REFLECTION WINDOWS 8.1
I’ll also discuss other ways to extend the system.Notice regarding ending support for Windows 8.1
REFLECTION HOW TO
In the next post, I’ll explain how to add built-in types to the reflection system, and what the “anonymous functions” are for in the above diagram. In the sample project, dumping objects to the console is the only functionality implemented, but you can imagine how type descriptors could serve as a framework for serializing to a binary format instead. By representing objects this way, it’s possible to write many kinds of generic algorithms. That’s why, in my game engine, objects represented by void pointers always travel around with their type descriptors in pairs. Clearly, if an invalid pointer is passed in, the program is likely to crash. You might wonder whether it’s safe to cast void pointers in this way.
Reflect::TypeDescriptor_Struct Node:: Reflection " Definition of the struct's type descriptor: The REFLECT() macro tells the system to enable reflection for this type. In Main.cpp, the sample project defines a struct named Node. If you’re more interested in using an existing solution, take a look at RTTR. It touches on many advanced features of C++, but the sample project is only 242 lines of code, so hopefully, with some persistence, any determined C++ programmer can follow along. This post is meant for programmers who are interested in how to develop a runtime reflection system, not just use one. In the next post, I’ll discuss how the system can be extended. That’s the part I’ll focus on in this post. It uses a tiny reflection system of its own, but the most interesting part – the way type descriptors are created, structured and found – is almost identical. This sample doesn’t actually use my game engine’s reflection system. To illustrate how it works, I’ve published a sample project on GitHub: I was burned many times by obscure language rules, order-of-initialization bugs and corner cases before settling on the system I have today. As anyone who’s written one knows, it’s tough to design a reflection system that’s easy to use, easily extended, and that actually works.
C++, at least in its current form, was not designed to make runtime reflection easy. This reflection system is based on preprocessor macros and templates. It’s used to import 3D models, level definitions and other assets. Importing JSON: The engine’s asset pipeline has a generic routine to synthesize a C++ object from a JSON file and a type descriptor.It makes graphics programming much more productive! 3D rendering: Every time the game engine draws something using OpenGL ES, it uses reflection to pass uniform parameters and describe vertex formats to the API.
Once that worked, I began to use runtime reflection for other engine features, too: My initial motivation for writing a reflection system was to support serialization in my custom C++ game engine, since I have very specific needs. I’ll call these objects type descriptors. The metadata takes the form of TypeDescriptor objects, created at runtime, that describe the structure of other runtime objects. This is a system to generate metadata for C++ types. In this post, I’ll present a small, flexible system for runtime reflection using C++11 language features.
0 kommentar(er)
