I've been reading about CUDA and OpenCL and have learned that before these frameworks developers could only use low level APIs like OPENGL and D3D. Unfortunately I haven't been able to find much information about it.
Was it a widespread or commercial practice or was it just something they used in research and military labs? I'm sure somebody here will have experience with earlier GPGPU programming.
There were a number of approaches to GPGPU before CUDA and OpenCL came along, e.g. the Brook and Cg programming languages.
It was mostly used in research. Of course, some GPGPU techniques was applied for software which needed to put pixels on the screen and for games, but mostly it was a research thingy.
If you're interested in the history, I think one of the earliest papers that made people realize GPGPU was possible was a SIGGRAPH 2000 paper by some SGI guys at the time, "Interactive Multi-Pass Programmable Shading". The idea was that they could translate any RenderMan Shading Language shader into a sequence of OpenGL calls (plus a few extensions). The amazing part about this is that it used no programmable shaders at all - it was all based on setting the right parameters to the blending equations and using many passes. The numerical precision was laughable (8 or 16 bits fixed-point), but the idea of using graphics hardware to compute was there.
From that point, they could do fancier per-pixel things, which together with the hardware improvement quickly led to the GPGPU fluid flow solvers circa 2003. Which is about the time everyone collectively blushed at the gigantic hack it all was, leading to CUDA and OpenCL.
Sorry if this is a broad question, but other than Objective-C, Cocoa, and OpenGL ES, what technologies or concepts would you suggest I read up on before writing a game for the iPhone? I'm a beginning game developer and need all the help I can get :)
MATHS - I would advise this topic
Some example areas of interest for applications in Game Development
Calculus, Geometry,The Cartesian Co-ordinate System, Vectors, Matrices, Transformations etc...
Sorry, my answer is not computing related.
A game tells a story, a great game tells a great story. So I would suggest to learn principles of storytelling.
Not going as scholar as Aristotle's Poetics, I recommend more modern Story by Robert McKee. It focuses on movie making, but I am pretty sure that many of the concepts he develops can be applied to game making.
You should read some articles on GameDev. Obviously, learning some of the fundamental concepts in computer graphics would be very helpful. But really, once you get to where you can write Objective-C and understand the APIs, go ahead and get started. You will learn a lot in the process; of course, keep learning and reading about these things I mentioned, but start coding. Find some books on game programming, particularly AI and so forth. Go ahead and get your feet wet programming though. Of course, be sure you learn your language thoroughly.
Quite frankly, I have found that I never know what I need to know until I actually get my hands dirty. That's why I suggested here that someone looking to jump into designing a 3-D iPhone game start with some simpler, targeted projects. These targeted projects can teach you core concepts as you put them to practical use. OpenGL seemed like this impossible-to-understand black box until I made myself perform some simple tasks with it. In a few weeks, I had an application based on it.
In college, I would spend weeks trying to understand the theory behind an aspect of thermodynamics, but then I would see one practical application for it and the whole thing would fall into place. Since then, I've focused on finding specific applications for concepts before spending too much time with the pure theory behind them.
A solid understanding of what makes a good gaming UI especially on the iPhone would be key, especially with the options it provides, be it accelerometers, or onscreen touch inputs.
I'd be sure to try out existing games and see what works, what doesn't, and what gets good feedback. You may also want to look at Flash and DS based games to see what works on other small screens/devices.
Does anyone know a good beginners guide to using OpenGLES on the iPhone? I have found some but they all require assumed knowledge which I don't have.
Simon Maurice has some great tutorials on the very first steps. Take a look: http://www.cocoachina.com/wiki/index.php?title=Category%3aSimon_Maurice_iPhone_OpenGL_ES. Do them from the beginning and you'll have a good sense of the basics.
EDIT:
Backup link
Source code
You need only one reference:
http://www.khronos.org/opengles/sdk/1.1/docs/man/
Yeah, some of the documentation doesn't make a lot of sense the first time you read it, but really, read the sentence/paragraph/page again, and again. It really does make sense, and it's very accurate. Which is something you really can't say from tutorials. Tutorials are almost always written by people that don't seem too fussed about leaving out important details while documentation like that is usually written by very nitpicky people that cram every little important fact into (possibly overly-complex) sentences.
Oh, and one golden tip: Add a search function to your browser that does this:
http://www.google.com/search?q=%s+site%3Awww.khronos.org%2Fopengles%2Fsdk%2F1.1%2Fdocs%2Fman%2F&btnI
(replace %s by whatever your browser's search term replacement string is, the above example is for Opera)
I've bound it to the o prefix, so whenever I need to look something up on OpenGL/ES, I just type o glDrawElements in the address bar and instantly get the documentation page on it.
Once again, if I may plug my own work, I have a short writeup on what I learned while writing Molecules for the iPhone. I came into this having no experience with the 3-D side of OpenGL (I had done a little 2-D hardware acceleration before), so I have a bit of a different perspective on the subject. The source code to Molecules is available, so you might be able to learn something from poking around inside it. I also have written a post on how to use Core Animation structures and functions to accelerate OpenGL ES rendering, if you want something a little more technical.
Bill Dudney has a post here about how he started getting into OpenGL ES, and then a follow-on here where he provides code for a Wavefront OBJ loader for the iPhone.
I believe that I've seen a few more good resources around Stack Overflow in various answers, so you might search around and see what else you can find here.
For OpenGL NeHe is a great tutorial. Though, it doesn't specifically cover OpenGLES, it should still be pretty helpful. Just be prepared to run into things now and again that won't work on the iphone.
Also you can get v1.1 if "The Red Book" online.
Simon Maurice's tutorial can be found here
"The Red Book" is not recommended to OpenGL/OpenGLES beginner. It is book for professionals.
The first step is should try to run downloaded simple programs or simple codes from OpenGL web sites.
Here's a good (non-Chinese) link to Simon Maurice's tutorials:
http://web.me.com/smaurice/iPhone_OpenGL_ES_Blog/iPhone_OpenGL/Archive.html
His tutorials are excellent; they're what I used to learn OpenGL ES.
In addition to "The Red Book", another useful book -with tutorials and reference- is OpenGL SuperBible.
Again not OpenGLES specific, but I believe it is useful to learn OpenGL features in general, then filter out the ones you don't need.
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Summary:
Can I program a "thick
client" game in C without reinventing
wheels, or should I just bite the
bullet and use some library or SDK?
I'm a moderate C programmer and am not
afraid to work with pointers, data
structures, memory locations, etc. if
it will give me the control I need to
make a great "thick-client" game.
However, I'm thinking of eschewing
high-level languages & frameworks for
the sake of power and control, not
ease of use.
I'm interesting in tinkering with a 2D fighting/platforming game as a side project sometime. I'm primarily a Linux server-side programmer with experience in Python, Ruby and PHP. I know that there are excellent frameworks in some of these languages, like PyGame. I am also aware of the success people have had with stuff like Air and .NET... but I have some concerns:
Performance: Scripting languages are notoriously slow. If I'm making a real-time game, I want it to be as snappy as possible.
Huge binaries: Using frameworks like .NET or scripting languages like Ruby often result in big CLRs or libraries that you wouldn't otherwise need. The game I want to make will be small and simple--I don't want its CLR to be bigger than the game itself!
Extra stuff: Honestly, I just don't like the idea of inheriting some big game library's baggage if I can wrap my head around my own code better.
I'm asking this question because I know I'm very susceptible to Not Invented Here Syndrome. I always want to program it myself, and I'm sure it wastes a lot of time. However, this works out for me remarkably often--for example, instead of using Rails (a very big web project framework with an ORM and GUI toolkit baked in), I used an array of smaller Ruby tools like rack and sequel that fit together beautifully.
So, I turn to you, SO experts. Am I being naive? Here's how I see it:
Use C
Cons
Will probably make me hate programming
High risk of reinventing wheels
High risk of it taking so long that I lose interest
Pros
Tried & true - most A-list games are done in C (is this still true today?)
High level of control over memory management, speed, asset management, etc., which I trust myself to learn to handle
No cruft
Use framework or SDK
Cons
Risk of oversized deliverable
Dependent on original library authors for all facets of game development--what if there isn't a feature I want? I'll have to program it myself, which isn't bad, but partially defeats the purpose of using a high-level framework in the first place
High risk of performance issues
Pros
MUCH faster development time
Might be easier to maintain
No time wasted reinventing common paradigms
What else can I add to this list? Is it a pure judgment call, or can someone seal the deal for me? Book suggestions welcome.
I believe you are working under a fallacy.
There are several frameworks out there specifically for game programming --- written by people with much experience with the complication of game design, almost certainly more tha you do.
In other words, you have a "High risk of performance issues" if you DON'T use a framework.
My current thinking is:
If you want to learn to program, start making the game engine from the base elements upwards (even implementing basic data structures - lists, maps, etc). I've done this once, and while it was a learning experience, I made many mistakes, and I wouldn't do this a second time around. However for learning how to program as well as making something cool and seeing results I'd rate this highly.
If you want to make a proper game, use whatever libraries that you want and design all of the game infrastructure yourself. This is what I'm doing now, and I'm using all of the nice things like STL, ATL/WTL, Boost, SQLite, DirectX, etc. So far I've learnt a lot about the middle/game logic aspect of the code and design.
If you just want to make a game with artists and other people collaborating to create a finished product, use one of the existing engines (OGRE, Irrlicht, Nebula, Torque, etc) and just add in your game logic and art.
One final bit of wisdom I've learnt is that don't worry about the Not Invented Here syndrome. As I've come to realise that other libraries (such as STL, Boost, DirectX, etc) have an order of magnitude (or three) more man-hours of development time in them, far more than I could ever spend on that portion of the game/engine. Therefore the only reason to implement these things yourself is if you want to learn about them.
I would recomend you try pyglet.
It has good performance, as it utilizes opengl
Its a compact all-in-one library
It has no extra dependencies besides python
Do some tests, see if you can make it fast enough for you. Only if you prove to yourself that it's not move to a lower level. Although, I'm fairly confident that python + pyglet can handle it... at worst you'll have to write a few C extensions.
Today, I believe you are at a point where you can safely ignore the performance issue unless you're specifically trying to do something that pushes the limits. If your game is, say, no more complicated than Quake II, then you should choose tools and libraries that let you do the most for your time.
Why did I choose Quake II? Because running in a version compiled for .NET, it runs with a software renderer at a more than acceptable frame rate on a current machine. (If you like - compare MAME which emulates multiple processors and graphics hardware at acceptable rates)
You need to ask yourself if you are in this to build an engine or to build a game. If your purpose is to create a game, you should definitely look at an established gaming engine. For 2D game development, look at Torque Game Builder. It is a very powerful 2D gaming engine/SDK that will put you into production from day 1. They have plenty of tools that integrate with it, content packs, and you get the full source code if you want to make changes and/or learn how it works. It is also Mac OSX compatible and has Linux versions in the community.
If you are looking for something on the console side, they have that too.
I'm surprised nobody has mentioned XNA. Its a framework built around DirectX for doing managed DirectX programming while removing a lot of the fluff and verbosity of lower level DirectX programming.
Performance-wise, for most 2D and 3D game tasks, especially building something like a fighting game, this platform works very well. Its not as fast as if you were doing bare metal DirectX programming, but it gets you very close, and in a managed environment, no less.
Another cool benefit of XNA is that most of the code can be run on an Xbox 360 and can even be debugged over the network connection was the game runs on the Xbox. XNA games are now allowed to be approved by the Xbox Live team for distribution and sale on Xbox Live Arcade as well. So if you're looking to take the project to a commercial state, you might have am available means of distribution at your disposal.
Like all MS development tools, the documentation and support is first rate, and there is a large developer community with plenty of tutorials, existing projects, etc.
Do you want to be able to play your game on a console? Do you want to do it as a learning experience? Do you want the final product to be cross platform? Which libraries have you looked into so far?
For a 2d game I don't think performance will be a problem, I recommend going with something that will get you results on screen in the shortest amount of time. If you have a lot of experience doing Python then pyGame is a good choice.
If you plan on doing some 3d games in the future, I would recommend taking a look at Ogre (http://www.ogre3d.org). It's a cross platform 3d graphics engine that abstracts away the graphics APIs. However for a 2d project it's probably overkill.
The most common implementation language for A-list games today is C++, and a lot of games embed a scripting language (such as Python or Lua) for game event scripting.
The tools you'd use to write a game have a lot to do with your reasons for writing it, and with your requirements. This is no different from any other programming project, really. If it's a side project, and you're doing it on your own, then only you can assess how much time you have to spend on this and what your performance requirements are.
Generally speaking, today's PCs are fast enough to run 2D platformers written in scripting languages. Using a scripting language will allow you to prototype things faster and you'll have more time to tweak the gameplay. Again, this is no different than with any other project.
If you go with C++, and your reasons don't have to be more elaborate than "because I want to," I would suggest that you look at SDL for rendering and audio support. It will make things a little bit easier.
If you want to learn the underlying technologies (DirectX, or you want to write optimized blitters for some perverse reason) then by all means, use C++.
Having said all that, I would caution you against premature optimization. For a 2D game, you'll probably be better off going with Python and PyGame first. I'd be surprised if those tools will prove to be inadequate on modern PCs.
As to what people have said about C/C++/Python, I'm a game developer and my company encourages C. Not b/c C++ is bad, but because badly written C++ is poison for game development due to it's difficulty to read/debug compared to C. (C++ gives benefits when used properly, but let a junior guy make some mistakes with it and your time sink is huge)
As to the actual question:
If your purpose is to just get something working, use a library.
Otherwise, code it yourself for a very important reason: Practice
Practice in manipulating data structures. There WILL be times you need to manage your own data. Practice in debugging utility code.
Often libs do just what you want and are great, but sometimes YOUR specific use case is handled very badly by the lib and you will gain big benefits from writing you own. This is especially on consoles compared to PCs
(edit:) Regarding script and garbage collection: it will kill you on a console, on a recent game I had to rewrite major portions of the garbage collection on Unreal just to fill our needs in the editor portion. Even more had to be done in the actual game (not just by me) (to be fair though we were pushing beyond Unreal's original specs)
Scripting often good, but it is not an "I win" button. In general the gains disappear if you are pushing against the limits of your platform. I would use "percent of platforms CPU that I have to spare" as my evaluation function in deciding how appropriate script is
One consideration in favor of C/C++/obj-C is that you can mix and match various libraries for different areas of concern. In other words, you are not stuck with the implementation of a feature in a framework.
I use this approach in my games; using chipmunk for 2D physics, Lua as an embedded scripting language, and an openGL ES implementation from Apple. I write the glue to tie all of these together in a C language. The final product being the ability to define game objects, create instances of them, and handle events as they interact with each other in C functions exposed to Lua. This approach is used in many high performance games to much success.
If you don't already know C++, I would definitely recommend you go forward with a scripting language. Making a game from start to finish takes a lot of motivation, and forcing yourself to learn a new language at the same time is a good way to make things go slowly enough that you lose interest (although it IS a good way to learn a new language...).
Most scripting languages will be compiled to byte code anyway, so their biggest performance hit will be the garbage collection. I'm not experienced enough to give a definite description of how big a hit garbage collection would be, but I would be inclined to think that it shouldn't be too bad in a small game.
Also, if you use an existing scripting language library to make your game, most of the performance critical areas (like graphics) can be written in C++ anyway (hopefully by the game libraries). So 80% of the CPU might actually be spent in C++ code anyway, despite the fact that most of your project is written in, say Python.
I would say, ask yourself what you want more: To write a game from start to finish and learn about game development, or to learn a new language (C++). If you want to write a game, do it in a scripting language. If you want to learn a new language, do it in C++.
Yeah unless you just want to learn all of the details of the things that go into making a game, you definitely want to go with a game engine and just focus on building your game logic rather than the details of graphics, audio, resource management, etc.
Personally I like to recommend the Torque Game Builder (aka Torque 2D) from GarageGames. But you can probably find some free game engines out there that will suit your needs as well.
I'm pretty sure most modern games are done in C++, not C. (Every gaming company I ever interviewed with asked C++ questions.)
Why not use C++ and existing libraries for physics + collisions, sound, graphics engine etc. You still write the game, but the mundane stuff is taken care of.
There are alot of different solutions to the issue of abstracting and each deals with it in different ways.
My current project uses C#, DirectX 9, HLSL and SlimDX. Each of these offers a carefully calibrated level of abstraction. HLSL allows me to actually read the shader code I'm writing and SlimDX/C# allows me to ignore pointers, circular dependencies and handling unmanaged code.
That said, none of these technologies has any impact on the ease of developing my AI, lighting or physics! I still have to break out my textbooks in a way that I wouldn't with a higher-level framework.
Even using a framework like XNA, if most video games development concepts are foreign to you there's a hell of a lot still to take in and learn. XNA will allow you to neatly sidestep gimbal lock, but woe betide those who don't understand basic shading concepts. On the other hand, something like DarkBASIC won't solve your gimbal lock problem, but shading is mostly handled for you.
It's a sufficiently big field that your first engine will never be the one you actually use. If you write it yourself, you won't write it well enough. If you use third party libraries, there's certainly aspects that will annoy you and you'll want to replace.
As an idea, it might be worth taking various libraries/frameworks (definately make XNA one of your stops, even if you decide you don't want to use it, it's a great benchmark) and trying to build various prototypes. Perhaps a landscape (with a body of water) or a space physics demo.