Qt 5.11 | Qt GUI | Hello Vulkan Cubes Example | renderer.cpp Example File

Qt 5.11.3 Reference Documentation

# renderer.cpp Example File

hellovulkancubes/renderer.cpp

      /****************************************************************************
      **
      ** Copyright (C) 2017 The Qt Company Ltd.
      ** Contact: https://www.qt.io/licensing/
      **
      ** This file is part of the examples of the Qt Toolkit.
      **
      ** $QT_BEGIN_LICENSE:BSD$
      ** Commercial License Usage
      ** Licensees holding valid commercial Qt licenses may use this file in
      ** accordance with the commercial license agreement provided with the
      ** Software or, alternatively, in accordance with the terms contained in
      ** a written agreement between you and The Qt Company. For licensing terms
      ** and conditions see https://www.qt.io/terms-conditions. For further
      ** information use the contact form at https://www.qt.io/contact-us.
      **
      ** BSD License Usage
      ** Alternatively, you may use this file under the terms of the BSD license
      ** as follows:
      **
      ** "Redistribution and use in source and binary forms, with or without
      ** modification, are permitted provided that the following conditions are
      ** met:
      **   * Redistributions of source code must retain the above copyright
      **     notice, this list of conditions and the following disclaimer.
      **   * Redistributions in binary form must reproduce the above copyright
      **     notice, this list of conditions and the following disclaimer in
      **     the documentation and/or other materials provided with the
      **     distribution.
      **   * Neither the name of The Qt Company Ltd nor the names of its
      **     contributors may be used to endorse or promote products derived
      **     from this software without specific prior written permission.
      **
      **
      ** THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
      ** "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
      ** LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
      ** A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
      ** OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
      ** SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
      ** LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
      ** DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
      ** THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
      ** (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
      ** OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE."
      **
      ** $QT_END_LICENSE$
      **
      ****************************************************************************/

      #include "renderer.h"
      #include <QVulkanFunctions>
      #include <QtConcurrentRun>
      #include <QTime>

      static float quadVert[] = { // Y up, front = CW
          -1, -1, 0,
          -1,  1, 0,
           1, -1, 0,
           1,  1, 0
      };

      #define DBG Q_UNLIKELY(m_window->isDebugEnabled())

      const int MAX_INSTANCES = 16384;
      const VkDeviceSize PER_INSTANCE_DATA_SIZE = 6 * sizeof(float); // instTranslate, instDiffuseAdjust

      static inline VkDeviceSize aligned(VkDeviceSize v, VkDeviceSize byteAlign)
      {
          return (v + byteAlign - 1) & ~(byteAlign - 1);
      }

      Renderer::Renderer(VulkanWindow *w, int initialCount)
          : m_window(w),
            // Have the light positioned just behind the default camera position, looking forward.
            m_lightPos(0.0f, 0.0f, 25.0f),
            m_cam(QVector3D(0.0f, 0.0f, 20.0f)), // starting camera position
            m_instCount(initialCount)
      {
          qsrand(QTime(0, 0, 0).secsTo(QTime::currentTime()));

          m_floorModel.translate(0, -5, 0);
          m_floorModel.rotate(-90, 1, 0, 0);
          m_floorModel.scale(20, 100, 1);

          m_blockMesh.load(QStringLiteral(":/block.buf"));
          m_logoMesh.load(QStringLiteral(":/qt_logo.buf"));

          QObject::connect(&m_frameWatcher, &QFutureWatcherBase::finished, [this] {
              if (m_framePending) {
                  m_framePending = false;
                  m_window->frameReady();
                  m_window->requestUpdate();
              }
          });
      }

      void Renderer::preInitResources()
      {
          const QVector<int> sampleCounts = m_window->supportedSampleCounts();
          if (DBG)
              qDebug() << "Supported sample counts:" << sampleCounts;
          if (sampleCounts.contains(4)) {
              if (DBG)
                  qDebug("Requesting 4x MSAA");
              m_window->setSampleCount(4);
          }
      }

      void Renderer::initResources()
      {
          if (DBG)
              qDebug("Renderer init");

          m_animating = true;
          m_framePending = false;

          QVulkanInstance *inst = m_window->vulkanInstance();
          VkDevice dev = m_window->device();
          const VkPhysicalDeviceLimits *pdevLimits = &m_window->physicalDeviceProperties()->limits;
          const VkDeviceSize uniAlign = pdevLimits->minUniformBufferOffsetAlignment;

          m_devFuncs = inst->deviceFunctions(dev);

          // Note the std140 packing rules. A vec3 still has an alignment of 16,
          // while a mat3 is like 3 * vec3.
          m_itemMaterial.vertUniSize = aligned(2 * 64 + 48, uniAlign); // see color_phong.vert
          m_itemMaterial.fragUniSize = aligned(6 * 16 + 12 + 2 * 4, uniAlign); // see color_phong.frag

          if (!m_itemMaterial.vs.isValid())
              m_itemMaterial.vs.load(inst, dev, QStringLiteral(":/color_phong_vert.spv"));
          if (!m_itemMaterial.fs.isValid())
              m_itemMaterial.fs.load(inst, dev, QStringLiteral(":/color_phong_frag.spv"));

          if (!m_floorMaterial.vs.isValid())
              m_floorMaterial.vs.load(inst, dev, QStringLiteral(":/color_vert.spv"));
          if (!m_floorMaterial.fs.isValid())
              m_floorMaterial.fs.load(inst, dev, QStringLiteral(":/color_frag.spv"));

          m_pipelinesFuture = QtConcurrent::run(this, &Renderer::createPipelines);
      }

      void Renderer::createPipelines()
      {
          VkDevice dev = m_window->device();

          VkPipelineCacheCreateInfo pipelineCacheInfo;
          memset(&pipelineCacheInfo, 0, sizeof(pipelineCacheInfo));
          pipelineCacheInfo.sType = VK_STRUCTURE_TYPE_PIPELINE_CACHE_CREATE_INFO;
          VkResult err = m_devFuncs->vkCreatePipelineCache(dev, &pipelineCacheInfo, nullptr, &m_pipelineCache);
          if (err != VK_SUCCESS)
              qFatal("Failed to create pipeline cache: %d", err);

          createItemPipeline();
          createFloorPipeline();
      }

      void Renderer::createItemPipeline()
      {
          VkDevice dev = m_window->device();

          // Vertex layout.
          VkVertexInputBindingDescription vertexBindingDesc[] = {
              {
                  0, // binding
                  8 * sizeof(float),
                  VK_VERTEX_INPUT_RATE_VERTEX
              },
              {
                  1,
                  6 * sizeof(float),
                  VK_VERTEX_INPUT_RATE_INSTANCE
              }
          };
          VkVertexInputAttributeDescription vertexAttrDesc[] = {
              { // position
                  0, // location
                  0, // binding
                  VK_FORMAT_R32G32B32_SFLOAT,
                  0 // offset
              },
              { // normal
                  1,
                  0,
                  VK_FORMAT_R32G32B32_SFLOAT,
                  5 * sizeof(float)
              },
              { // instTranslate
                  2,
                  1,
                  VK_FORMAT_R32G32B32_SFLOAT,
                  0
              },
              { // instDiffuseAdjust
                  3,
                  1,
                  VK_FORMAT_R32G32B32_SFLOAT,
                  3 * sizeof(float)
              }
          };

          VkPipelineVertexInputStateCreateInfo vertexInputInfo;
          vertexInputInfo.sType = VK_STRUCTURE_TYPE_PIPELINE_VERTEX_INPUT_STATE_CREATE_INFO;
          vertexInputInfo.pNext = nullptr;
          vertexInputInfo.flags = 0;
          vertexInputInfo.vertexBindingDescriptionCount = sizeof(vertexBindingDesc) / sizeof(vertexBindingDesc[0]);
          vertexInputInfo.pVertexBindingDescriptions = vertexBindingDesc;
          vertexInputInfo.vertexAttributeDescriptionCount = sizeof(vertexAttrDesc) / sizeof(vertexAttrDesc[0]);
          vertexInputInfo.pVertexAttributeDescriptions = vertexAttrDesc;

          // Descriptor set layout.
          VkDescriptorPoolSize descPoolSizes[] = {
              { VK_DESCRIPTOR_TYPE_UNIFORM_BUFFER_DYNAMIC, 2 }
          };
          VkDescriptorPoolCreateInfo descPoolInfo;
          memset(&descPoolInfo, 0, sizeof(descPoolInfo));
          descPoolInfo.sType = VK_STRUCTURE_TYPE_DESCRIPTOR_POOL_CREATE_INFO;
          descPoolInfo.maxSets = 1; // a single set is enough due to the dynamic uniform buffer
          descPoolInfo.poolSizeCount = sizeof(descPoolSizes) / sizeof(descPoolSizes[0]);
          descPoolInfo.pPoolSizes = descPoolSizes;
          VkResult err = m_devFuncs->vkCreateDescriptorPool(dev, &descPoolInfo, nullptr, &m_itemMaterial.descPool);
          if (err != VK_SUCCESS)
              qFatal("Failed to create descriptor pool: %d", err);

          VkDescriptorSetLayoutBinding layoutBindings[] =
          {
              {
                  0, // binding
                  VK_DESCRIPTOR_TYPE_UNIFORM_BUFFER_DYNAMIC,
                  1, // descriptorCount
                  VK_SHADER_STAGE_VERTEX_BIT,
                  nullptr
              },
              {
                  1,
                  VK_DESCRIPTOR_TYPE_UNIFORM_BUFFER_DYNAMIC,
                  1,
                  VK_SHADER_STAGE_FRAGMENT_BIT,
                  nullptr
              }
          };
          VkDescriptorSetLayoutCreateInfo descLayoutInfo = {
              VK_STRUCTURE_TYPE_DESCRIPTOR_SET_LAYOUT_CREATE_INFO,
              nullptr,
              0,
              sizeof(layoutBindings) / sizeof(layoutBindings[0]),
              layoutBindings
          };
          err = m_devFuncs->vkCreateDescriptorSetLayout(dev, &descLayoutInfo, nullptr, &m_itemMaterial.descSetLayout);
          if (err != VK_SUCCESS)
              qFatal("Failed to create descriptor set layout: %d", err);

          VkDescriptorSetAllocateInfo descSetAllocInfo = {
              VK_STRUCTURE_TYPE_DESCRIPTOR_SET_ALLOCATE_INFO,
              nullptr,
              m_itemMaterial.descPool,
              1,
              &m_itemMaterial.descSetLayout
          };
          err = m_devFuncs->vkAllocateDescriptorSets(dev, &descSetAllocInfo, &m_itemMaterial.descSet);
          if (err != VK_SUCCESS)
              qFatal("Failed to allocate descriptor set: %d", err);

          // Graphics pipeline.
          VkPipelineLayoutCreateInfo pipelineLayoutInfo;
          memset(&pipelineLayoutInfo, 0, sizeof(pipelineLayoutInfo));
          pipelineLayoutInfo.sType = VK_STRUCTURE_TYPE_PIPELINE_LAYOUT_CREATE_INFO;
          pipelineLayoutInfo.setLayoutCount = 1;
          pipelineLayoutInfo.pSetLayouts = &m_itemMaterial.descSetLayout;

          err = m_devFuncs->vkCreatePipelineLayout(dev, &pipelineLayoutInfo, nullptr, &m_itemMaterial.pipelineLayout);
          if (err != VK_SUCCESS)
              qFatal("Failed to create pipeline layout: %d", err);

          VkGraphicsPipelineCreateInfo pipelineInfo;
          memset(&pipelineInfo, 0, sizeof(pipelineInfo));
          pipelineInfo.sType = VK_STRUCTURE_TYPE_GRAPHICS_PIPELINE_CREATE_INFO;

          VkPipelineShaderStageCreateInfo shaderStages[2] = {
              {
                  VK_STRUCTURE_TYPE_PIPELINE_SHADER_STAGE_CREATE_INFO,
                  nullptr,
                  0,
                  VK_SHADER_STAGE_VERTEX_BIT,
                  m_itemMaterial.vs.data()->shaderModule,
                  "main",
                  nullptr
              },
              {
                  VK_STRUCTURE_TYPE_PIPELINE_SHADER_STAGE_CREATE_INFO,
                  nullptr,
                  0,
                  VK_SHADER_STAGE_FRAGMENT_BIT,
                  m_itemMaterial.fs.data()->shaderModule,
                  "main",
                  nullptr
              }
          };
          pipelineInfo.stageCount = 2;
          pipelineInfo.pStages = shaderStages;

          pipelineInfo.pVertexInputState = &vertexInputInfo;

          VkPipelineInputAssemblyStateCreateInfo ia;
          memset(&ia, 0, sizeof(ia));
          ia.sType = VK_STRUCTURE_TYPE_PIPELINE_INPUT_ASSEMBLY_STATE_CREATE_INFO;
          ia.topology = VK_PRIMITIVE_TOPOLOGY_TRIANGLE_LIST;
          pipelineInfo.pInputAssemblyState = &ia;

          VkPipelineViewportStateCreateInfo vp;
          memset(&vp, 0, sizeof(vp));
          vp.sType = VK_STRUCTURE_TYPE_PIPELINE_VIEWPORT_STATE_CREATE_INFO;
          vp.viewportCount = 1;
          vp.scissorCount = 1;
          pipelineInfo.pViewportState = &vp;

          VkPipelineRasterizationStateCreateInfo rs;
          memset(&rs, 0, sizeof(rs));
          rs.sType = VK_STRUCTURE_TYPE_PIPELINE_RASTERIZATION_STATE_CREATE_INFO;
          rs.polygonMode = VK_POLYGON_MODE_FILL;
          rs.cullMode = VK_CULL_MODE_BACK_BIT;
          rs.frontFace = VK_FRONT_FACE_COUNTER_CLOCKWISE;
          rs.lineWidth = 1.0f;
          pipelineInfo.pRasterizationState = &rs;

          VkPipelineMultisampleStateCreateInfo ms;
          memset(&ms, 0, sizeof(ms));
          ms.sType = VK_STRUCTURE_TYPE_PIPELINE_MULTISAMPLE_STATE_CREATE_INFO;
          ms.rasterizationSamples = m_window->sampleCountFlagBits();
          pipelineInfo.pMultisampleState = &ms;

          VkPipelineDepthStencilStateCreateInfo ds;
          memset(&ds, 0, sizeof(ds));
          ds.sType = VK_STRUCTURE_TYPE_PIPELINE_DEPTH_STENCIL_STATE_CREATE_INFO;
          ds.depthTestEnable = VK_TRUE;
          ds.depthWriteEnable = VK_TRUE;
          ds.depthCompareOp = VK_COMPARE_OP_LESS_OR_EQUAL;
          pipelineInfo.pDepthStencilState = &ds;

          VkPipelineColorBlendStateCreateInfo cb;
          memset(&cb, 0, sizeof(cb));
          cb.sType = VK_STRUCTURE_TYPE_PIPELINE_COLOR_BLEND_STATE_CREATE_INFO;
          VkPipelineColorBlendAttachmentState att;
          memset(&att, 0, sizeof(att));
          att.colorWriteMask = 0xF;
          cb.attachmentCount = 1;
          cb.pAttachments = &att;
          pipelineInfo.pColorBlendState = &cb;

          VkDynamicState dynEnable[] = { VK_DYNAMIC_STATE_VIEWPORT, VK_DYNAMIC_STATE_SCISSOR };
          VkPipelineDynamicStateCreateInfo dyn;
          memset(&dyn, 0, sizeof(dyn));
          dyn.sType = VK_STRUCTURE_TYPE_PIPELINE_DYNAMIC_STATE_CREATE_INFO;
          dyn.dynamicStateCount = sizeof(dynEnable) / sizeof(VkDynamicState);
          dyn.pDynamicStates = dynEnable;
          pipelineInfo.pDynamicState = &dyn;

          pipelineInfo.layout = m_itemMaterial.pipelineLayout;
          pipelineInfo.renderPass = m_window->defaultRenderPass();

          err = m_devFuncs->vkCreateGraphicsPipelines(dev, m_pipelineCache, 1, &pipelineInfo, nullptr, &m_itemMaterial.pipeline);
          if (err != VK_SUCCESS)
              qFatal("Failed to create graphics pipeline: %d", err);
      }

      void Renderer::createFloorPipeline()
      {
          VkDevice dev = m_window->device();

          // Vertex layout.
          VkVertexInputBindingDescription vertexBindingDesc = {
              0, // binding
              3 * sizeof(float),
              VK_VERTEX_INPUT_RATE_VERTEX
          };
          VkVertexInputAttributeDescription vertexAttrDesc[] = {
              { // position
                  0, // location
                  0, // binding
                  VK_FORMAT_R32G32B32_SFLOAT,
                  0 // offset
              },
          };

          VkPipelineVertexInputStateCreateInfo vertexInputInfo;
          vertexInputInfo.sType = VK_STRUCTURE_TYPE_PIPELINE_VERTEX_INPUT_STATE_CREATE_INFO;
          vertexInputInfo.pNext = nullptr;
          vertexInputInfo.flags = 0;
          vertexInputInfo.vertexBindingDescriptionCount = 1;
          vertexInputInfo.pVertexBindingDescriptions = &vertexBindingDesc;
          vertexInputInfo.vertexAttributeDescriptionCount = sizeof(vertexAttrDesc) / sizeof(vertexAttrDesc[0]);
          vertexInputInfo.pVertexAttributeDescriptions = vertexAttrDesc;

          // Do not bother with uniform buffers and descriptors, all the data fits
          // into the spec mandated minimum of 128 bytes for push constants.
          VkPushConstantRange pcr[] = {
              // mvp
              {
                  VK_SHADER_STAGE_VERTEX_BIT,
                  0,
                  64
              },
              // color
              {
                  VK_SHADER_STAGE_FRAGMENT_BIT,
                  64,
                  12
              }
          };

          VkPipelineLayoutCreateInfo pipelineLayoutInfo;
          memset(&pipelineLayoutInfo, 0, sizeof(pipelineLayoutInfo));
          pipelineLayoutInfo.sType = VK_STRUCTURE_TYPE_PIPELINE_LAYOUT_CREATE_INFO;
          pipelineLayoutInfo.pushConstantRangeCount = sizeof(pcr) / sizeof(pcr[0]);
          pipelineLayoutInfo.pPushConstantRanges = pcr;

          VkResult err = m_devFuncs->vkCreatePipelineLayout(dev, &pipelineLayoutInfo, nullptr, &m_floorMaterial.pipelineLayout);
          if (err != VK_SUCCESS)
              qFatal("Failed to create pipeline layout: %d", err);

          VkGraphicsPipelineCreateInfo pipelineInfo;
          memset(&pipelineInfo, 0, sizeof(pipelineInfo));
          pipelineInfo.sType = VK_STRUCTURE_TYPE_GRAPHICS_PIPELINE_CREATE_INFO;

          VkPipelineShaderStageCreateInfo shaderStages[2] = {
              {
                  VK_STRUCTURE_TYPE_PIPELINE_SHADER_STAGE_CREATE_INFO,
                  nullptr,
                  0,
                  VK_SHADER_STAGE_VERTEX_BIT,
                  m_floorMaterial.vs.data()->shaderModule,
                  "main",
                  nullptr
              },
              {
                  VK_STRUCTURE_TYPE_PIPELINE_SHADER_STAGE_CREATE_INFO,
                  nullptr,
                  0,
                  VK_SHADER_STAGE_FRAGMENT_BIT,
                  m_floorMaterial.fs.data()->shaderModule,
                  "main",
                  nullptr
              }
          };
          pipelineInfo.stageCount = 2;
          pipelineInfo.pStages = shaderStages;

          pipelineInfo.pVertexInputState = &vertexInputInfo;

          VkPipelineInputAssemblyStateCreateInfo ia;
          memset(&ia, 0, sizeof(ia));
          ia.sType = VK_STRUCTURE_TYPE_PIPELINE_INPUT_ASSEMBLY_STATE_CREATE_INFO;
          ia.topology = VK_PRIMITIVE_TOPOLOGY_TRIANGLE_STRIP;
          pipelineInfo.pInputAssemblyState = &ia;

          VkPipelineViewportStateCreateInfo vp;
          memset(&vp, 0, sizeof(vp));
          vp.sType = VK_STRUCTURE_TYPE_PIPELINE_VIEWPORT_STATE_CREATE_INFO;
          vp.viewportCount = 1;
          vp.scissorCount = 1;
          pipelineInfo.pViewportState = &vp;

          VkPipelineRasterizationStateCreateInfo rs;
          memset(&rs, 0, sizeof(rs));
          rs.sType = VK_STRUCTURE_TYPE_PIPELINE_RASTERIZATION_STATE_CREATE_INFO;
          rs.polygonMode = VK_POLYGON_MODE_FILL;
          rs.cullMode = VK_CULL_MODE_BACK_BIT;
          rs.frontFace = VK_FRONT_FACE_CLOCKWISE;
          rs.lineWidth = 1.0f;
          pipelineInfo.pRasterizationState = &rs;

          VkPipelineMultisampleStateCreateInfo ms;
          memset(&ms, 0, sizeof(ms));
          ms.sType = VK_STRUCTURE_TYPE_PIPELINE_MULTISAMPLE_STATE_CREATE_INFO;
          ms.rasterizationSamples = m_window->sampleCountFlagBits();
          pipelineInfo.pMultisampleState = &ms;

          VkPipelineDepthStencilStateCreateInfo ds;
          memset(&ds, 0, sizeof(ds));
          ds.sType = VK_STRUCTURE_TYPE_PIPELINE_DEPTH_STENCIL_STATE_CREATE_INFO;
          ds.depthTestEnable = VK_TRUE;
          ds.depthWriteEnable = VK_TRUE;
          ds.depthCompareOp = VK_COMPARE_OP_LESS_OR_EQUAL;
          pipelineInfo.pDepthStencilState = &ds;

          VkPipelineColorBlendStateCreateInfo cb;
          memset(&cb, 0, sizeof(cb));
          cb.sType = VK_STRUCTURE_TYPE_PIPELINE_COLOR_BLEND_STATE_CREATE_INFO;
          VkPipelineColorBlendAttachmentState att;
          memset(&att, 0, sizeof(att));
          att.colorWriteMask = 0xF;
          cb.attachmentCount = 1;
          cb.pAttachments = &att;
          pipelineInfo.pColorBlendState = &cb;

          VkDynamicState dynEnable[] = { VK_DYNAMIC_STATE_VIEWPORT, VK_DYNAMIC_STATE_SCISSOR };
          VkPipelineDynamicStateCreateInfo dyn;
          memset(&dyn, 0, sizeof(dyn));
          dyn.sType = VK_STRUCTURE_TYPE_PIPELINE_DYNAMIC_STATE_CREATE_INFO;
          dyn.dynamicStateCount = sizeof(dynEnable) / sizeof(VkDynamicState);
          dyn.pDynamicStates = dynEnable;
          pipelineInfo.pDynamicState = &dyn;

          pipelineInfo.layout = m_floorMaterial.pipelineLayout;
          pipelineInfo.renderPass = m_window->defaultRenderPass();

          err = m_devFuncs->vkCreateGraphicsPipelines(dev, m_pipelineCache, 1, &pipelineInfo, nullptr, &m_floorMaterial.pipeline);
          if (err != VK_SUCCESS)
              qFatal("Failed to create graphics pipeline: %d", err);
      }

      void Renderer::initSwapChainResources()
      {
          m_proj = m_window->clipCorrectionMatrix();
          const QSize sz = m_window->swapChainImageSize();
          m_proj.perspective(45.0f, sz.width() / (float) sz.height(), 0.01f, 1000.0f);
          markViewProjDirty();
      }

      void Renderer::releaseSwapChainResources()
      {
          // It is important to finish the pending frame right here since this is the
          // last opportunity to act with all resources intact.
          m_frameWatcher.waitForFinished();
          // Cannot count on the finished() signal being emitted before returning
          // from here.
          if (m_framePending) {
              m_framePending = false;
              m_window->frameReady();
          }
      }

      void Renderer::releaseResources()
      {
          if (DBG)
              qDebug("Renderer release");

          m_pipelinesFuture.waitForFinished();

          VkDevice dev = m_window->device();

          if (m_itemMaterial.descSetLayout) {
              m_devFuncs->vkDestroyDescriptorSetLayout(dev, m_itemMaterial.descSetLayout, nullptr);
              m_itemMaterial.descSetLayout = VK_NULL_HANDLE;
          }

          if (m_itemMaterial.descPool) {
              m_devFuncs->vkDestroyDescriptorPool(dev, m_itemMaterial.descPool, nullptr);
              m_itemMaterial.descPool = VK_NULL_HANDLE;
          }

          if (m_itemMaterial.pipeline) {
              m_devFuncs->vkDestroyPipeline(dev, m_itemMaterial.pipeline, nullptr);
              m_itemMaterial.pipeline = VK_NULL_HANDLE;
          }

          if (m_itemMaterial.pipelineLayout) {
              m_devFuncs->vkDestroyPipelineLayout(dev, m_itemMaterial.pipelineLayout, nullptr);
              m_itemMaterial.pipelineLayout = VK_NULL_HANDLE;
          }

          if (m_floorMaterial.pipeline) {
              m_devFuncs->vkDestroyPipeline(dev, m_floorMaterial.pipeline, nullptr);
              m_floorMaterial.pipeline = VK_NULL_HANDLE;
          }

          if (m_floorMaterial.pipelineLayout) {
              m_devFuncs->vkDestroyPipelineLayout(dev, m_floorMaterial.pipelineLayout, nullptr);
              m_floorMaterial.pipelineLayout = VK_NULL_HANDLE;
          }

          if (m_pipelineCache) {
              m_devFuncs->vkDestroyPipelineCache(dev, m_pipelineCache, nullptr);
              m_pipelineCache = VK_NULL_HANDLE;
          }

          if (m_blockVertexBuf) {
              m_devFuncs->vkDestroyBuffer(dev, m_blockVertexBuf, nullptr);
              m_blockVertexBuf = VK_NULL_HANDLE;
          }

          if (m_logoVertexBuf) {
              m_devFuncs->vkDestroyBuffer(dev, m_logoVertexBuf, nullptr);
              m_logoVertexBuf = VK_NULL_HANDLE;
          }

          if (m_floorVertexBuf) {
              m_devFuncs->vkDestroyBuffer(dev, m_floorVertexBuf, nullptr);
              m_floorVertexBuf = VK_NULL_HANDLE;
          }

          if (m_uniBuf) {
              m_devFuncs->vkDestroyBuffer(dev, m_uniBuf, nullptr);
              m_uniBuf = VK_NULL_HANDLE;
          }

          if (m_bufMem) {
              m_devFuncs->vkFreeMemory(dev, m_bufMem, nullptr);
              m_bufMem = VK_NULL_HANDLE;
          }

          if (m_instBuf) {
              m_devFuncs->vkDestroyBuffer(dev, m_instBuf, nullptr);
              m_instBuf = VK_NULL_HANDLE;
          }

          if (m_instBufMem) {
              m_devFuncs->vkFreeMemory(dev, m_instBufMem, nullptr);
              m_instBufMem = VK_NULL_HANDLE;
          }

          if (m_itemMaterial.vs.isValid()) {
              m_devFuncs->vkDestroyShaderModule(dev, m_itemMaterial.vs.data()->shaderModule, nullptr);
              m_itemMaterial.vs.reset();
          }
          if (m_itemMaterial.fs.isValid()) {
              m_devFuncs->vkDestroyShaderModule(dev, m_itemMaterial.fs.data()->shaderModule, nullptr);
              m_itemMaterial.fs.reset();
          }

          if (m_floorMaterial.vs.isValid()) {
              m_devFuncs->vkDestroyShaderModule(dev, m_floorMaterial.vs.data()->shaderModule, nullptr);
              m_floorMaterial.vs.reset();
          }
          if (m_floorMaterial.fs.isValid()) {
              m_devFuncs->vkDestroyShaderModule(dev, m_floorMaterial.fs.data()->shaderModule, nullptr);
              m_floorMaterial.fs.reset();
          }
      }

      void Renderer::ensureBuffers()
      {
          if (m_blockVertexBuf)
              return;

          VkDevice dev = m_window->device();
          const int concurrentFrameCount = m_window->concurrentFrameCount();

          // Vertex buffer for the block.
          VkBufferCreateInfo bufInfo;
          memset(&bufInfo, 0, sizeof(bufInfo));
          bufInfo.sType = VK_STRUCTURE_TYPE_BUFFER_CREATE_INFO;
          const int blockMeshByteCount = m_blockMesh.data()->vertexCount * 8 * sizeof(float);
          bufInfo.size = blockMeshByteCount;
          bufInfo.usage = VK_BUFFER_USAGE_VERTEX_BUFFER_BIT;
          VkResult err = m_devFuncs->vkCreateBuffer(dev, &bufInfo, nullptr, &m_blockVertexBuf);
          if (err != VK_SUCCESS)
              qFatal("Failed to create vertex buffer: %d", err);

          VkMemoryRequirements blockVertMemReq;
          m_devFuncs->vkGetBufferMemoryRequirements(dev, m_blockVertexBuf, &blockVertMemReq);

          // Vertex buffer for the logo.
          const int logoMeshByteCount = m_logoMesh.data()->vertexCount * 8 * sizeof(float);
          bufInfo.size = logoMeshByteCount;
          bufInfo.usage = VK_BUFFER_USAGE_VERTEX_BUFFER_BIT;
          err = m_devFuncs->vkCreateBuffer(dev, &bufInfo, nullptr, &m_logoVertexBuf);
          if (err != VK_SUCCESS)
              qFatal("Failed to create vertex buffer: %d", err);

          VkMemoryRequirements logoVertMemReq;
          m_devFuncs->vkGetBufferMemoryRequirements(dev, m_logoVertexBuf, &logoVertMemReq);

          // Vertex buffer for the floor.
          bufInfo.size = sizeof(quadVert);
          err = m_devFuncs->vkCreateBuffer(dev, &bufInfo, nullptr, &m_floorVertexBuf);
          if (err != VK_SUCCESS)
              qFatal("Failed to create vertex buffer: %d", err);

          VkMemoryRequirements floorVertMemReq;
          m_devFuncs->vkGetBufferMemoryRequirements(dev, m_floorVertexBuf, &floorVertMemReq);

          // Uniform buffer. Instead of using multiple descriptor sets, we take a
          // different approach: have a single dynamic uniform buffer and specify the
          // active-frame-specific offset at the time of binding the descriptor set.
          bufInfo.size = (m_itemMaterial.vertUniSize + m_itemMaterial.fragUniSize) * concurrentFrameCount;
          bufInfo.usage = VK_BUFFER_USAGE_UNIFORM_BUFFER_BIT;
          err = m_devFuncs->vkCreateBuffer(dev, &bufInfo, nullptr, &m_uniBuf);
          if (err != VK_SUCCESS)
              qFatal("Failed to create uniform buffer: %d", err);

          VkMemoryRequirements uniMemReq;
          m_devFuncs->vkGetBufferMemoryRequirements(dev, m_uniBuf, &uniMemReq);

          // Allocate memory for everything at once.
          VkDeviceSize logoVertStartOffset = aligned(0 + blockVertMemReq.size, logoVertMemReq.alignment);
          VkDeviceSize floorVertStartOffset = aligned(logoVertStartOffset + logoVertMemReq.size, floorVertMemReq.alignment);
          m_itemMaterial.uniMemStartOffset = aligned(floorVertStartOffset + floorVertMemReq.size, uniMemReq.alignment);
          VkMemoryAllocateInfo memAllocInfo = {
              VK_STRUCTURE_TYPE_MEMORY_ALLOCATE_INFO,
              nullptr,
              m_itemMaterial.uniMemStartOffset + uniMemReq.size,
              m_window->hostVisibleMemoryIndex()
          };
          err = m_devFuncs->vkAllocateMemory(dev, &memAllocInfo, nullptr, &m_bufMem);
          if (err != VK_SUCCESS)
              qFatal("Failed to allocate memory: %d", err);

          err = m_devFuncs->vkBindBufferMemory(dev, m_blockVertexBuf, m_bufMem, 0);
          if (err != VK_SUCCESS)
              qFatal("Failed to bind vertex buffer memory: %d", err);
          err = m_devFuncs->vkBindBufferMemory(dev, m_logoVertexBuf, m_bufMem, logoVertStartOffset);
          if (err != VK_SUCCESS)
              qFatal("Failed to bind vertex buffer memory: %d", err);
          err = m_devFuncs->vkBindBufferMemory(dev, m_floorVertexBuf, m_bufMem, floorVertStartOffset);
          if (err != VK_SUCCESS)
              qFatal("Failed to bind vertex buffer memory: %d", err);
          err = m_devFuncs->vkBindBufferMemory(dev, m_uniBuf, m_bufMem, m_itemMaterial.uniMemStartOffset);
          if (err != VK_SUCCESS)
              qFatal("Failed to bind uniform buffer memory: %d", err);

          // Copy vertex data.
          quint8 *p;
          err = m_devFuncs->vkMapMemory(dev, m_bufMem, 0, m_itemMaterial.uniMemStartOffset, 0, reinterpret_cast<void **>(&p));
          if (err != VK_SUCCESS)
              qFatal("Failed to map memory: %d", err);
          memcpy(p, m_blockMesh.data()->geom.constData(), blockMeshByteCount);
          memcpy(p + logoVertStartOffset, m_logoMesh.data()->geom.constData(), logoMeshByteCount);
          memcpy(p + floorVertStartOffset, quadVert, sizeof(quadVert));
          m_devFuncs->vkUnmapMemory(dev, m_bufMem);

          // Write descriptors for the uniform buffers in the vertex and fragment shaders.
          VkDescriptorBufferInfo vertUni = { m_uniBuf, 0, m_itemMaterial.vertUniSize };
          VkDescriptorBufferInfo fragUni = { m_uniBuf, m_itemMaterial.vertUniSize, m_itemMaterial.fragUniSize };

          VkWriteDescriptorSet descWrite[2];
          memset(descWrite, 0, sizeof(descWrite));
          descWrite[0].sType = VK_STRUCTURE_TYPE_WRITE_DESCRIPTOR_SET;
          descWrite[0].dstSet = m_itemMaterial.descSet;
          descWrite[0].dstBinding = 0;
          descWrite[0].descriptorCount = 1;
          descWrite[0].descriptorType = VK_DESCRIPTOR_TYPE_UNIFORM_BUFFER_DYNAMIC;
          descWrite[0].pBufferInfo = &vertUni;

          descWrite[1].sType = VK_STRUCTURE_TYPE_WRITE_DESCRIPTOR_SET;
          descWrite[1].dstSet = m_itemMaterial.descSet;
          descWrite[1].dstBinding = 1;
          descWrite[1].descriptorCount = 1;
          descWrite[1].descriptorType = VK_DESCRIPTOR_TYPE_UNIFORM_BUFFER_DYNAMIC;
          descWrite[1].pBufferInfo = &fragUni;

          m_devFuncs->vkUpdateDescriptorSets(dev, 2, descWrite, 0, nullptr);
      }

      void Renderer::ensureInstanceBuffer()
      {
          if (m_instCount == m_preparedInstCount && m_instBuf)
              return;

          Q_ASSERT(m_instCount <= MAX_INSTANCES);

          VkDevice dev = m_window->device();

          // allocate only once, for the maximum instance count
          if (!m_instBuf) {
              VkBufferCreateInfo bufInfo;
              memset(&bufInfo, 0, sizeof(bufInfo));
              bufInfo.sType = VK_STRUCTURE_TYPE_BUFFER_CREATE_INFO;
              bufInfo.size = MAX_INSTANCES * PER_INSTANCE_DATA_SIZE;
              bufInfo.usage = VK_BUFFER_USAGE_VERTEX_BUFFER_BIT;

              // Keep a copy of the data since we may lose all graphics resources on
              // unexpose, and reinitializing to new random positions afterwards
              // would not be nice.
              m_instData.resize(bufInfo.size);

              VkResult err = m_devFuncs->vkCreateBuffer(dev, &bufInfo, nullptr, &m_instBuf);
              if (err != VK_SUCCESS)
                  qFatal("Failed to create instance buffer: %d", err);

              VkMemoryRequirements memReq;
              m_devFuncs->vkGetBufferMemoryRequirements(dev, m_instBuf, &memReq);
              if (DBG)
                  qDebug("Allocating %u bytes for instance data", uint32_t(memReq.size));

              VkMemoryAllocateInfo memAllocInfo = {
                  VK_STRUCTURE_TYPE_MEMORY_ALLOCATE_INFO,
                  nullptr,
                  memReq.size,
                  m_window->hostVisibleMemoryIndex()
              };
              err = m_devFuncs->vkAllocateMemory(dev, &memAllocInfo, nullptr, &m_instBufMem);
              if (err != VK_SUCCESS)
                  qFatal("Failed to allocate memory: %d", err);

              err = m_devFuncs->vkBindBufferMemory(dev, m_instBuf, m_instBufMem, 0);
              if (err != VK_SUCCESS)
                  qFatal("Failed to bind instance buffer memory: %d", err);
          }

          if (m_instCount != m_preparedInstCount) {
              if (DBG)
                  qDebug("Preparing instances %d..%d", m_preparedInstCount, m_instCount - 1);
              char *p = m_instData.data();
              p += m_preparedInstCount * PER_INSTANCE_DATA_SIZE;
              auto gen = [](float a, float b) { return float((qrand() % int(b - a + 1)) + a); };
              for (int i = m_preparedInstCount; i < m_instCount; ++i) {
                  // Apply a random translation to each instance of the mesh.
                  float t[] = { gen(-5, 5), gen(-4, 6), gen(-30, 5) };
                  memcpy(p, t, 12);
                  // Apply a random adjustment to the diffuse color for each instance. (default is 0.7)
                  float d[] = { gen(-6, 3) / 10.0f, gen(-6, 3) / 10.0f, gen(-6, 3) / 10.0f };
                  memcpy(p + 12, d, 12);
                  p += PER_INSTANCE_DATA_SIZE;
              }
              m_preparedInstCount = m_instCount;
          }

          quint8 *p;
          VkResult err = m_devFuncs->vkMapMemory(dev, m_instBufMem, 0, m_instCount * PER_INSTANCE_DATA_SIZE, 0,
                                                 reinterpret_cast<void **>(&p));
          if (err != VK_SUCCESS)
              qFatal("Failed to map memory: %d", err);
          memcpy(p, m_instData.constData(), m_instData.size());
          m_devFuncs->vkUnmapMemory(dev, m_instBufMem);
      }

      void Renderer::getMatrices(QMatrix4x4 *vp, QMatrix4x4 *model, QMatrix3x3 *modelNormal, QVector3D *eyePos)
      {
          model->setToIdentity();
          if (m_useLogo)
              model->rotate(90, 1, 0, 0);
          model->rotate(m_rotation, 1, 1, 0);

          *modelNormal = model->normalMatrix();

          QMatrix4x4 view = m_cam.viewMatrix();
          *vp = m_proj * view;

          *eyePos = view.inverted().column(3).toVector3D();
      }

      void Renderer::writeFragUni(quint8 *p, const QVector3D &eyePos)
      {
          float ECCameraPosition[] = { eyePos.x(), eyePos.y(), eyePos.z() };
          memcpy(p, ECCameraPosition, 12);
          p += 16;

          // Material
          float ka[] = { 0.05f, 0.05f, 0.05f };
          memcpy(p, ka, 12);
          p += 16;

          float kd[] = { 0.7f, 0.7f, 0.7f };
          memcpy(p, kd, 12);
          p += 16;

          float ks[] = { 0.66f, 0.66f, 0.66f };
          memcpy(p, ks, 12);
          p += 16;

          // Light parameters
          float ECLightPosition[] = { m_lightPos.x(), m_lightPos.y(), m_lightPos.z() };
          memcpy(p, ECLightPosition, 12);
          p += 16;

          float att[] = { 1, 0, 0 };
          memcpy(p, att, 12);
          p += 16;

          float color[] = { 1.0f, 1.0f, 1.0f };
          memcpy(p, color, 12);
          p += 12; // next we have two floats which have an alignment of 4, hence 12 only

          float intensity = 0.8f;
          memcpy(p, &intensity, 4);
          p += 4;

          float specularExp = 150.0f;
          memcpy(p, &specularExp, 4);
          p += 4;
      }

      void Renderer::startNextFrame()
      {
          // For demonstration purposes offload the command buffer generation onto a
          // worker thread and continue with the frame submission only when it has
          // finished.
          Q_ASSERT(!m_framePending);
          m_framePending = true;
          QFuture<void> future = QtConcurrent::run(this, &Renderer::buildFrame);
          m_frameWatcher.setFuture(future);
      }

      void Renderer::buildFrame()
      {
          QMutexLocker locker(&m_guiMutex);

          ensureBuffers();
          ensureInstanceBuffer();
          m_pipelinesFuture.waitForFinished();

          VkCommandBuffer cb = m_window->currentCommandBuffer();
          const QSize sz = m_window->swapChainImageSize();

          VkClearColorValue clearColor = {{ 0.67f, 0.84f, 0.9f, 1.0f }};
          VkClearDepthStencilValue clearDS = { 1, 0 };
          VkClearValue clearValues[3];
          memset(clearValues, 0, sizeof(clearValues));
          clearValues[0].color = clearValues[2].color = clearColor;
          clearValues[1].depthStencil = clearDS;

          VkRenderPassBeginInfo rpBeginInfo;
          memset(&rpBeginInfo, 0, sizeof(rpBeginInfo));
          rpBeginInfo.sType = VK_STRUCTURE_TYPE_RENDER_PASS_BEGIN_INFO;
          rpBeginInfo.renderPass = m_window->defaultRenderPass();
          rpBeginInfo.framebuffer = m_window->currentFramebuffer();
          rpBeginInfo.renderArea.extent.width = sz.width();
          rpBeginInfo.renderArea.extent.height = sz.height();
          rpBeginInfo.clearValueCount = m_window->sampleCountFlagBits() > VK_SAMPLE_COUNT_1_BIT ? 3 : 2;
          rpBeginInfo.pClearValues = clearValues;
          VkCommandBuffer cmdBuf = m_window->currentCommandBuffer();
          m_devFuncs->vkCmdBeginRenderPass(cmdBuf, &rpBeginInfo, VK_SUBPASS_CONTENTS_INLINE);

          VkViewport viewport = {
              0, 0,
              float(sz.width()), float(sz.height()),
              0, 1
          };
          m_devFuncs->vkCmdSetViewport(cb, 0, 1, &viewport);

          VkRect2D scissor = {
              { 0, 0 },
              { uint32_t(sz.width()), uint32_t(sz.height()) }
          };
          m_devFuncs->vkCmdSetScissor(cb, 0, 1, &scissor);

          buildDrawCallsForFloor();
          buildDrawCallsForItems();

          m_devFuncs->vkCmdEndRenderPass(cmdBuf);
      }

      void Renderer::buildDrawCallsForItems()
      {
          VkDevice dev = m_window->device();
          VkCommandBuffer cb = m_window->currentCommandBuffer();

          m_devFuncs->vkCmdBindPipeline(cb, VK_PIPELINE_BIND_POINT_GRAPHICS, m_itemMaterial.pipeline);

          VkDeviceSize vbOffset = 0;
          m_devFuncs->vkCmdBindVertexBuffers(cb, 0, 1, m_useLogo ? &m_logoVertexBuf : &m_blockVertexBuf, &vbOffset);
          m_devFuncs->vkCmdBindVertexBuffers(cb, 1, 1, &m_instBuf, &vbOffset);

          // Now provide offsets so that the two dynamic buffers point to the
          // beginning of the vertex and fragment uniform data for the current frame.
          uint32_t frameUniOffset = m_window->currentFrame() * (m_itemMaterial.vertUniSize + m_itemMaterial.fragUniSize);
          uint32_t frameUniOffsets[] = { frameUniOffset, frameUniOffset };
          m_devFuncs->vkCmdBindDescriptorSets(cb, VK_PIPELINE_BIND_POINT_GRAPHICS, m_itemMaterial.pipelineLayout, 0, 1,
                                              &m_itemMaterial.descSet, 2, frameUniOffsets);

          if (m_animating)
              m_rotation += 0.5;

          if (m_animating || m_vpDirty) {
              if (m_vpDirty)
                  --m_vpDirty;
              QMatrix4x4 vp, model;
              QMatrix3x3 modelNormal;
              QVector3D eyePos;
              getMatrices(&vp, &model, &modelNormal, &eyePos);

              // Map the uniform data for the current frame, ignore the geometry data at
              // the beginning and the uniforms for other frames.
              quint8 *p;
              VkResult err = m_devFuncs->vkMapMemory(dev, m_bufMem,
                                                     m_itemMaterial.uniMemStartOffset + frameUniOffset,
                                                     m_itemMaterial.vertUniSize + m_itemMaterial.fragUniSize,
                                                     0, reinterpret_cast<void **>(&p));
              if (err != VK_SUCCESS)
                  qFatal("Failed to map memory: %d", err);

              // Vertex shader uniforms
              memcpy(p, vp.constData(), 64);
              memcpy(p + 64, model.constData(), 64);
              const float *mnp = modelNormal.constData();
              memcpy(p + 128, mnp, 12);
              memcpy(p + 128 + 16, mnp + 3, 12);
              memcpy(p + 128 + 32, mnp + 6, 12);

              // Fragment shader uniforms
              p += m_itemMaterial.vertUniSize;
              writeFragUni(p, eyePos);

              m_devFuncs->vkUnmapMemory(dev, m_bufMem);
          }

          m_devFuncs->vkCmdDraw(cb, (m_useLogo ? m_logoMesh.data() : m_blockMesh.data())->vertexCount, m_instCount, 0, 0);
      }

      void Renderer::buildDrawCallsForFloor()
      {
          VkCommandBuffer cb = m_window->currentCommandBuffer();

          m_devFuncs->vkCmdBindPipeline(cb, VK_PIPELINE_BIND_POINT_GRAPHICS, m_floorMaterial.pipeline);

          VkDeviceSize vbOffset = 0;
          m_devFuncs->vkCmdBindVertexBuffers(cb, 0, 1, &m_floorVertexBuf, &vbOffset);

          QMatrix4x4 mvp = m_proj * m_cam.viewMatrix() * m_floorModel;
          m_devFuncs->vkCmdPushConstants(cb, m_floorMaterial.pipelineLayout, VK_SHADER_STAGE_VERTEX_BIT, 0, 64, mvp.constData());
          float color[] = { 0.67f, 1.0f, 0.2f };
          m_devFuncs->vkCmdPushConstants(cb, m_floorMaterial.pipelineLayout, VK_SHADER_STAGE_FRAGMENT_BIT, 64, 12, color);

          m_devFuncs->vkCmdDraw(cb, 4, 1, 0, 0);
      }

      void Renderer::addNew()
      {
          QMutexLocker locker(&m_guiMutex);
          m_instCount = qMin(m_instCount + 16, MAX_INSTANCES);
      }

      void Renderer::yaw(float degrees)
      {
          QMutexLocker locker(&m_guiMutex);
          m_cam.yaw(degrees);
          markViewProjDirty();
      }

      void Renderer::pitch(float degrees)
      {
          QMutexLocker locker(&m_guiMutex);
          m_cam.pitch(degrees);
          markViewProjDirty();
      }

      void Renderer::walk(float amount)
      {
          QMutexLocker locker(&m_guiMutex);
          m_cam.walk(amount);
          markViewProjDirty();
      }

      void Renderer::strafe(float amount)
      {
          QMutexLocker locker(&m_guiMutex);
          m_cam.strafe(amount);
          markViewProjDirty();
      }

      void Renderer::setUseLogo(bool b)
      {
          QMutexLocker locker(&m_guiMutex);
          m_useLogo = b;
          if (!m_animating)
              m_window->requestUpdate();
      }