CSC352 Game of Life Lab 2017
--D. Thiebaut (talk) 17:02, 8 February 2017 (EST)
Contents
Game of Life
In this lab you will write a multithreaded version of Conway's Game of Life.
Serial Game of Life
Wikipedia has a good page on Conway's game of life. Please read the first section containing the rules.
The program below is a serial version of the game of life taken from RosettaCode.org.
It displays the generation of cells using simply ascii characters on the console. To run it, copy/paste it in a file called GameOfLife.java in your 352b account.
Compile and run it as follows:
javac GameOfLife.java java GameOfLife
and adjust the size of your terminal/console to make sure you can see the pattern evolving.
The game is coded so that the array wraps around horizontally, and vertically. So a pattern sliding on the array will reach the bottom and reappear at the top. Similarly, a pattern sliding off the left will reappear on the right.
The generations are stable for a few seconds, then one of the moving patterns (glider) hits the blinker, and the population of cells start growing until it freezes with just a few cells blinking.
/* Game of life D. Thiebaut Heavily adapted from code found in java section at this URL: https://rosettacode.org/wiki/Conway%27s_Game_of_Life#Java This code works in console mode, displaying successive generations of the game of life on the screen, and clearing the screen between each one. The initial pattern is defined in the array dish (as in petri dish). To compile and run: javac GameOfLife.java java GameOfLife */ public class GameOfLife{ public static void main(String[] args){ String[] dish2 = { " ", " # ", " # ", " # ", " " }; String[] dish= { " ", " # ", " # # ### ", " ## ", " ", " # ", " # # ", " ## ", " ", " ", " ", " ", " # ", " # # ", " ## ", " ", " ", " ", " ", " ", " ", " ", " ", " ", " ", " ", " ", " " }; int gens= 30000; for (int i= 0;i < gens;i++) { //System.out.println("Generation " + i + ":\n\n\n"); print(dish); dish= life(dish); clearScreen(); // add a bit of a delay to better see the visualization // remove this part to get full timing. try { Thread.sleep(50); } catch(InterruptedException ex) { return; } } } public static void clearScreen(){ final String ANSI_CLS = "\u001b[2J"; final String ANSI_HOME = "\u001b[H"; //System.out.print(ANSI_CLS + ANSI_HOME); System.out.print( ANSI_HOME); System.out.flush(); } public static String[] life(String[] dish){ String[] newGen= new String[dish.length]; for ( int row= 0; row < dish.length; row++ ) {//each row newGen[row]= ""; for ( int i= 0; i < dish[row].length(); i++ ) {//each char in the row int neighbors = 0; char current = dish[row].charAt(i); // loop in a block that is 3x3 around the current cell // and count the number of '#' cells. for ( int r=row-1; r<=row+1; r++ ) { // make sure we wrap around from bottom to top int realr = r; if ( r==-1 ) realr = dish.length-1; if ( r==dish.length) realr = 0; for ( int j=i-1; j<=i+1; j++ ) { // make sure we wrap around from left to right int realj = j; if ( j==-1 ) realj = dish[row].length()-1; if ( j==dish[row].length() ) realj = 0; if (r==row && j==i ) continue; // current cell is not its // neighbor if (dish[realr].charAt(realj) == '#' ) neighbors++; } } if ( current=='#' ) if (neighbors < 2 || neighbors > 3) newGen[row] += " "; else newGen[row] += "#"; if ( current==' ' ) if ( neighbors == 3 ) newGen[row] += "#"; else newGen[row] += " "; } } return newGen; } public static int getNeighbors(char above, char below, char left, char right ) { int ans= 0; if ( above == '#' ) ans++; if ( below == '#' ) ans++; if ( left == '#' ) ans++; if ( right == '#' ) ans++; return ans; } public static void print( String[] dish ) { for ( String s: dish ) System.out.println(s); } }
Exploring the Serial Version
- Explore the code and make sure you get some reasonable understanding of it.
- Play with the Thread.sleep() delay to see how it influences the display.
Part 1: Class discussion
How could we make this program parallel, and make it work faster with 2 threads?
