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