Game Development Megathread

The Something Awful Forums > Discussion > Serious Hardware/Software Crap > The Cavern of COBOL > Game Development Megathread

Thug Bonnet: Sep 22, 2004; anime tits ftw

Why is my perspective projection matrix looking down positive z rather than negative z?

code:

float n, f, r;
/* near and far clip */
n = 0.1;
f = 500.0;
/* ratio of viewport */
r = ( float ) glWidth / ( float ) glHeight;


float mp[16];
mp[0] = (1.0/r)*-(1.0/(tan(fov * 3.14159 / 360.0 ))); mp[4] = 0.0;				  mp[8] = 0.0;	    mp[12] = 0.0;
mp[1] = 0.0;					      mp[5] = 1.0/(tan(fov * (3.14159 / 360.0))); mp[9] = 0.0;	    mp[13] = 0.0;
mp[2] = 0.0;					      mp[6] = 0.0;				  mp[10] = f/(f-n); mp[14] = -((f*n)/(f-n));
mp[3] = 0.0;					      mp[7] = 0.0; 				  mp[11] = 1.0;     mp[15] = 0.0;

When i use glFrustum it works fine (looks down negative z):

code:

glFrustum(
		( ( float ) glWidth / ( float ) glHeight ) * - ( tan ( fov * 3.14159 / 360.0 ) * .1 ),
		( ( float ) glWidth / ( float ) glHeight ) * ( tan ( fov * 3.14159 / 360.0 ) * .1 ),
		- ( tan ( fov * 3.14159 / 360.0 ) * .1 ),
		tan( fov * 3.14159 / 360.0 ) * .1,
		0.1,
		500.0f
);

Thug Bonnet fucked around with this message at 23:00 on Dec 10, 2007

# ¿ Dec 10, 2007 22:56

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# ¿ May 3, 2024 21:40

Thug Bonnet: Sep 22, 2004; anime tits ftw

Can someone point me toward a good, no-bullshit discussion of quaternions that includes practical code examples? I always end up finding either high-level descriptions of the math involved or API-specific implementations. I'd love to see a bridge between the two somewhere. I haven't found the gamedev articles to be particularly helpful (they seem to suffer from the same problems).

# ¿ Jun 13, 2008 01:44

Thug Bonnet: Sep 22, 2004; anime tits ftw

Wuntvor posted:

Well, since this is a question I've been dealing with again and again, I thought I might as well post here. Basically, I have a very hard time deciding what language to do my game programming in. C# is what I'm most comfortable with, so XNA would be the natural choice, but I'd like at least the possibility to run the game on Linux as well.

Basically, it comes down to the fact that it is hard finding a decent library that does all I need. Especially, I'd like a solid UI library etc., so I always think of the days when I was doing stuff in C++ and ClanLib offered all I needed. Graphics, Sound, GUI, networking etc., so I am always tempted to move back to that. However, C++ is more of a hassle, so stuff in general takes longer to write.

I have even tried writing a SWIG wrapper around ClanLib, but their signal/slot-stuff was pretty much impossible to wrap and I gave up.

With all other languages and game libraries, there seems to be a lot of library-hunting involved. I just haven't found a combination that works for me yet, maybe it is indeed time to try out a few more python options.

You're going to have a hard time finding a single library that does it all and is completely cross platform. I don't know if I would recommend it but you could probably use C# for your Win32 gui code, use managed C++ for the core, and of course use something other than C# for the gui on other platforms. I think you'd be making life harder for yourself that way, though.

The other option is to mix and match your libs, say SDL (or whatever) for your video/input/sound, and something else (probably platform specific) for your gui lib. You could also write your own in SDL, too.

# ¿ Dec 1, 2008 12:04

Thug Bonnet: Sep 22, 2004; anime tits ftw

bullet is way, way overkill if you just want to know if things are bumping into each other

# ¿ Jan 18, 2009 01:35

The Something Awful Forums > Discussion > Serious Hardware/Software Crap > The Cavern of COBOL > Game Development Megathread

code:

code:

more falafel please posted:

Wuntvor posted: