1 /***
2 * Redistribution and use in source and binary forms, with or without
3 * modification, are permitted provided that the following conditions are
4 * met :
5 *
6 * . Redistributions of source code must retain the above copyright
7 * notice, this list of conditions and the following disclaimer.
8 *
9 * . Redistributions in binary form must reproduce the above copyright
10 * notice, this list of conditions and the following disclaimer in the
11 * documentation and/or other materials provided with the distribution.
12 *
13 * . The name of the author may not be used to endorse or promote products
14 * derived from this software without specific prior written permission.
15 *
16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
17 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
18 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
19 * DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT,
20 * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
21 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
22 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
24 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
25 * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
26 * POSSIBILITY OF SUCH DAMAGE.
27 *
28 * $Id: Dice.java,v 1.4 2005/07/15 11:20:08 mat007 Exp $
29 */
30
31 package jtge.util.random;
32
33 /***
34 * Emulates a dice.
35 * <p>
36 * A dice is defined by :
37 * <ul>
38 * <li>the type of dice (ie the range of possible values)
39 * <li>the number of dices to roll
40 * <li>the bonus added to the result
41 * </ul>
42 * <p>
43 * Example : 2d8+3 stands for 2 dices of type 8 with a bonus of 3.
44 *
45 * @author Jean-Laurent
46 * @version $Revision: 1.4 $ $Date: 2005/07/15 11:20:08 $
47 */
48 public class Dice
49
50
51 {
52 /***
53 * Number of dices to throw.
54 */
55 private final int number;
56 /***
57 * Maximum number of each dice.
58 */
59 private final int type;
60 /***
61 * Bonus (or malus) to apply on the result.
62 */
63 private final int bonus;
64
65 /***
66 * Create a dice out of the number of dices, the type and the bonus value.
67 * <p>
68 * Number and type must be positive.
69 *
70 * @param number the number of rolls
71 * @param type the type of dice
72 * @param bonus the number added to the result
73 */
74 public Dice( final int number, final int type, final int bonus )
75 {
76 if( number < 0 )
77 throw new IllegalArgumentException( "parameter 'number' must be positive (is " + number + ")" );
78 if( type < 0 )
79 throw new IllegalArgumentException( "parameter 'type' must be positive (is " + type + ")" );
80 this.number = number;
81 this.type = type;
82 this.bonus = bonus;
83 }
84
85 /***
86 * Create a dice out of the number of dices and a type (e.g. no bonus).
87 * <p>
88 * Number and type must be positive.
89 *
90 * @param number the number of rolls
91 * @param type the type of dice
92 */
93 public Dice( final int number, final int type )
94 {
95 this( number, type, 0 );
96 }
97
98 /***
99 * Create a dice from a textual definition.
100 * <p>
101 * The expected format is : <i>{diceNumber}</i><b>d</b><i>{diceType}</i><b>+</b><i>{bonus}</i>.
102 *
103 * @param definition the definition.
104 */
105 public Dice( final String definition )
106 {
107
108 int diceIndex = definition.indexOf( 'd' );
109 if( diceIndex == -1 )
110 throw new RuntimeException( "wrong dice definition: " + definition );
111 this.number = Integer.parseInt( definition.substring( 0, diceIndex ) );
112
113 int plusIndex = definition.indexOf( '+' );
114 if( plusIndex != -1 )
115 {
116 this.type = Integer.parseInt( definition.substring( diceIndex + 1, plusIndex ) );
117 this.bonus = Integer.parseInt( definition.substring( plusIndex + 1, definition.length() ) );
118 }
119 else
120 {
121 this.type = Integer.parseInt( definition.substring( diceIndex + 1, definition.length() ) );
122 this.bonus = 0;
123 }
124 }
125
126 /***
127 * Roll the dice.
128 *
129 * @return the result
130 */
131 public final int roll()
132 {
133 int result = 0;
134 for( int i = 0; i < number; i++ )
135 result += getRandom( type ) + 1;
136 return result + bonus;
137 }
138
139 private int getRandom( final int maxVal )
140 {
141 return (int)Math.floor( (Math.random() * maxVal) % maxVal );
142 }
143
144 /***
145 * {@inheritDoc}
146 */
147 public final String toString()
148 {
149 String result;
150 if( bonus > 0 )
151 result = number + "d" + type + "+" + bonus;
152 else if( bonus < 0 )
153 result = number + "d" + type + bonus;
154 else
155 result = number + "d" + type;
156 return result;
157 }
158 }