/* bits: 0 = snake 1 = food 2 = checked (for searching algorithms) */ // Bit functions for ease function isBitSet(value: number, bit: number): boolean { return ((value >> bit) % 2 != 0) } function bitSet(value: number, bit: number): number { return value | 1 << bit; } function bitClear(value: number, bit: number): number { return value & ~(1 << bit); } class Point { x: number; y: number; constructor(x = 0, y = 0) { this.x = x; this.y = y; } copy(other: Point) { this.x = other.x; this.y = other.y; } add(other: Point) { var result = new Point; result.x = this.x + other.x; result.y = this.y + other.y; return result; } subtract(other: Point) { var result = new Point; result.x = this.x - other.x; result.y = this.y - other.y; return result; } } class SnakeCore { canvas: HTMLCanvasElement; context: CanvasRenderingContext2D; grid: number; timeout: number; width: number; height: number; board: number[][]; body: Point[]; gameover: boolean; foodAte: boolean; constructor() { // TODO: Add CSS stuff for page this.canvas = document.getElementById('snake') as HTMLCanvasElement; this.context = this.canvas.getContext('2d') as CanvasRenderingContext2D; this.grid = 25; // size of grid squares this.timeout = 100; // speed in ms this.width = 25; this.height = 15; this.board = []; for (let i = 0; i < this.height; i++) { this.board.push(new Array(this.width)); for (let j = 0; j < this.width; j++) { this.board[i][j] = 0; } } this.body = []; this.gameover = false; this.foodAte = true; this.body.push(new Point(12, 8)); this.board[8][12] = 1; } get head(): Point { return this.body[this.body.length - 1]; } reset() { snake.gameover = false; snake.foodAte = true; for (let i = 0; i < this.height; i++) { for (let j = 0; j < this.width; j++) { this.board[i][j] = 0; } } snake.context.fillStyle = "black"; for (let i = 0; i < snake.height; i++) { for (let j = 0; j < snake.width; j++) { snake.context.fillRect(j * snake.grid, i * snake.grid, snake.grid, snake.grid); } } } foodRegen() { if (!this.foodAte) return; this.foodAte = false; while (true) { let tmp = new Point(Math.floor(Math.random() * this.width), Math.floor(Math.random() * this.height)); if (isBitSet(this.board[tmp.y][tmp.x], 0)) continue; this.board[tmp.y][tmp.x] = bitSet(this.board[tmp.y][tmp.x], 1); return; } } // Simulate game logic simulate() { // Move snake // TODO: Fix teleporting snake let next: Point = new Point; next.copy(bot.nextMove()); if (next.x < 0 || next.x > snake.width || next.y < 0 || next.y > snake.height) { snake.gameover = true; return; } if (isBitSet(snake.board[next.y][next.x], 0) && (snake.body.length > 1)) { snake.gameover = true; // Game should end (Snake touching snake) return; } snake.board[next.y][next.x] = bitSet(snake.board[next.y][next.x], 0); snake.body.push(next); if (!isBitSet(snake.board[next.y][next.x], 1)) { let old: Point = snake.body.shift() as Point; snake.board[old.y][old.x] = bitClear(snake.board[old.y][old.x], 0); } else { snake.board[next.y][next.x] = bitClear(snake.board[next.y][next.x], 1); snake.foodAte = true; while (bot.path.length > 0) bot.path.pop(); } } // Draw game to canvas draw() { // Clear the screen snake.context.clearRect(0, 0, snake.canvas.width, snake.canvas.height); // Draw game for (let i = 0; i < snake.height; i++) { for (let j = 0; j < snake.width; j++) { if (isBitSet(snake.board[i][j], 0)) snake.context.fillStyle = "green"; else if (isBitSet(snake.board[i][j], 1)) snake.context.fillStyle = "red"; else snake.context.fillStyle = "black"; snake.context.fillRect(j * snake.grid, i * snake.grid, snake.grid, snake.grid); } } } } class Bot { pathUntrimmed: Point[]; path: Point[]; constructor() { this.pathUntrimmed = []; this.path = []; } bfs() { var search: Point[] = [snake.head]; while (search.length !== 0) { let current: Point = search.shift() as Point; if (isBitSet(snake.board[current.y][current.x], 2)) continue; this.pathUntrimmed.push(current); let locals: Point[] = new Array(4); for (var i = 0; i < 4; i++) { locals[i] = new Point; locals[i].copy(current); } locals[0].y += 1; locals[1].x += 1; locals[2].y -= 1; locals[3].x -= 1; for (const local of locals) { if (local.x < 0 || local.x > snake.width - 1 || local.y < 0 || local.y > snake.height - 1) { continue; } let value = snake.board[local.y][local.x]; if (isBitSet(value, 1)) { this.pathUntrimmed.push(local); return; } if (isBitSet(value, 2)) continue; if (isBitSet(value, 0)) continue; search.push(local); } snake.board[current.y][current.x] = bitSet(snake.board[current.y][current.x], 2); } } // TODO: Fix trim function trim() { let reachedSnake = false; this.path.push(this.pathUntrimmed.pop() as Point); // Push food location while (this.pathUntrimmed.length !== 0) { if (!reachedSnake) { let location: Point = new Point; location.copy(this.pathUntrimmed[this.pathUntrimmed.length - 1]); if (isBitSet(snake.board[location.y][location.x], 0)) reachedSnake = true; var delta = new Point; delta = location.subtract(this.path[this.path.length - 1]); if ((Math.abs(delta.x) + Math.abs(delta.y)) === 1) this.path.push(location); } this.pathUntrimmed.pop(); } } unvisit() { for (let i = 0; i < snake.height; i++) { for (let j = 0; j < snake.width; j++) { snake.board[i][j] = bitClear(snake.board[i][j], 2); } } } /* values: 0 = left 1 = up 2 = right 4 = down */ nextMove() { var next: Point = new Point; next.copy(this.path.pop()); var delta = new Point; delta = next.subtract(snake.head); if (delta.x > 1) { console.log("[ERR] delta.x > 1"); } else if (delta.x < -1) { console.log("[ERR] delta.x < 1"); } if (delta.y > 1) { console.log("[ERR] delta.y > 1"); } else if (delta.y < -1) { console.log("[ERR] delta.y < 1"); } return next; } autoplay() { if (this.path.length > 0) return; this.bfs(); this.trim(); this.unvisit(); } } const snake: SnakeCore = new SnakeCore(); // Singleton for snake game const bot: Bot = new Bot(); // Singleton for bot playing // game loop function snakeloop() { // Reset of needed if (snake.gameover) snake.reset(); // Input bot.autoplay(); snake.simulate(); // Regenerate food if needed snake.foodRegen(); snake.draw(); } // start the game setInterval(snakeloop, snake.timeout);