Link Four is a browser based replication of the classic game Connect Four. There are two modes - single and multiplayer. A defensive AI was implemented for single player mode. Players can choose which mode to begin with and simply click on a column to make their first move.
const computerMove = (board, offsetTop) => {
let moveCol;
for (let column = 0; column < 7; column++) {
let boardDup = deepDup(board);
possibleDropToken(boardDup, column, "yellow");
if (isWin(boardDup, "yellow")) {
moveCol = column;
break;
} else {
let boardDup2 = deepDup(board);
possibleDropToken(boardDup2, column, "red");
if (isWin(boardDup2, "red")) {
moveCol = column;
break;
}
}
}
if (moveCol) {
dropToken(board, moveCol, offsetTop, "yellow");
} else {
dropToken(board, Math.floor(Math.random() * 7), offsetTop, "yellow");
}
if(isWin(board,"yellow")) {
context.fillStyle = "#3f6db5";
context.fillText("YOU LOST", 300, 700);
}
};The board is first duped in order to test for the AI's win/lose condition on the board's next state. It tests all 7 potential moves that can be made, since there are only 7 columns for the AI to make a move into. If the next board state results in a win for the AI, it'll break out of the loop and drop its token into that column. Otherwise, it'll create a new duped board so it can check which column it needs to drop into in order to "block" the win for the player.
This project was implemented with the following technologies:
- JavaScript for game logic
- HTML5 Canvas