Qt 5.11 | Qt GUI | Hello Vulkan Window Example | hellovulkanwindow.cpp Example File

Qt 5.11.3 Reference Documentation

# hellovulkanwindow.cpp Example File

hellovulkanwindow/hellovulkanwindow.cpp

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      #include "hellovulkanwindow.h"
      #include <QVulkanFunctions>

      QVulkanWindowRenderer *VulkanWindow::createRenderer()
      {
          return new VulkanRenderer(this);
      }

      VulkanRenderer::VulkanRenderer(QVulkanWindow *w)
          : m_window(w)
      {
      }

      void VulkanRenderer::initResources()
      {
          qDebug("initResources");

          m_devFuncs = m_window->vulkanInstance()->deviceFunctions(m_window->device());
      }

      void VulkanRenderer::initSwapChainResources()
      {
          qDebug("initSwapChainResources");
      }

      void VulkanRenderer::releaseSwapChainResources()
      {
          qDebug("releaseSwapChainResources");
      }

      void VulkanRenderer::releaseResources()
      {
          qDebug("releaseResources");
      }

      void VulkanRenderer::startNextFrame()
      {
          m_green += 0.005f;
          if (m_green > 1.0f)
              m_green = 0.0f;

          VkClearColorValue clearColor = {{ 0.0f, m_green, 0.0f, 1.0f }};
          VkClearDepthStencilValue clearDS = { 1.0f, 0 };
          VkClearValue clearValues[2];
          memset(clearValues, 0, sizeof(clearValues));
          clearValues[0].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();
          const QSize sz = m_window->swapChainImageSize();
          rpBeginInfo.renderArea.extent.width = sz.width();
          rpBeginInfo.renderArea.extent.height = sz.height();
          rpBeginInfo.clearValueCount = 2;
          rpBeginInfo.pClearValues = clearValues;
          VkCommandBuffer cmdBuf = m_window->currentCommandBuffer();
          m_devFuncs->vkCmdBeginRenderPass(cmdBuf, &rpBeginInfo, VK_SUBPASS_CONTENTS_INLINE);

          // Do nothing else. We will just clear to green, changing the component on
          // every invocation. This also helps verifying the rate to which the thread
          // is throttled to. (The elapsed time between startNextFrame calls should
          // typically be around 16 ms. Note that rendering is 2 frames ahead of what
          // is displayed.)

          m_devFuncs->vkCmdEndRenderPass(cmdBuf);

          m_window->frameReady();
          m_window->requestUpdate(); // render continuously, throttled by the presentation rate
      }