迷宫

createMaze.js

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+/**
+	* 创建迷宫 
+	* @param {迷宫高度} height  
+	* @param {迷宫宽度} width 
+	* @param {入口坐标} startPoint  {x:numer,y:numer}
+	* @param {出口坐标} endPoint  {x:numer,y:numer}
+	* 8 是入口 ，9 是出口,只有唯一一条路线.
+	*/
+function createMaze(height, width, startPoint, endPoint) {
+	class CreateMaze {
+		constructor(height, width, startPoint, endPoint) {
+			// 验证参数合法
+			if (isNaN(height)) throw new Error('heiht 不是数字')
+			if (isNaN(width)) throw new Error('width 不是数字')
+			if (isNaN(startPoint.x)) throw new Error('startPoint.x 不是数字')
+			if (isNaN(startPoint.y)) throw new Error('startPoint.y 不是数字')
+			if (isNaN(endPoint.x)) throw new Error('endPoint.x 不是数字')
+			if (isNaN(endPoint.y)) throw new Error('endPoint.y 不是数字')
+			if (startPoint.x === 0 && startPoint.y === 0) throw new Error('startPoint 不能是顶角')
+			if (startPoint.x === 0 && startPoint.y === height - 1) throw new Error('startPoint 不能是顶角')
+			if (startPoint.x === width - 1 && startPoint.y === height - 1) throw new Error('startPoint 不能是顶角')
+			if (startPoint.x === width - 1 && startPoint.y === 0) throw new Error('startPoint 不能是顶角')
+			if (endPoint.x === 0 && endPoint.y === 0) throw new Error('endPoint 不能是顶角')
+			if (endPoint.x === 0 && endPoint.y === height - 1) throw new Error('endPoint 不能是顶角')
+			if (endPoint.x === width - 1 && endPoint.y === height - 1) throw new Error('endPoint 不能是顶角')
+			if (endPoint.x === width - 1 && endPoint.y === 0) throw new Error('endPoint 不能是顶角')
+			this.height = height
+			this.width = width
+			this.startPoint = startPoint
+			this.endPoint = endPoint
+			this.map = []
+			// 走过的点
+			this.points = []
+			// 走过的点且节点没有路可走的总数
+			this.pointCount = -1
+			this.init()
+		}
+		/**
+		* 初始化
+		*/
+		init() {
+			this.map = []
+			this.points = []
+			this.pointCount = -1
+			// 地图数组生成
+			for (let i = 0; i < this.height; i++) {
+				let row = Array(this.width).fill(0)
+				this.map.push(row)
+			}
+			// 设置迷宫开始点
+			this.map[this.startPoint.y][this.startPoint.x] = 1
+			// 记录走过的点
+			this.points.push(Object.assign({}, this.startPoint))
+
+			this.currentPoint = Object.assign({}, this.startPoint)
+			// 创建迷宫路线
+			this.createMaze(this.currentPoint)
+			// 判断结尾没有链接出口，没有则重新生成迷宫
+			if (this.endLine()) {
+				this.init()
+			} else {
+				this.map[this.startPoint.y][this.startPoint.x] = 8
+				this.map[this.endPoint.y][this.endPoint.x] = 9
+				return this.map;
+			}
+		}
+		/**
+		* 结束点是否连通迷宫，没有连通重新生成迷宫
+		* 返回 false 已经连通
+		*/
+		endLine() {
+			if (this.endPoint.y === 0) {
+				// top                    
+				if (this.map[this.endPoint.y - 1][this.endPoint.x])
+					return false
+			} else if (this.endPoint.x === this.width - 1) {
+				// right
+				if (this.map[this.endPoint.y][this.endPoint.x - 1])
+					return false
+			} else if (this.endPoint.y === this.height - 1) {
+				// bottom
+				if (this.map[this.endPoint.y - 1][this.endPoint.x])
+					return false
+			} else if (this.endPoint.x === 0) {
+				// left
+				if (this.map[this.endPoint.y][this.endPoint.x + 1])
+					return false
+			}
+			return true
+		}
+		/**
+		* 创建迷宫路线
+		*/
+		createMaze(point) {
+			while (this.pointCount <= this.points.length) {
+				let bool = this.goAheadOne(point)
+				if (bool) {
+					this.pointCount++
+					this.createMaze(this.points[this.pointCount])
+				} else {
+					// 记录当前走过的点
+					this.points.push(Object.assign({}, point))
+				}
+			}
+		}
+		/**
+		* 向前一步，返回 true 当前点没有路可走
+		*/
+		goAheadOne(point) {
+			// 获取当前节点能走的点
+			const direction = this.pointWalk(point)
+			// 随机选取可走节点
+			const n = this.randomDirection(direction)
+			// 走
+			switch (n) {
+				case 0:
+					// top
+					point.y -= 1
+					break;
+				case 1:
+					//right
+					point.x += 1
+					break;
+				case 2:
+					//bottom
+					point.y += 1
+					break;
+				case 3:
+					//left
+					point.x -= 1
+					break;
+				default:
+					return true
+					break;
+			}
+			this.map[point.y][point.x] = 1
+			return false;
+		}
+		/**
+		* 这个点是否能走
+		*/
+		pointWalk(currentPoint) {
+			currentPoint = Object.assign({}, currentPoint)
+			let direction = [0, 0, 0, 0]
+			// top
+			if (currentPoint.y - 1 > 0 &&
+				currentPoint.x > 0 &&
+				currentPoint.x !== this.width &&
+				this.map[currentPoint.y - 1][currentPoint.x] === 0) {
+				if (this.currentAround(0, { x: currentPoint.x, y: currentPoint.y - 1 }))
+					direction[0] = 1
+			}
+			// right
+			if (currentPoint.x + 2 !== this.width &&
+				currentPoint.y > 0 &&
+				currentPoint.y !== this.height &&
+				this.map[currentPoint.y][currentPoint.x + 1] === 0) {
+				if (this.currentAround(1, { x: currentPoint.x + 1, y: currentPoint.y }))
+					direction[1] = 1
+			}
+			// bottom
+			if (currentPoint.y + 2 !== this.height &&
+				currentPoint.x !== this.width &&
+				currentPoint.x > 0 &&
+				this.map[currentPoint.y + 1][currentPoint.x] === 0) {
+				if (this.currentAround(2, { x: currentPoint.x, y: currentPoint.y + 1 }))
+					direction[2] = 1
+			}
+			// left
+			if (currentPoint.x - 1 > 0 &&
+				currentPoint.y > 0 &&
+				currentPoint.y !== this.height &&
+				this.map[currentPoint.y][currentPoint.x - 1] === 0) {
+				if (this.currentAround(3, { x: currentPoint.x - 1, y: currentPoint.y }))
+					direction[3] = 1
+			}
+			return direction
+		}
+		/**
+		* 当前点是否能落脚
+		*/
+		currentAround(n, point) {
+			let bool = true
+			//top
+			if (n !== 2 && point.y !== 0 && this.map[point.y - 1][point.x] === 1) {
+				bool = false
+			}
+			//right
+			if (n !== 3 && point.x !== this.width - 1 && this.map[point.y][point.x + 1] === 1) {
+				bool = false
+			}
+			//bottom
+			if (n !== 0 && point.y !== this.height - 1 && this.map[point.y + 1][point.x] === 1) {
+				bool = false
+			}
+			//left
+			if (n !== 1 && point.x !== 0 && this.map[point.y][point.x - 1] === 1) {
+				bool = false
+			}
+			return bool
+		}
+		/**
+		* 随机获取一个方向
+		*/
+		randomDirection(direction) {
+			let i = 0
+			direction.forEach((item) => {
+				i += item
+			})
+			if (i === 0) {
+				return -1
+			}
+			const n = parseInt(Math.random() * 4)
+			if (direction[n] === 0) {
+				return this.randomDirection(direction)
+			}
+			return n
+		}
+	}
+
+	new CreateMaze(height, width, startPoint, endPoint)
+}
+
+module.exports = createMaze;