hellovulkanwindow.cpp Example File

 /****************************************************************************
 **
 ** 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 "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
 }