Game of Life

The rules for the game are really very simple:

• The game is played on a rectangular board.
• The board is made up of squares.
• Each square can be either empty or occupied (contains a cell).
• To start the game, the user selects which squares are initially occupied. This is the zeroith (start) generation.
• For each generation, the next generation is computed. The transition from one generation to another is called a turn.
• In each turn the next generation is computed as follows:
• If an empty square is surrounded by exactly 3 neighbors, a new cell is born (that square becomes occupied).
• A cell dies of overcrowding if it is surrounded by 4 or more neighbors (that square becomes empty).
• A cell dies of loneliness if it has zero or one neighbors (that square becomes empty).
• If a cell has 2 neighbors it remains as it is (square stays either empty or occupied)

+---+---+---+

| 1 | 2 | 3 |

+---+---+---+

| 4 | 5 | 6 | So a cell at 5, would need to check its neighbors at 1,2,3,4,6,7,8,9.

+---+---+---+

| 7 | 8 | 9 |

+---+---+---+

If a cell is at a border, then treat all locations off-board as empty.

Here are a few sample illustrations to help demonstrate the rules. A C means the square is occupied by a cell.

+---+---+---+

| C |   |   |

+---+---+---+

|   | C |   | This center cell would die (become an empty square) in the next generation

+---+---+---+ since it only has 1 neighbor.

|   |   |   |

+---+---+---+

+---+---+---+

|   |   |   |

+---+---+---+

| C | C | C |  This center cell would die (become an empty square) in the next generation

+---+---+---+  since it has 4 neighbors.

| C |   | C |

+---+---+---+

+---+---+---+

| C |   |   |

+---+---+---+

|   |   |   | This center cell would be born (become an occupied square) in the next generation

+---+---+---+ since it has exactly 3 neighbors.

| C |   | C |

+---+---+---+

Program Requirements

User Interface

Your program should run as a GUI application in a JFrame. You should have a JPanel-derived class containing 4 buttons, a JLabel, a text entry field and a drawing area.

• Clear: Clear all the cells, Make all squares unoccupied. When the Run button has been pressed, this button has no effect until the Stop button has been pressed. (You cannot clear the cells while an animation is in progress)
• Step: Advance the game one turn, calculate and show the next generation. This operates the simulation in single step mode. This button has no effect in animate mode.
• Run: Run the game animated. Calculate and show each generation automatically based upon the time delay.
• Stop: Stop the game when running in animate mode. Has no effect if in single step mode.

You should display the current generation number (turn number) in a JLabel.

You should allow the user to enter a delay to use for the animate mode. The default delay if no other entry has been made is 100ms.

In the drawing area, you should display the grid representing the squares that hold the cells. The default grid size should be 20 x 20. (For extra credit, you may allow user specified grid sizes to be entered.)

When starting the game, the user should be allowed to click with the mouse inside each cell to make that cell occupied or empty. Clicking on an empty cell makes it occupied. Clicking on an occupied cell makes it empty. Once the user presses the Step or Run button, mouse clicks in the grid area are ignored until the clear button is pressed.

When a square is occupied it should be filled in with the color of your choice. All the squares should be the same color. (For extra credit, newly born cells in each generation can be colored with a different color from the older cells in a generation).

Deliverables

• Square.java (Represents one square on the grid)
• CellModel.java (Holds a generation)
• GameOfLife.java (Main startup class, makes the JFrame)
• GamePanel.java (Displays everything)

Extra Credit Opportunities

• User selectable grid size (see above)
• Color coded cell generations (see above)
• Serializable start position (allow user to save and reload complex starting positions

Some special start cell sequences