#include <stdio.h>
#include <stdlib.h>
+#include <unistd.h>
+
#include "defines.h"
-extern int sum_z_segments;
+/* global and extern variables */
+extern u32 sum_z_cells;
+extern int random_fd;
/* return random integer between 0 - max */
-int rand_get(int max) {
- return((int) (rand() * (max*1.0/RAND_MAX)) );
+u32 rand_get(u32 max)
+{
+ u32 rand_int;
+ if(read(random_fd,&rand_int,4)!=4)
+ {
+ puts("failed reading 4 bytes of random data");
+ return -23;
+ }
+ /* cells numbered 0...max-1 */
+ return((u32)(rand_int*(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_nel,int start_nel) {
+ 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);
if(z<=0) break;
}
- return i;
+ return(i-1); /* return values 0...z_cell-1 */
}