27 replies to this topic

[Chris_F]

For example, even if everyone loves Linux, one should still criticize why version 2.6 is 30% slower than version 2.4.

That's not even remotely correct. If you are going to critique anything, maybe you should get the facts correct first.

[Davaris1]

I think it is pretty clear I am referring to the green arrows as an sort of abstraction thing, and not the grey boxes that is the lists and maps etc.

Okay, I see you don't understand the diagram at all. If it is a library like Utility Library, or Math Library, that can be used anywhere and don't rely on anything else, the arrows don't point anywhere, they end just outside their yellow box.

Arrows that extend from one yellow box to another, mean those boxes rely on them. For instance Job Manager needs System Utilities.

If you don't understand something, its better to ask how it works, than to say there is something wrong with it.


Edit:
I see Eric L. explained it above, better than I did.

[ddn3]

The C4 engine is fine, the diagram is overly confusing with the excessive use of arrows but I'm hard press to come up with anything better. Mostly your engine design will be predicated by your game design, a few things all graphical applications need in some form or another (not just games) and that will be common to all designs.. Like data persistence, loading, logic, rendering of some form, input, etc..

Usually there are 3 levels of structural breakdown in code, low level, middle and high level. These levels don't say anything about the code (these could be libraries million of lines long) it said more about the dependencies upon that code. Low level stuff have a wide dependency and narrowly defined purpose. Ie timing libraries, data persistence function, network functions, etc.. Low level stuff is used to build the next level, the middle layer. This middle layer encompasses application specific domain functionality ie. scripting engine, animation engine, rendering engine, physics engine.. Then there is the high level, controller logic and UI. This layer usually handles the dynamic or data driven aspects of the application and interfaces to external elements such as various networks (ie Xbox live, Internet, custom servers, etc..) or the user etc.. I've found this breakdown to be helpful in designing my applications, your mileage may vary good luck!

-ddn

[flodihn]

I provided a link to the C4 diagram just because I thought the OP might have been interested in seeing how one example of a professional game engine is put together. Nothing more. I'm not telling people that's the only way to do things, and I'm not saying that other solutions are wrong. The diagram itself is just a big picture of how a bunch of different systems are related, and there is nothing exact about it. The green/orange boxes represent large collections of code, and the gray boxes represent features. The green arrows loosely represent dependencies, and the little black arrows simply show where in the engine specific features are handled. Red arrows are the same as green arrows, but come from plugin modules as opposed to the main engine. Arrows that are not connected to anything mean that a collection of code is used throughout the engine and that it would be silly to connect arrows from that box to almost all the other boxes.

Thank you for your explanation, if you put this together with the diagram, you would invalidate most critique I had on the diagram.

flodihn, some of your comments are way out of line, and you've shown a complete lack of respect for people (not just me) who clearly know a lot more than you.

I agree and apologize to you, accusing people for not being software engineers when they are in the software industry is something very disrepectful, I would never do that (knowingly) to anyone face to face or over the Internet.
To my defense I must say that I thought you were just random dude on the Internet, if I knew you actually the person that created the whole engine and that diagram, I would have not said such a thing, or if I had, I would have been much more diplomatic.
Also when I wrote that, I thought the C4 Engine and its architecture diagram as company/entity, which would likely not read this post, therefore I was quite harsh.

I have a Ph.D. in computer science, I've written or contributed to 9 books on the topics of game programming and computer graphics (and my game math book has been a bestseller for over a decade), I designed the graphics driver architecture for the PlayStation 3 (see patent #20090002380), I've worked in the industry for 16 years at companies including Sierra, Apple, and Naughty Dog, I regularly speak at the Game Developers Conference, and I've been running a successful game engine company for the past 7 years where I am the sole programmer for the C4 Engine. The C4 Engine architecture and source code are widely regarded by professional game programmers as some of the cleanest design in existence. Now tell me, exactly what qualifies you to say I don't have a clue about software engineering?

I have no doubts the engine has a very good archicture, in hindsight, my posts might looked like I did critisize the engine architecture itself, I just want to clarify my only critique has been about the diagram itself.

I am pretty sure you have one of the best game engine in the industry, a couple of years, when doing some research I tried to find the architecture of the largest engines around, like Unity3D, CryEngine, etc. I did not find anyone explaining how they have designed their engine, which makes yours stand out.

Also, I was just to clarify that I did not really accuse Eric for not being an software engineer, so I quote myself:

I did not call the developers clueless about software development, I called them clueless about software engineering on very loose basis, perhaps they are awesome software enginners but it does not show on that diagram.

[Soaps79]

I learned tons reading Game Coding Complete and the blog at http://gamearchitect.net/, then also digging through the XNA engine at http://xnafinalengine.codeplex.com/. Thank you for showing that diagram of C4, I'd love to read more about the high-level overview. Does anyone have more links to discussions or breakdowns of engine designs? I have implemented small ones in different school projects, but am now looking to really cement the same concept as the OP; the separation of graphics and game logic.

[flodihn]

Try scholar.google.com:
http://scholar.google.com/scholar?q=game+engine&hl=en&btnG=Search&as_sdt=1%2C5&as_sdtp=on

[jischneider]

I learned tons reading Game Coding Complete and the blog at http://gamearchitect.net/, then also digging through the XNA engine at http://xnafinalengine.codeplex.com/. Thank you for showing that diagram of C4, I'd love to read more about the high-level overview. Does anyone have more links to discussions or breakdowns of engine designs? I have implemented small ones in different school projects, but am now looking to really cement the same concept as the OP; the separation of graphics and game logic.

Hi Soaps79. Like I said in another thread:

“I find the Jason Gregory’s book (Game Engine Architecture) to be a great survey of graphic engine technologies.
I don’t know the time frame that you have, your skills, and the level of technology that you want to achieve. However, I can recommend that you research about data oriented design and component oriented design. For me the core of the engine start there, then you can plan the assets and stuff. “

I learn a lot from this book and it helps to develop the current structure of my engine.

Bye!!!

[rocklobster]

I learned tons reading Game Coding Complete and the blog at http://gamearchitect.net/, then also digging through the XNA engine at http://xnafinalengine.codeplex.com/. Thank you for showing that diagram of C4, I'd love to read more about the high-level overview. Does anyone have more links to discussions or breakdowns of engine designs? I have implemented small ones in different school projects, but am now looking to really cement the same concept as the OP; the separation of graphics and game logic.

Hi Soaps79. Like I said in another thread:

“I find the Jason Gregory’s book (Game Engine Architecture) to be a great survey of graphic engine technologies.
I don’t know the time frame that you have, your skills, and the level of technology that you want to achieve. However, I can recommend that you research about data oriented design and component oriented design. For me the core of the engine start there, then you can plan the assets and stuff. “

I learn a lot from this book and it helps to develop the current structure of my engine.

Bye!!!

I can also vouch for this book. I've been learning about game engine's recently and this book has helped tremendously. It's not really about implementation (although there is a little bit) as much as it is about the overall architecture and design of a game engine. it includes some useful diagrams and gives a brief overview of each section before breaking them all up and going in depth.