Book Image

Game Programming Using Qt: Beginner's Guide

By : Lorenz Haas, Witold Wysota, Witold Wysota, Lorenz Haas
Book Image

Game Programming Using Qt: Beginner's Guide

By: Lorenz Haas, Witold Wysota, Witold Wysota, Lorenz Haas

Overview of this book

Qt is the leading cross-platform toolkit for all significant desktop, mobile, and embedded platforms and is becoming more popular by the day, especially on mobile and embedded devices. Despite its simplicity, it's a powerful tool that perfectly fits game developers’ needs. Using Qt and Qt Quick, it is easy to build fun games or shiny user interfaces. You only need to create your game once and deploy it on all major platforms like iOS, Android, and WinRT without changing a single source file. The book begins with a brief introduction to creating an application and preparing a working environment for both desktop and mobile platforms. It then dives deeper into the basics of creating graphical interfaces and Qt core concepts of data processing and display before you try creating a game. As you progress through the chapters, you’ll learn to enrich your games by implementing network connectivity and employing scripting. We then delve into Qt Quick, OpenGL, and various other tools to add game logic, design animation, add game physics, and build astonishing UI for the games. Towards the final chapters, you’ll learn to exploit mobile device features such as accelerators and sensors to build engaging user experiences. If you are planning to learn about Qt and its associated toolsets to build apps and games, this book is a must have.
Table of Contents (18 chapters)
Game Programming Using Qt
About the Authors
About the Reviewers

Time for action – constructing the query

Whenever the button is pressed, the sendRequest() slot is called:

void MainWindow::sendRequest()
  if (m_reply != 0 && m_reply->isRunning())

In this slot, we first check whether there is an old request, which was stored in m_reply, and if it is still running. If that is true, we abort the old request as we are about to schedule a new one. Then, we also wipe out the result of the last request by calling QPlainTextEdit::clear() on the text edit.

Next, we will construct the URL for the request. We can do this by composing the string by hand where we add the query parameters to the base URL similar to:

url = baseUrl + "?origin=" + ui->from->text() + "&...";

Besides the problem that this quickly becomes hard to read when we include multiple parameters, it is also rather error-prone. The values of the line edits have to be encoded to fit the criteria for a valid URL. For every user...