#include "defines.h"
/* global and extern variables */
-extern u32 sum_z_cells;
+extern u32 gr;
extern int random_fd;
+extern u32 *rand_buf,*rand_current;
/* return random integer between 0 - max-1 */
u32 rand_get(u32 max)
{
- u32 rand_int;
- if(read(random_fd,&rand_int,4)!=4)
+ if(rand_current>=rand_buf+(RAND_BUF_SIZE/sizeof(u32)))
{
- puts("failed reading 4 bytes of random data");
- return -23;
+ printfd("debug: reading new random bytes\n");
+ if(read(random_fd,rand_buf,RAND_BUF_SIZE)!=RAND_BUF_SIZE)
+ {
+ puts("failed reading 1 mega bytes of random data");
+ return -23;
+ }
+ rand_current=rand_buf;
}
/* cells numbered 0...max-1 */
- return((u32)(rand_int*(max*1.0/URAND_MAX)));
+ return((u32)(*(rand_current++)*(max*1.0/URAND_MAX)));
}
/* get z value (linear growth of probability with depths) */
-u32 rand_get_lgp(int slope_nel,int start_nel) {
+u32 rand_get_lgp(int slope,int start,u32 z_max)
+{
int z;
- u32 i;
- z=rand_get(sum_z_cells)+1; /* +1 as rand_get returns values 0...max-1 */
- for(i=1;;i++) {
- z-=(start_nel+i*slope_nel);
+ 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-1); /* return values 0...z_cell-1 */
}
-