Conway's Game Of Life 01

/* 

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 Game of Life 1 - simple code example

 Rules from wikipedia: https://en.wikipedia.org/wiki/Conway%27s_Game_of_Life

 Article disusssing artificial life and conway's game of life:

 http://makeyourownalgorithmicart.blogspot.co.uk/2018/05/artificial-life-and-conways-game-of-life.html

​

*/

​

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// create cells

var number_of_rows = 50;

var number_of_columns = 50;

var grid_array = [];

​

// cell size on screen

cell_size = 10;

​

​

function setup() {

  createCanvas(800, 600);

  background('white');

  //noLoop();

  stroke(200);

  // slow down the calling of draw() so we can see the patterns evolve

  frameRate(20);

  // border

  noFill(); rect(0,0, width-1, height-1);

  // populate grid randomly

  for (var j = 0; j < number_of_rows; j += 1) {

    for (var i = 0; i < number_of_columns; i += 1) {

      // convert (i,j) to position in array

      var index = i + (j * number_of_columns);

      // set cell value to either 0 or 1, but mostly 0

      grid_array[index] = 0;

      if (random() < 0.3) {

        grid_array[index] = 1;

      }

      // test shapes

      // 

      //grid_array[1 + (3*number_of_columns)] = 1;

      //grid_array[2 + (3*number_of_columns)] = 1;

      //grid_array[3 + (3*number_of_columns)] = 1;

      //grid_array[2 + (2*number_of_columns)] = 1;

    }

  }

}

​

function draw() {

  // move origin so grid is centres

  translate((width - (number_of_columns * cell_size))/2, (height - (number_of_rows * cell_size))/2);

  // draw grid

  for (var j = 0; j < number_of_rows; j += 1) {

    for (var i = 0; i < number_of_columns; i += 1) {

      // convert (i,j) to position in array

      var index = i + (j * number_of_columns);

      // get current value and draw cell

      var cell_value = grid_array[index];

      fill((1-cell_value) * 255);

      rect(i*cell_size, j*cell_size, cell_size, cell_size);

    }

  }

  // initialise new temporary array

  var grid_array_2 = [];

  for (var j = 0; j < number_of_rows; j += 1) {

    for (var i = 0; i < number_of_columns; i += 1) {

      // convert (i,j) to position in array

      var index = i + (j * number_of_columns);

      grid_array_2[index] = 0;

    }

  }

  // update grid  

  for (var j = 0; j < number_of_rows; j += 1) {

    for (var i = 0; i < number_of_columns; i += 1) {

      // get number of neighbours

      var neighbours = 0;

      // look at immediate neighbourhood

      for (y = -1; y <= 1; y +=1 ){

        for (x = -1; x <= 1; x +=1 ){

          // wrap coordinates around

          var wrapped_i = (i + x + number_of_rows) % number_of_rows;

          var wrapped_j = (j + y + number_of_columns) % number_of_columns;

          // don't include current cell, only neighbours

          if (!(x == 0 && y == 0)) {

            // convert (i,j) to position in array

            var index = (wrapped_i) + (wrapped_j * number_of_columns);

            neighbours += grid_array[index];

          }

        }

      }

      // apply rules

      // convert (i,j) to position in array

      var index = i + (j * number_of_columns);

      // Rule 1. Any live cell with fewer than two live neighbors dies, as if caused by under population.

      if (grid_array[index] == 1 && neighbours < 2) {

        grid_array_2[index] = 0;

      }

      // Rule 2. Any live cell with two or three live neighbors lives on to the next generation.

      if (grid_array[index] == 1 && (neighbours == 2 || neighbours == 3)) {

        grid_array_2[index] = 1;

      }

      // Rule 3. Any live cell with more than three live neighbors dies, as if by overpopulation.

      if (grid_array[index] == 1 && neighbours > 3) {

        grid_array_2[index] = 0;

      }

      // Rule 4. Any dead cell with exactly three live neighbors becomes a live cell, as if by reproduction.

      if (grid_array[index] == 0 && neighbours == 3) {

        grid_array_2[index] = 1;

      }

    }

  }

  // point grid_array to new array, old one should be garbage collected

  grid_array = grid_array_2;

}