Game Engine Scripting Languages

Question

I am trying to build out a useful 3d game engine out of the Ogre3d rendering engine for mocking up some of the ideas i have come up with and have come to a bit of a crossroads. There are a number of scripting languages that are available and i was wondering if there were one or two that were vetted and had a proper following.

LUA and Squirrel seem to be the more vetted, but im open to any and all.

Optimally it would be best if there were a compiled form for the language for distribution and ease of loading.

Answer 1

I'd go with Lua since writing bindings is extremely easy, the license is very friendly (MIT) and existing libraries also tend to be under said license. Scheme is also nice and easy to bind which is why it was chosen for the Gimp image editor for example. But Lua is simply great. World of Warcraft uses it, as a very high profile example. LuaJIT gives you native-compiled performance. It's less than an order of magnitude from pure C.

Answer 2

I wouldn't recommend LUA, it has a peculiar syntax so takes some time to get used to. Depending on who will be doing the scripting, this may not be a problem, but I would try to use something fairly accessible.

I would probably choose python. It normally compiles to bytecode, so you would need to embed the interpreter. However, if you must you can use PyPy to for example translate the code to C, and then compile it.

Answer 3

Embedding the interpreter is no issue. I am more interested in features and performance at this point in time. LUA and Squirrel are both interpreted, which is nice because one of the games i am building out is to include modifiable code, which has an editor in game.

I would love to hear about python, as i have seen its use within the battlefield series i believe.

Answer 4

The syntax is a matter of taste, Lua is like Javascript but with curly braces replaced with Pascal-like keywords. It has the nice syntactic feature that semicolons are never required but whitespace is still not significant, so you can even remove all line breaks and have it still work. As someone who started with C I'd say Python is the one with esoteric syntax compared to all the other languages.

LuaJIT is also around 10 times as fast as Python and the Lua interpreter is much much smaller (150kb or around 15k lines of C which you can actually read through and understand). You can let the user script your game without having to embed a massive language. On the other hand if you rip the parser part out of Lua it becomes even smaller.

Answer 5

One interesting option is stackless-python. This was used in the Eve-Online game.

Answer 6

The Python/C API manual is longer than the whole Lua manual (including the Lua/C API).

Another reason for Lua is the built-in support for coroutines (co-operative multitasking within the one OS thread). It allows one to have like 1000's of seemingly individual scripts running very fast alongside each other. Like one script per monster/weapon or so.

( Why do people write Lua in upper case so much on SO? It's "Lua" (see here). )

Answer 7

One more vote for Lua. Small, fast, easy to integrate, what's important for modern consoles - you can easily control its memory operations.