Random Functions that People Might Find Useful!!!

[Error]

These are just a few that I've found quite useful in my mods. Feel free to post your own, as they may make peoples' lives easier.

I know these aren't the best, maybe could be simplified, but they'd be good for a newb to have. Maybe......

I'll feel like an idiot if I typed those in wrong

Code: Select all

//
// Random Whole Number Generator
// Use: to find a whole number between lower and higher
//
float(float lower, float higher) rand =
{
   local float ra;
   ra = lower + (random() * (higher - lower);
   ra = rint(ra); // rounds the number
   return ra;
};

//
// Convert Feet to Quake Units
// Use: Easier for the programmer to understand
//
float(float feet) ft_to_qu =
{
   local float qu;
   qu = feet * 8;
   return qu;
};

//
// Convert Quake Units to Feet
// Use: Easier to display information to the player
//
float(float qu) qu_to_ft =
{
   local float ft;
   ft = qu / 8;
   return ft;
};


[Chip]

Thanks, this could be the beginning of a snippet collection.

[andrewj]

Error, your rand() function should use floor() instead of rint(), otherwise the results are not uniform.

Example of results of your code generating numbers 1 to 8:

1: 64341
2: 129276
3: 128774
4: 129092
5: 129327
6: 128659
7: 129035
8: 64320

[Tomaz]

QU to Metre would make more sense

Also I agree about the floor with a small addition, need to add 0.999 to the higher

1-8 makes it rand between 1.000 t0 8.999 with a floor making it pretty much equal chance to get any of the numbers 1-8

[frag.machine]

Whn programming in QuakeC, I only force random number to ints if unavoidable. Consider this example:

Code: Select all

local float r;
r = 1 + rint (random() * 8);
// or, as suggested
// r = 0.9999 + floor (random() * 8);
if (r == 1)
{
 // do something
}
else if (r == 2)
{
// do something else
}
(...)


Most of the cases this can be safely replaced by:

Code: Select all

local float r;
r = random ();
if (r > 0.87) // 0.87 == (1/8)*7 more or less :)
{
// do something
}
else if (r > 0.75)
{
// do something else
}
(...)


If we are talking about code being called inside an intensive loop (for example, iterating thru a long entity chain list generated by a call to findradius() or find()), avoiding the extra builtin call and sum can bring some gain in performance terms.

[Spike]

fteqcc actually has some intrinsics.
random() -> returns 0-1
random(x) -> returns 0-x
random(x,y) -> returns x-y
randomv() -> returns '0 0 0' to '1 1 1'
randomv(x) -> returns '0 0 0' to x
randomv(x,y) -> follow the trend, they're vectors, its a cube.

fteqcc supports these, as they are required for hexenc code too (fteqcc directly supports both syntaxes thus supports these, even for qc code).
Results are not rounded.

Thus mixing that with switch statements:
switch(random(3))
{
case 0 .. 1:
dostuff1();
break;
case 1 .. 2:
dostuff2();
break;
case 2 .. 3:
dostuff3();
break;
}

(its a double-dot between the two bounds)

Also, I feel strangely compelled to point out that if your player is 6'6" tall, then hes also 4' wide. Seriously, that guy needs to go on a diet. :P

[Error]

thanks andrewj

[mrmmaclean]

Spike, thanks for the info on fteqcc. I've been using it for compiling but haven't really looked into documentation that much (oops) and those features totally slipped under my radar!