Book Image

Integrate Lua with C++

By : Wenhuan Li
Book Image

Integrate Lua with C++

By: Wenhuan Li

Overview of this book

C++ is a popular choice in the developer community for building complex and large-scale performant applications and systems. Often a need arises to extend the system at runtime, without recompiling the whole C++ program. Using a scripting language like Lua can help achieve this goal efficiently. Integrate Lua to C++ is a comprehensive guide to integrating Lua to C++ and will enable you to achieve the goal of extending C++ programs at runtime. You’ll learn, in sequence, how to get and compile the Lua library, the Lua programming language, calling Lua code from C++, and calling C++ code from Lua. In each topic, you’ll practice with code examples, and learn the in-depth mechanisms for smooth working. Throughout the book, the latter examples build on the earlier ones while also acting as a standalone. You’ll learn to implement Lua executor and Lua binding generator, which you can use in your projects directly with further customizations. By the end of this book, you’ll have mastered integrating Lua into C++ and using Lua in your C++ project efficiently, gained the skills to extend your applications at runtime, and achieved dynamic and adaptable C++ development.
Table of Contents (18 chapters)
Free Chapter
1
Part 1 – Lua Basics
4
Part 2 – Calling Lua from C++
8
Part 3 – Calling C++ from Lua
12
Part 4 – Advanced Topics

How to override Lua library functions

Why would you want to override Lua library functions? First, it helps to learn more about calling C++ functions from Lua in a progressive way, before moving on to C++ modules. Second, but more importantly, it is a frequent requirement for real-life projects.

Suppose you are working on a game where assets are packed inside a private archive and your Lua scripts need to access them. Overriding the Lua io and file libraries can provide a seamless experience for your fellow Lua developers and enforce security at the same time. You can make sure Lua scripts can only access assets you want them to, but nothing else on the host filesystem. This is even more important when your users can change the Lua scripts.

Let us implement a more trivial case. We use the Lua print function to output debug information. We want to merge the Lua debug output with C++ output so that we get all our logs in the same place ordered by the time they are printed.

Reimplementing...