1// Copyright (C) 2022 The Qt Company Ltd.
2// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR LGPL-3.0-only OR GPL-2.0-only OR GPL-3.0-only
3
4#include "qvulkandefaultinstance_p.h"
5#include <rhi/qrhi.h>
6#include <QLoggingCategory>
7
8QT_BEGIN_NAMESPACE
9
10Q_LOGGING_CATEGORY(lcGuiVk, "qt.vulkan")
11
12static QVulkanInstance *s_vulkanInstance;
13Q_CONSTINIT static QVulkanDefaultInstance::Flags s_vulkanInstanceFlags;
14
15QVulkanDefaultInstance::Flags QVulkanDefaultInstance::flags()
16{
17 return s_vulkanInstanceFlags;
18}
19
20// As always, calling this when hasInstance() is already true has no effect. (unless cleanup() is called)
21void QVulkanDefaultInstance::setFlag(Flag flag, bool on)
22{
23 s_vulkanInstanceFlags.setFlag(flag, on);
24}
25
26bool QVulkanDefaultInstance::hasInstance()
27{
28 return s_vulkanInstance != nullptr;
29}
30
31QVulkanInstance *QVulkanDefaultInstance::instance()
32{
33 if (s_vulkanInstance)
34 return s_vulkanInstance;
35
36 s_vulkanInstance = new QVulkanInstance;
37
38 // With a Vulkan implementation >= 1.1 we can check what
39 // vkEnumerateInstanceVersion() says and request 1.3/1.2/1.1 based on the
40 // result. To prevent future surprises, be conservative and ignore any > 1.3
41 // versions for now. For 1.0 implementations nothing will be requested, the
42 // default 0 in VkApplicationInfo means 1.0.
43 //
44 // Vulkan 1.0 is actually sufficient for 99% of Qt Quick (3D)'s
45 // functionality. In addition, Vulkan implementations tend to enable 1.1+
46 // functionality regardless of the VkInstance API request. However, the
47 // validation layer seems to take this fairly seriously, so we should be
48 // prepared for using 1.1+ features in a fully correct manner. This also
49 // helps custom Vulkan code in applications, which is not under out
50 // control; it is ideal if Vulkan 1.1+ versions are usable without
51 // requiring such applications to create their own QVulkanInstance just to
52 // be able to make an appropriate setApiVersion() call on it.
53
54 const QVersionNumber supportedVersion = s_vulkanInstance->supportedApiVersion();
55 if (supportedVersion >= QVersionNumber(1, 3))
56 s_vulkanInstance->setApiVersion(QVersionNumber(1, 3));
57 else if (supportedVersion >= QVersionNumber(1, 2))
58 s_vulkanInstance->setApiVersion(QVersionNumber(1, 2));
59 else if (supportedVersion >= QVersionNumber(1, 1))
60 s_vulkanInstance->setApiVersion(QVersionNumber(1, 1));
61 qCDebug(lcGuiVk) << "QVulkanDefaultInstance: Creating Vulkan instance"
62 << "Requesting Vulkan API" << s_vulkanInstance->apiVersion()
63 << "Instance-level version was reported as" << supportedVersion;
64
65 if (s_vulkanInstanceFlags.testFlag(flag: EnableValidation))
66 s_vulkanInstance->setLayers({ "VK_LAYER_KHRONOS_validation" });
67
68 s_vulkanInstance->setExtensions(QRhiVulkanInitParams::preferredInstanceExtensions());
69
70 if (!s_vulkanInstance->create()) {
71 qWarning(msg: "QVulkanDefaultInstance: Failed to create Vulkan instance");
72 delete s_vulkanInstance;
73 s_vulkanInstance = nullptr;
74 }
75
76 return s_vulkanInstance;
77}
78
79void QVulkanDefaultInstance::cleanup()
80{
81 delete s_vulkanInstance;
82 s_vulkanInstance = nullptr;
83}
84
85QT_END_NAMESPACE
86

source code of qtbase/src/gui/vulkan/qvulkandefaultinstance.cpp