/*------------------------------------------------------------------------
 * Vulkan Conformance Tests
 * ------------------------
 *
 * Copyright (c) 2018 The Khronos Group Inc.
 * Copyright (c) 2018 The Android Open Source Project
 *
 * 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.
 *
 *//*!
 * \file
 * \brief Use of gl_Layer in Vertex and Tessellation Shaders
 *        (part of VK_EXT_ShaderViewportIndexLayer)
 *//*--------------------------------------------------------------------*/

#include "vktDrawShaderLayerTests.hpp"

#include "vktDrawBaseClass.hpp"
#include "vktTestCaseUtil.hpp"

#include "vkDefs.hpp"
#include "vkRef.hpp"
#include "vkRefUtil.hpp"
#include "vkTypeUtil.hpp"
#include "vkMemUtil.hpp"
#include "vkPrograms.hpp"
#include "vkImageUtil.hpp"
#include "vkQueryUtil.hpp"
#include "vkCmdUtil.hpp"
#include "vkObjUtil.hpp"

#include "tcuTestLog.hpp"
#include "tcuVector.hpp"
#include "tcuImageCompare.hpp"
#include "tcuTextureUtil.hpp"

#include "deUniquePtr.hpp"
#include "deMath.h"

#include <vector>

namespace vkt
{
namespace Draw
{
using namespace vk;
using de::UniquePtr;
using de::MovePtr;
using de::SharedPtr;
using tcu::Vec4;
using tcu::Vec2;
using tcu::UVec2;
using tcu::UVec4;

namespace
{

enum Constants
{
	MIN_MAX_FRAMEBUFFER_LAYERS = 256,	//!< Minimum number of framebuffer layers.
	MIN_MAX_VIEWPORTS = 16,				//!< Minimum number of viewports for an implementation supporting multiViewport.
};

template<typename T>
inline VkDeviceSize sizeInBytes(const std::vector<T>& vec)
{
	return vec.size() * sizeof(vec[0]);
}

MovePtr<Allocation> bindImage (const DeviceInterface& vk, const VkDevice device, Allocator& allocator, const VkImage image, const MemoryRequirement requirement)
{
	MovePtr<Allocation> alloc = allocator.allocate(getImageMemoryRequirements(vk, device, image), requirement);
	VK_CHECK(vk.bindImageMemory(device, image, alloc->getMemory(), alloc->getOffset()));
	return alloc;
}

inline vk::Move<vk::VkImage> makeImage (const vk::DeviceInterface& vk, const vk::VkDevice device, const vk::VkImageCreateInfo& createInfo)
{
	return createImage(vk, device, &createInfo);
}

VkImageCreateInfo makeImageCreateInfo (const VkFormat format, const UVec2& size, const deUint32 numLayers, VkImageUsageFlags usage)
{
	const VkImageCreateInfo imageParams =
	{
		VK_STRUCTURE_TYPE_IMAGE_CREATE_INFO,			// VkStructureType			sType;
		DE_NULL,										// const void*				pNext;
		(VkImageCreateFlags)0,							// VkImageCreateFlags		flags;
		VK_IMAGE_TYPE_2D,								// VkImageType				imageType;
		format,											// VkFormat					format;
		makeExtent3D(size.x(), size.y(), 1),			// VkExtent3D				extent;
		1u,												// deUint32					mipLevels;
		numLayers,										// deUint32					arrayLayers;
		VK_SAMPLE_COUNT_1_BIT,							// VkSampleCountFlagBits	samples;
		VK_IMAGE_TILING_OPTIMAL,						// VkImageTiling			tiling;
		usage,											// VkImageUsageFlags		usage;
		VK_SHARING_MODE_EXCLUSIVE,						// VkSharingMode			sharingMode;
		0u,												// deUint32					queueFamilyIndexCount;
		DE_NULL,										// const deUint32*			pQueueFamilyIndices;
		VK_IMAGE_LAYOUT_UNDEFINED,						// VkImageLayout			initialLayout;
	};
	return imageParams;
}

Move<VkPipeline> makeGraphicsPipeline (const DeviceInterface&		vk,
									   const VkDevice				device,
									   const VkPipelineLayout		pipelineLayout,
									   const VkRenderPass			renderPass,
									   const VkShaderModule			vertexModule,
									   const VkShaderModule			tessellationControlModule,
									   const VkShaderModule			tessellationEvaluationModule,
									   const VkShaderModule			fragmentModule,
									   const UVec2					renderSize)
{
	const VkVertexInputBindingDescription vertexInputBindingDescription =
	{
		0u,								// uint32_t				binding;
		sizeof(PositionColorVertex),	// uint32_t				stride;
		VK_VERTEX_INPUT_RATE_VERTEX,	// VkVertexInputRate	inputRate;
	};

	const VkVertexInputAttributeDescription vertexInputAttributeDescriptions[] =
	{
		{
			0u,									// uint32_t			location;
			0u,									// uint32_t			binding;
			VK_FORMAT_R32G32B32A32_SFLOAT,		// VkFormat			format;
			0u,									// uint32_t			offset;
		},
		{
			1u,									// uint32_t			location;
			0u,									// uint32_t			binding;
			VK_FORMAT_R32G32B32A32_SFLOAT,		// VkFormat			format;
			sizeof(Vec4),						// uint32_t			offset;
		},
	};

	const VkPipelineVertexInputStateCreateInfo vertexInputStateInfo =
	{
		VK_STRUCTURE_TYPE_PIPELINE_VERTEX_INPUT_STATE_CREATE_INFO,		// VkStructureType                             sType;
		DE_NULL,														// const void*                                 pNext;
		(VkPipelineVertexInputStateCreateFlags)0,						// VkPipelineVertexInputStateCreateFlags       flags;
		1u,																// uint32_t                                    vertexBindingDescriptionCount;
		&vertexInputBindingDescription,									// const VkVertexInputBindingDescription*      pVertexBindingDescriptions;
		DE_LENGTH_OF_ARRAY(vertexInputAttributeDescriptions),			// uint32_t                                    vertexAttributeDescriptionCount;
		vertexInputAttributeDescriptions,								// const VkVertexInputAttributeDescription*    pVertexAttributeDescriptions;
	};

	const bool useTessellationShaders = (tessellationControlModule != DE_NULL) && (tessellationEvaluationModule != DE_NULL);

	const VkPipelineInputAssemblyStateCreateInfo pipelineInputAssemblyStateInfo =
	{
		VK_STRUCTURE_TYPE_PIPELINE_INPUT_ASSEMBLY_STATE_CREATE_INFO,										// VkStructureType                             sType;
		DE_NULL,																							// const void*                                 pNext;
		(VkPipelineInputAssemblyStateCreateFlags)0,															// VkPipelineInputAssemblyStateCreateFlags     flags;
		useTessellationShaders ? VK_PRIMITIVE_TOPOLOGY_PATCH_LIST : VK_PRIMITIVE_TOPOLOGY_TRIANGLE_LIST,	// VkPrimitiveTopology                         topology;
		VK_FALSE,																							// VkBool32                                    primitiveRestartEnable;
	};


	VkViewport viewport = makeViewport(0.0f, 0.0f, static_cast<float>(renderSize.x()), static_cast<float>(renderSize.y()), 0.0f, 1.0f);
	VkRect2D rectScissor = { { 0, 0 }, { renderSize.x(), renderSize.y() } };

	const VkPipelineViewportStateCreateInfo pipelineViewportStateInfo =
	{
		VK_STRUCTURE_TYPE_PIPELINE_VIEWPORT_STATE_CREATE_INFO,			// VkStructureType                             sType;
		DE_NULL,														// const void*                                 pNext;
		(VkPipelineViewportStateCreateFlags)0,							// VkPipelineViewportStateCreateFlags          flags;
		1u,																// uint32_t                                    viewportCount;
		&viewport,														// const VkViewport*                           pViewports;
		1u,																// uint32_t                                    scissorCount;
		&rectScissor,													// const VkRect2D*                             pScissors;
	};

	const VkPipelineRasterizationStateCreateInfo pipelineRasterizationStateInfo =
	{
		VK_STRUCTURE_TYPE_PIPELINE_RASTERIZATION_STATE_CREATE_INFO,		// VkStructureType                          sType;
		DE_NULL,														// const void*                              pNext;
		(VkPipelineRasterizationStateCreateFlags)0,						// VkPipelineRasterizationStateCreateFlags  flags;
		VK_FALSE,														// VkBool32                                 depthClampEnable;
		VK_FALSE,														// VkBool32                                 rasterizerDiscardEnable;
		VK_POLYGON_MODE_FILL,											// VkPolygonMode							polygonMode;
		VK_CULL_MODE_NONE,												// VkCullModeFlags							cullMode;
		VK_FRONT_FACE_COUNTER_CLOCKWISE,								// VkFrontFace								frontFace;
		VK_FALSE,														// VkBool32									depthBiasEnable;
		0.0f,															// float									depthBiasConstantFactor;
		0.0f,															// float									depthBiasClamp;
		0.0f,															// float									depthBiasSlopeFactor;
		1.0f,															// float									lineWidth;
	};

	const VkPipelineMultisampleStateCreateInfo pipelineMultisampleStateInfo =
	{
		VK_STRUCTURE_TYPE_PIPELINE_MULTISAMPLE_STATE_CREATE_INFO,		// VkStructureType							sType;
		DE_NULL,														// const void*								pNext;
		(VkPipelineMultisampleStateCreateFlags)0,						// VkPipelineMultisampleStateCreateFlags	flags;
		VK_SAMPLE_COUNT_1_BIT,											// VkSampleCountFlagBits					rasterizationSamples;
		VK_FALSE,														// VkBool32									sampleShadingEnable;
		0.0f,															// float									minSampleShading;
		DE_NULL,														// const VkSampleMask*						pSampleMask;
		VK_FALSE,														// VkBool32									alphaToCoverageEnable;
		VK_FALSE														// VkBool32									alphaToOneEnable;
	};

	const VkStencilOpState stencilOpState = makeStencilOpState(
		VK_STENCIL_OP_KEEP,				// stencil fail
		VK_STENCIL_OP_KEEP,				// depth & stencil pass
		VK_STENCIL_OP_KEEP,				// depth only fail
		VK_COMPARE_OP_ALWAYS,			// compare op
		0u,								// compare mask
		0u,								// write mask
		0u);							// reference

	VkPipelineDepthStencilStateCreateInfo pipelineDepthStencilStateInfo =
	{
		VK_STRUCTURE_TYPE_PIPELINE_DEPTH_STENCIL_STATE_CREATE_INFO,		// VkStructureType							sType;
		DE_NULL,														// const void*								pNext;
		(VkPipelineDepthStencilStateCreateFlags)0,						// VkPipelineDepthStencilStateCreateFlags	flags;
		VK_FALSE,														// VkBool32									depthTestEnable;
		VK_FALSE,														// VkBool32									depthWriteEnable;
		VK_COMPARE_OP_LESS,												// VkCompareOp								depthCompareOp;
		VK_FALSE,														// VkBool32									depthBoundsTestEnable;
		VK_FALSE,														// VkBool32									stencilTestEnable;
		stencilOpState,													// VkStencilOpState							front;
		stencilOpState,													// VkStencilOpState							back;
		0.0f,															// float									minDepthBounds;
		1.0f,															// float									maxDepthBounds;
	};

	const VkColorComponentFlags					colorComponentsAll					= VK_COLOR_COMPONENT_R_BIT | VK_COLOR_COMPONENT_G_BIT | VK_COLOR_COMPONENT_B_BIT | VK_COLOR_COMPONENT_A_BIT;
	const VkPipelineColorBlendAttachmentState	pipelineColorBlendAttachmentState	=
	{
		VK_FALSE,						// VkBool32					blendEnable;
		VK_BLEND_FACTOR_ONE,			// VkBlendFactor			srcColorBlendFactor;
		VK_BLEND_FACTOR_ZERO,			// VkBlendFactor			dstColorBlendFactor;
		VK_BLEND_OP_ADD,				// VkBlendOp				colorBlendOp;
		VK_BLEND_FACTOR_ONE,			// VkBlendFactor			srcAlphaBlendFactor;
		VK_BLEND_FACTOR_ZERO,			// VkBlendFactor			dstAlphaBlendFactor;
		VK_BLEND_OP_ADD,				// VkBlendOp				alphaBlendOp;
		colorComponentsAll,				// VkColorComponentFlags	colorWriteMask;
	};

	const VkPipelineColorBlendStateCreateInfo pipelineColorBlendStateInfo =
	{
		VK_STRUCTURE_TYPE_PIPELINE_COLOR_BLEND_STATE_CREATE_INFO,		// VkStructureType								sType;
		DE_NULL,														// const void*									pNext;
		(VkPipelineColorBlendStateCreateFlags)0,						// VkPipelineColorBlendStateCreateFlags			flags;
		VK_FALSE,														// VkBool32										logicOpEnable;
		VK_LOGIC_OP_COPY,												// VkLogicOp									logicOp;
		1u,																// deUint32										attachmentCount;
		&pipelineColorBlendAttachmentState,								// const VkPipelineColorBlendAttachmentState*	pAttachments;
		{ 0.0f, 0.0f, 0.0f, 0.0f },										// float										blendConstants[4];
	};

	const VkPipelineShaderStageCreateInfo pShaderStages[] =
	{
		{
			VK_STRUCTURE_TYPE_PIPELINE_SHADER_STAGE_CREATE_INFO,		// VkStructureType						sType;
			DE_NULL,													// const void*							pNext;
			(VkPipelineShaderStageCreateFlags)0,						// VkPipelineShaderStageCreateFlags		flags;
			VK_SHADER_STAGE_VERTEX_BIT,									// VkShaderStageFlagBits				stage;
			vertexModule,												// VkShaderModule						module;
			"main",														// const char*							pName;
			DE_NULL,													// const VkSpecializationInfo*			pSpecializationInfo;
		},
		{
			VK_STRUCTURE_TYPE_PIPELINE_SHADER_STAGE_CREATE_INFO,		// VkStructureType						sType;
			DE_NULL,													// const void*							pNext;
			(VkPipelineShaderStageCreateFlags)0,						// VkPipelineShaderStageCreateFlags		flags;
			VK_SHADER_STAGE_FRAGMENT_BIT,								// VkShaderStageFlagBits				stage;
			fragmentModule,												// VkShaderModule						module;
			"main",														// const char*							pName;
			DE_NULL,													// const VkSpecializationInfo*			pSpecializationInfo;
		},
		{
			VK_STRUCTURE_TYPE_PIPELINE_SHADER_STAGE_CREATE_INFO,		// VkStructureType						sType;
			DE_NULL,													// const void*							pNext;
			(VkPipelineShaderStageCreateFlags)0,						// VkPipelineShaderStageCreateFlags		flags;
			VK_SHADER_STAGE_TESSELLATION_CONTROL_BIT,					// VkShaderStageFlagBits				stage;
			tessellationControlModule,									// VkShaderModule						module;
			"main",														// const char*							pName;
			DE_NULL,													// const VkSpecializationInfo*			pSpecializationInfo;
		},
		{
			VK_STRUCTURE_TYPE_PIPELINE_SHADER_STAGE_CREATE_INFO,		// VkStructureType						sType;
			DE_NULL,													// const void*							pNext;
			(VkPipelineShaderStageCreateFlags)0,						// VkPipelineShaderStageCreateFlags		flags;
			VK_SHADER_STAGE_TESSELLATION_EVALUATION_BIT,				// VkShaderStageFlagBits				stage;
			tessellationEvaluationModule,								// VkShaderModule						module;
			"main",														// const char*							pName;
			DE_NULL,													// const VkSpecializationInfo*			pSpecializationInfo;
		},
	};

	const VkPipelineTessellationStateCreateInfo pipelineTessellationStateInfo =
	{
		VK_STRUCTURE_TYPE_PIPELINE_TESSELLATION_STATE_CREATE_INFO,		// VkStructureType							sType;
		DE_NULL,														// const void*								pNext;
		(VkPipelineTessellationStateCreateFlags)0,						// VkPipelineTessellationStateCreateFlags	flags;
		3,																// uint32_t									patchControlPoints;
	};

	const VkGraphicsPipelineCreateInfo graphicsPipelineInfo =
	{
		VK_STRUCTURE_TYPE_GRAPHICS_PIPELINE_CREATE_INFO,					// VkStructureType									sType;
		DE_NULL,															// const void*										pNext;
		(VkPipelineCreateFlags)0,											// VkPipelineCreateFlags							flags;
		useTessellationShaders ? deUint32(4) : deUint32(2),					// deUint32											stageCount;
		pShaderStages,														// const VkPipelineShaderStageCreateInfo*			pStages;
		&vertexInputStateInfo,												// const VkPipelineVertexInputStateCreateInfo*		pVertexInputState;
		&pipelineInputAssemblyStateInfo,									// const VkPipelineInputAssemblyStateCreateInfo*	pInputAssemblyState;
		useTessellationShaders ? &pipelineTessellationStateInfo : DE_NULL,	// const VkPipelineTessellationStateCreateInfo*		pTessellationState;
		&pipelineViewportStateInfo,											// const VkPipelineViewportStateCreateInfo*			pViewportState;
		&pipelineRasterizationStateInfo,									// const VkPipelineRasterizationStateCreateInfo*	pRasterizationState;
		&pipelineMultisampleStateInfo,										// const VkPipelineMultisampleStateCreateInfo*		pMultisampleState;
		&pipelineDepthStencilStateInfo,										// const VkPipelineDepthStencilStateCreateInfo*		pDepthStencilState;
		&pipelineColorBlendStateInfo,										// const VkPipelineColorBlendStateCreateInfo*		pColorBlendState;
		DE_NULL,															// const VkPipelineDynamicStateCreateInfo*			pDynamicState;
		pipelineLayout,														// VkPipelineLayout									layout;
		renderPass,															// VkRenderPass										renderPass;
		0u,																	// deUint32											subpass;
		DE_NULL,															// VkPipeline										basePipelineHandle;
		0,																	// deInt32											basePipelineIndex;
	};

	return createGraphicsPipeline(vk, device, DE_NULL, &graphicsPipelineInfo);
}

//! Renders a colorful grid of rectangles.
tcu::TextureLevel generateReferenceImage (const tcu::TextureFormat	format,
										  const UVec2&				renderSize,
										  const Vec4&				clearColor,
										  const UVec4&				cell,
										  const Vec4&				cellColor)
{
	tcu::TextureLevel image(format, renderSize.x(), renderSize.y());
	tcu::clear(image.getAccess(), clearColor);

	tcu::clear(tcu::getSubregion(image.getAccess(), cell.x(), cell.y(), cell.z(), cell.w()),
			   cellColor);

	return image;
}

void initVertexTestPrograms (SourceCollections& programCollection, const int numViewports)
{
	DE_UNREF(numViewports);

	// Vertex shader
	{
		std::ostringstream src;
		src << glu::getGLSLVersionDeclaration(glu::GLSL_VERSION_450) << "\n"
			<< "#extension GL_ARB_shader_viewport_layer_array : require\n"
			<< "\n"
			<< "layout(location = 0) in  vec4 in_position;\n"
			<< "layout(location = 1) in  vec4 in_color;\n"
			<< "layout(location = 0) out vec4 out_color;\n"
			<< "\n"
			<< "void main(void)\n"
			<< "{\n"
			<< "    gl_Layer = gl_VertexIndex / 6;\n"
			<< "    gl_Position = in_position;\n"
			<< "    out_color = in_color;\n"
			<< "}\n";

		programCollection.glslSources.add("vert") << glu::VertexSource(src.str());
	}

	// Fragment shader
	{
		std::ostringstream src;
		src << glu::getGLSLVersionDeclaration(glu::GLSL_VERSION_450) << "\n"
			<< "\n"
			<< "layout(location = 0) in  vec4 in_color;\n"
			<< "layout(location = 0) out vec4 out_color;\n"
			<< "\n"
			<< "void main(void)\n"
			<< "{\n"
			<< "    out_color = in_color;\n"
			<< "}\n";

		programCollection.glslSources.add("frag") << glu::FragmentSource(src.str());
	}
}

void initTessellationTestPrograms (SourceCollections& programCollection, const int numViewports)
{
	DE_UNREF(numViewports);

	// Vertex shader
	{
		std::ostringstream src;
		src << glu::getGLSLVersionDeclaration(glu::GLSL_VERSION_450) << "\n"
			<< "\n"
			<< "layout(location = 0) in  vec4 in_position;\n"
			<< "layout(location = 1) in  vec4 in_color;\n"
			<< "layout(location = 0) out vec4 out_color;\n"
			<< "\n"
			<< "void main(void)\n"
			<< "{\n"
			<< "    gl_Position = in_position;\n"
			<< "    out_color = in_color;\n"
			<< "}\n";

		programCollection.glslSources.add("vert") << glu::VertexSource(src.str());
	}

	// Tessellation control shader
	{
		std::ostringstream src;
		src << glu::getGLSLVersionDeclaration(glu::GLSL_VERSION_450) << "\n"
			<< "\n"
			<< "layout(vertices = 3) out;\n"
			<< "\n"
			<< "layout(location = 0) in  vec4 in_color[];\n"
			<< "layout(location = 0) out vec4 out_color[];\n"
			<< "\n"
			<< "void main(void)\n"
			<< "{\n"
			<< "    if (gl_InvocationID == 0) {\n"
			<< "        gl_TessLevelInner[0] = 1.0;\n"
			<< "        gl_TessLevelInner[1] = 1.0;\n"
			<< "        gl_TessLevelOuter[0] = 1.0;\n"
			<< "        gl_TessLevelOuter[1] = 1.0;\n"
			<< "        gl_TessLevelOuter[2] = 1.0;\n"
			<< "        gl_TessLevelOuter[3] = 1.0;\n"
			<< "    }\n"
			<< "    gl_out[gl_InvocationID].gl_Position = gl_in[gl_InvocationID].gl_Position;\n"
			<< "    out_color[gl_InvocationID] = in_color[gl_InvocationID];\n"
			<< "}\n";

		programCollection.glslSources.add("tesc") << glu::TessellationControlSource(src.str());
	}

	// Tessellation evaluation shader
	{
		std::ostringstream src;
		src << glu::getGLSLVersionDeclaration(glu::GLSL_VERSION_450) << "\n"
			<< "#extension GL_ARB_shader_viewport_layer_array : require\n"
			<< "\n"
			<< "layout(triangles, equal_spacing, cw) in;\n"
			<< "\n"
			<< "layout(location = 0) in  vec4 in_color[];\n"
			<< "layout(location = 0) out vec4 out_color;\n"
			<< "\n"
			<< "void main(void)\n"
			<< "{\n"
			<< "    gl_Layer = gl_PrimitiveID / 2;\n"
			<< "    gl_Position = gl_in[0].gl_Position * gl_TessCoord.x +\n"
			<< "                  gl_in[1].gl_Position * gl_TessCoord.y +\n"
			<< "                  gl_in[2].gl_Position * gl_TessCoord.z;\n"
			<< "\n"
			<< "    out_color = in_color[0] * gl_TessCoord.x +\n"
			<< "                in_color[1] * gl_TessCoord.y +\n"
			<< "                in_color[2] * gl_TessCoord.z;\n"
			<< "}\n";

		programCollection.glslSources.add("tese") << glu::TessellationEvaluationSource(src.str());
	}

	// Fragment shader
	{
		std::ostringstream src;
		src << glu::getGLSLVersionDeclaration(glu::GLSL_VERSION_450) << "\n"
			<< "\n"
			<< "layout(location = 0) in  vec4 in_color;\n"
			<< "layout(location = 0) out vec4 out_color;\n"
			<< "\n"
			<< "void main(void)\n"
			<< "{\n"
			<< "    out_color = in_color;\n"
			<< "}\n";

		programCollection.glslSources.add("frag") << glu::FragmentSource(src.str());
	}
}

std::vector<UVec4> generateGrid (const int numCells, const UVec2& renderSize)
{
	const int numCols		= deCeilFloatToInt32(deFloatSqrt(static_cast<float>(numCells)));
	const int numRows		= deCeilFloatToInt32(static_cast<float>(numCells) / static_cast<float>(numCols));
	const int rectWidth		= renderSize.x() / numCols;
	const int rectHeight	= renderSize.y() / numRows;

	std::vector<UVec4> cells;
	cells.reserve(numCells);

	int x = 0;
	int y = 0;

	for (int cellNdx = 0; cellNdx < numCells; ++cellNdx)
	{
		const bool nextRow = (cellNdx != 0) && (cellNdx % numCols == 0);
		if (nextRow)
		{
			x  = 0;
			y += rectHeight;
		}

		cells.push_back(UVec4(x, y, rectWidth, rectHeight));

		x += rectWidth;
	}

	return cells;
}

std::vector<Vec4> generateColors (int numColors)
{
	const Vec4 colors[] =
	{
		Vec4(0.18f, 0.42f, 0.17f, 1.0f),
		Vec4(0.29f, 0.62f, 0.28f, 1.0f),
		Vec4(0.59f, 0.84f, 0.44f, 1.0f),
		Vec4(0.96f, 0.95f, 0.72f, 1.0f),
		Vec4(0.94f, 0.55f, 0.39f, 1.0f),
		Vec4(0.82f, 0.19f, 0.12f, 1.0f),
		Vec4(0.46f, 0.15f, 0.26f, 1.0f),
		Vec4(0.24f, 0.14f, 0.24f, 1.0f),
		Vec4(0.49f, 0.31f, 0.26f, 1.0f),
		Vec4(0.78f, 0.52f, 0.33f, 1.0f),
		Vec4(0.94f, 0.82f, 0.31f, 1.0f),
		Vec4(0.98f, 0.65f, 0.30f, 1.0f),
		Vec4(0.22f, 0.65f, 0.53f, 1.0f),
		Vec4(0.67f, 0.81f, 0.91f, 1.0f),
		Vec4(0.43f, 0.44f, 0.75f, 1.0f),
		Vec4(0.26f, 0.24f, 0.48f, 1.0f),
	};

	std::vector<Vec4> result;
	result.reserve(numColors);

	for (int i = 0; i < numColors; ++i)
	{
		result.push_back(colors[i % DE_LENGTH_OF_ARRAY(colors)]);
	}

	return result;
}

std::vector<PositionColorVertex> generateVertices (const std::vector<UVec4>& grid, const std::vector<Vec4>& colors, const UVec2& renderSize)
{
	DE_ASSERT(colors.size() == grid.size());

	// Two triangles for each cell. Each cell correspond to a layer.
	std::size_t total = grid.size() * 6;

	std::vector<PositionColorVertex> result;
	result.reserve(total);

	for (std::size_t i = 0; i < total; ++i)
	{
		Vec4 pos;
		pos.z() = 0.0;
		pos.w() = 1.0;

		Vec4 cell = grid[i/6].asFloat() * 2.0f;
		float x			= cell.x() / float(renderSize.x()) - 1.0f;
		float y			= cell.y() / float(renderSize.y()) - 1.0f;
		float width		= cell.z() / float(renderSize.x());
		float height	= cell.w() / float(renderSize.y());

		switch (i % 6)
		{
		case 0: pos.xy() = Vec2(x,			y + height);	break;
		case 1: pos.xy() = Vec2(x + width,	y + height);	break;
		case 2: pos.xy() = Vec2(x,			y);				break;
		case 3: pos.xy() = Vec2(x + width,	y);				break;
		case 4: pos.xy() = Vec2(x + width,	y + height);	break;
		case 5: pos.xy() = Vec2(x,			y);				break;
		}

		result.push_back(PositionColorVertex(pos, colors[i/6]));
	}

	return result;
}

// Renderer generates two triangles per layer, each pair using a different
// color and a different position.
class Renderer
{
public:
	enum Shader
	{
		VERTEX,
		TESSELLATION,
	};

	Renderer (Context&									context,
			  const UVec2&								renderSize,
			  const int									numLayers,
			  const VkFormat							colorFormat,
			  const Vec4&								clearColor,
			  const std::vector<PositionColorVertex>&	vertices,
			  const Shader								shader)
		: m_renderSize				(renderSize)
		, m_colorFormat				(colorFormat)
		, m_colorSubresourceRange	(makeImageSubresourceRange(VK_IMAGE_ASPECT_COLOR_BIT, 0u, 1u, 0u, numLayers))
		, m_clearColor				(clearColor)
		, m_numLayers				(numLayers)
		, m_vertices				(vertices)
	{
		const DeviceInterface&		vk					= context.getDeviceInterface();
		const VkDevice				device				= context.getDevice();
		const deUint32				queueFamilyIndex	= context.getUniversalQueueFamilyIndex();
		Allocator&					allocator			= context.getDefaultAllocator();
		const VkDeviceSize			vertexBufferSize    = sizeInBytes(m_vertices);

		m_colorImage		= makeImage					(vk, device, makeImageCreateInfo(m_colorFormat, m_renderSize, m_numLayers, VK_IMAGE_USAGE_COLOR_ATTACHMENT_BIT | VK_IMAGE_USAGE_TRANSFER_SRC_BIT));
		m_colorImageAlloc	= bindImage					(vk, device, allocator, *m_colorImage, MemoryRequirement::Any);
		m_colorAttachment	= makeImageView				(vk, device, *m_colorImage, VK_IMAGE_VIEW_TYPE_2D_ARRAY, m_colorFormat, m_colorSubresourceRange);

		m_vertexBuffer		= Buffer::createAndAlloc	(vk, device, makeBufferCreateInfo(vertexBufferSize, VK_BUFFER_USAGE_VERTEX_BUFFER_BIT), allocator, MemoryRequirement::HostVisible);

		deMemcpy(m_vertexBuffer->getBoundMemory().getHostPtr(), &m_vertices[0], static_cast<std::size_t>(vertexBufferSize));
		flushAlloc(vk, device, m_vertexBuffer->getBoundMemory());

		if (shader == TESSELLATION)
		{
			m_tessellationControlModule		= createShaderModule	(vk, device, context.getBinaryCollection().get("tesc"), 0u);
			m_tessellationEvaluationModule	= createShaderModule	(vk, device, context.getBinaryCollection().get("tese"), 0u);
		}

		m_vertexModule		= createShaderModule	(vk, device, context.getBinaryCollection().get("vert"), 0u);
		m_fragmentModule	= createShaderModule	(vk, device, context.getBinaryCollection().get("frag"), 0u);
		m_renderPass		= makeRenderPass		(vk, device, m_colorFormat);
		m_framebuffer		= makeFramebuffer		(vk, device, *m_renderPass, m_colorAttachment.get(),
													 static_cast<deUint32>(m_renderSize.x()),
													 static_cast<deUint32>(m_renderSize.y()),
													 numLayers);
		m_pipelineLayout	= makePipelineLayout	(vk, device);
		m_pipeline			= makeGraphicsPipeline	(vk, device, *m_pipelineLayout, *m_renderPass, *m_vertexModule, *m_tessellationControlModule,
													 *m_tessellationEvaluationModule, *m_fragmentModule, m_renderSize);
		m_cmdPool			= createCommandPool		(vk, device, VK_COMMAND_POOL_CREATE_RESET_COMMAND_BUFFER_BIT, queueFamilyIndex);
		m_cmdBuffer			= allocateCommandBuffer	(vk, device, *m_cmdPool, VK_COMMAND_BUFFER_LEVEL_PRIMARY);
	}

	void draw (Context& context, const VkBuffer colorBuffer) const
	{
		const DeviceInterface&		vk			= context.getDeviceInterface();
		const VkDevice				device		= context.getDevice();
		const VkQueue				queue		= context.getUniversalQueue();

		beginCommandBuffer(vk, *m_cmdBuffer);

		const VkClearValue			clearValue	= makeClearValueColor(m_clearColor);
		const VkRect2D				renderArea	=
		{
			makeOffset2D(0, 0),
			makeExtent2D(m_renderSize.x(), m_renderSize.y()),
		};
		const VkRenderPassBeginInfo renderPassBeginInfo =
		{
			VK_STRUCTURE_TYPE_RENDER_PASS_BEGIN_INFO,		// VkStructureType         sType;
			DE_NULL,										// const void*             pNext;
			*m_renderPass,									// VkRenderPass            renderPass;
			*m_framebuffer,									// VkFramebuffer           framebuffer;
			renderArea,										// VkRect2D                renderArea;
			1u,												// uint32_t                clearValueCount;
			&clearValue,									// const VkClearValue*     pClearValues;
		};
		vk.cmdBeginRenderPass(*m_cmdBuffer, &renderPassBeginInfo, VK_SUBPASS_CONTENTS_INLINE);

		vk.cmdBindPipeline(*m_cmdBuffer, VK_PIPELINE_BIND_POINT_GRAPHICS, *m_pipeline);
		{
			const VkBuffer vertexBuffer = m_vertexBuffer->object();
			const VkDeviceSize vertexBufferOffset = 0ull;
			vk.cmdBindVertexBuffers(*m_cmdBuffer, 0u, 1u, &vertexBuffer, &vertexBufferOffset);
		}
		vk.cmdDraw(*m_cmdBuffer, static_cast<deUint32>(m_numLayers * 6), 1u, 0u, 0u);	// two triangles per layer
		vk.cmdEndRenderPass(*m_cmdBuffer);

		copyImageToBuffer(vk, *m_cmdBuffer, *m_colorImage, colorBuffer, tcu::IVec2(m_renderSize.x(), m_renderSize.y()), VK_ACCESS_COLOR_ATTACHMENT_WRITE_BIT, VK_IMAGE_LAYOUT_COLOR_ATTACHMENT_OPTIMAL, m_colorSubresourceRange.layerCount);

		endCommandBuffer(vk, *m_cmdBuffer);
		submitCommandsAndWait(vk, device, queue, *m_cmdBuffer);
	}

private:
	const UVec2								m_renderSize;
	const VkFormat							m_colorFormat;
	const VkImageSubresourceRange			m_colorSubresourceRange;
	const Vec4								m_clearColor;
	const int								m_numLayers;
	const std::vector<PositionColorVertex>	m_vertices;

	Move<VkImage>							m_colorImage;
	MovePtr<Allocation>						m_colorImageAlloc;
	Move<VkImageView>						m_colorAttachment;
	SharedPtr<Buffer>						m_vertexBuffer;
	Move<VkShaderModule>					m_vertexModule;
	Move<VkShaderModule>					m_tessellationControlModule;
	Move<VkShaderModule>					m_tessellationEvaluationModule;
	Move<VkShaderModule>					m_fragmentModule;
	Move<VkRenderPass>						m_renderPass;
	Move<VkFramebuffer>						m_framebuffer;
	Move<VkPipelineLayout>					m_pipelineLayout;
	Move<VkPipeline>						m_pipeline;
	Move<VkCommandPool>						m_cmdPool;
	Move<VkCommandBuffer>					m_cmdBuffer;

	// "deleted"
				Renderer	(const Renderer&);
	Renderer&	operator=	(const Renderer&);
};

void checkRequirements (Context& context, const int)
{
	context.requireDeviceCoreFeature(DEVICE_CORE_FEATURE_MULTI_VIEWPORT);
	context.requireDeviceExtension("VK_EXT_shader_viewport_index_layer");

	const VkPhysicalDeviceLimits	limits	= context.getDeviceProperties().limits;

	if (limits.maxFramebufferLayers < MIN_MAX_FRAMEBUFFER_LAYERS)
		TCU_FAIL("maxFramebuffersLayers is less than the minimum required");

	if (limits.maxViewports < MIN_MAX_VIEWPORTS)
		TCU_FAIL("multiViewport supported but maxViewports is less than the minimum required");
}

tcu::TestStatus testVertexShader (Context& context, const int numLayers)
{
	const DeviceInterface&					vk					= context.getDeviceInterface();
	const VkDevice							device				= context.getDevice();
	Allocator&								allocator			= context.getDefaultAllocator();

	const UVec2								renderSize			(256, 256);
	const VkFormat							colorFormat			= VK_FORMAT_R8G8B8A8_UNORM;
	const Vec4								clearColor			(0.5f, 0.5f, 0.5f, 1.0f);
	const std::vector<UVec4>				grid				= generateGrid(numLayers, renderSize);
	const std::vector<Vec4>					colors				= generateColors(numLayers);
	const std::vector<PositionColorVertex>	vertices			= generateVertices(grid, colors, renderSize);

	const VkDeviceSize						colorBufferSize		= renderSize.x() * renderSize.y() * tcu::getPixelSize(mapVkFormat(colorFormat)) * numLayers;

	const SharedPtr<Buffer>					colorBuffer			= Buffer::createAndAlloc(vk, device, makeBufferCreateInfo(colorBufferSize, VK_BUFFER_USAGE_TRANSFER_DST_BIT), allocator, MemoryRequirement::HostVisible);

	// Zero buffer.
	{
		const Allocation alloc = colorBuffer->getBoundMemory();
		deMemset(alloc.getHostPtr(), 0, static_cast<std::size_t>(colorBufferSize));
		flushAlloc(vk, device, alloc);
	}

	{
		context.getTestContext().getLog()
			<< tcu::TestLog::Message << "Rendering a rectangle in each of the " << numLayers << " layer(s)." << tcu::TestLog::EndMessage
			<< tcu::TestLog::Message << "Not covered area will be filled with a gray color." << tcu::TestLog::EndMessage;
	}

	// Draw.
	{
		const Renderer renderer (context, renderSize, numLayers, colorFormat, clearColor, vertices, Renderer::VERTEX);
		renderer.draw(context, colorBuffer->object());
	}

	// Verify layers.
	{
		const Allocation alloc = colorBuffer->getBoundMemory();
		invalidateMappedMemoryRange(vk, device, alloc.getMemory(), 0ull, colorBufferSize);

		deUint8* resultMem = reinterpret_cast<deUint8*>(alloc.getHostPtr());
		for (int i = 0; i < numLayers; i++)
		{
			const tcu::ConstPixelBufferAccess	resultImage		(mapVkFormat(colorFormat), renderSize.x(), renderSize.y(), 1u, resultMem + ((colorBufferSize / numLayers) * i));
			const tcu::TextureLevel				referenceImage	= generateReferenceImage(mapVkFormat(colorFormat), renderSize, clearColor, grid[i], colors[i]);
			std::string imageSetName = "layer_" + de::toString(i);
			std::string imageSetDesc = "Image compare for layer " + de::toString(i);
			if (!tcu::floatThresholdCompare(context.getTestContext().getLog(), imageSetName.c_str(), imageSetDesc.c_str(), referenceImage.getAccess(), resultImage, Vec4(0.02f), tcu::COMPARE_LOG_RESULT))
				TCU_FAIL("Rendered image is not correct");
		}
	}

	return tcu::TestStatus::pass("OK");
}

tcu::TestStatus testTessellationShader (Context& context, const int numLayers)
{
	const VkPhysicalDeviceFeatures&			features			= context.getDeviceFeatures();
	if (!features.tessellationShader)
		TCU_THROW(NotSupportedError, "Required feature is not supported: tessellationShader");

	const DeviceInterface&					vk					= context.getDeviceInterface();
	const VkDevice							device				= context.getDevice();
	Allocator&								allocator			= context.getDefaultAllocator();

	const UVec2								renderSize			(256, 256);
	const VkFormat							colorFormat			= VK_FORMAT_R8G8B8A8_UNORM;
	const Vec4								clearColor			(0.5f, 0.5f, 0.5f, 1.0f);
	const std::vector<UVec4>				grid				= generateGrid(numLayers, renderSize);
	const std::vector<Vec4>					colors				= generateColors(numLayers);
	const std::vector<PositionColorVertex>	vertices			= generateVertices(grid, colors, renderSize);

	const VkDeviceSize						colorBufferSize		= renderSize.x() * renderSize.y() * tcu::getPixelSize(mapVkFormat(colorFormat)) * numLayers;

	const SharedPtr<Buffer>					colorBuffer			= Buffer::createAndAlloc(vk, device, makeBufferCreateInfo(colorBufferSize, VK_BUFFER_USAGE_TRANSFER_DST_BIT), allocator, MemoryRequirement::HostVisible);

	// Zero buffer.
	{
		const Allocation alloc = colorBuffer->getBoundMemory();
		deMemset(alloc.getHostPtr(), 0, static_cast<std::size_t>(colorBufferSize));
		flushAlloc(vk, device, alloc);
	}

	{
		context.getTestContext().getLog()
			<< tcu::TestLog::Message << "Rendering a rectangle in each of the " << numLayers << " layer(s)." << tcu::TestLog::EndMessage
			<< tcu::TestLog::Message << "Not covered area will be filled with a gray color." << tcu::TestLog::EndMessage;
	}

	// Draw.
	{
		const Renderer renderer (context, renderSize, numLayers, colorFormat, clearColor, vertices, Renderer::TESSELLATION);
		renderer.draw(context, colorBuffer->object());
	}

	// Verify layers.
	{
		const Allocation alloc = colorBuffer->getBoundMemory();
		invalidateMappedMemoryRange(vk, device, alloc.getMemory(), 0ull, colorBufferSize);

		deUint8* resultMem = reinterpret_cast<deUint8*>(alloc.getHostPtr());
		for (int i = 0; i < numLayers; i++) {
			const tcu::ConstPixelBufferAccess	resultImage		(mapVkFormat(colorFormat), renderSize.x(), renderSize.y(), 1u, resultMem + ((colorBufferSize / numLayers) * i));
			const tcu::TextureLevel				referenceImage	= generateReferenceImage(mapVkFormat(colorFormat), renderSize, clearColor, grid[i], colors[i]);
			std::string imageSetName = "layer_" + de::toString(i);
			std::string imageSetDesc = "Image compare for layer " + de::toString(i);
			if (!tcu::floatThresholdCompare(context.getTestContext().getLog(), imageSetName.c_str(), imageSetDesc.c_str(), referenceImage.getAccess(), resultImage, Vec4(0.02f), tcu::COMPARE_LOG_RESULT))
				TCU_FAIL("Rendered image is not correct");
		}
	}

	return tcu::TestStatus::pass("OK");
}

} // anonymous

tcu::TestCaseGroup* createShaderLayerTests	(tcu::TestContext& testCtx)
{
	MovePtr<tcu::TestCaseGroup> group (new tcu::TestCaseGroup(testCtx, "shader_layer", ""));

	int numLayersToTest[] =
	{
		1,
		2,
		3,
		4,
		5,
		6,
		7,
		8,
		MIN_MAX_FRAMEBUFFER_LAYERS,
	};

	for (int i = 0; i < DE_LENGTH_OF_ARRAY(numLayersToTest); ++i)
	{
		int numLayers = numLayersToTest[i];
		addFunctionCaseWithPrograms(group.get(), "vertex_shader_" + de::toString(numLayers), "", checkRequirements, initVertexTestPrograms, testVertexShader, numLayers);
	}

	for (int i = 0; i < DE_LENGTH_OF_ARRAY(numLayersToTest); ++i)
	{
		int numLayers = numLayersToTest[i];
		addFunctionCaseWithPrograms(group.get(), "tessellation_shader_" + de::toString(numLayers), "", checkRequirements, initTessellationTestPrograms, testTessellationShader, numLayers);
	}

	return group.release();
}

} // Draw
} // vkt