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-rw-r--r--examples/vulkan/doc/src/hellovulkantriangle.qdoc77
1 files changed, 48 insertions, 29 deletions
diff --git a/examples/vulkan/doc/src/hellovulkantriangle.qdoc b/examples/vulkan/doc/src/hellovulkantriangle.qdoc
index f030d61578..bafa026ccd 100644
--- a/examples/vulkan/doc/src/hellovulkantriangle.qdoc
+++ b/examples/vulkan/doc/src/hellovulkantriangle.qdoc
@@ -1,29 +1,5 @@
-/****************************************************************************
-**
-** Copyright (C) 2017 The Qt Company Ltd.
-** Contact: https://www.qt.io/licensing/
-**
-** This file is part of the documentation of the Qt Toolkit.
-**
-** $QT_BEGIN_LICENSE:FDL$
-** 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.
-**
-** GNU Free Documentation License Usage
-** Alternatively, this file may be used under the terms of the GNU Free
-** Documentation License version 1.3 as published by the Free Software
-** Foundation and appearing in the file included in the packaging of
-** this file. Please review the following information to ensure
-** the GNU Free Documentation License version 1.3 requirements
-** will be met: https://www.gnu.org/licenses/fdl-1.3.html.
-** $QT_END_LICENSE$
-**
-****************************************************************************/
+// Copyright (C) 2017 The Qt Company Ltd.
+// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR GFDL-1.3-no-invariants-only
/*!
\example hellovulkantriangle
@@ -31,13 +7,56 @@
\ingroup examples-vulkan
\title Hello Vulkan Triangle Example
\brief Shows the basics of rendering with QVulkanWindow and the Vulkan API.
+ \examplecategory {Graphics}
- The \e{Hello Vulkan Triangle Example} builds on \l hellovulkanwindow. This
- time a full graphics pipeline is created, including a vertex and fragment
- shader. This pipeline is then used to render a triangle.
+ The \e{Hello Vulkan Triangle Example} creates a full graphics pipeline,
+ including a vertex and fragment shader, to render a triangle.
\image hellovulkantriangle.png
+ \section1 Startup
+
+ Each Qt application using Vulkan will have to have a \c{Vulkan instance}
+ which encapsulates application-level state and initializes a Vulkan library.
+
+ A QVulkanWindow must always be associated with a QVulkanInstance and hence
+ the example performs instance creation before the window. The
+ QVulkanInstance object must also outlive the window.
+
+ \snippet hellovulkantriangle/main.cpp 0
+
+ The example enables validation layers, when supported. When the requested
+ layers are not present, the request will be ignored. Additional layers and
+ extensions can be enabled in a similar manner.
+
+ \snippet hellovulkantriangle/main.cpp 1
+
+ Once the instance is ready, it is time to create a window. Note that \c w
+ lives on the stack and is declared after \c inst.
+
+ \section1 The QVulkanWindow Subclass
+
+ To add custom functionality to a QVulkanWindow, subclassing is used. This
+ follows the existing patterns from QOpenGLWindow and QOpenGLWidget.
+ However, QVulkanWindow utilizes a separate QVulkanWindowRenderer object.
+
+ The QVulkanWindow subclass reimplements the factory function
+ QVulkanWindow::createRenderer(). This simply returns a new instance of the
+ QVulkanWindowRenderer subclass. In order to be able to access various
+ Vulkan resources via the window object, a pointer to the window is passed
+ and stored via the constructor.
+
+ \snippet hellovulkantriangle/main.cpp 2
+
+ \section1 The Actual Rendering
+
+ QVulkanWindow subclasses queue their draw calls in their reimplementation
+ of QVulkanWindowRenderer::startNextFrame(). Once done, they are required to
+ call back QVulkanWindow::frameReady(). The example has no asynchronous
+ command generation, so the frameReady() call is made directly from
+ startNextFrame(). To get continuous updates, the example simply invokes
+ QWindow::requestUpdate() in order to schedule a repaint.
+
The example also demonstrates multisample antialiasing. Based on the
supported sample counts reported by QVulkanWindow::supportedSampleCounts()
the example chooses between 8x, 4x, or no multisampling. Once configured