1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
|
/* Starshatter OpenSource Distribution
Copyright (c) 1997-2004, Destroyer Studios LLC.
All Rights Reserved.
Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions are met:
* Redistributions of source code must retain the above copyright notice,
this list of conditions and the following disclaimer.
* Redistributions in binary form must reproduce the above copyright notice,
this list of conditions and the following disclaimer in the documentation
and/or other materials provided with the distribution.
* Neither the name "Destroyer Studios" nor the names of its contributors
may be used to endorse or promote products derived from this software
without specific prior written permission.
THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
POSSIBILITY OF SUCH DAMAGE.
SUBSYSTEM: nGenEx.lib
FILE: Random.cpp
AUTHOR: John DiCamillo
OVERVIEW
========
Utility functions for generating random numbers and locations.
*/
#include "MemDebug.h"
#include "Random.h"
// +----------------------------------------------------------------------+
void RandomInit()
{
srand(timeGetTime());
}
// +----------------------------------------------------------------------+
Point RandomDirection()
{
Point p = Point(rand() - 16384, rand() - 16384, 0);
p.Normalize();
return p;
}
// +----------------------------------------------------------------------+
Point RandomPoint()
{
Point p = Point(rand() - 16384, rand() - 16384, 0);
p.Normalize();
p *= 15e3 + rand()/3;
return p;
}
// +----------------------------------------------------------------------+
Vec3 RandomVector(double radius)
{
Vec3 v = Vec3(rand() - 16384, rand() - 16384, rand() - 16384);
v.Normalize();
if (radius > 0)
v *= (float) radius;
else
v *= (float) Random(radius/3, radius);
return v;
}
// +----------------------------------------------------------------------+
double Random(double min, double max)
{
double delta = max - min;
double r = delta * rand() / 32768.0;
return min + r;
}
// +----------------------------------------------------------------------+
int RandomIndex()
{
static int index = 0;
static int table[16] = { 0, 9, 4, 7, 14, 11, 2, 12, 1, 5, 13, 8, 6, 10, 3, 15 };
int r = 1 + ((rand() & 0x0700) >> 8);
index += r;
if (index > 1e7) index = 0;
return table[index % 16];
}
// +----------------------------------------------------------------------+
bool RandomChance(int wins, int tries)
{
double fraction = 256.0 * wins / tries;
double r = (rand() >> 4) & 0xFF;
return r < fraction;
}
// +----------------------------------------------------------------------+
int RandomSequence(int current, int range)
{
if (range > 1) {
int step = (int) Random(1, range-1);
return (current + step) % range;
}
return current;
}
// +----------------------------------------------------------------------+
int RandomShuffle(int count)
{
static int set_size = -1;
static BYTE set[256];
static int index = -1;
if (count < 0 || count > 250)
return 0;
if (set_size != count) {
set_size = count;
index = -1;
}
// need to reshuffle
if (index < 0 || index > set_size-1) {
// set up the deck
int tmp[256];
for (int i = 0; i < 256; i++)
tmp[i] = i;
// shuffle the cards
for (int i = 0; i < set_size; i++) {
int n = (int) Random(0, set_size);
int tries = set_size;
while (tmp[n] < 0 && tries--) {
n = (n+1) % set_size;
}
if (tmp[n] >= 0) {
set[i] = tmp[n];
tmp[n] = -1;
}
else {
set[i] = 0;
}
}
index = 0;
}
return set[index++];
}
|
