Game of Life code in Processing Handbook
in
Programming Questions
•
10 months ago
What I can't figure is the bit about swapping the current and future grids @ line 36 - 40. Yes, the current grid should be replaced with the future grid but why the need for the "temp" array in line 37 and the switch in line 39? I've taken these lines of code out, leaving just line 38 (swapping current for future grid) and the Game acts funny...too many cells are born and survive, taking over the screen.
The code in question...rest is below...
int[][] temp = grid; Why?
grid = futureGrid; I get this, I think
futureGrid = temp; Why?
Please tell me what I'm missing!
- int[][] grid, futureGrid;
- void setup() {
- size(540, 100);
- frameRate(8);
- grid = new int[width][height];
- futureGrid = new int[width][height];
- float density = 0.3 * width * height;
- for (int i = 0; i < density; i++) {
- grid[int(random(width))][int(random(height))] = 1;
- }
- background(0);
- }
- void draw() {
- for (int x = 1; x < width - 1; x++) {
- for (int y = 1; y < height - 1; y++) {
- // Check the number of neighbors (adjacent cells)
- int nb = neighbors(x, y);
- if ((grid[x][y] == 1) && (nb < 2)) {
- futureGrid[x][y] = 0; // Isolation death
- set(x, y, color(0));
- } else if ((grid[x][y] == 1) && (nb > 3)) {
- futureGrid[x][y] = 0; // Overpopulation death
- set(x, y, color(0));
- } else if ((grid[x][y] == 0) && (nb == 3)) {
- futureGrid[x][y] = 1; // Birth
- set(x, y, color(255));
- } else {
- futureGrid[x][y] = grid[x][y]; // Survive
- }
- }
- }
- // Swap current and future grids
- int[][] temp = grid;
- grid = futureGrid;
- futureGrid = temp;
- }
- // Count the number of adjacent cells 'on'
- int neighbors(int x, int y) {
- return grid[x][y-1] + // North
- grid[x+1][y-1] + // Northeast
- grid[x+1][y] + // East
- grid[x+1][y+1] + // Souteast
- grid[x][y+1] + // South
- grid[x-1][y+1] + // Southwest
- grid[x-1][y] + // West
- grid[x-1][y-1]; // Northwest
- }
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