/Classes/RNG.m

 1//
 2//  RNG.m
 3//
 4//  Created by Karl Stenerud on 10-02-15.
 5//
 6
 7#import "RNG.h"
 8
 9SYNTHESIZE_SINGLETON_FOR_CLASS_PROTOTYPE(RNG);
10
11
12@implementation RNG
13
14SYNTHESIZE_SINGLETON_FOR_CLASS(RNG);
15
16- (id) init
17{
18	return [self initWithSeed:time(NULL)];
19}
20
21- (id) initWithSeed:(unsigned int) seedValueIn
22{
23	if(nil != (self = [super init]))
24	{
25		self.seedValue = seedValueIn;
26	}
27	return self;
28}
29
30@synthesize seedValue;
31
32- (void) setSeedValue:(unsigned int) value
33{
34	seedValue = value;
35	srand(seedValue);
36}
37
38- (unsigned int) randomUnsignedInt
39{
40	return rand();
41}
42
43- (double) randomProbability
44{
45	return rand() / 2147483647.0;
46}
47
48- (int) randomNumberFrom: (int) minValue to: (int) maxValue
49{
50	double probability = rand() / 2147483648.0;
51	double range = maxValue - minValue + 1;
52	return (int)(range * probability + minValue);
53}
54
55- (int) randomNumberFrom: (int) minValue to: (int) maxValue except:(int) exceptValue
56{
57	if(minValue == maxValue)
58	{
59		return minValue;
60	}
61	int result;
62	while(exceptValue == (result = [self randomNumberFrom:minValue to:maxValue]))
63	{
64	}
65	return result;
66}
67
68- (bool) randomBool
69{
70	return rand() & 1;
71}
72
73@end