0, 0 };
	SIMD::Float q = 0;
	SIMD::Float lodOrBias = 0; // Explicit level-of-detail, or bias added to the implicit level-of-detail (depending on samplerMethod).
	Vector4f dsx = { 0, 0, 0, 0 };
	Vector4f dsy = { 0, 0, 0, 0 };
	Vector4f offset = { 0, 0, 0, 0 };
	SIMD::Int sampleId = 0;
	SamplerFunction samplerFunction = instruction.getSamplerFunction();

	uint32_t i = 0;
	for(; i < instruction.coordinates; i++)
	{
	uvw[i] = in[i];
	}

	if(instruction.isDref())
	{
	q = in[i];
	i++;
	}

	// TODO(b/134669567): Currently 1D textures are treated as 2D by setting the second coordinate to 0.
	// Implement optimized 1D sampling.
	if(samplerState.textureType == VK_IMAGE_VIEW_TYPE_1D)
	{
	uvw[1] = SIMD::Float(0);
	}
	else if(samplerState.textureType == VK_IMAGE_VIEW_TYPE_1D_ARRAY)
	{
	uvw[1] = SIMD::Float(0);
	uvw[2] = in[1]; // Move 1D layer coordinate to 2D layer coordinate index.
	}

	if(instruction.samplerMethod == Lod \|\| instruction.samplerMethod == Bias \|\| instruction.samplerMethod == Fetch)
	{
	lodOrBias = in[i];
	i++;
	}
	else if(instruction.samplerMethod == Grad)
	{
	for(uint32_t j = 0; j < instruction.grad; j++, i++)
	{
	dsx[j] = in[i];
	}

	for(uint32_t j = 0; j < instruction.grad; j++, i++)
	{
	dsy[j] = in[i];
	}
	}

	for(uint32_t j = 0; j < instruction.offset; j++, i++)
	{
	offset[j] = in[i];
	}

	if(instruction.sample)
	{
	sampleId = As<SIMD::Int>(in[i]);
	}

	SamplerCore s(constants, samplerState);

	// For explicit-lod instructions the LOD can be different per SIMD lane. SamplerCore currently assumes
	// a single LOD per four elements, so we sample the image again for each LOD separately.
	if(samplerFunction.method == Lod \|\| samplerFunction.method == Grad) // TODO(b/133868964): Also handle divergent Bias and Fetch with Lod.
	{
	auto lod = Pointer<Float>(&lodOrBias);

	For(Int i = 0, i < SIMD::Width, i++)
	{
	SIMD::Float dPdx;
	SIMD::Float dPdy;

	dPdx.x = Pointer<Float>(&dsx.x)[i];
	dPdx.y = Pointer<Float>(&dsx.y)[i];
	dPdx.z = Pointer<Float>(&dsx.z)[i];

	dPdy.x = Pointer<Float>(&dsy.x)[i];
	dPdy.y = Pointer<Float>(&dsy.y)[i];
	dPdy.z = Pointer<Float>(&dsy.z)[i];

	// 1D textures are treated as 2D texture with second coordinate 0, so we also need to zero out the second grad component. TODO(b/134669567)
	if(samplerState.textureType == VK_IMAGE_VIEW_TYPE_1D \|\| samplerState.textureType == VK_IMAGE_VIEW_TYPE_1D_ARRAY)
	{
	dPdx.y = Float(0.0f);
	dPdy.y = Float(0.0f);
	}

	Vector4f sample = s.sampleTexture(texture, uvw, q, lod[i], dPdx, dPdy, offset, sampleId, samplerFunction);

	Pointer<Float> rgba = out;
	rgba[0 * SIMD::Width + i] = Pointer<Float>(&sample.x)[i];
	rgba[1 * SIMD::Width + i] = Pointer<Float>(&sample.y)[i];
	rgba[2 * SIMD::Width + i] = Pointer<Float>(&sample.z)[i];
	rgba[3 * SIMD::Width + i] = Pointer<Float>(&sample.w)[i];
	}
	}
	else
	{
	Vector4f sample = s.sampleTexture(texture, uvw, q, lodOrBias.x, (dsx.x), (dsy.x), offset, sampleId, samplerFunction);

	Pointer<SIMD::Float> rgba = out;
	rgba[0] = sample.x;
	rgba[1] = sample.y;
	rgba[2] = sample.z;
	rgba[3] = sample.w;
	}
	}

	return function("sampler");
	}

	sw::FilterType SpirvShader::convertFilterMode(const vk::Sampler *sampler)
	{
	if(sampler->anisotropyEnable != VK_FALSE)
	{
	return FILTER_ANISOTROPIC;
	}

	switch(sampler->magFilter)
	{
	case VK_FILTER_NEAREST:
	switch(sampler->minFilter)
	{
	case VK_FILTER_NEAREST: return FILTER_POINT;
	case VK_FILTER_LINEAR: return FILTER_MIN_LINEAR_MAG_POINT;
	default:
	UNSUPPORTED("minFilter %d", sampler->minFilter);
	return FILTER_POINT;
	}
	break;
	case VK_FILTER_LINEAR:
	switch(sampler->minFilter)
	{
	case VK_FILTER_NEAREST: return FILTER_MIN_POINT_MAG_LINEAR;
	case VK_FILTER_LINEAR: return FILTER_LINEAR;
	default:
	UNSUPPORTED("minFilter %d", sampler->minFilter);
	return FILTER_POINT;
	}
	break;
	default:
	break;
	}

	UNSUPPORTED("magFilter %d", sampler->magFilter);
	return FILTER_POINT;
	}

	sw::MipmapType SpirvShader::convertMipmapMode(const vk::Sampler *sampler)
	{
	if(!sampler)
	{
	return MIPMAP_POINT; // Samplerless operations (OpImageFetch) can take an integer Lod operand.
	}

	if(sampler->ycbcrModel != VK_SAMPLER_YCBCR_MODEL_CONVERSION_RGB_IDENTITY)
	{
	// TODO(b/151263485): Check image view level count instead.
	return MIPMAP_NONE;
	}

	switch(sampler->mipmapMode)
	{
	case VK_SAMPLER_MIPMAP_MODE_NEAREST: return MIPMAP_POINT;
	case VK_SAMPLER_MIPMAP_MODE_LINEAR: return MIPMAP_LINEAR;
	default:
	UNSUPPORTED("mipmapMode %d", sampler->mipmapMode);
	return MIPMAP_POINT;
	}
	}

	sw::AddressingMode SpirvShader::convertAddressingMode(int coordinateIndex, const vk::Sampler *sampler, VkImageViewType imageViewType)
	{
	switch(imageViewType)
	{
	case VK_IMAGE_VIEW_TYPE_CUBE_ARRAY:
	if(coordinateIndex == 3)
	{
	return ADDRESSING_LAYER;
	}
	// Fall through to CUBE case:
	case VK_IMAGE_VIEW_TYPE_CUBE:
	if(coordinateIndex <= 1) // Cube faces themselves are addressed as 2D images.
	{
	// Vulkan 1.1 spec:
	// "Cube images ignore the wrap modes specified in the sampler. Instead, if VK_FILTER_NEAREST is used within a mip level then
	// VK_SAMPLER_ADDRESS_MODE_CLAMP_TO_EDGE is used, and if VK_FILTER_LINEAR is used within a mip level then sampling at the edges
	// is performed as described earlier in the Cube map edge handling section."
	// This corresponds with our 'SEAMLESS' addressing mode.
	return ADDRESSING_SEAMLESS;
	}
	else if(coordinateIndex == 2)
	{
	// The cube face is an index into array layers.
	return ADDRESSING_CUBEFACE;
	}
	else
	{
	return ADDRESSING_UNUSED;
	}
	break;

	case VK_IMAGE_VIEW_TYPE_1D: // Treated as 2D texture with second coordinate 0. TODO(b/134669567)
	if(coordinateIndex == 1)
	{
	return ADDRESSING_WRAP;
	}
	else if(coordinateIndex >= 2)
	{
	return ADDRESSING_UNUSED;
	}
	break;

	case VK_IMAGE_VIEW_TYPE_3D:
	if(coordinateIndex >= 3)
	{
	return ADDRESSING_UNUSED;
	}
	break;

	case VK_IMAGE_VIEW_TYPE_1D_ARRAY: // Treated as 2D texture with second coordinate 0. TODO(b/134669567)
	if(coordinateIndex == 1)
	{
	return ADDRESSING_WRAP;
	}
	// Fall through to 2D_ARRAY case:
	case VK_IMAGE_VIEW_TYPE_2D_ARRAY:
	if(coordinateIndex == 2)
	{
	return ADDRESSING_LAYER;
	}
	else if(coordinateIndex >= 3)
	{
	return ADDRESSING_UNUSED;
	}
	// Fall through to 2D case:
	case VK_IMAGE_VIEW_TYPE_2D:
	if(coordinateIndex >= 2)
	{
	return ADDRESSING_UNUSED;
	}
	break;

	default:
	UNSUPPORTED("imageViewType %d", imageViewType);
	return ADDRESSING_WRAP;
	}

	if(!sampler)
	{
	// OpImageFetch does not take a sampler descriptor, but still needs a valid,
	// arbitrary addressing mode that prevents out-of-bounds accesses:
	// "The value returned by a read of an invalid texel is undefined, unless that
	// read operation is from a buffer resource and the robustBufferAccess feature
	// is enabled. In that case, an invalid texel is replaced as described by the
	// robustBufferAccess feature." - Vulkan 1.1

	return ADDRESSING_WRAP;
	}

	VkSamplerAddressMode addressMode = VK_SAMPLER_ADDRESS_MODE_REPEAT;
	switch(coordinateIndex)
	{
	case 0: addressMode = sampler->addressModeU; break;
	case 1: addressMode = sampler->addressModeV; break;
	case 2: addressMode = sampler->addressModeW; break;
	default: UNSUPPORTED("coordinateIndex: %d", coordinateIndex);
	}

	switch(addressMode)
	{
	case VK_SAMPLER_ADDRESS_MODE_REPEAT: return ADDRESSING_WRAP;
	case VK_SAMPLER_ADDRESS_MODE_MIRRORED_REPEAT: return ADDRESSING_MIRROR;
	case VK_SAMPLER_ADDRESS_MODE_CLAMP_TO_EDGE: return ADDRESSING_CLAMP;
	case VK_SAMPLER_ADDRESS_MODE_CLAMP_TO_BORDER: return ADDRESSING_BORDER;
	case VK_SAMPLER_ADDRESS_MODE_MIRROR_CLAMP_TO_EDGE: return ADDRESSING_MIRRORONCE;
	default:
	UNSUPPORTED("addressMode %d", addressMode);
	return ADDRESSING_WRAP;
	}
	}

	} // namespace sw