x

Same thing.


A library is a collection of code. The term "game engine" is slightly more general and vague, and generally means a library of code plus some tools to go with it.

what is the difference between game engines and libraries. I have been looking for game engines, but I constantly keep stumbling across game libraries. A nice explanation would be nice.

a game engine will typically have some sort of graphical programming environment that you can use to position game objects in 3d space. a library is just a collection of api used to code with. a library is a subset of a game engine

[quote name='Czar05' timestamp='1312861382' post='4846513']
what is the difference between game engines and libraries. I have been looking for game engines, but I constantly keep stumbling across game libraries. A nice explanation would be nice.

a game engine will typically have some sort of graphical programming environment that you can use to position game objects in 3d space. a library is just a collection of api used to code with. a library is a subset of a game engine
[/quote]

That's not really true. A Game Engine is a set of API's (and accompanying libraries) that is designed to help provide most of the machinations required to make that type of game. It might be an engine to promote a 3D FPS, a 2D platformer, or even a Text Adventure game.

What you're calling libraries may be some of the Multimedia libraries available (DirectX, SDL, SFML, etc.) These are typically API's to allow access to the pieces that control and display the game. They would provide access to input (mouse, keyboard, joystick), Audio, Graphics, and networking. For many of the "Game Engines", you may need to use a Multimedia Library to control the Game Engine, although, typically, the Game Engine already provide some abstraction for those calls.

A game engine is a unified set of run-time software technology upon which you can build a game. It will generally have systems for things such as:

• Asset Loading and Management (streaming, etc.)
• Physics
• Rendering
• Animation
• World Representation
• Entities
• Path Finding
• AI
• GUI & Menuing
• Input Acquisition
• Networking
• Game State Persistence
• Sound Effects & Music Streaming
• Etc.

The thing that makes it an engine, is its frame-based multi-tasking nature. The thing that makes it a game engine is all the functionality it delivers that makes it useful for building games.

A set of libraries is one form in which that unified set of technology can be organized to make it usable by engineers.

In my experience, this is the way most engineers prefer, because it gives them the most control and flexibility over how they use them.

The Unreal Engine is one example of a different approach. Their approach is to build a game stub in a single monolithic (though not un-organized) codebase, and to give you all of the source code so you can sort of just pick up where they left off, or re-write and replace whatever you want. The idea behind this approach is that you start with a working game and so if the game you want to make is very similar, you can convert it to that game much more quickly.

Engineers tend not to like this because it's much tougher to dig into that code, and figure out exactly what to redesign and how, without breaking everything, than it would be to build on top of a clear, clean, well defined set of library interfaces. And if the game you're making is not that close to what you start with, then it could take longer to get there.

On 8/9/2011 at 10:15 AM, mmakrzem said:

a game engine will typically have some sort of graphical programming environment that you can use to position game objects in 3d space. a library is just a collection of api used to code with. a library is a subset of a game engine

An engine will typically utilize (essentially be useless without) a layout tool, but they are two separate things. And a layout tool typically generates run-time assets, not code.

On 8/8/2011 at 9:04 PM, Hodgman said:

Same thing.

An engine isn't necessarily encapsulated in a library. And a library doesn't necessarily comprise an engine.

One of the followup pieces of advice regarding my introductory post was confusion at the basic terminology and this is a very valid concern. I am considering putting together a complimentary post which is simply a glossary of common (game) programming expressions. Once you learn a term you simply assume everyone knows what it is. SDK, library, engine, etc... are the bread and butter of what we do, but by no means are they intuitive to a new developer.