qvulkanwindow.cpp

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// Copyright (C) 2017 The Qt Company Ltd.
// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR LGPL-3.0-only OR GPL-2.0-only OR GPL-3.0-only
 
#include "qvulkanwindow_p.h"
#include "qvulkanfunctions.h"
#include <QLoggingCategory>
#include <QTimer>
#include <QThread>
#include <QCoreApplication>
#include <qevent.h>
 
QT_BEGIN_NAMESPACE
 
Q_DECLARE_LOGGING_CATEGORY(lcGuiVk)
 
 
QVulkanWindow::QVulkanWindow(QWindow *parent)
    : QWindow(*(new QVulkanWindowPrivate), parent)
{
    setSurfaceType(QSurface::VulkanSurface);
}
 
QVulkanWindow::~QVulkanWindow()
{
}
 
QVulkanWindowPrivate::~QVulkanWindowPrivate()
{
    // graphics resource cleanup is already done at this point due to
    // QPlatformSurfaceEvent::SurfaceAboutToBeDestroyed
 
    delete renderer;
}
 
void QVulkanWindow::setFlags(Flags flags)
{
    Q_D(QVulkanWindow);
    if (d->status != QVulkanWindowPrivate::StatusUninitialized) {
        qWarning("QVulkanWindow: Attempted to set flags when already initialized");
        return;
    }
    d->flags = flags;
}
 
QVulkanWindow::Flags QVulkanWindow::flags() const
{
    Q_D(const QVulkanWindow);
    return d->flags;
}
 
QList<VkPhysicalDeviceProperties> QVulkanWindow::availablePhysicalDevices()
{
    Q_D(QVulkanWindow);
    if (!d->physDevs.isEmpty() && !d->physDevProps.isEmpty())
        return d->physDevProps;
 
    QVulkanInstance *inst = vulkanInstance();
    if (!inst) {
        qWarning("QVulkanWindow: Attempted to call availablePhysicalDevices() without a QVulkanInstance");
        return d->physDevProps;
    }
 
    QVulkanFunctions *f = inst->functions();
    uint32_t count = 1;
    VkResult err = f->vkEnumeratePhysicalDevices(inst->vkInstance(), &count, nullptr);
    if (err != VK_SUCCESS) {
        qWarning("QVulkanWindow: Failed to get physical device count: %d", err);
        return d->physDevProps;
    }
 
    qCDebug(lcGuiVk, "%d physical devices", count);
    if (!count)
        return d->physDevProps;
 
    QList<VkPhysicalDevice> devs(count);
    err = f->vkEnumeratePhysicalDevices(inst->vkInstance(), &count, devs.data());
    if (err != VK_SUCCESS) {
        qWarning("QVulkanWindow: Failed to enumerate physical devices: %d", err);
        return d->physDevProps;
    }
 
    d->physDevs = devs;
    d->physDevProps.resize(count);
    for (uint32_t i = 0; i < count; ++i) {
        VkPhysicalDeviceProperties *p = &d->physDevProps[i];
        f->vkGetPhysicalDeviceProperties(d->physDevs.at(i), p);
        qCDebug(lcGuiVk, "Physical device [%d]: name '%s' version %d.%d.%d", i, p->deviceName,
                VK_VERSION_MAJOR(p->driverVersion), VK_VERSION_MINOR(p->driverVersion),
                VK_VERSION_PATCH(p->driverVersion));
    }
 
    return d->physDevProps;
}
 
void QVulkanWindow::setPhysicalDeviceIndex(int idx)
{
    Q_D(QVulkanWindow);
    if (d->status != QVulkanWindowPrivate::StatusUninitialized) {
        qWarning("QVulkanWindow: Attempted to set physical device when already initialized");
        return;
    }
    const int count = availablePhysicalDevices().size();
    if (idx < 0 || idx >= count) {
        qWarning("QVulkanWindow: Invalid physical device index %d (total physical devices: %d)", idx, count);
        return;
    }
    d->physDevIndex = idx;
}
 
QVulkanInfoVector<QVulkanExtension> QVulkanWindow::supportedDeviceExtensions()
{
    Q_D(QVulkanWindow);
 
    availablePhysicalDevices();
 
    if (d->physDevs.isEmpty()) {
        qWarning("QVulkanWindow: No physical devices found");
        return QVulkanInfoVector<QVulkanExtension>();
    }
 
    VkPhysicalDevice physDev = d->physDevs.at(d->physDevIndex);
    if (d->supportedDevExtensions.contains(physDev))
        return d->supportedDevExtensions.value(physDev);
 
    QVulkanFunctions *f = vulkanInstance()->functions();
    uint32_t count = 0;
    VkResult err = f->vkEnumerateDeviceExtensionProperties(physDev, nullptr, &count, nullptr);
    if (err == VK_SUCCESS) {
        QList<VkExtensionProperties> extProps(count);
        err = f->vkEnumerateDeviceExtensionProperties(physDev, nullptr, &count, extProps.data());
        if (err == VK_SUCCESS) {
            QVulkanInfoVector<QVulkanExtension> exts;
            for (const VkExtensionProperties &prop : extProps) {
                QVulkanExtension ext;
                ext.name = prop.extensionName;
                ext.version = prop.specVersion;
                exts.append(ext);
            }
            d->supportedDevExtensions.insert(physDev, exts);
            qDebug(lcGuiVk) << "Supported device extensions:" << exts;
            return exts;
        }
    }
 
    qWarning("QVulkanWindow: Failed to query device extension count: %d", err);
    return QVulkanInfoVector<QVulkanExtension>();
}
 
void QVulkanWindow::setDeviceExtensions(const QByteArrayList &extensions)
{
    Q_D(QVulkanWindow);
    if (d->status != QVulkanWindowPrivate::StatusUninitialized) {
        qWarning("QVulkanWindow: Attempted to set device extensions when already initialized");
        return;
    }
    d->requestedDevExtensions = extensions;
}
 
void QVulkanWindow::setPreferredColorFormats(const QList<VkFormat> &formats)
{
    Q_D(QVulkanWindow);
    if (d->status != QVulkanWindowPrivate::StatusUninitialized) {
        qWarning("QVulkanWindow: Attempted to set preferred color format when already initialized");
        return;
    }
    d->requestedColorFormats = formats;
}
 
static struct {
    VkSampleCountFlagBits mask;
    int count;
} q_vk_sampleCounts[] = {
    // keep this sorted by 'count'
    { VK_SAMPLE_COUNT_1_BIT, 1 },
    { VK_SAMPLE_COUNT_2_BIT, 2 },
    { VK_SAMPLE_COUNT_4_BIT, 4 },
    { VK_SAMPLE_COUNT_8_BIT, 8 },
    { VK_SAMPLE_COUNT_16_BIT, 16 },
    { VK_SAMPLE_COUNT_32_BIT, 32 },
    { VK_SAMPLE_COUNT_64_BIT, 64 }
};
 
QList<int> QVulkanWindow::supportedSampleCounts()
{
    Q_D(const QVulkanWindow);
    QList<int> result;
 
    availablePhysicalDevices();
 
    if (d->physDevs.isEmpty()) {
        qWarning("QVulkanWindow: No physical devices found");
        return result;
    }
 
    const VkPhysicalDeviceLimits *limits = &d->physDevProps[d->physDevIndex].limits;
    VkSampleCountFlags color = limits->framebufferColorSampleCounts;
    VkSampleCountFlags depth = limits->framebufferDepthSampleCounts;
    VkSampleCountFlags stencil = limits->framebufferStencilSampleCounts;
 
    for (const auto &qvk_sampleCount : q_vk_sampleCounts) {
        if ((color & qvk_sampleCount.mask)
                && (depth & qvk_sampleCount.mask)
                && (stencil & qvk_sampleCount.mask))
        {
            result.append(qvk_sampleCount.count);
        }
    }
 
    return result;
}
 
void QVulkanWindow::setSampleCount(int sampleCount)
{
    Q_D(QVulkanWindow);
    if (d->status != QVulkanWindowPrivate::StatusUninitialized) {
        qWarning("QVulkanWindow: Attempted to set sample count when already initialized");
        return;
    }
 
    // Stay compatible with QSurfaceFormat and friends where samples == 0 means the same as 1.
    sampleCount = qBound(1, sampleCount, 64);
 
    if (!supportedSampleCounts().contains(sampleCount)) {
        qWarning("QVulkanWindow: Attempted to set unsupported sample count %d", sampleCount);
        return;
    }
 
    for (const auto &qvk_sampleCount : q_vk_sampleCounts) {
        if (qvk_sampleCount.count == sampleCount) {
            d->sampleCount = qvk_sampleCount.mask;
            return;
        }
    }
 
    Q_UNREACHABLE();
}
 
void QVulkanWindowPrivate::init()
{
    Q_Q(QVulkanWindow);
    Q_ASSERT(status == StatusUninitialized);
 
    qCDebug(lcGuiVk, "QVulkanWindow init");
 
    inst = q->vulkanInstance();
    if (!inst) {
        qWarning("QVulkanWindow: Attempted to initialize without a QVulkanInstance");
        // This is a simple user error, recheck on the next expose instead of
        // going into the permanent failure state.
        status = StatusFailRetry;
        return;
    }
 
    if (!renderer)
        renderer = q->createRenderer();
 
    surface = QVulkanInstance::surfaceForWindow(q);
    if (surface == VK_NULL_HANDLE) {
        qWarning("QVulkanWindow: Failed to retrieve Vulkan surface for window");
        status = StatusFailRetry;
        return;
    }
 
    q->availablePhysicalDevices();
 
    if (physDevs.isEmpty()) {
        qWarning("QVulkanWindow: No physical devices found");
        status = StatusFail;
        return;
    }
 
    if (physDevIndex < 0 || physDevIndex >= physDevs.size()) {
        qWarning("QVulkanWindow: Invalid physical device index; defaulting to 0");
        physDevIndex = 0;
    }
    qCDebug(lcGuiVk, "Using physical device [%d]", physDevIndex);
 
    // Give a last chance to do decisions based on the physical device and the surface.
    if (renderer)
        renderer->preInitResources();
 
    VkPhysicalDevice physDev = physDevs.at(physDevIndex);
    QVulkanFunctions *f = inst->functions();
 
    uint32_t queueCount = 0;
    f->vkGetPhysicalDeviceQueueFamilyProperties(physDev, &queueCount, nullptr);
    QList<VkQueueFamilyProperties> queueFamilyProps(queueCount);
    f->vkGetPhysicalDeviceQueueFamilyProperties(physDev, &queueCount, queueFamilyProps.data());
    gfxQueueFamilyIdx = uint32_t(-1);
    presQueueFamilyIdx = uint32_t(-1);
    for (int i = 0; i < queueFamilyProps.size(); ++i) {
        const bool supportsPresent = inst->supportsPresent(physDev, i, q);
        qCDebug(lcGuiVk, "queue family %d: flags=0x%x count=%d supportsPresent=%d", i,
                queueFamilyProps[i].queueFlags, queueFamilyProps[i].queueCount, supportsPresent);
        if (gfxQueueFamilyIdx == uint32_t(-1)
                && (queueFamilyProps[i].queueFlags & VK_QUEUE_GRAPHICS_BIT)
                && supportsPresent)
            gfxQueueFamilyIdx = i;
    }
    if (gfxQueueFamilyIdx != uint32_t(-1)) {
        presQueueFamilyIdx = gfxQueueFamilyIdx;
    } else {
        qCDebug(lcGuiVk, "No queue with graphics+present; trying separate queues");
        for (int i = 0; i < queueFamilyProps.size(); ++i) {
            if (gfxQueueFamilyIdx == uint32_t(-1) && (queueFamilyProps[i].queueFlags & VK_QUEUE_GRAPHICS_BIT))
                gfxQueueFamilyIdx = i;
            if (presQueueFamilyIdx == uint32_t(-1) && inst->supportsPresent(physDev, i, q))
                presQueueFamilyIdx = i;
        }
    }
    if (gfxQueueFamilyIdx == uint32_t(-1)) {
        qWarning("QVulkanWindow: No graphics queue family found");
        status = StatusFail;
        return;
    }
    if (presQueueFamilyIdx == uint32_t(-1)) {
        qWarning("QVulkanWindow: No present queue family found");
        status = StatusFail;
        return;
    }
#ifdef QT_DEBUG
    // allow testing the separate present queue case in debug builds on AMD cards
    if (qEnvironmentVariableIsSet("QT_VK_PRESENT_QUEUE_INDEX"))
        presQueueFamilyIdx = qEnvironmentVariableIntValue("QT_VK_PRESENT_QUEUE_INDEX");
#endif
    qCDebug(lcGuiVk, "Using queue families: graphics = %u present = %u", gfxQueueFamilyIdx, presQueueFamilyIdx);
 
    QList<VkDeviceQueueCreateInfo> queueInfo;
    queueInfo.reserve(2);
    const float prio[] = { 0 };
    VkDeviceQueueCreateInfo addQueueInfo;
    memset(&addQueueInfo, 0, sizeof(addQueueInfo));
    addQueueInfo.sType = VK_STRUCTURE_TYPE_DEVICE_QUEUE_CREATE_INFO;
    addQueueInfo.queueFamilyIndex = gfxQueueFamilyIdx;
    addQueueInfo.queueCount = 1;
    addQueueInfo.pQueuePriorities = prio;
    queueInfo.append(addQueueInfo);
    if (gfxQueueFamilyIdx != presQueueFamilyIdx) {
        addQueueInfo.queueFamilyIndex = presQueueFamilyIdx;
        addQueueInfo.queueCount = 1;
        addQueueInfo.pQueuePriorities = prio;
        queueInfo.append(addQueueInfo);
    }
    if (queueCreateInfoModifier) {
        queueCreateInfoModifier(queueFamilyProps.constData(), queueCount, queueInfo);
        bool foundGfxQueue = false;
        bool foundPresQueue = false;
        for (const VkDeviceQueueCreateInfo& createInfo : std::as_const(queueInfo)) {
            foundGfxQueue |= createInfo.queueFamilyIndex == gfxQueueFamilyIdx;
            foundPresQueue |= createInfo.queueFamilyIndex == presQueueFamilyIdx;
        }
        if (!foundGfxQueue) {
            qWarning("QVulkanWindow: Graphics queue missing after call to queueCreateInfoModifier");
            status = StatusFail;
            return;
        }
        if (!foundPresQueue) {
            qWarning("QVulkanWindow: Present queue missing after call to queueCreateInfoModifier");
            status = StatusFail;
            return;
        }
    }
 
    // Filter out unsupported extensions in order to keep symmetry
    // with how QVulkanInstance behaves. Add the swapchain extension.
    QList<const char *> devExts;
    QVulkanInfoVector<QVulkanExtension> supportedExtensions = q->supportedDeviceExtensions();
    QByteArrayList reqExts = requestedDevExtensions;
    reqExts.append("VK_KHR_swapchain");
 
    QByteArray envExts = qgetenv("QT_VULKAN_DEVICE_EXTENSIONS");
    if (!envExts.isEmpty()) {
        QByteArrayList envExtList =  envExts.split(';');
        for (auto ext : reqExts)
            envExtList.removeAll(ext);
        reqExts.append(envExtList);
    }
 
    for (const QByteArray &ext : reqExts) {
        if (supportedExtensions.contains(ext))
            devExts.append(ext.constData());
    }
    qCDebug(lcGuiVk) << "Enabling device extensions:" << devExts;
 
    VkDeviceCreateInfo devInfo;
    memset(&devInfo, 0, sizeof(devInfo));
    devInfo.sType = VK_STRUCTURE_TYPE_DEVICE_CREATE_INFO;
    devInfo.queueCreateInfoCount = queueInfo.size();
    devInfo.pQueueCreateInfos = queueInfo.constData();
    devInfo.enabledExtensionCount = devExts.size();
    devInfo.ppEnabledExtensionNames = devExts.constData();
 
    VkPhysicalDeviceFeatures features = {};
    VkPhysicalDeviceFeatures2 features2 = {};
    if (enabledFeatures2Modifier) {
        features2.sType = VK_STRUCTURE_TYPE_PHYSICAL_DEVICE_FEATURES_2;
        enabledFeatures2Modifier(features2);
        devInfo.pNext = &features2;
    } else if (enabledFeaturesModifier) {
        enabledFeaturesModifier(features);
        devInfo.pEnabledFeatures = &features;
    } else {
        // Enable all supported 1.0 core features, except ones that likely
        // involve a performance penalty.
        f->vkGetPhysicalDeviceFeatures(physDev, &features);
        features.robustBufferAccess = VK_FALSE;
        devInfo.pEnabledFeatures = &features;
    }
 
    // Device layers are not supported by QVulkanWindow since that's an already deprecated
    // API. However, have a workaround for systems with older API and layers (f.ex. L4T
    // 24.2 for the Jetson TX1 provides API 1.0.13 and crashes when the validation layer
    // is enabled for the instance but not the device).
    uint32_t apiVersion = physDevProps[physDevIndex].apiVersion;
    if (VK_VERSION_MAJOR(apiVersion) == 1
        && VK_VERSION_MINOR(apiVersion) == 0
        && VK_VERSION_PATCH(apiVersion) <= 13)
    {
        // Make standard validation work at least.
        const QByteArray stdValName = QByteArrayLiteral("VK_LAYER_KHRONOS_validation");
        const char *stdValNamePtr = stdValName.constData();
        if (inst->layers().contains(stdValName)) {
            uint32_t count = 0;
            VkResult err = f->vkEnumerateDeviceLayerProperties(physDev, &count, nullptr);
            if (err == VK_SUCCESS) {
                QList<VkLayerProperties> layerProps(count);
                err = f->vkEnumerateDeviceLayerProperties(physDev, &count, layerProps.data());
                if (err == VK_SUCCESS) {
                    for (const VkLayerProperties &prop : layerProps) {
                        if (!strncmp(prop.layerName, stdValNamePtr, stdValName.size())) {
                            devInfo.enabledLayerCount = 1;
                            devInfo.ppEnabledLayerNames = &stdValNamePtr;
                            break;
                        }
                    }
                }
            }
        }
    }
 
    VkResult err = f->vkCreateDevice(physDev, &devInfo, nullptr, &dev);
    if (err == VK_ERROR_DEVICE_LOST) {
        qWarning("QVulkanWindow: Physical device lost");
        if (renderer)
            renderer->physicalDeviceLost();
        // clear the caches so the list of physical devices is re-queried
        physDevs.clear();
        physDevProps.clear();
        status = StatusUninitialized;
        qCDebug(lcGuiVk, "Attempting to restart in 2 seconds");
        QTimer::singleShot(2000, q, [this]() { ensureStarted(); });
        return;
    }
    if (err != VK_SUCCESS) {
        qWarning("QVulkanWindow: Failed to create device: %d", err);
        status = StatusFail;
        return;
    }
 
    devFuncs = inst->deviceFunctions(dev);
    Q_ASSERT(devFuncs);
 
    devFuncs->vkGetDeviceQueue(dev, gfxQueueFamilyIdx, 0, &gfxQueue);
    if (gfxQueueFamilyIdx == presQueueFamilyIdx)
        presQueue = gfxQueue;
    else
        devFuncs->vkGetDeviceQueue(dev, presQueueFamilyIdx, 0, &presQueue);
 
    VkCommandPoolCreateInfo poolInfo;
    memset(&poolInfo, 0, sizeof(poolInfo));
    poolInfo.sType = VK_STRUCTURE_TYPE_COMMAND_POOL_CREATE_INFO;
    poolInfo.queueFamilyIndex = gfxQueueFamilyIdx;
    err = devFuncs->vkCreateCommandPool(dev, &poolInfo, nullptr, &cmdPool);
    if (err != VK_SUCCESS) {
        qWarning("QVulkanWindow: Failed to create command pool: %d", err);
        status = StatusFail;
        return;
    }
    if (gfxQueueFamilyIdx != presQueueFamilyIdx) {
        poolInfo.queueFamilyIndex = presQueueFamilyIdx;
        err = devFuncs->vkCreateCommandPool(dev, &poolInfo, nullptr, &presCmdPool);
        if (err != VK_SUCCESS) {
            qWarning("QVulkanWindow: Failed to create command pool for present queue: %d", err);
            status = StatusFail;
            return;
        }
    }
 
    hostVisibleMemIndex = 0;
    VkPhysicalDeviceMemoryProperties physDevMemProps;
    bool hostVisibleMemIndexSet = false;
    f->vkGetPhysicalDeviceMemoryProperties(physDev, &physDevMemProps);
    for (uint32_t i = 0; i < physDevMemProps.memoryTypeCount; ++i) {
        const VkMemoryType *memType = physDevMemProps.memoryTypes;
        qCDebug(lcGuiVk, "memtype %d: flags=0x%x", i, memType[i].propertyFlags);
        // Find a host visible, host coherent memtype. If there is one that is
        // cached as well (in addition to being coherent), prefer that.
        const int hostVisibleAndCoherent = VK_MEMORY_PROPERTY_HOST_VISIBLE_BIT | VK_MEMORY_PROPERTY_HOST_COHERENT_BIT;
        if ((memType[i].propertyFlags & hostVisibleAndCoherent) == hostVisibleAndCoherent) {
            if (!hostVisibleMemIndexSet
                    || (memType[i].propertyFlags & VK_MEMORY_PROPERTY_HOST_CACHED_BIT)) {
                hostVisibleMemIndexSet = true;
                hostVisibleMemIndex = i;
            }
        }
    }
    qCDebug(lcGuiVk, "Picked memtype %d for host visible memory", hostVisibleMemIndex);
    deviceLocalMemIndex = 0;
    for (uint32_t i = 0; i < physDevMemProps.memoryTypeCount; ++i) {
        const VkMemoryType *memType = physDevMemProps.memoryTypes;
        // Just pick the first device local memtype.
        if (memType[i].propertyFlags & VK_MEMORY_PROPERTY_DEVICE_LOCAL_BIT) {
            deviceLocalMemIndex = i;
            break;
        }
    }
    qCDebug(lcGuiVk, "Picked memtype %d for device local memory", deviceLocalMemIndex);
 
    if (!vkGetPhysicalDeviceSurfaceCapabilitiesKHR || !vkGetPhysicalDeviceSurfaceFormatsKHR) {
        vkGetPhysicalDeviceSurfaceCapabilitiesKHR = reinterpret_cast<PFN_vkGetPhysicalDeviceSurfaceCapabilitiesKHR>(
            inst->getInstanceProcAddr("vkGetPhysicalDeviceSurfaceCapabilitiesKHR"));
        vkGetPhysicalDeviceSurfaceFormatsKHR = reinterpret_cast<PFN_vkGetPhysicalDeviceSurfaceFormatsKHR>(
            inst->getInstanceProcAddr("vkGetPhysicalDeviceSurfaceFormatsKHR"));
        if (!vkGetPhysicalDeviceSurfaceCapabilitiesKHR || !vkGetPhysicalDeviceSurfaceFormatsKHR) {
            qWarning("QVulkanWindow: Physical device surface queries not available");
            status = StatusFail;
            return;
        }
    }
 
    // Figure out the color format here. Must not wait until recreateSwapChain()
    // because the renderpass should be available already from initResources (so
    // that apps do not have to defer pipeline creation to
    // initSwapChainResources), but the renderpass needs the final color format.
 
    uint32_t formatCount = 0;
    vkGetPhysicalDeviceSurfaceFormatsKHR(physDev, surface, &formatCount, nullptr);
    QList<VkSurfaceFormatKHR> formats(formatCount);
    if (formatCount)
        vkGetPhysicalDeviceSurfaceFormatsKHR(physDev, surface, &formatCount, formats.data());
 
    colorFormat = VK_FORMAT_B8G8R8A8_UNORM; // our documented default if all else fails
    colorSpace = VkColorSpaceKHR(0); // this is in fact VK_COLOR_SPACE_SRGB_NONLINEAR_KHR
 
    // Pick the preferred format, if there is one.
    if (!formats.isEmpty() && formats[0].format != VK_FORMAT_UNDEFINED) {
        colorFormat = formats[0].format;
        colorSpace = formats[0].colorSpace;
    }
 
    // Try to honor the user request.
    if (!formats.isEmpty() && !requestedColorFormats.isEmpty()) {
        for (VkFormat reqFmt : std::as_const(requestedColorFormats)) {
            auto r = std::find_if(formats.cbegin(), formats.cend(),
                                  [reqFmt](const VkSurfaceFormatKHR &sfmt) { return sfmt.format == reqFmt; });
            if (r != formats.cend()) {
                colorFormat = r->format;
                colorSpace = r->colorSpace;
                break;
            }
        }
    }
 
    const VkFormat dsFormatCandidates[] = {
        VK_FORMAT_D24_UNORM_S8_UINT,
        VK_FORMAT_D32_SFLOAT_S8_UINT,
        VK_FORMAT_D16_UNORM_S8_UINT
    };
    const int dsFormatCandidateCount = sizeof(dsFormatCandidates) / sizeof(VkFormat);
    int dsFormatIdx = 0;
    while (dsFormatIdx < dsFormatCandidateCount) {
        dsFormat = dsFormatCandidates[dsFormatIdx];
        VkFormatProperties fmtProp;
        f->vkGetPhysicalDeviceFormatProperties(physDev, dsFormat, &fmtProp);
        if (fmtProp.optimalTilingFeatures & VK_FORMAT_FEATURE_DEPTH_STENCIL_ATTACHMENT_BIT)
            break;
        ++dsFormatIdx;
    }
    if (dsFormatIdx == dsFormatCandidateCount)
        qWarning("QVulkanWindow: Failed to find an optimal depth-stencil format");
 
    qCDebug(lcGuiVk, "Color format: %d Depth-stencil format: %d", colorFormat, dsFormat);
 
    if (!createDefaultRenderPass())
        return;
 
    if (renderer)
        renderer->initResources();
 
    status = StatusDeviceReady;
}
 
void QVulkanWindowPrivate::reset()
{
    if (!dev) // do not rely on 'status', a half done init must be cleaned properly too
        return;
 
    qCDebug(lcGuiVk, "QVulkanWindow reset");
 
    devFuncs->vkDeviceWaitIdle(dev);
 
    if (renderer) {
        renderer->releaseResources();
        devFuncs->vkDeviceWaitIdle(dev);
    }
 
    if (defaultRenderPass) {
        devFuncs->vkDestroyRenderPass(dev, defaultRenderPass, nullptr);
        defaultRenderPass = VK_NULL_HANDLE;
    }
 
    if (cmdPool) {
        devFuncs->vkDestroyCommandPool(dev, cmdPool, nullptr);
        cmdPool = VK_NULL_HANDLE;
    }
 
    if (presCmdPool) {
        devFuncs->vkDestroyCommandPool(dev, presCmdPool, nullptr);
        presCmdPool = VK_NULL_HANDLE;
    }
 
    if (frameGrabImage) {
        devFuncs->vkDestroyImage(dev, frameGrabImage, nullptr);
        frameGrabImage = VK_NULL_HANDLE;
    }
 
    if (frameGrabImageMem) {
        devFuncs->vkFreeMemory(dev, frameGrabImageMem, nullptr);
        frameGrabImageMem = VK_NULL_HANDLE;
    }
 
    if (dev) {
        devFuncs->vkDestroyDevice(dev, nullptr);
        inst->resetDeviceFunctions(dev);
        dev = VK_NULL_HANDLE;
        vkCreateSwapchainKHR = nullptr; // re-resolve swapchain funcs later on since some come via the device
    }
 
    surface = VK_NULL_HANDLE;
 
    status = StatusUninitialized;
}
 
bool QVulkanWindowPrivate::createDefaultRenderPass()
{
    VkAttachmentDescription attDesc[3];
    memset(attDesc, 0, sizeof(attDesc));
 
    const bool msaa = sampleCount > VK_SAMPLE_COUNT_1_BIT;
 
    // This is either the non-msaa render target or the resolve target.
    attDesc[0].format = colorFormat;
    attDesc[0].samples = VK_SAMPLE_COUNT_1_BIT;
    attDesc[0].loadOp = VK_ATTACHMENT_LOAD_OP_CLEAR; // ignored when msaa
    attDesc[0].storeOp = VK_ATTACHMENT_STORE_OP_STORE;
    attDesc[0].stencilLoadOp = VK_ATTACHMENT_LOAD_OP_DONT_CARE;
    attDesc[0].stencilStoreOp = VK_ATTACHMENT_STORE_OP_DONT_CARE;
    attDesc[0].initialLayout = VK_IMAGE_LAYOUT_UNDEFINED;
    attDesc[0].finalLayout = VK_IMAGE_LAYOUT_PRESENT_SRC_KHR;
 
    attDesc[1].format = dsFormat;
    attDesc[1].samples = sampleCount;
    attDesc[1].loadOp = VK_ATTACHMENT_LOAD_OP_CLEAR;
    attDesc[1].storeOp = VK_ATTACHMENT_STORE_OP_DONT_CARE;
    attDesc[1].stencilLoadOp = VK_ATTACHMENT_LOAD_OP_CLEAR;
    attDesc[1].stencilStoreOp = VK_ATTACHMENT_STORE_OP_DONT_CARE;
    attDesc[1].initialLayout = VK_IMAGE_LAYOUT_UNDEFINED;
    attDesc[1].finalLayout = VK_IMAGE_LAYOUT_DEPTH_STENCIL_ATTACHMENT_OPTIMAL;
 
    if (msaa) {
        // msaa render target
        attDesc[2].format = colorFormat;
        attDesc[2].samples = sampleCount;
        attDesc[2].loadOp = VK_ATTACHMENT_LOAD_OP_CLEAR;
        attDesc[2].storeOp = VK_ATTACHMENT_STORE_OP_STORE;
        attDesc[2].stencilLoadOp = VK_ATTACHMENT_LOAD_OP_DONT_CARE;
        attDesc[2].stencilStoreOp = VK_ATTACHMENT_STORE_OP_DONT_CARE;
        attDesc[2].initialLayout = VK_IMAGE_LAYOUT_UNDEFINED;
        attDesc[2].finalLayout = VK_IMAGE_LAYOUT_COLOR_ATTACHMENT_OPTIMAL;
    }
 
    VkAttachmentReference colorRef = { 0, VK_IMAGE_LAYOUT_COLOR_ATTACHMENT_OPTIMAL };
    VkAttachmentReference resolveRef = { 0, VK_IMAGE_LAYOUT_COLOR_ATTACHMENT_OPTIMAL };
    VkAttachmentReference dsRef = { 1, VK_IMAGE_LAYOUT_DEPTH_STENCIL_ATTACHMENT_OPTIMAL };
 
    VkSubpassDescription subPassDesc;
    memset(&subPassDesc, 0, sizeof(subPassDesc));
    subPassDesc.pipelineBindPoint = VK_PIPELINE_BIND_POINT_GRAPHICS;
    subPassDesc.colorAttachmentCount = 1;
    subPassDesc.pColorAttachments = &colorRef;
    subPassDesc.pDepthStencilAttachment = &dsRef;
 
    VkRenderPassCreateInfo rpInfo;
    memset(&rpInfo, 0, sizeof(rpInfo));
    rpInfo.sType = VK_STRUCTURE_TYPE_RENDER_PASS_CREATE_INFO;
    rpInfo.attachmentCount = 2;
    rpInfo.pAttachments = attDesc;
    rpInfo.subpassCount = 1;
    rpInfo.pSubpasses = &subPassDesc;
 
    if (msaa) {
        colorRef.attachment = 2;
        subPassDesc.pResolveAttachments = &resolveRef;
        rpInfo.attachmentCount = 3;
    }
 
    VkResult err = devFuncs->vkCreateRenderPass(dev, &rpInfo, nullptr, &defaultRenderPass);
    if (err != VK_SUCCESS) {
        qWarning("QVulkanWindow: Failed to create renderpass: %d", err);
        return false;
    }
 
    return true;
}
 
void QVulkanWindowPrivate::recreateSwapChain()
{
    Q_Q(QVulkanWindow);
    Q_ASSERT(status >= StatusDeviceReady);
 
    swapChainImageSize = q->size() * q->devicePixelRatio(); // note: may change below due to surfaceCaps
 
    if (swapChainImageSize.isEmpty()) // handle null window size gracefully
        return;
 
    QVulkanInstance *inst = q->vulkanInstance();
    QVulkanFunctions *f = inst->functions();
    devFuncs->vkDeviceWaitIdle(dev);
 
    if (!vkCreateSwapchainKHR) {
        vkCreateSwapchainKHR = reinterpret_cast<PFN_vkCreateSwapchainKHR>(f->vkGetDeviceProcAddr(dev, "vkCreateSwapchainKHR"));
        vkDestroySwapchainKHR = reinterpret_cast<PFN_vkDestroySwapchainKHR>(f->vkGetDeviceProcAddr(dev, "vkDestroySwapchainKHR"));
        vkGetSwapchainImagesKHR = reinterpret_cast<PFN_vkGetSwapchainImagesKHR>(f->vkGetDeviceProcAddr(dev, "vkGetSwapchainImagesKHR"));
        vkAcquireNextImageKHR = reinterpret_cast<PFN_vkAcquireNextImageKHR>(f->vkGetDeviceProcAddr(dev, "vkAcquireNextImageKHR"));
        vkQueuePresentKHR = reinterpret_cast<PFN_vkQueuePresentKHR>(f->vkGetDeviceProcAddr(dev, "vkQueuePresentKHR"));
    }
 
    VkPhysicalDevice physDev = physDevs.at(physDevIndex);
    VkSurfaceCapabilitiesKHR surfaceCaps;
    vkGetPhysicalDeviceSurfaceCapabilitiesKHR(physDev, surface, &surfaceCaps);
    uint32_t reqBufferCount;
    if (surfaceCaps.maxImageCount == 0)
        reqBufferCount = qMax<uint32_t>(2, surfaceCaps.minImageCount);
    else
        reqBufferCount = qMax(qMin<uint32_t>(surfaceCaps.maxImageCount, 3), surfaceCaps.minImageCount);
 
    VkExtent2D bufferSize = surfaceCaps.currentExtent;
    if (bufferSize.width == uint32_t(-1)) {
        Q_ASSERT(bufferSize.height == uint32_t(-1));
        bufferSize.width = swapChainImageSize.width();
        bufferSize.height = swapChainImageSize.height();
    } else {
        swapChainImageSize = QSize(bufferSize.width, bufferSize.height);
    }
 
    VkSurfaceTransformFlagBitsKHR preTransform =
        (surfaceCaps.supportedTransforms & VK_SURFACE_TRANSFORM_IDENTITY_BIT_KHR)
        ? VK_SURFACE_TRANSFORM_IDENTITY_BIT_KHR
        : surfaceCaps.currentTransform;
 
    VkCompositeAlphaFlagBitsKHR compositeAlpha =
        (surfaceCaps.supportedCompositeAlpha & VK_COMPOSITE_ALPHA_INHERIT_BIT_KHR)
        ? VK_COMPOSITE_ALPHA_INHERIT_BIT_KHR
        : VK_COMPOSITE_ALPHA_OPAQUE_BIT_KHR;
 
    if (q->requestedFormat().hasAlpha()) {
        if (surfaceCaps.supportedCompositeAlpha & VK_COMPOSITE_ALPHA_PRE_MULTIPLIED_BIT_KHR)
            compositeAlpha = VK_COMPOSITE_ALPHA_PRE_MULTIPLIED_BIT_KHR;
        else if (surfaceCaps.supportedCompositeAlpha & VK_COMPOSITE_ALPHA_POST_MULTIPLIED_BIT_KHR)
            compositeAlpha = VK_COMPOSITE_ALPHA_POST_MULTIPLIED_BIT_KHR;
    }
 
    VkImageUsageFlags usage = VK_IMAGE_USAGE_COLOR_ATTACHMENT_BIT;
    swapChainSupportsReadBack = (surfaceCaps.supportedUsageFlags & VK_IMAGE_USAGE_TRANSFER_SRC_BIT);
    if (swapChainSupportsReadBack)
        usage |= VK_IMAGE_USAGE_TRANSFER_SRC_BIT;
 
    VkSwapchainKHR oldSwapChain = swapChain;
    VkSwapchainCreateInfoKHR swapChainInfo;
    memset(&swapChainInfo, 0, sizeof(swapChainInfo));
    swapChainInfo.sType = VK_STRUCTURE_TYPE_SWAPCHAIN_CREATE_INFO_KHR;
    swapChainInfo.surface = surface;
    swapChainInfo.minImageCount = reqBufferCount;
    swapChainInfo.imageFormat = colorFormat;
    swapChainInfo.imageColorSpace = colorSpace;
    swapChainInfo.imageExtent = bufferSize;
    swapChainInfo.imageArrayLayers = 1;
    swapChainInfo.imageUsage = usage;
    swapChainInfo.imageSharingMode = VK_SHARING_MODE_EXCLUSIVE;
    swapChainInfo.preTransform = preTransform;
    swapChainInfo.compositeAlpha = compositeAlpha;
    swapChainInfo.presentMode = presentMode;
    swapChainInfo.clipped = true;
    swapChainInfo.oldSwapchain = oldSwapChain;
 
    qCDebug(lcGuiVk, "Creating new swap chain of %d buffers, size %dx%d", reqBufferCount, bufferSize.width, bufferSize.height);
 
    VkSwapchainKHR newSwapChain;
    VkResult err = vkCreateSwapchainKHR(dev, &swapChainInfo, nullptr, &newSwapChain);
    if (err != VK_SUCCESS) {
        qWarning("QVulkanWindow: Failed to create swap chain: %d", err);
        return;
    }
 
    if (oldSwapChain)
        releaseSwapChain();
 
    swapChain = newSwapChain;
 
    uint32_t actualSwapChainBufferCount = 0;
    err = vkGetSwapchainImagesKHR(dev, swapChain, &actualSwapChainBufferCount, nullptr);
    if (err != VK_SUCCESS || actualSwapChainBufferCount < 2) {
        qWarning("QVulkanWindow: Failed to get swapchain images: %d (count=%d)", err, actualSwapChainBufferCount);
        return;
    }
 
    qCDebug(lcGuiVk, "Actual swap chain buffer count: %d (supportsReadback=%d)",
            actualSwapChainBufferCount, swapChainSupportsReadBack);
    if (actualSwapChainBufferCount > MAX_SWAPCHAIN_BUFFER_COUNT) {
        qWarning("QVulkanWindow: Too many swapchain buffers (%d)", actualSwapChainBufferCount);
        return;
    }
    swapChainBufferCount = actualSwapChainBufferCount;
 
    VkImage swapChainImages[MAX_SWAPCHAIN_BUFFER_COUNT];
    err = vkGetSwapchainImagesKHR(dev, swapChain, &actualSwapChainBufferCount, swapChainImages);
    if (err != VK_SUCCESS) {
        qWarning("QVulkanWindow: Failed to get swapchain images: %d", err);
        return;
    }
 
    if (!createTransientImage(dsFormat,
                              VK_IMAGE_USAGE_DEPTH_STENCIL_ATTACHMENT_BIT,
                              VK_IMAGE_ASPECT_DEPTH_BIT | VK_IMAGE_ASPECT_STENCIL_BIT,
                              &dsImage,
                              &dsMem,
                              &dsView,
                              1))
    {
        return;
    }
 
    const bool msaa = sampleCount > VK_SAMPLE_COUNT_1_BIT;
    VkImage msaaImages[MAX_SWAPCHAIN_BUFFER_COUNT];
    VkImageView msaaViews[MAX_SWAPCHAIN_BUFFER_COUNT];
 
    if (msaa) {
        if (!createTransientImage(colorFormat,
                                  VK_IMAGE_USAGE_COLOR_ATTACHMENT_BIT,
                                  VK_IMAGE_ASPECT_COLOR_BIT,
                                  msaaImages,
                                  &msaaImageMem,
                                  msaaViews,
                                  swapChainBufferCount))
        {
            return;
        }
    }
 
    VkFenceCreateInfo fenceInfo = { VK_STRUCTURE_TYPE_FENCE_CREATE_INFO, nullptr, VK_FENCE_CREATE_SIGNALED_BIT };
 
    for (int i = 0; i < swapChainBufferCount; ++i) {
        ImageResources &image(imageRes[i]);
        image.image = swapChainImages[i];
 
        if (msaa) {
            image.msaaImage = msaaImages[i];
            image.msaaImageView = msaaViews[i];
        }
 
        VkImageViewCreateInfo imgViewInfo;
        memset(&imgViewInfo, 0, sizeof(imgViewInfo));
        imgViewInfo.sType = VK_STRUCTURE_TYPE_IMAGE_VIEW_CREATE_INFO;
        imgViewInfo.image = swapChainImages[i];
        imgViewInfo.viewType = VK_IMAGE_VIEW_TYPE_2D;
        imgViewInfo.format = colorFormat;
        imgViewInfo.components.r = VK_COMPONENT_SWIZZLE_R;
        imgViewInfo.components.g = VK_COMPONENT_SWIZZLE_G;
        imgViewInfo.components.b = VK_COMPONENT_SWIZZLE_B;
        imgViewInfo.components.a = VK_COMPONENT_SWIZZLE_A;
        imgViewInfo.subresourceRange.aspectMask = VK_IMAGE_ASPECT_COLOR_BIT;
        imgViewInfo.subresourceRange.levelCount = imgViewInfo.subresourceRange.layerCount = 1;
        err = devFuncs->vkCreateImageView(dev, &imgViewInfo, nullptr, &image.imageView);
        if (err != VK_SUCCESS) {
            qWarning("QVulkanWindow: Failed to create swapchain image view %d: %d", i, err);
            return;
        }
 
        err = devFuncs->vkCreateFence(dev, &fenceInfo, nullptr, &image.cmdFence);
        if (err != VK_SUCCESS) {
            qWarning("QVulkanWindow: Failed to create command buffer fence: %d", err);
            return;
        }
        image.cmdFenceWaitable = true; // fence was created in signaled state
 
        VkImageView views[3] = { image.imageView,
                                 dsView,
                                 msaa ? image.msaaImageView : VK_NULL_HANDLE };
        VkFramebufferCreateInfo fbInfo;
        memset(&fbInfo, 0, sizeof(fbInfo));
        fbInfo.sType = VK_STRUCTURE_TYPE_FRAMEBUFFER_CREATE_INFO;
        fbInfo.renderPass = defaultRenderPass;
        fbInfo.attachmentCount = msaa ? 3 : 2;
        fbInfo.pAttachments = views;
        fbInfo.width = swapChainImageSize.width();
        fbInfo.height = swapChainImageSize.height();
        fbInfo.layers = 1;
        VkResult err = devFuncs->vkCreateFramebuffer(dev, &fbInfo, nullptr, &image.fb);
        if (err != VK_SUCCESS) {
            qWarning("QVulkanWindow: Failed to create framebuffer: %d", err);
            return;
        }
 
        if (gfxQueueFamilyIdx != presQueueFamilyIdx) {
            // pre-build the static image-acquire-on-present-queue command buffer
            VkCommandBufferAllocateInfo cmdBufInfo = {
                VK_STRUCTURE_TYPE_COMMAND_BUFFER_ALLOCATE_INFO, nullptr, presCmdPool, VK_COMMAND_BUFFER_LEVEL_PRIMARY, 1 };
            err = devFuncs->vkAllocateCommandBuffers(dev, &cmdBufInfo, &image.presTransCmdBuf);
            if (err != VK_SUCCESS) {
                qWarning("QVulkanWindow: Failed to allocate acquire-on-present-queue command buffer: %d", err);
                return;
            }
            VkCommandBufferBeginInfo cmdBufBeginInfo = {
                VK_STRUCTURE_TYPE_COMMAND_BUFFER_BEGIN_INFO, nullptr,
                VK_COMMAND_BUFFER_USAGE_SIMULTANEOUS_USE_BIT, nullptr };
            err = devFuncs->vkBeginCommandBuffer(image.presTransCmdBuf, &cmdBufBeginInfo);
            if (err != VK_SUCCESS) {
                qWarning("QVulkanWindow: Failed to begin acquire-on-present-queue command buffer: %d", err);
                return;
            }
            VkImageMemoryBarrier presTrans;
            memset(&presTrans, 0, sizeof(presTrans));
            presTrans.sType = VK_STRUCTURE_TYPE_IMAGE_MEMORY_BARRIER;
            presTrans.dstAccessMask = VK_ACCESS_COLOR_ATTACHMENT_WRITE_BIT;
            presTrans.oldLayout = presTrans.newLayout = VK_IMAGE_LAYOUT_PRESENT_SRC_KHR;
            presTrans.srcQueueFamilyIndex = gfxQueueFamilyIdx;
            presTrans.dstQueueFamilyIndex = presQueueFamilyIdx;
            presTrans.image = image.image;
            presTrans.subresourceRange.aspectMask = VK_IMAGE_ASPECT_COLOR_BIT;
            presTrans.subresourceRange.levelCount = presTrans.subresourceRange.layerCount = 1;
            devFuncs->vkCmdPipelineBarrier(image.presTransCmdBuf,
                                           VK_PIPELINE_STAGE_TOP_OF_PIPE_BIT,
                                           VK_PIPELINE_STAGE_TOP_OF_PIPE_BIT,
                                           0, 0, nullptr, 0, nullptr,
                                           1, &presTrans);
            err = devFuncs->vkEndCommandBuffer(image.presTransCmdBuf);
            if (err != VK_SUCCESS) {
                qWarning("QVulkanWindow: Failed to end acquire-on-present-queue command buffer: %d", err);
                return;
            }
        }
    }
 
    currentImage = 0;
 
    VkSemaphoreCreateInfo semInfo = { VK_STRUCTURE_TYPE_SEMAPHORE_CREATE_INFO, nullptr, 0 };
    for (int i = 0; i < frameLag; ++i) {
        FrameResources &frame(frameRes[i]);
 
        frame.imageAcquired = false;
        frame.imageSemWaitable = false;
 
        devFuncs->vkCreateFence(dev, &fenceInfo, nullptr, &frame.fence);
        frame.fenceWaitable = true; // fence was created in signaled state
 
        devFuncs->vkCreateSemaphore(dev, &semInfo, nullptr, &frame.imageSem);
        devFuncs->vkCreateSemaphore(dev, &semInfo, nullptr, &frame.drawSem);
        if (gfxQueueFamilyIdx != presQueueFamilyIdx)
            devFuncs->vkCreateSemaphore(dev, &semInfo, nullptr, &frame.presTransSem);
    }
 
    currentFrame = 0;
 
    if (renderer)
        renderer->initSwapChainResources();
 
    status = StatusReady;
}
 
uint32_t QVulkanWindowPrivate::chooseTransientImageMemType(VkImage img, uint32_t startIndex)
{
    VkPhysicalDeviceMemoryProperties physDevMemProps;
    inst->functions()->vkGetPhysicalDeviceMemoryProperties(physDevs[physDevIndex], &physDevMemProps);
 
    VkMemoryRequirements memReq;
    devFuncs->vkGetImageMemoryRequirements(dev, img, &memReq);
    uint32_t memTypeIndex = uint32_t(-1);
 
    if (memReq.memoryTypeBits) {
        // Find a device local + lazily allocated, or at least device local memtype.
        const VkMemoryType *memType = physDevMemProps.memoryTypes;
        bool foundDevLocal = false;
        for (uint32_t i = startIndex; i < physDevMemProps.memoryTypeCount; ++i) {
            if (memReq.memoryTypeBits & (1 << i)) {
                if (memType[i].propertyFlags & VK_MEMORY_PROPERTY_DEVICE_LOCAL_BIT) {
                    if (!foundDevLocal) {
                        foundDevLocal = true;
                        memTypeIndex = i;
                    }
                    if (memType[i].propertyFlags & VK_MEMORY_PROPERTY_LAZILY_ALLOCATED_BIT) {
                        memTypeIndex = i;
                        break;
                    }
                }
            }
        }
    }
 
    return memTypeIndex;
}
 
static inline VkDeviceSize aligned(VkDeviceSize v, VkDeviceSize byteAlign)
{
    return (v + byteAlign - 1) & ~(byteAlign - 1);
}
 
bool QVulkanWindowPrivate::createTransientImage(VkFormat format,
                                                VkImageUsageFlags usage,
                                                VkImageAspectFlags aspectMask,
                                                VkImage *images,
                                                VkDeviceMemory *mem,
                                                VkImageView *views,
                                                int count)
{
    VkMemoryRequirements memReq;
    VkResult err;
 
    Q_ASSERT(count > 0);
    for (int i = 0; i < count; ++i) {
        VkImageCreateInfo imgInfo;
        memset(&imgInfo, 0, sizeof(imgInfo));
        imgInfo.sType = VK_STRUCTURE_TYPE_IMAGE_CREATE_INFO;
        imgInfo.imageType = VK_IMAGE_TYPE_2D;
        imgInfo.format = format;
        imgInfo.extent.width = swapChainImageSize.width();
        imgInfo.extent.height = swapChainImageSize.height();
        imgInfo.extent.depth = 1;
        imgInfo.mipLevels = imgInfo.arrayLayers = 1;
        imgInfo.samples = sampleCount;
        imgInfo.tiling = VK_IMAGE_TILING_OPTIMAL;
        imgInfo.usage = usage | VK_IMAGE_USAGE_TRANSIENT_ATTACHMENT_BIT;
 
        err = devFuncs->vkCreateImage(dev, &imgInfo, nullptr, images + i);
        if (err != VK_SUCCESS) {
            qWarning("QVulkanWindow: Failed to create image: %d", err);
            return false;
        }
 
        // Assume the reqs are the same since the images are same in every way.
        // Still, call GetImageMemReq for every image, in order to prevent the
        // validation layer from complaining.
        devFuncs->vkGetImageMemoryRequirements(dev, images[i], &memReq);
    }
 
    VkMemoryAllocateInfo memInfo;
    memset(&memInfo, 0, sizeof(memInfo));
    memInfo.sType = VK_STRUCTURE_TYPE_MEMORY_ALLOCATE_INFO;
    memInfo.allocationSize = aligned(memReq.size, memReq.alignment) * count;
 
    uint32_t startIndex = 0;
    do {
        memInfo.memoryTypeIndex = chooseTransientImageMemType(images[0], startIndex);
        if (memInfo.memoryTypeIndex == uint32_t(-1)) {
            qWarning("QVulkanWindow: No suitable memory type found");
            return false;
        }
        startIndex = memInfo.memoryTypeIndex + 1;
        qCDebug(lcGuiVk, "Allocating %u bytes for transient image (memtype %u)",
                uint32_t(memInfo.allocationSize), memInfo.memoryTypeIndex);
        err = devFuncs->vkAllocateMemory(dev, &memInfo, nullptr, mem);
        if (err != VK_SUCCESS && err != VK_ERROR_OUT_OF_DEVICE_MEMORY) {
            qWarning("QVulkanWindow: Failed to allocate image memory: %d", err);
            return false;
        }
    } while (err != VK_SUCCESS);
 
    VkDeviceSize ofs = 0;
    for (int i = 0; i < count; ++i) {
        err = devFuncs->vkBindImageMemory(dev, images[i], *mem, ofs);
        if (err != VK_SUCCESS) {
            qWarning("QVulkanWindow: Failed to bind image memory: %d", err);
            return false;
        }
        ofs += aligned(memReq.size, memReq.alignment);
 
        VkImageViewCreateInfo imgViewInfo;
        memset(&imgViewInfo, 0, sizeof(imgViewInfo));
        imgViewInfo.sType = VK_STRUCTURE_TYPE_IMAGE_VIEW_CREATE_INFO;
        imgViewInfo.image = images[i];
        imgViewInfo.viewType = VK_IMAGE_VIEW_TYPE_2D;
        imgViewInfo.format = format;
        imgViewInfo.components.r = VK_COMPONENT_SWIZZLE_R;
        imgViewInfo.components.g = VK_COMPONENT_SWIZZLE_G;
        imgViewInfo.components.b = VK_COMPONENT_SWIZZLE_B;
        imgViewInfo.components.a = VK_COMPONENT_SWIZZLE_A;
        imgViewInfo.subresourceRange.aspectMask = aspectMask;
        imgViewInfo.subresourceRange.levelCount = imgViewInfo.subresourceRange.layerCount = 1;
 
        err = devFuncs->vkCreateImageView(dev, &imgViewInfo, nullptr, views + i);
        if (err != VK_SUCCESS) {
            qWarning("QVulkanWindow: Failed to create image view: %d", err);
            return false;
        }
    }
 
    return true;
}
 
void QVulkanWindowPrivate::releaseSwapChain()
{
    if (!dev || !swapChain) // do not rely on 'status', a half done init must be cleaned properly too
        return;
 
    qCDebug(lcGuiVk, "Releasing swapchain");
 
    devFuncs->vkDeviceWaitIdle(dev);
 
    if (renderer) {
        renderer->releaseSwapChainResources();
        devFuncs->vkDeviceWaitIdle(dev);
    }
 
    for (int i = 0; i < frameLag; ++i) {
        FrameResources &frame(frameRes[i]);
        if (frame.fence) {
            if (frame.fenceWaitable)
                devFuncs->vkWaitForFences(dev, 1, &frame.fence, VK_TRUE, UINT64_MAX);
            devFuncs->vkDestroyFence(dev, frame.fence, nullptr);
            frame.fence = VK_NULL_HANDLE;
            frame.fenceWaitable = false;
        }
        if (frame.imageSem) {
            devFuncs->vkDestroySemaphore(dev, frame.imageSem, nullptr);
            frame.imageSem = VK_NULL_HANDLE;
        }
        if (frame.drawSem) {
            devFuncs->vkDestroySemaphore(dev, frame.drawSem, nullptr);
            frame.drawSem = VK_NULL_HANDLE;
        }
        if (frame.presTransSem) {
            devFuncs->vkDestroySemaphore(dev, frame.presTransSem, nullptr);
            frame.presTransSem = VK_NULL_HANDLE;
        }
    }
 
    for (int i = 0; i < swapChainBufferCount; ++i) {
        ImageResources &image(imageRes[i]);
        if (image.cmdFence) {
            if (image.cmdFenceWaitable)
                devFuncs->vkWaitForFences(dev, 1, &image.cmdFence, VK_TRUE, UINT64_MAX);
            devFuncs->vkDestroyFence(dev, image.cmdFence, nullptr);
            image.cmdFence = VK_NULL_HANDLE;
            image.cmdFenceWaitable = false;
        }
        if (image.fb) {
            devFuncs->vkDestroyFramebuffer(dev, image.fb, nullptr);
            image.fb = VK_NULL_HANDLE;
        }
        if (image.imageView) {
            devFuncs->vkDestroyImageView(dev, image.imageView, nullptr);
            image.imageView = VK_NULL_HANDLE;
        }
        if (image.cmdBuf) {
            devFuncs->vkFreeCommandBuffers(dev, cmdPool, 1, &image.cmdBuf);
            image.cmdBuf = VK_NULL_HANDLE;
        }
        if (image.presTransCmdBuf) {
            devFuncs->vkFreeCommandBuffers(dev, presCmdPool, 1, &image.presTransCmdBuf);
            image.presTransCmdBuf = VK_NULL_HANDLE;
        }
        if (image.msaaImageView) {
            devFuncs->vkDestroyImageView(dev, image.msaaImageView, nullptr);
            image.msaaImageView = VK_NULL_HANDLE;
        }
        if (image.msaaImage) {
            devFuncs->vkDestroyImage(dev, image.msaaImage, nullptr);
            image.msaaImage = VK_NULL_HANDLE;
        }
    }
 
    if (msaaImageMem) {
        devFuncs->vkFreeMemory(dev, msaaImageMem, nullptr);
        msaaImageMem = VK_NULL_HANDLE;
    }
 
    if (dsView) {
        devFuncs->vkDestroyImageView(dev, dsView, nullptr);
        dsView = VK_NULL_HANDLE;
    }
    if (dsImage) {
        devFuncs->vkDestroyImage(dev, dsImage, nullptr);
        dsImage = VK_NULL_HANDLE;
    }
    if (dsMem) {
        devFuncs->vkFreeMemory(dev, dsMem, nullptr);
        dsMem = VK_NULL_HANDLE;
    }
 
    if (swapChain) {
        vkDestroySwapchainKHR(dev, swapChain, nullptr);
        swapChain = VK_NULL_HANDLE;
    }
 
    if (status == StatusReady)
        status = StatusDeviceReady;
}
 
void QVulkanWindow::exposeEvent(QExposeEvent *)
{
    Q_D(QVulkanWindow);
 
    if (isExposed()) {
        d->ensureStarted();
    } else {
        if (!d->flags.testFlag(PersistentResources)) {
            d->releaseSwapChain();
            d->reset();
        }
    }
}
 
void QVulkanWindowPrivate::ensureStarted()
{
    Q_Q(QVulkanWindow);
    if (status == QVulkanWindowPrivate::StatusFailRetry)
        status = QVulkanWindowPrivate::StatusUninitialized;
    if (status == QVulkanWindowPrivate::StatusUninitialized) {
        init();
        if (status == QVulkanWindowPrivate::StatusDeviceReady)
            recreateSwapChain();
    }
    if (status == QVulkanWindowPrivate::StatusReady)
        q->requestUpdate();
}
 
void QVulkanWindow::resizeEvent(QResizeEvent *)
{
    // Nothing to do here - recreating the swapchain is handled when building the next frame.
}
 
bool QVulkanWindow::event(QEvent *e)
{
    Q_D(QVulkanWindow);
 
    switch (e->type()) {
    case QEvent::UpdateRequest:
        d->beginFrame();
        break;
 
    // The swapchain must be destroyed before the surface as per spec. This is
    // not ideal for us because the surface is managed by the QPlatformWindow
    // which may be gone already when the unexpose comes, making the validation
    // layer scream. The solution is to listen to the PlatformSurface events.
    case QEvent::PlatformSurface:
        if (static_cast<QPlatformSurfaceEvent *>(e)->surfaceEventType() == QPlatformSurfaceEvent::SurfaceAboutToBeDestroyed) {
            d->releaseSwapChain();
            d->reset();
        }
        break;
 
    default:
        break;
    }
 
    return QWindow::event(e);
}
 
void QVulkanWindow::setQueueCreateInfoModifier(const QueueCreateInfoModifier &modifier)
{
    Q_D(QVulkanWindow);
    d->queueCreateInfoModifier = modifier;
}
 
void QVulkanWindow::setEnabledFeaturesModifier(const EnabledFeaturesModifier &modifier)
{
    Q_D(QVulkanWindow);
    d->enabledFeaturesModifier = modifier;
}
 
void QVulkanWindow::setEnabledFeaturesModifier(EnabledFeatures2Modifier modifier)
{
    Q_D(QVulkanWindow);
    d->enabledFeatures2Modifier = std::move(modifier);
}
 
bool QVulkanWindow::isValid() const
{
    Q_D(const QVulkanWindow);
    return d->status == QVulkanWindowPrivate::StatusReady;
}
 
QVulkanWindowRenderer *QVulkanWindow::createRenderer()
{
    return nullptr;
}
 
QVulkanWindowRenderer::~QVulkanWindowRenderer()
{
}
 
void QVulkanWindowRenderer::preInitResources()
{
}
 
void QVulkanWindowRenderer::initResources()
{
}
 
void QVulkanWindowRenderer::initSwapChainResources()
{
}
 
void QVulkanWindowRenderer::releaseSwapChainResources()
{
}
 
void QVulkanWindowRenderer::releaseResources()
{
}
 
void QVulkanWindowRenderer::physicalDeviceLost()
{
}
 
void QVulkanWindowRenderer::logicalDeviceLost()
{
}
 
QSize QVulkanWindowPrivate::surfacePixelSize() const
{
    Q_Q(const QVulkanWindow);
    VkSurfaceCapabilitiesKHR surfaceCaps = {};
    vkGetPhysicalDeviceSurfaceCapabilitiesKHR(physDevs.at(physDevIndex), surface, &surfaceCaps);
    VkExtent2D bufferSize = surfaceCaps.currentExtent;
    if (bufferSize.width == uint32_t(-1)) {
        Q_ASSERT(bufferSize.height == uint32_t(-1));
        return q->size() * q->devicePixelRatio();
    }
    return QSize(int(bufferSize.width), int(bufferSize.height));
}
 
void QVulkanWindowPrivate::beginFrame()
{
    if (!swapChain || framePending)
        return;
 
    Q_Q(QVulkanWindow);
    if (swapChainImageSize != surfacePixelSize()) {
        recreateSwapChain();
        if (!swapChain)
            return;
    }
 
    FrameResources &frame(frameRes[currentFrame]);
 
    if (!frame.imageAcquired) {
        // Wait if we are too far ahead, i.e. the thread gets throttled based on the presentation rate
        // (note that we are using FIFO mode -> vsync)
        if (frame.fenceWaitable) {
            devFuncs->vkWaitForFences(dev, 1, &frame.fence, VK_TRUE, UINT64_MAX);
            devFuncs->vkResetFences(dev, 1, &frame.fence);
            frame.fenceWaitable = false;
        }
 
        // move on to next swapchain image
        VkResult err = vkAcquireNextImageKHR(dev, swapChain, UINT64_MAX,
                                             frame.imageSem, frame.fence, &currentImage);
        if (err == VK_SUCCESS || err == VK_SUBOPTIMAL_KHR) {
            frame.imageSemWaitable = true;
            frame.imageAcquired = true;
            frame.fenceWaitable = true;
        } else if (err == VK_ERROR_OUT_OF_DATE_KHR) {
            recreateSwapChain();
            q->requestUpdate();
            return;
        } else {
            if (!checkDeviceLost(err))
                qWarning("QVulkanWindow: Failed to acquire next swapchain image: %d", err);
            q->requestUpdate();
            return;
        }
    }
 
    // make sure the previous draw for the same image has finished
    ImageResources &image(imageRes[currentImage]);
    if (image.cmdFenceWaitable) {
        devFuncs->vkWaitForFences(dev, 1, &image.cmdFence, VK_TRUE, UINT64_MAX);
        devFuncs->vkResetFences(dev, 1, &image.cmdFence);
        image.cmdFenceWaitable = false;
    }
 
    // build new draw command buffer
    if (image.cmdBuf) {
        devFuncs->vkFreeCommandBuffers(dev, cmdPool, 1, &image.cmdBuf);
        image.cmdBuf = nullptr;
    }
 
    VkCommandBufferAllocateInfo cmdBufInfo = {
        VK_STRUCTURE_TYPE_COMMAND_BUFFER_ALLOCATE_INFO, nullptr, cmdPool, VK_COMMAND_BUFFER_LEVEL_PRIMARY, 1 };
    VkResult err = devFuncs->vkAllocateCommandBuffers(dev, &cmdBufInfo, &image.cmdBuf);
    if (err != VK_SUCCESS) {
        if (!checkDeviceLost(err))
            qWarning("QVulkanWindow: Failed to allocate frame command buffer: %d", err);
        return;
    }
 
    VkCommandBufferBeginInfo cmdBufBeginInfo = {
        VK_STRUCTURE_TYPE_COMMAND_BUFFER_BEGIN_INFO, nullptr, 0, nullptr };
    err = devFuncs->vkBeginCommandBuffer(image.cmdBuf, &cmdBufBeginInfo);
    if (err != VK_SUCCESS) {
        if (!checkDeviceLost(err))
            qWarning("QVulkanWindow: Failed to begin frame command buffer: %d", err);
        return;
    }
 
    if (frameGrabbing)
        frameGrabTargetImage = QImage(swapChainImageSize, QImage::Format_RGBA8888); // the format is as documented
 
    if (renderer) {
        framePending = true;
        renderer->startNextFrame();
        // done for now - endFrame() will get invoked when frameReady() is called back
    } else {
        VkClearColorValue clearColor = { { 0.0f, 0.0f, 0.0f, 1.0f } };
        VkClearDepthStencilValue clearDS = { 1.0f, 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 = defaultRenderPass;
        rpBeginInfo.framebuffer = image.fb;
        rpBeginInfo.renderArea.extent.width = swapChainImageSize.width();
        rpBeginInfo.renderArea.extent.height = swapChainImageSize.height();
        rpBeginInfo.clearValueCount = sampleCount > VK_SAMPLE_COUNT_1_BIT ? 3 : 2;
        rpBeginInfo.pClearValues = clearValues;
        devFuncs->vkCmdBeginRenderPass(image.cmdBuf, &rpBeginInfo, VK_SUBPASS_CONTENTS_INLINE);
        devFuncs->vkCmdEndRenderPass(image.cmdBuf);
 
        endFrame();
    }
}
 
void QVulkanWindowPrivate::endFrame()
{
    Q_Q(QVulkanWindow);
 
    FrameResources &frame(frameRes[currentFrame]);
    ImageResources &image(imageRes[currentImage]);
 
    if (gfxQueueFamilyIdx != presQueueFamilyIdx && !frameGrabbing) {
        // Add the swapchain image release to the command buffer that will be
        // submitted to the graphics queue.
        VkImageMemoryBarrier presTrans;
        memset(&presTrans, 0, sizeof(presTrans));
        presTrans.sType = VK_STRUCTURE_TYPE_IMAGE_MEMORY_BARRIER;
        presTrans.dstAccessMask = VK_ACCESS_COLOR_ATTACHMENT_WRITE_BIT;
        presTrans.oldLayout = presTrans.newLayout = VK_IMAGE_LAYOUT_PRESENT_SRC_KHR;
        presTrans.srcQueueFamilyIndex = gfxQueueFamilyIdx;
        presTrans.dstQueueFamilyIndex = presQueueFamilyIdx;
        presTrans.image = image.image;
        presTrans.subresourceRange.aspectMask = VK_IMAGE_ASPECT_COLOR_BIT;
        presTrans.subresourceRange.levelCount = presTrans.subresourceRange.layerCount = 1;
        devFuncs->vkCmdPipelineBarrier(image.cmdBuf,
                                       VK_PIPELINE_STAGE_COLOR_ATTACHMENT_OUTPUT_BIT,
                                       VK_PIPELINE_STAGE_BOTTOM_OF_PIPE_BIT,
                                       0, 0, nullptr, 0, nullptr,
                                       1, &presTrans);
    }
 
    // When grabbing a frame, add a readback at the end and skip presenting.
    if (frameGrabbing)
        addReadback();
 
    VkResult err = devFuncs->vkEndCommandBuffer(image.cmdBuf);
    if (err != VK_SUCCESS) {
        if (!checkDeviceLost(err))
            qWarning("QVulkanWindow: Failed to end frame command buffer: %d", err);
        return;
    }
 
    // submit draw calls
    VkSubmitInfo submitInfo;
    memset(&submitInfo, 0, sizeof(submitInfo));
    submitInfo.sType = VK_STRUCTURE_TYPE_SUBMIT_INFO;
    submitInfo.commandBufferCount = 1;
    submitInfo.pCommandBuffers = &image.cmdBuf;
    if (frame.imageSemWaitable) {
        submitInfo.waitSemaphoreCount = 1;
        submitInfo.pWaitSemaphores = &frame.imageSem;
    }
    if (!frameGrabbing) {
        submitInfo.signalSemaphoreCount = 1;
        submitInfo.pSignalSemaphores = &frame.drawSem;
    }
    VkPipelineStageFlags psf = VK_PIPELINE_STAGE_COLOR_ATTACHMENT_OUTPUT_BIT;
    submitInfo.pWaitDstStageMask = &psf;
 
    Q_ASSERT(!image.cmdFenceWaitable);
 
    err = devFuncs->vkQueueSubmit(gfxQueue, 1, &submitInfo, image.cmdFence);
    if (err == VK_SUCCESS) {
        frame.imageSemWaitable = false;
        image.cmdFenceWaitable = true;
    } else {
        if (!checkDeviceLost(err))
            qWarning("QVulkanWindow: Failed to submit to graphics queue: %d", err);
        return;
    }
 
    // block and then bail out when grabbing
    if (frameGrabbing) {
        finishBlockingReadback();
        frameGrabbing = false;
        // Leave frame.imageAcquired set to true.
        // Do not change currentFrame.
        emit q->frameGrabbed(frameGrabTargetImage);
        return;
    }
 
    if (gfxQueueFamilyIdx != presQueueFamilyIdx) {
        // Submit the swapchain image acquire to the present queue.
        submitInfo.pWaitSemaphores = &frame.drawSem;
        submitInfo.pSignalSemaphores = &frame.presTransSem;
        submitInfo.pCommandBuffers = &image.presTransCmdBuf; // must be USAGE_SIMULTANEOUS
        err = devFuncs->vkQueueSubmit(presQueue, 1, &submitInfo, VK_NULL_HANDLE);
        if (err != VK_SUCCESS) {
            if (!checkDeviceLost(err))
                qWarning("QVulkanWindow: Failed to submit to present queue: %d", err);
            return;
        }
    }
 
    // queue present
    VkPresentInfoKHR presInfo;
    memset(&presInfo, 0, sizeof(presInfo));
    presInfo.sType = VK_STRUCTURE_TYPE_PRESENT_INFO_KHR;
    presInfo.swapchainCount = 1;
    presInfo.pSwapchains = &swapChain;
    presInfo.pImageIndices = &currentImage;
    presInfo.waitSemaphoreCount = 1;
    presInfo.pWaitSemaphores = gfxQueueFamilyIdx == presQueueFamilyIdx ? &frame.drawSem : &frame.presTransSem;
 
    // Do platform-specific WM notification. F.ex. essential on Wayland in
    // order to circumvent driver frame callbacks
    inst->presentAboutToBeQueued(q);
 
    err = vkQueuePresentKHR(presQueue, &presInfo);
    if (err != VK_SUCCESS) {
        if (err == VK_ERROR_OUT_OF_DATE_KHR) {
            recreateSwapChain();
            q->requestUpdate();
            return;
        } else if (err != VK_SUBOPTIMAL_KHR) {
            if (!checkDeviceLost(err))
                qWarning("QVulkanWindow: Failed to present: %d", err);
            return;
        }
    }
 
    frame.imageAcquired = false;
 
    inst->presentQueued(q);
 
    currentFrame = (currentFrame + 1) % frameLag;
}
 
void QVulkanWindow::frameReady()
{
    Q_ASSERT_X(QThread::currentThread() == QCoreApplication::instance()->thread(),
        "QVulkanWindow", "frameReady() can only be called from the GUI (main) thread");
 
    Q_D(QVulkanWindow);
 
    if (!d->framePending) {
        qWarning("QVulkanWindow: frameReady() called without a corresponding startNextFrame()");
        return;
    }
 
    d->framePending = false;
 
    d->endFrame();
}
 
bool QVulkanWindowPrivate::checkDeviceLost(VkResult err)
{
    if (err == VK_ERROR_DEVICE_LOST) {
        qWarning("QVulkanWindow: Device lost");
        if (renderer)
            renderer->logicalDeviceLost();
        qCDebug(lcGuiVk, "Releasing all resources due to device lost");
        releaseSwapChain();
        reset();
        qCDebug(lcGuiVk, "Restarting");
        ensureStarted();
        return true;
    }
    return false;
}
 
void QVulkanWindowPrivate::addReadback()
{
    VkImageCreateInfo imageInfo;
    memset(&imageInfo, 0, sizeof(imageInfo));
    imageInfo.sType = VK_STRUCTURE_TYPE_IMAGE_CREATE_INFO;
    imageInfo.imageType = VK_IMAGE_TYPE_2D;
    imageInfo.format = VK_FORMAT_R8G8B8A8_UNORM;
    imageInfo.extent.width = frameGrabTargetImage.width();
    imageInfo.extent.height = frameGrabTargetImage.height();
    imageInfo.extent.depth = 1;
    imageInfo.mipLevels = 1;
    imageInfo.arrayLayers = 1;
    imageInfo.samples = VK_SAMPLE_COUNT_1_BIT;
    imageInfo.tiling = VK_IMAGE_TILING_LINEAR;
    imageInfo.usage = VK_IMAGE_USAGE_TRANSFER_DST_BIT;
    imageInfo.initialLayout = VK_IMAGE_LAYOUT_PREINITIALIZED;
 
    VkResult err = devFuncs->vkCreateImage(dev, &imageInfo, nullptr, &frameGrabImage);
    if (err != VK_SUCCESS) {
        qWarning("QVulkanWindow: Failed to create image for readback: %d", err);
        return;
    }
 
    VkMemoryRequirements memReq;
    devFuncs->vkGetImageMemoryRequirements(dev, frameGrabImage, &memReq);
 
    VkMemoryAllocateInfo allocInfo = {
        VK_STRUCTURE_TYPE_MEMORY_ALLOCATE_INFO,
        nullptr,
        memReq.size,
        hostVisibleMemIndex
    };
 
    err = devFuncs->vkAllocateMemory(dev, &allocInfo, nullptr, &frameGrabImageMem);
    if (err != VK_SUCCESS) {
        qWarning("QVulkanWindow: Failed to allocate memory for readback image: %d", err);
        return;
    }
 
    err = devFuncs->vkBindImageMemory(dev, frameGrabImage, frameGrabImageMem, 0);
    if (err != VK_SUCCESS) {
        qWarning("QVulkanWindow: Failed to bind readback image memory: %d", err);
        return;
    }
 
    ImageResources &image(imageRes[currentImage]);
 
    VkImageMemoryBarrier barrier;
    memset(&barrier, 0, sizeof(barrier));
    barrier.sType = VK_STRUCTURE_TYPE_IMAGE_MEMORY_BARRIER;
    barrier.subresourceRange.aspectMask = VK_IMAGE_ASPECT_COLOR_BIT;
    barrier.subresourceRange.levelCount = barrier.subresourceRange.layerCount = 1;
 
    barrier.oldLayout = VK_IMAGE_LAYOUT_PRESENT_SRC_KHR;
    barrier.newLayout = VK_IMAGE_LAYOUT_TRANSFER_SRC_OPTIMAL;
    barrier.srcAccessMask = VK_ACCESS_MEMORY_READ_BIT;
    barrier.dstAccessMask = VK_ACCESS_TRANSFER_READ_BIT;
    barrier.image = image.image;
 
    devFuncs->vkCmdPipelineBarrier(image.cmdBuf,
                                   VK_PIPELINE_STAGE_COLOR_ATTACHMENT_OUTPUT_BIT,
                                   VK_PIPELINE_STAGE_TRANSFER_BIT,
                                   0, 0, nullptr, 0, nullptr,
                                   1, &barrier);
 
    barrier.oldLayout = VK_IMAGE_LAYOUT_PREINITIALIZED;
    barrier.newLayout = VK_IMAGE_LAYOUT_TRANSFER_DST_OPTIMAL;
    barrier.srcAccessMask = 0;
    barrier.dstAccessMask = VK_ACCESS_TRANSFER_WRITE_BIT;
    barrier.image = frameGrabImage;
 
    devFuncs->vkCmdPipelineBarrier(image.cmdBuf,
                                   VK_PIPELINE_STAGE_TOP_OF_PIPE_BIT,
                                   VK_PIPELINE_STAGE_TRANSFER_BIT,
                                   0, 0, nullptr, 0, nullptr,
                                   1, &barrier);
 
    VkImageCopy copyInfo;
    memset(&copyInfo, 0, sizeof(copyInfo));
    copyInfo.srcSubresource.aspectMask = copyInfo.dstSubresource.aspectMask = VK_IMAGE_ASPECT_COLOR_BIT;
    copyInfo.srcSubresource.layerCount = copyInfo.dstSubresource.layerCount = 1;
    copyInfo.extent.width = frameGrabTargetImage.width();
    copyInfo.extent.height = frameGrabTargetImage.height();
    copyInfo.extent.depth = 1;
 
    devFuncs->vkCmdCopyImage(image.cmdBuf, image.image, VK_IMAGE_LAYOUT_TRANSFER_SRC_OPTIMAL,
                             frameGrabImage, VK_IMAGE_LAYOUT_TRANSFER_DST_OPTIMAL, 1, &copyInfo);
 
    barrier.oldLayout = VK_IMAGE_LAYOUT_TRANSFER_DST_OPTIMAL;
    barrier.newLayout = VK_IMAGE_LAYOUT_GENERAL;
    barrier.srcAccessMask = VK_ACCESS_TRANSFER_WRITE_BIT;
    barrier.dstAccessMask = VK_ACCESS_HOST_READ_BIT;
    barrier.image = frameGrabImage;
 
    devFuncs->vkCmdPipelineBarrier(image.cmdBuf,
                                   VK_PIPELINE_STAGE_TRANSFER_BIT,
                                   VK_PIPELINE_STAGE_HOST_BIT,
                                   0, 0, nullptr, 0, nullptr,
                                   1, &barrier);
}
 
void QVulkanWindowPrivate::finishBlockingReadback()
{
    ImageResources &image(imageRes[currentImage]);
 
    // Block until the current frame is done. Normally this wait would only be
    // done in current + concurrentFrameCount().
    devFuncs->vkWaitForFences(dev, 1, &image.cmdFence, VK_TRUE, UINT64_MAX);
    devFuncs->vkResetFences(dev, 1, &image.cmdFence);
    // will reuse the same image for the next "real" frame, do not wait then
    image.cmdFenceWaitable = false;
 
    VkImageSubresource subres = { VK_IMAGE_ASPECT_COLOR_BIT, 0, 0 };
    VkSubresourceLayout layout;
    devFuncs->vkGetImageSubresourceLayout(dev, frameGrabImage, &subres, &layout);
 
    uchar *p;
    VkResult err = devFuncs->vkMapMemory(dev, frameGrabImageMem, layout.offset, layout.size, 0, reinterpret_cast<void **>(&p));
    if (err != VK_SUCCESS) {
        qWarning("QVulkanWindow: Failed to map readback image memory after transfer: %d", err);
        return;
    }
 
    for (int y = 0; y < frameGrabTargetImage.height(); ++y) {
        memcpy(frameGrabTargetImage.scanLine(y), p, frameGrabTargetImage.width() * 4);
        p += layout.rowPitch;
    }
 
    devFuncs->vkUnmapMemory(dev, frameGrabImageMem);
 
    devFuncs->vkDestroyImage(dev, frameGrabImage, nullptr);
    frameGrabImage = VK_NULL_HANDLE;
    devFuncs->vkFreeMemory(dev, frameGrabImageMem, nullptr);
    frameGrabImageMem = VK_NULL_HANDLE;
}
 
VkPhysicalDevice QVulkanWindow::physicalDevice() const
{
    Q_D(const QVulkanWindow);
    if (d->physDevIndex < d->physDevs.size())
        return d->physDevs[d->physDevIndex];
    qWarning("QVulkanWindow: Physical device not available");
    return VK_NULL_HANDLE;
}
 
const VkPhysicalDeviceProperties *QVulkanWindow::physicalDeviceProperties() const
{
    Q_D(const QVulkanWindow);
    if (d->physDevIndex < d->physDevProps.size())
        return &d->physDevProps[d->physDevIndex];
    qWarning("QVulkanWindow: Physical device properties not available");
    return nullptr;
}
 
VkDevice QVulkanWindow::device() const
{
    Q_D(const QVulkanWindow);
    return d->dev;
}
 
VkQueue QVulkanWindow::graphicsQueue() const
{
    Q_D(const QVulkanWindow);
    return d->gfxQueue;
}
 
uint32_t QVulkanWindow::graphicsQueueFamilyIndex() const
{
    Q_D(const QVulkanWindow);
    return d->gfxQueueFamilyIdx;
}
 
VkCommandPool QVulkanWindow::graphicsCommandPool() const
{
    Q_D(const QVulkanWindow);
    return d->cmdPool;
}
 
uint32_t QVulkanWindow::hostVisibleMemoryIndex() const
{
    Q_D(const QVulkanWindow);
    return d->hostVisibleMemIndex;
}
 
uint32_t QVulkanWindow::deviceLocalMemoryIndex() const
{
    Q_D(const QVulkanWindow);
    return d->deviceLocalMemIndex;
}
 
VkRenderPass QVulkanWindow::defaultRenderPass() const
{
    Q_D(const QVulkanWindow);
    return d->defaultRenderPass;
}
 
VkFormat QVulkanWindow::colorFormat() const
{
    Q_D(const QVulkanWindow);
    return d->colorFormat;
}
 
VkFormat QVulkanWindow::depthStencilFormat() const
{
    Q_D(const QVulkanWindow);
    return d->dsFormat;
}
 
QSize QVulkanWindow::swapChainImageSize() const
{
    Q_D(const QVulkanWindow);
    return d->swapChainImageSize;
}
 
VkCommandBuffer QVulkanWindow::currentCommandBuffer() const
{
    Q_D(const QVulkanWindow);
    if (!d->framePending) {
        qWarning("QVulkanWindow: Attempted to call currentCommandBuffer() without an active frame");
        return VK_NULL_HANDLE;
    }
    return d->imageRes[d->currentImage].cmdBuf;
}
 
VkFramebuffer QVulkanWindow::currentFramebuffer() const
{
    Q_D(const QVulkanWindow);
    if (!d->framePending) {
        qWarning("QVulkanWindow: Attempted to call currentFramebuffer() without an active frame");
        return VK_NULL_HANDLE;
    }
    return d->imageRes[d->currentImage].fb;
}
 
int QVulkanWindow::currentFrame() const
{
    Q_D(const QVulkanWindow);
    if (!d->framePending)
        qWarning("QVulkanWindow: Attempted to call currentFrame() without an active frame");
    return d->currentFrame;
}
 
int QVulkanWindow::concurrentFrameCount() const
{
    Q_D(const QVulkanWindow);
    return d->frameLag;
}
 
int QVulkanWindow::swapChainImageCount() const
{
    Q_D(const QVulkanWindow);
    return d->swapChainBufferCount;
}
 
int QVulkanWindow::currentSwapChainImageIndex() const
{
    Q_D(const QVulkanWindow);
    if (!d->framePending)
        qWarning("QVulkanWindow: Attempted to call currentSwapChainImageIndex() without an active frame");
    return d->currentImage;
}
 
VkImage QVulkanWindow::swapChainImage(int idx) const
{
    Q_D(const QVulkanWindow);
    return idx >= 0 && idx < d->swapChainBufferCount ? d->imageRes[idx].image : VK_NULL_HANDLE;
}
 
VkImageView QVulkanWindow::swapChainImageView(int idx) const
{
    Q_D(const QVulkanWindow);
    return idx >= 0 && idx < d->swapChainBufferCount ? d->imageRes[idx].imageView : VK_NULL_HANDLE;
}
 
VkImage QVulkanWindow::depthStencilImage() const
{
    Q_D(const QVulkanWindow);
    return d->dsImage;
}
 
VkImageView QVulkanWindow::depthStencilImageView() const
{
    Q_D(const QVulkanWindow);
    return d->dsView;
}
 
VkSampleCountFlagBits QVulkanWindow::sampleCountFlagBits() const
{
    Q_D(const QVulkanWindow);
    return d->sampleCount;
}
 
VkImage QVulkanWindow::msaaColorImage(int idx) const
{
    Q_D(const QVulkanWindow);
    return idx >= 0 && idx < d->swapChainBufferCount ? d->imageRes[idx].msaaImage : VK_NULL_HANDLE;
}
 
VkImageView QVulkanWindow::msaaColorImageView(int idx) const
{
    Q_D(const QVulkanWindow);
    return idx >= 0 && idx < d->swapChainBufferCount ? d->imageRes[idx].msaaImageView : VK_NULL_HANDLE;
}
 
bool QVulkanWindow::supportsGrab() const
{
    Q_D(const QVulkanWindow);
    return d->swapChainSupportsReadBack;
}
 
QImage QVulkanWindow::grab()
{
    Q_D(QVulkanWindow);
    if (!d->swapChain) {
        qWarning("QVulkanWindow: Attempted to call grab() without a swapchain");
        return QImage();
    }
    if (d->framePending) {
        qWarning("QVulkanWindow: Attempted to call grab() while a frame is still pending");
        return QImage();
    }
    if (!d->swapChainSupportsReadBack) {
        qWarning("QVulkanWindow: Attempted to call grab() with a swapchain that does not support usage as transfer source");
        return QImage();
    }
 
    d->frameGrabbing = true;
    d->beginFrame();
 
    if (d->colorFormat == VK_FORMAT_B8G8R8A8_UNORM)
        d->frameGrabTargetImage = std::move(d->frameGrabTargetImage).rgbSwapped();
 
    return d->frameGrabTargetImage;
}
 
QMatrix4x4 QVulkanWindow::clipCorrectionMatrix()
{
    Q_D(QVulkanWindow);
    if (d->m_clipCorrect.isIdentity()) {
        // NB the ctor takes row-major
        d->m_clipCorrect = QMatrix4x4(1.0f, 0.0f, 0.0f, 0.0f,
                                      0.0f, -1.0f, 0.0f, 0.0f,
                                      0.0f, 0.0f, 0.5f, 0.5f,
                                      0.0f, 0.0f, 0.0f, 1.0f);
    }
    return d->m_clipCorrect;
}
 
QT_END_NAMESPACE
 
#include "moc_qvulkanwindow.cpp"