The code shown below will perform [#]d{#}[+#] rolls.
Examples:
d20
d10
4d6
6d6+8
4d12 + 10
When you run this code, you will run it as:
java RollD '4d12 + 10'
or
java RollD 6d6+8
public class RollD {
public static void usage() {
System.out.println("\n\nRollD {#}d##{+#}\n");
System.exit(1);
}
public static int dRandom(int d) {
// always returns value in range 1 to d.
int r = (int)(Math.random() * d) + 1;
// debug
//System.out.println("d" + d + "=" + r);
return r;
}
public static void main(String[] args) {
int plusPos, dPos, x;
int plus, die, numD, total;
String roll;
// Need something...
if (args.length == 0)
usage();
// got something
// remove spaces
roll = args[0].replace(" ", "");
// be there a plus sign?
plusPos = roll.indexOf('+');
// look for the 'd'
dPos = roll.indexOf('d');
// no 'd'? well, that's not good...
if ( dPos == -1 )
usage();
// if there is a plus, convert the additive to an int.
if ( plusPos != -1 ) {
plus = Integer.parseInt(roll.substring(plusPos + 1));
roll = roll.substring(0, plusPos);
} else
plus = 0;
// if 'd' is not the first char,
// there should be more than one of that 'd' rolled.
if ( dPos > 0 )
numD = Integer.parseInt(roll.substring(0, dPos));
else
numD = 1;
// which 'd' are we talking about here?
die = Integer.parseInt(roll.substring(dPos + 1));
total = 0;
for ( x = 0; x < numD; x++ )
total = total + dRandom(die);
System.out.println(total + plus);
}
}
While the previous example allows for command line ability, the following piece of code had turned the concept into a library.
public class D20 {
public static boolean DBG = false;
public static int dRandom(int d) {
// always returns value in range 1 to d.
int r = (int)(Math.random() * d) + 1;
if (DBG)
System.out.println("d" + d + " = " + r);
return r;
}
public static int hi3of4d6() {
int r1, r2, r3, r4, sm, sum;
r1 = dRandom(6);
r2 = dRandom(6);
r3 = dRandom(6);
r4 = dRandom(6);
// debug
if (DBG)
System.out.println("r1 = " + r1 + " r2 = " + r2 + " r3 = " + r3 + " r4 = " + r4);
sm = Math.min(Math.min(r1, r2), Math.min(r3, r4));
if ( r4 != sm )
if ( r1 == sm )
r1 = r4;
else if ( r2 == sm )
r2 = r4;
else if ( r3 == sm )
r3 = r4;
sum = r1 + r2 + r3;
// debug
if (DBG) {
System.out.println("r1 = " + r1 + " r2 = " + r2 + " r3 = " + r3 + " r4 = " + r4);
System.out.println("Total = " + (sum));
}
return sum;
}
public static int rollD(String s) {
int plusPos, dPos, x;
int plus = 0, die, numD = 1, total = 0;
String roll;
// Need something...
if (s.length() == 0)
return -1;
// got something
// remove spaces
if (DBG)
System.out.println("roll before \"" + s + "\"");
roll = s.replace(" ", "");
if (DBG)
System.out.println("roll after \"" + roll + "\"");
// be there a plus sign?
plusPos = roll.indexOf('+');
// look for the 'd'
dPos = roll.indexOf('d');
// no 'd'? well, that's not good...
if ( dPos == -1 )
return -1;
// if there is a plus, convert the additive to an int.
if ( plusPos != -1 ) {
plus = Integer.parseInt(roll.substring(plusPos + 1));
roll = roll.substring(0, plusPos);
if (DBG) {
System.out.println("plus is " + plus);
System.out.println("roll is now \"" + roll + "\"");
}
}
// if 'd' is not the first char,
// there should be more than one of that 'd' rolled.
if ( dPos > 0 )
numD = Integer.parseInt(roll.substring(0, dPos));
if (DBG)
System.out.println("numD is " + numD);
// which 'd' are we talking about here?
die = Integer.parseInt(roll.substring(dPos + 1));
if (DBG)
System.out.println("die is " + die);
for ( x = 0; x < numD; x++ ) {
int d;
d = dRandom(die);
if (DBG)
System.out.println("For roll " + (x + 1) + ", d is " + d);
total = total + d;
}
if (DBG)
System.out.println("total is " + total);
return total + plus;
}
public static void main(String[] args) {
// This is the test suite for D20.
if ( args.length == 1 && args[0].compareTo("-d") == 0 ) {
DBG = true;
System.out.println("hi3of4d6 is " + hi3of4d6());
String[] tests = {"d4", "d6", "d8", "d10", "d12", "d20", "d100", "6d6 + 10", "6 d 6 + 10"};
for (int x = 0 ; x < tests.length ; x++ ) {
System.out.println("\nDEBUG for Roll #" + (x+1) + "\n");
System.out.println("\nRoll #" + (x+1) + ": " + tests[x] + " = " + rollD(tests[x]));
}
}
}
}
And now we have a Swing version of a GUI that utilizes the D20 class from above.
import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
public class RollDGUI extends JFrame implements ActionListener {
String[] bval = {"d4", "d6", "d8", "d10", "d12", "d20", "d100"};
JButton[] buttons = new JButton[7];
JLabel rollLabel = new JLabel("Roll"), resultLabel = new JLabel("Result");
JTextField rollTF = new JTextField(""), resultTF = new JTextField("");
JButton rollButton = new JButton("ROLL!");
JButton hi3of4d6 = new JButton(">3 of 4d6");
public RollDGUI() {
int x;
setTitle("RollD");
//setResizable(false);
setSize(500,300);
setDefaultCloseOperation(EXIT_ON_CLOSE);
setLayout(new GridLayout(3,5));
// Fill the buttons with values and setup ActionListener
for (x = 0; x < buttons.length; x++) {
buttons[x] = new JButton(bval[x]);
buttons[x].addActionListener(this);
//buttons[x].setBackground(Color.blue);
}
rollButton.addActionListener(this);
hi3of4d6.addActionListener(this);
// row 1
add(rollLabel);
add(rollTF);
add(buttons[0]);
add(buttons[1]);
add(buttons[2]);
// row 2
add(rollButton);
add(new JLabel(""));
add(buttons[3]);
add(buttons[4]);
add(buttons[5]);
// row 3
add(resultLabel);
add(resultTF);
resultTF.setEditable(false);
add(hi3of4d6);
add(buttons[6]);
add(new JLabel(""));
getRootPane().setDefaultButton(rollButton);
setVisible(true);
}
public void actionPerformed(ActionEvent e) {
Object s = e.getSource();
//System.err.println("Source is " + s);
if ( s == buttons[0] || s == buttons[1] || s == buttons[2] || s == buttons[3] ||
s == buttons[4] || s == buttons[5] || s == buttons[6] )
resultTF.setText("" + D20.rollD(((JButton)s).getText()));
else if ( s == rollButton ) {
resultTF.setText("" + D20.rollD(rollTF.getText()));
} else if ( s == hi3of4d6 ) {
resultTF.setText("" + D20.hi3of4d6());
}
}
public static void main(String[] args) {
try {
UIManager.setLookAndFeel(UIManager.getCrossPlatformLookAndFeelClassName());
}
catch (Exception e) {
// Not good.
}
RollDGUI t = new RollDGUI();
}
}
Example to calculate ability modifiers (not proficiency-based!)
public class AbilityModifier {
public static void main(String[] args) {
for (int x = 1; x <= 30; x++)
System.out.println(x + " = " + modifier(x));
}
public static int modifier(int ab) {
return (int)(Math.floor((ab - 10) / 2.0));
}
}
class Abilities {
private int STR, DEX, CON, INT, WIS, CHA;
public int getSTR() {
return STR;
}
public int getDEX() {
return DEX;
}
public int getCON() {
return CON;
}
public int getINT() {
return INT;
}
public int getWIS() {
return WIS;
}
public int getCHA() {
return CHA;
}
public void setSTR(int v) {
STR = v;
}
public void setDEX(int v) {
DEX = v;
}
public void setCON(int v) {
CON = v;
}
public void setINT(int v) {
INT = v;
}
public void setWIS(int v) {
WIS = v;
}
public void setCHA(int v) {
CHA = v;
}
public static void main(String[] args) {
}
}
public class DNDCharacter {
// housekeeping
private int a1, a2, a3, a4, a5, a6;
// for character
private int AC;
private Abilities abilities;
private int initiative;
private int level;
private int speed;
private int hit_die;
public static int dRandom(int d) {
// always returns value in range 1 to d.
int r = (int)(Math.random() * d) + 1;
// debug
//System.out.println("d" + d + "=" + r);
return r;
}
private static int hi3of4d6() {
int r1, r2, r3, r4, sm, sum;
r1 = dRandom(6);
r2 = dRandom(6);
r3 = dRandom(6);
r4 = dRandom(6);
// debug
System.out.println("r1 = " + r1 + " r2 = " + r2 + " r3 = " + r3 + " r4 = " + r4);
sm = Math.min(Math.min(r1, r2), Math.min(r3, r4));
if ( r4 != sm )
if ( r1 == sm )
r1 = r4;
else if ( r2 == sm )
r2 = r4;
else if ( r3 == sm )
r3 = r4;
sum = r1 + r2 + r3;
// debug
System.out.println("r1 = " + r1 + " r2 = " + r2 + " r3 = " + r3 + " r4 = " + r4);
System.out.println("Total = " + (sum));
return sum;
}
public DNDCharacter() {
abilities = new Abilities();
}
public DNDCharacter(int level) {
abilities = new Abilities();
this.level = level;
}
private void setDefaultScores() {
a1 = 15;
a2 = 14;
a3 = 13;
a4 = 12;
a5 = 10;
a6 = 8;
}
private void setRandomScores() {
a1 = hi3of4d6();
a2 = hi3of4d6();
a3 = hi3of4d6();
a4 = hi3of4d6();
a5 = hi3of4d6();
a6 = hi3of4d6();
}
public static void main(String args []) {
hi3of4d6();
}
}