Server Help

[Mine GO BOOM]

id Software has released Quake3's source code. A fun read if you are into learning to write games.

Since their servers are being hammered, you can download a copy here (5.45 MB).

[Dr Brain]

Hrm, I thought it already was. Maybe that's the other two quakes. Can't say that I've ever played any of them.
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Hyperspace Owner

Smong> so long as 99% deaths feel lame it will always be hyperspace to me

[CypherJF]

Never played it either. But, I guess this is good?
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Performance is often the art of cheating carefully. - James Gosling

[Purge]

Yes, we can all stare at it now.

[Solo Ace]

I'd actually enjoy reading it.
My friends have been playing it a lot, and well, I didn't, because I... sucked.
Anyway, I was forced to run a server for them.
The game really made me wonder what it'd look like "behind the scene".
Too bad this is 1.32, not 1.16j, but I guess the real difference would only be the Punkbuster protection and the updates in the menu.
Thanks though, I'll read it, as far as I can understand it.

[Mine GO BOOM]

I still like the cool hacks used to help speed up the game.

Code: Show/Hide int Q_log2( int val ) {    int answer;    answer = 0;    while ( ( val>>=1 ) != 0 ) {       answer++;    }    return answer; }

Code: Show/Hide float Q_rsqrt( float number ) {    long i;    float x2, y;    const float threehalfs = 1.5F;    x2 = number * 0.5F;    y  = number;    i  = * ( long * ) &y;                  // evil floating point bit level hacking    i  = 0x5f3759df - ( i >> 1 );               // what the fuck?    y  = * ( float * ) &i;    y  = y * ( threehalfs - ( x2 * y * y ) );   // 1st iteration //   y  = y * ( threehalfs - ( x2 * y * y ) );   // 2nd iteration, this can be removed #ifndef Q3_VM #ifdef __linux__    assert( !isnan(y) ); // bk010122 - FPE? #endif #endif    return y; }

[Cyan~Fire]

Optimizers can't do that? I hate micro-optimized C.
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Wise men STILL seek Him.

[Mine GO BOOM]

[Cyan~Fire]

Well, if I ever write an optimizing compiler, I'm going to detect if someone needs a floating pt/integer function and call different code.

[Mr Ekted]

[Gravitron]

I thought fear factor was the geek version.

[Mine GO BOOM]

[Mr Ekted]

In hardware design languages optimizations of this kind are much easier for the compilers because the use of the inputs and outputs is explicit. If you have an add "function" that takes 2 8-bit values, adds the upper 7 bits, then outputs only the lower 6 of those...In C it would look kinda like this:

Code: Show/Hide wire[6:0] add (wire [7:0] a, wire [7:0] b) { wire [7:0] c; c = a[7:1] + b[7:1]; add = c[6:0]; }

One bit of each input, and one bit of the output are not used, so they are completely removed from the final compiled result, including "outside the function". No wires will exist for them. It's much more explicit but much more of a pain in the ass.

I'm glad C is the way it is.

[Dr Brain]

Here's some VHDL code for a circuit that adds two 3 bit lines and puts the output on a 4 bit line. This is straight from a calculator circuit I did last semester.

Code: Show/Hide entity summer is   port(input1, input2: in std_logic_vector(2 downto 0); output: out std_logic_vector(3 downto 0)); end summer; architecture algorithmic of summer is begin   process(input1, input2)   begin     -- the ampersand is concatenation. it's used here to change     -- the three wide inputs to four wide.     output <= ('0' & input1) + ('0' & input2);   end process; end algorithmic;

[Mr Ekted]

I've only ever used Verilog.

[Cyan~Fire]

I was just talking about floating point of integer. Yes, I guess overloading functions would work just as well, but a compiler should be able to detect a typecast from, say, int to double for a log or sqrt function.

[SamHughes]

Depending on your distribution of numbers for val, this log2 function might run significantly faster. It works faster for higher values of val -- the border is at 128 or 256.

Code: Show/Hide int log2(unsigned long val) {     int ret = 0;     if (val >> 16) {         ret |= 16;         val >>= 16;     }     if (val >> 8) {         ret |= 8;         val >>= 8;     }     if (val >> 4) {         ret |= 4;         val >>= 4;     }         if (val >> 2) {         ret |= 2;         val >>= 2;     }     ret |= val >> 1;     return ret; }

[Mr Ekted]

Something tells me this is wrong, but I don't want to spend the time to figure it out.

[SamHughes]

Or maybe this version, which in my testing beats or ties Q_log2 for like, all inputs except 0 and 1.

Code: Show/Hide int log2quick(unsigned long val) {    int ret;    if (val >> 8) {       val >>= 8;       ret = 8;       if (val >> 12) {          ret = 20;          val >>= 12;       }       if (val >> 6) {          ret += 6;          val >>= 6;       }       if (val >> 3) {          ret += 3;          val >>= 3;       }       ret += (val >> 1) & 1 + (val >> 2);    } else {       ret = 0;       if (val >> 4) {          ret = 4;          val >>= 4;       }       if (val >> 2) {          ret |= 2;          val >>= 2;       }       ret |= val >> 1;    }    return ret; }