Java-Gaming.org    
Featured games (91)
games approved by the League of Dukes
Games in Showcase (581)
games submitted by our members
Games in WIP (500)
games currently in development
News: Read the Java Gaming Resources, or peek at the official Java tutorials
 
   Home   Help   Search   Login   Register   
  Show Posts
Pages: [1] 2 3 ... 20
1  Game Development / Newbie & Debugging Questions / Re: What kind of version control system should I use? on: 2014-04-20 12:50:21
Anything  but SVN (or CVS and sourceforge will make you want to kill yourself). Centralized version control simply doesn't work and is outdated. Even with just one dev.
2  Discussions / Miscellaneous Topics / Re: What are Anti-Virus Developers Protecting us From? on: 2014-04-14 12:16:14
Proof of how much of a con they are, was when a very large AV vendor whitelisted a rootkit from a large music retailer. Because they ask nicely.
3  Game Development / Networking & Multiplayer / Re: UDP Packets over LAN on: 2014-03-06 11:59:14
Start with TCP. Only move to UDP if you really need it. Which i doubt you do.

Then use something like tcpdump to inspect packets and see if your are in fact sending packets you expect and double check that ip address are right or that your not trying to go across subnet boundaries etc. ie can you ftp/ssh between these devices.
4  Game Development / Newbie & Debugging Questions / Re: Curved shape collision detection? on: 2013-12-09 10:43:28
The  SAT states that if its not overlapping in one axis its not overlapping (more or less). But it does not say that if they are over lapping that it has collided. In particular convex object can overlap on all axis and not be a collision.

Normally to accurately calculate collisions in these kind of cases we use math. So we use the mathematical definition of the curve and the AABB and come up with a set of simulations equations which we solve.  However in a game this is not usually done since its too slow or just not required. There are a number of different ways to approximate the curve/shape whatever. Small bounding spheres, line segments, polygons etc. Or just a AABB....
5  Games Center / Contests / Re: AI Contest : Chess on: 2013-12-06 13:22:07
There are already quite a few such AI plugin frameworks out there for chess. Perhaps not in java, but the interfaces don't prevent java AFAIK. AI in chess is more or less a done deal with a min/max tree pruning being the way to do it.

I think it is perhaps less interesting that some other games like Go, or Stratego.
6  Game Development / Performance Tuning / Re: Which is faster? :P on: 2013-12-05 15:29:11
I use something very similar to Roquen's rng, its somewhere in the code section. It can generate 2^31 random numbers in seconds on modern machines. Not minutes. It is also "more random" than that stupid mersenne twister.
7  Game Development / Performance Tuning / Re: Which is faster? :P on: 2013-12-05 12:42:11
Roquen is right. A L3 cache miss can cost 100s of cycles, even L2 cache is many cycles, you can calculate a lot in that time. LUT are something that worked only a long time ago. Memory access is the dominate feature in performance on modern CPUs. Cache coherency is more or less everything.

Microbenchmarks are even worse with LUT at missleading people. Cache performance when doing the same things a million times back to back is not the same as doing something else in between each lookup.

Finally who cares. The thing you do in your branch is going to cost more cpu than this branch.
8  Discussions / General Discussions / Re: Give me a game or program idea! on: 2013-12-03 17:01:51
Ludum Dare games. Just pick one. Do it with or without time constraints and see what falls out.

Consider all this web html node.js whatever crap too. You can never know to many lanuages or tools. 
9  Game Development / Newbie & Debugging Questions / Re: java.io.File bug in Linux? on: 2013-12-03 09:29:16
Making assumptions about where PWD is not a good idea. On all platforms its something that should not be assumed.

For example if i have a launch icon on the desktop, what is the pwd? in the windows start menu? What about simlinks?

That is why many applications will have a "installed in"  directory. I use a launch script to ensure that all appropriate directories are set. In unix this means using things like readlink so you can use simlinks properly.
10  Discussions / General Discussions / Re: Bad Habits on: 2013-12-02 10:06:25
Spending weeks planing the perfect code layout without writing a single line of code....
11  Game Development / Performance Tuning / Re: Large resolution performance boosting on: 2013-12-02 10:04:58
I many ways the HD tv thing and DVI have put monitor resolutions back quite a bit, the DVI/HDMI in particular. Spent too much time on encryption that wasn't needed in the first place. We are only just now getting back to resolutions comparable to CRT monitors i once had.

Of course it did weigh 60kg and cost as much as 10 computers do today... but meh, I want my 4k display now already. Dual Displays. Wait i have 2 video cards in this system. Quad 4k monitors for the win. 
12  Game Development / Newbie & Debugging Questions / Re: BLOB vs flat file tables on: 2013-11-29 18:25:20

The problem here is you'd need to track where each and every one of the items is, not to mention map them with their unique key in server memory.

In a fast changing environment like a MMORPG this quickly becomes wasteful, hard to track and bug prone.
What are you talking about? updating something is just as easy and in fact easier than deleting it and re-adding it and assigning new keys. Not to mention less likely to result in lost data when it crashes.

All MMO's have to keep track of everything no matter how they are implemented.
13  Game Development / Newbie & Debugging Questions / Re: BLOB vs flat file tables on: 2013-11-29 15:57:14
Your assigning new primary keys for an update operation. This is not how it should be done, an update should just update, not delete and insert. Also that is a *lot* of updates and 2**64 stupid many.

Say you have 10000 players and you update the data once every second (hint, that is too often). It will take  119 hours to use all the keys. If you just update you only use 10000 keys. If you have 2**64 keys it will take 58 million years to use all the keys at a rate of 10000 per second.
14  Java Game APIs & Engines / Engines, Libraries and Tools / Re: LWJGL: Random direction thoughts on: 2013-11-27 11:50:20
The hyperthreading thing was in the context of simulations. So fairly optimized code that is vectorized with little branching. In this case HT was over slower than none. Since just about all code that is run on the High performance clusters is like that, most have it disabled. We should note it wasn't a huge difference, 10-20% or thereabouts.

This is not the case for the "general purpose" clusters. ie where a lot of python scripts and database intensive jobs are run.

For games and desktop apps i have no idea what would work out faster. I would suspect HT to win slightly or to be a tie since there should be more waiting around for most processes.
15  Discussions / General Discussions / Re: Picking Techniques on: 2013-11-26 15:33:42
If you dead against a physics engine, or like me didn't want to waste time with one for just picking. I found that ray tracing with bounding spheres worked awesome. I was picking things on objects too. I used a hierarchy  of such spheres for that. I would group them a bit with bounding spheres as well if there are lots of objects on the screen. Note that its very easy to check if a ray intersects a sphere. For odd shapes i use more than one sphere. 

Not sure about pixel perfect however. My models have quite a lot of triangles if up close.
16  Java Game APIs & Engines / Engines, Libraries and Tools / Re: LWJGL: Random direction thoughts on: 2013-11-26 15:23:55
Quote
You generally don't want to mix two "compute-heavy" threads in the same hyper-threaded core, performance will suffer.
This has been our experience to the point where hyper threading is disabled on our clusters.

As for including this or not or other performance related feature. I can't see any harm if its easy, doesn't create unreasonable dependencies and fails somewhat gracefully.
17  Java Game APIs & Engines / Engines, Libraries and Tools / Re: LWJGL: Random direction thoughts on: 2013-11-26 14:35:14
Well personally i like to be able to restrict how many cpu's a game is running when i have sims going. Just because i have cores does not mean i want the game/app to use them

This is however an edge case. I just wish people would always let such settings be manually overridden.
18  Java Game APIs & Engines / Engines, Libraries and Tools / Re: LWJGL: Random direction thoughts on: 2013-11-26 14:23:49
Can you even get that info? I mean with virtualization, hyper threading etc does the number of "physical cores" even have a simple answer?
19  Games Center / Showcase / Re: Zombie Hordes on: 2013-11-21 10:41:21
OT: i am still waiting for my Zombicide game sets. I got them all!
20  Discussions / General Discussions / Re: Developing on mobile phones and tablets on: 2013-11-20 11:38:33
that's not a tablet, that's a table.
21  Discussions / General Discussions / Re: Developing on mobile phones and tablets on: 2013-11-20 09:30:53
I am inclined to think not. There is one thing you can't do with a tablet. Make it have a large screen. Its not a tablet once its 40-80cm across. Even if you have some roll up nano fandangled uber whatever tech, its primary purpose is to be more compact and lighter than a laptop--and with better battery life. Accessories quickly make this not a tablet. So a laptop works better. EVEN if the laptop is a Large tablet with a keyboard, its a form factor of a laptop and will be used as one. Not a tablet. Think about using that roll out whatever holo thing on a bus... or in a plane etc.

Tablets shine for people who don't really use a computer as a computer, but as a uber fancy TV they can almost fit in their pocket.

Add that many of us have a desk/office space then a desktop/laptop with dock make more sense. And they are cheap now. My dual 1080 monitors where real cheap. I am thinking of upgrading to 4k soon, big 4k monitors.
22  Game Development / Networking & Multiplayer / Re: hosting java socket based server on: 2013-11-20 09:20:07
With virtualization, hosted servers can be real cheap and can easily scale to the size you need if you get popular. The last one i had was less than 10EUR a month and about 100Gig of data+20Gig space. Less than i spend on beer. It was a while ago, i expect the space to be much larger now. Bandwidth really costs typically but again can scale real well.

Prices go up fast for co location, but again this is something you wouldn't bother with till your big enough that the cost is not going to be a problem anyway. Linode has a decent reputation last i heard but is also not the cheapest either. 
23  Game Development / Game Mechanics / Re: any experience with gravity simulations? on: 2013-11-15 18:44:08
To back up Roquen's point. NASA and co use these simple parametric orbits for everything from space probes to knowing where to point that dish to get signals of a satellite. That is you know they are ellipsis and how fast it goes at different parts of the ellipses. Of course i think that is too much. Just stick to circles. If its good enough for multi million dollar space missions surely its enough for a game.

In Eve planets don't even move.
24  Game Development / Game Mechanics / Re: any experience with gravity simulations? on: 2013-11-15 14:32:24
I assume you talking to me and you are asking about the simulation stuff. Basically you can do a PhD thesis on this stuff. Its that hard to get accurate and right.

But a simple integrator, just use a 2nd order leap frog. If you don't know what that is. Stick with parametric representations.
25  Discussions / General Discussions / Re: Yet another transputer-like experiment on: 2013-11-12 09:32:32
These types of cores and architectures, like the transputer does not share memory. It has communication buses between cores and you pass messages to share data and synchronize. The general "mesh" like arrangement is quite popular for study at the moment and was back in 2010 as well. I reviewed a few papers on it. There is even hardware around.
26  Game Development / Game Mechanics / Re: any experience with gravity simulations? on: 2013-11-12 09:27:37
So not to negate what was already said. But even with super accurate integrators, or even perfect math, under the laws of gravity 3 body systems are not stable. There are like 3 exact configurations of 3 body's that are stable as far as mathematics are concerned but perturb them in any way.... 

Its called the 3 body problem. http://en.wikipedia.org/wiki/Three-body_problem

However in reality there is typically only one important body and the rest can be ignored. For example when considering the earths orbit around the sun, we can even ignore the earths mass and we have approximately a 1 body system with an infinitely light mass orbiting it. When considering earth, moon and sun we can consider earth moon as a system, then the earth/moon center of mass orbits the sun. If we want to add Jupiter to the mix, we ignore the effects of earth on Jupiter  etc.

However full simulations are also possible, BUT you do it different from just brute force accuracy. You need the integration method to be reversible to conserve important properties of the system (mostly momentum). So a 2nd order leapfrog is typically way better than a 4th order RK method. 

But do you need this accuracy for a game? Using parametric orbits probably works better anyway.
27  Game Development / Networking & Multiplayer / Re: Artificial Latency and package dropping on: 2013-11-06 12:21:53
These days its typically almost no packet loss or reordering.. Or you get close to no packets at all and your wasting your time. There are some exceptions with some wireless stuff. But typically this is all hidden in lower layers of the stack as well.

Did you know that upd still can fragment packets and wait for them if the MTU size is smaller than packet size? 

Perhaps its too late. But really always start with TCP and only change if there is a really really good reason to. With UDP you need to know about flow control, congestion collapse, and the 2 generals problem at a minimum. Considering it took experts in the field years to get this all right in TCP, it pays to use that expertise and experience. 
28  Java Game APIs & Engines / Java 2D / Re: Getting all available screen resolutions on Linux on: 2013-10-22 16:20:17
On linux you will often need some mode lines in your xorg config file. Since these days there isn't one. You end up with just one valid mode, the current one. I have always had to add modelines when i want to use more than the current mode on my linux distros with nvidia drivers.
29  Discussions / General Discussions / Re: Is it bad to start with Python and then move the Java? on: 2013-08-14 15:49:12
And 11 is plenty old enough to "google it". Its not a 5 year old that need help crossing the road anymore. If they won't do that... we there is the saying about a smelly kind of creek and no paddles. 
30  Discussions / General Discussions / Re: Space game scale on: 2013-08-07 14:06:33
As a regular eve player, and someone who did astrophysics. Eve does what every space game should do. Cheat.
<br><br>
Ships are mostly to "scale", and can be quite high poly. But with LOD and the fact that typically only one ship is close enough to the camera to be polys most of the time, the total poly count is really low compared to many modern games. They aim for quite low end hardware in general.
<br><br>
They cheat with planet sizes and suns and backgrounds.  For example i can be 70AU from the local sun, at that distance it would look like a very bright star, not a sun. But they still render it as a fully sized sun. And the results are a much more fun game.
Pages: [1] 2 3 ... 20
 

Add your game by posting it in the WIP section,
or publish it in Showcase.

The first screenshot will be displayed as a thumbnail.

xsi3rr4x (54 views)
2014-04-15 18:08:23

BurntPizza (53 views)
2014-04-15 03:46:01

UprightPath (66 views)
2014-04-14 17:39:50

UprightPath (49 views)
2014-04-14 17:35:47

Porlus (66 views)
2014-04-14 15:48:38

tom_mai78101 (90 views)
2014-04-10 04:04:31

BurntPizza (151 views)
2014-04-08 23:06:04

tom_mai78101 (246 views)
2014-04-05 13:34:39

trollwarrior1 (204 views)
2014-04-04 12:06:45

CJLetsGame (211 views)
2014-04-01 02:16:10
List of Learning Resources
by SHC
2014-04-18 03:17:39

List of Learning Resources
by Longarmx
2014-04-08 03:14:44

Good Examples
by matheus23
2014-04-05 13:51:37

Good Examples
by Grunnt
2014-04-03 15:48:46

Good Examples
by Grunnt
2014-04-03 15:48:37

Good Examples
by matheus23
2014-04-01 18:40:51

Good Examples
by matheus23
2014-04-01 18:40:34

Anonymous/Local/Inner class gotchas
by Roquen
2014-03-11 15:22:30
java-gaming.org is not responsible for the content posted by its members, including references to external websites, and other references that may or may not have a relation with our primarily gaming and game production oriented community. inquiries and complaints can be sent via email to the info‑account of the company managing the website of java‑gaming.org
Powered by MySQL Powered by PHP Powered by SMF 1.1.18 | SMF © 2013, Simple Machines | Managed by Enhanced Four Valid XHTML 1.0! Valid CSS!