Book Image

Cross-Platform Development with Qt 6 and Modern C++

By : Nibedit Dey
Book Image

Cross-Platform Development with Qt 6 and Modern C++

By: Nibedit Dey

Overview of this book

Qt is a cross-platform application development framework widely used for developing applications that can run on a wide range of hardware platforms with little to no change in the underlying codebase. If you have basic knowledge of C++ and want to build desktop or mobile applications with a modern graphical user interface (GUI), Qt is the right choice for you. Cross-Platform Development with Qt 6 and Modern C++ helps you understand why Qt is one of the favorite GUI frameworks adopted by industries worldwide, covering the essentials of programming GUI apps across a multitude of platforms using the standard C++17 and Qt 6 features. Starting with the fundamentals of the Qt framework, including the features offered by Qt Creator, this practical guide will show you how to create classic user interfaces using Qt Widgets and touch-friendly user interfaces using Qt Quick. As you advance, you'll explore the Qt Creator IDE for developing applications for multiple desktops as well as for embedded and mobile platforms. You will also learn advanced concepts about signals and slots. Finally, the book takes you through debugging and testing your app with Qt Creator IDE. By the end of this book, you'll be able to build cross-platform applications with a modern GUI along with the speed and power of native apps.
Table of Contents (17 chapters)
Section 1: The Basics
Section 2: Cross-Platform Development
Section 3: Advanced Programming, Debugging, and Deployment

Understanding the Qt Quick scene graph

Qt Quick 2 employs a dedicated scene graph that is traversed and rendered using a graphics API, including OpenGL, OpenGL ES, Metal, Vulkan, or Direct 3D. Using a scene graph for graphics instead of traditional imperative painting systems (QPainter and similar), allows the scene to be rendered to be retained between frames and the entire set of primitives to render to be known before rendering begins. This allows for a variety of optimizations, including batch rendering to reduce state changes and discarding obscured primitives.

Let's assume a GUI comprises a list of 10 elements and each one has a different background color, text, and icon. This would give us 30 draw calls and an identical number of state changes using traditional drawing techniques. Contrarily, a scene graph reorganizes the primitives to render so that one call can draw all backgrounds, icons, and text, dropping the total number of draw calls to three. This type of batching...