qcsrc/lib/random.qc

   1 #include "random.qh"
   2
   3 void RandomSelection_Init()
   4 {
   5     RandomSelection_totalweight = 0;
   6     RandomSelection_chosen_ent = NULL;
   7     RandomSelection_chosen_float = 0;
   8     RandomSelection_chosen_string = string_null;
   9     RandomSelection_best_priority = -1;
  10 }
  11
  12 void RandomSelection_Add(entity e, float f, string s, float weight, float priority)
  13 {
  14     if (priority > RandomSelection_best_priority)
  15     {
  16         RandomSelection_best_priority = priority;
  17         RandomSelection_chosen_ent = e;
  18         RandomSelection_chosen_float = f;
  19         RandomSelection_chosen_string = s;
  20         RandomSelection_totalweight = weight;
  21     }
  22     else if (priority == RandomSelection_best_priority)
  23     {
  24         RandomSelection_totalweight += weight;
  25         if (random() * RandomSelection_totalweight <= weight)
  26         {
  27             RandomSelection_chosen_ent = e;
  28             RandomSelection_chosen_float = f;
  29             RandomSelection_chosen_string = s;
  30         }
  31     }
  32 }
  33
  34
  35 // prandom - PREDICTABLE random number generator (not seeded yet)
  36
  37 #ifdef USE_PRANDOM
  38 float prandom_seed;
  39 float prandom()
  40 {
  41     float c;
  42     c = crc16(false, strcat(ftos(prandom_seed), ftos(prandom_seed + M_PI)));
  43     prandom_seed = c;
  44
  45 #ifdef USE_PRANDOM_DEBUG
  46     LOG_TRACE("RANDOM -> ", ftos(c), "\n");
  47 #endif
  48
  49     return c / 65536; // in [0..1[
  50 }
  51
  52 vector prandomvec()
  53 {
  54     vector v;
  55
  56     do
  57     {
  58         v.x = prandom();
  59         v.y = prandom();
  60         v.z = prandom();
  61     }
  62     while(v * v > 1);
  63
  64     return v;
  65 }
  66
  67 void psrandom(float seed)
  68 {
  69     prandom_seed = seed;
  70 #ifdef USE_PRANDOM_DEBUG
  71     LOG_TRACE("SRANDOM ", ftos(seed), "\n");
  72 #endif
  73 }
  74
  75 #ifdef USE_PRANDOM_DEBUG
  76 void prandom_debug()
  77 {
  78     LOG_TRACE("Current random seed = ", ftos(prandom_seed), "\n");
  79 }
  80 #endif
  81 #endif