X-Git-Url: https://hackdaworld.org/gitweb/?p=physik%2Fmorpheus.git;a=blobdiff_plain;f=random.c;h=81a066752eb3d1de6fa0f71ef72c9b9e0c8b5c42;hp=73e69f5e070082a98754d84df64fd5785b51c963;hb=10f0b7a7cb49dbd9cbeef240c7eb814cf822596c;hpb=f463ab26135aa2850eee73b75f11103dd5f52a40 diff --git a/random.c b/random.c index 73e69f5..81a0667 100644 --- a/random.c +++ b/random.c @@ -5,23 +5,56 @@ #include #include +#include +#include +#include +#include + #include "defines.h" -extern int sum_z_segments; +/* global and extern variables */ +extern u32 gr; +extern int random_fd; +extern u32 *rand_buf,*rand_current; +extern char random_file[MAX_CHARS_RANDOM_FILE]; -/* return random integer between 0 - max */ -int rand_get(int max) { - return((int) (rand() * (max*1.0/RAND_MAX)) ); +/* return random integer between 0 - max-1 */ +u32 rand_get(u32 max) +{ + if(rand_current>=rand_buf+(RAND_BUF_SIZE/sizeof(u32))) + { + printfd("debug: reading new random bytes\n"); + if(read(random_fd,rand_buf,RAND_BUF_SIZE)!=RAND_BUF_SIZE) + { + if(strcmp(random_file,"")) + { + puts("random file end, starting over ..."); + lseek(random_fd,0,SEEK_SET); + } else + { + puts("failed reading 1 mega bytes of random data"); + return -23; + } + } + printfd("debug: finished reading random bytes\n"); + rand_current=rand_buf; + } + /* cells numbered 0...max-1 */ + return((u32)(*(rand_current++)*(max*1.0/URAND_MAX))); } /* get z value (linear growth of probability with depths) */ -int rand_get_lgp(int slope_cc,int start_cc) { - int z,i; - z=rand_get(sum_z_segments); - for(i=0;;i++) { - z-=i*slope_cc; +u32 rand_get_lgp(int slope,int start,u32 z_max) +{ + int z; + u32 i,weighted_sum_z; + weighted_sum_z=z_max*start+slope*gr; + z=rand_get(weighted_sum_z)+1; /* +1 as rand_get returns values 0...max-1 */ + for(i=1;;i++) + { + z-=(start+i*slope); if(z<=0) break; } - return i; + return(i-1); /* return values 0...z_cell-1 */ }