From c4318bcbd3c7aecab58b1b49ed5db92981504bc0 Mon Sep 17 00:00:00 2001 From: "James B. Pollack" Date: Fri, 6 Nov 2015 17:38:53 -0800 Subject: [PATCH] add easystar lib --- examples/libraries/easyStar.js | 744 ++++++++++++++++++++++++++ examples/libraries/easyStarExample.js | 30 ++ 2 files changed, 774 insertions(+) create mode 100644 examples/libraries/easyStar.js create mode 100644 examples/libraries/easyStarExample.js diff --git a/examples/libraries/easyStar.js b/examples/libraries/easyStar.js new file mode 100644 index 0000000000..b76ff1d7ec --- /dev/null +++ b/examples/libraries/easyStar.js @@ -0,0 +1,744 @@ +// The MIT License (MIT) + +// Copyright (c) 2012-2015 Bryce Neal + +// Permission is hereby granted, free of charge, to any person obtaining a copy +// of this software and associated documentation files (the "Software"), to deal +// in the Software without restriction, including without limitation the rights +// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell +// copies of the Software, and to permit persons to whom the Software is +// furnished to do so, subject to the following conditions: + +// The above copyright notice and this permission notice shall be included in +// all copies or substantial portions of the Software. + +// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR +// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, +// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE +// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER +// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, +// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN +// THE SOFTWARE. + +// Adapted for High Fidelity by James B. Pollack on 11/6/2015 + +loadEasyStar = function() { + var ezStar = eStar(); + return new ezStar.js() +} + +var eStar = function() { + + var EasyStar = EasyStar || {}; + + + /** + * A simple Node that represents a single tile on the grid. + * @param {Object} parent The parent node. + * @param {Number} x The x position on the grid. + * @param {Number} y The y position on the grid. + * @param {Number} costSoFar How far this node is in moves*cost from the start. + * @param {Number} simpleDistanceToTarget Manhatten distance to the end point. + **/ + EasyStar.Node = function(parent, x, y, costSoFar, simpleDistanceToTarget) { + this.parent = parent; + this.x = x; + this.y = y; + this.costSoFar = costSoFar; + this.simpleDistanceToTarget = simpleDistanceToTarget; + + /** + * @return {Number} Best guess distance of a cost using this node. + **/ + this.bestGuessDistance = function() { + return this.costSoFar + this.simpleDistanceToTarget; + } + }; + + // Constants + EasyStar.Node.OPEN_LIST = 0; + EasyStar.Node.CLOSED_LIST = 1; + /** + * This is an improved Priority Queue data type implementation that can be used to sort any object type. + * It uses a technique called a binary heap. + * + * For more on binary heaps see: http://en.wikipedia.org/wiki/Binary_heap + * + * @param {String} criteria The criteria by which to sort the objects. + * This should be a property of the objects you're sorting. + * + * @param {Number} heapType either PriorityQueue.MAX_HEAP or PriorityQueue.MIN_HEAP. + **/ + EasyStar.PriorityQueue = function(criteria, heapType) { + this.length = 0; //The current length of heap. + var queue = []; + var isMax = false; + + //Constructor + if (heapType == EasyStar.PriorityQueue.MAX_HEAP) { + isMax = true; + } else if (heapType == EasyStar.PriorityQueue.MIN_HEAP) { + isMax = false; + } else { + throw heapType + " not supported."; + } + + /** + * Inserts the value into the heap and sorts it. + * + * @param value The object to insert into the heap. + **/ + this.insert = function(value) { + if (!value.hasOwnProperty(criteria)) { + throw "Cannot insert " + value + " because it does not have a property by the name of " + criteria + "."; + } + queue.push(value); + this.length++; + bubbleUp(this.length - 1); + } + + /** + * Peeks at the highest priority element. + * + * @return the highest priority element + **/ + this.getHighestPriorityElement = function() { + return queue[0]; + } + + /** + * Removes and returns the highest priority element from the queue. + * + * @return the highest priority element + **/ + this.shiftHighestPriorityElement = function() { + if (this.length === 0) { + throw ("There are no more elements in your priority queue."); + } else if (this.length === 1) { + var onlyValue = queue[0]; + queue = []; + this.length = 0; + return onlyValue; + } + var oldRoot = queue[0]; + var newRoot = queue.pop(); + this.length--; + queue[0] = newRoot; + swapUntilQueueIsCorrect(0); + return oldRoot; + } + + var bubbleUp = function(index) { + if (index === 0) { + return; + } + var parent = getParentOf(index); + if (evaluate(index, parent)) { + swap(index, parent); + bubbleUp(parent); + } else { + return; + } + } + + var swapUntilQueueIsCorrect = function(value) { + var left = getLeftOf(value); + var right = getRightOf(value); + if (evaluate(left, value)) { + swap(value, left); + swapUntilQueueIsCorrect(left); + } else if (evaluate(right, value)) { + swap(value, right); + swapUntilQueueIsCorrect(right); + } else if (value == 0) { + return; + } else { + swapUntilQueueIsCorrect(0); + } + } + + var swap = function(self, target) { + var placeHolder = queue[self]; + queue[self] = queue[target]; + queue[target] = placeHolder; + } + + var evaluate = function(self, target) { + if (queue[target] === undefined || queue[self] === undefined) { + return false; + } + + var selfValue; + var targetValue; + + // Check if the criteria should be the result of a function call. + if (typeof queue[self][criteria] === 'function') { + selfValue = queue[self][criteria](); + targetValue = queue[target][criteria](); + } else { + selfValue = queue[self][criteria]; + targetValue = queue[target][criteria]; + } + + if (isMax) { + if (selfValue > targetValue) { + return true; + } else { + return false; + } + } else { + if (selfValue < targetValue) { + return true; + } else { + return false; + } + } + } + + var getParentOf = function(index) { + return Math.floor((index - 1) / 2); + } + + var getLeftOf = function(index) { + return index * 2 + 1; + } + + var getRightOf = function(index) { + return index * 2 + 2; + } + }; + + // Constants + EasyStar.PriorityQueue.MAX_HEAP = 0; + EasyStar.PriorityQueue.MIN_HEAP = 1; + + /** + * Represents a single instance of EasyStar. + * A path that is in the queue to eventually be found. + */ + EasyStar.instance = function() { + this.isDoneCalculating = true; + this.pointsToAvoid = {}; + this.startX; + this.callback; + this.startY; + this.endX; + this.endY; + this.nodeHash = {}; + this.openList; + }; + /** + * EasyStar.js + * github.com/prettymuchbryce/EasyStarJS + * Licensed under the MIT license. + * + * Implementation By Bryce Neal (@prettymuchbryce) + **/ + EasyStar.js = function() { + var STRAIGHT_COST = 1.0; + var DIAGONAL_COST = 1.4; + var syncEnabled = false; + var pointsToAvoid = {}; + var collisionGrid; + var costMap = {}; + var pointsToCost = {}; + var allowCornerCutting = true; + var iterationsSoFar; + var instances = []; + var iterationsPerCalculation = Number.MAX_VALUE; + var acceptableTiles; + var diagonalsEnabled = false; + + /** + * Sets the collision grid that EasyStar uses. + * + * @param {Array|Number} tiles An array of numbers that represent + * which tiles in your grid should be considered + * acceptable, or "walkable". + **/ + this.setAcceptableTiles = function(tiles) { + if (tiles instanceof Array) { + // Array + acceptableTiles = tiles; + } else if (!isNaN(parseFloat(tiles)) && isFinite(tiles)) { + // Number + acceptableTiles = [tiles]; + } + }; + + /** + * Enables sync mode for this EasyStar instance.. + * if you're into that sort of thing. + **/ + this.enableSync = function() { + syncEnabled = true; + }; + + /** + * Disables sync mode for this EasyStar instance. + **/ + this.disableSync = function() { + syncEnabled = false; + }; + + /** + * Enable diagonal pathfinding. + */ + this.enableDiagonals = function() { + diagonalsEnabled = true; + } + + /** + * Disable diagonal pathfinding. + */ + this.disableDiagonals = function() { + diagonalsEnabled = false; + } + + /** + * Sets the collision grid that EasyStar uses. + * + * @param {Array} grid The collision grid that this EasyStar instance will read from. + * This should be a 2D Array of Numbers. + **/ + this.setGrid = function(grid) { + print('EASY GRID') + collisionGrid = grid; + + //Setup cost map + for (var y = 0; y < collisionGrid.length; y++) { + for (var x = 0; x < collisionGrid[0].length; x++) { + if (!costMap[collisionGrid[y][x]]) { + costMap[collisionGrid[y][x]] = 1 + } + } + } + }; + + /** + * Sets the tile cost for a particular tile type. + * + * @param {Number} The tile type to set the cost for. + * @param {Number} The multiplicative cost associated with the given tile. + **/ + this.setTileCost = function(tileType, cost) { + costMap[tileType] = cost; + }; + + /** + * Sets the an additional cost for a particular point. + * Overrides the cost from setTileCost. + * + * @param {Number} x The x value of the point to cost. + * @param {Number} y The y value of the point to cost. + * @param {Number} The multiplicative cost associated with the given point. + **/ + this.setAdditionalPointCost = function(x, y, cost) { + pointsToCost[x + '_' + y] = cost; + }; + + /** + * Remove the additional cost for a particular point. + * + * @param {Number} x The x value of the point to stop costing. + * @param {Number} y The y value of the point to stop costing. + **/ + this.removeAdditionalPointCost = function(x, y) { + delete pointsToCost[x + '_' + y]; + } + + /** + * Remove all additional point costs. + **/ + this.removeAllAdditionalPointCosts = function() { + pointsToCost = {}; + } + + /** + * Sets the number of search iterations per calculation. + * A lower number provides a slower result, but more practical if you + * have a large tile-map and don't want to block your thread while + * finding a path. + * + * @param {Number} iterations The number of searches to prefrom per calculate() call. + **/ + this.setIterationsPerCalculation = function(iterations) { + iterationsPerCalculation = iterations; + }; + + /** + * Avoid a particular point on the grid, + * regardless of whether or not it is an acceptable tile. + * + * @param {Number} x The x value of the point to avoid. + * @param {Number} y The y value of the point to avoid. + **/ + this.avoidAdditionalPoint = function(x, y) { + pointsToAvoid[x + "_" + y] = 1; + }; + + /** + * Stop avoiding a particular point on the grid. + * + * @param {Number} x The x value of the point to stop avoiding. + * @param {Number} y The y value of the point to stop avoiding. + **/ + this.stopAvoidingAdditionalPoint = function(x, y) { + delete pointsToAvoid[x + "_" + y]; + }; + + /** + * Enables corner cutting in diagonal movement. + **/ + this.enableCornerCutting = function() { + allowCornerCutting = true; + }; + + /** + * Disables corner cutting in diagonal movement. + **/ + this.disableCornerCutting = function() { + allowCornerCutting = false; + }; + + /** + * Stop avoiding all additional points on the grid. + **/ + this.stopAvoidingAllAdditionalPoints = function() { + pointsToAvoid = {}; + }; + + /** + * Find a path. + * + * @param {Number} startX The X position of the starting point. + * @param {Number} startY The Y position of the starting point. + * @param {Number} endX The X position of the ending point. + * @param {Number} endY The Y position of the ending point. + * @param {Function} callback A function that is called when your path + * is found, or no path is found. + * + **/ + this.findPath = function(startX, startY, endX, endY, callback) { + // Wraps the callback for sync vs async logic + var callbackWrapper = function(result) { + if (syncEnabled) { + callback(result); + } else { + Script.setTimeout(function() { + callback(result); + }, 1); + } + } + + // No acceptable tiles were set + if (acceptableTiles === undefined) { + throw new Error("You can't set a path without first calling setAcceptableTiles() on EasyStar."); + } + // No grid was set + if (collisionGrid === undefined) { + throw new Error("You can't set a path without first calling setGrid() on EasyStar."); + } + + // Start or endpoint outside of scope. + if (startX < 0 || startY < 0 || endX < 0 || endX < 0 || + startX > collisionGrid[0].length - 1 || startY > collisionGrid.length - 1 || + endX > collisionGrid[0].length - 1 || endY > collisionGrid.length - 1) { + throw new Error("Your start or end point is outside the scope of your grid."); + } + + // Start and end are the same tile. + if (startX === endX && startY === endY) { + callbackWrapper([]); + return; + } + + // End point is not an acceptable tile. + var endTile = collisionGrid[endY][endX]; + var isAcceptable = false; + for (var i = 0; i < acceptableTiles.length; i++) { + if (endTile === acceptableTiles[i]) { + isAcceptable = true; + break; + } + } + + if (isAcceptable === false) { + callbackWrapper(null); + return; + } + + // Create the instance + var instance = new EasyStar.instance(); + instance.openList = new EasyStar.PriorityQueue("bestGuessDistance", EasyStar.PriorityQueue.MIN_HEAP); + instance.isDoneCalculating = false; + instance.nodeHash = {}; + instance.startX = startX; + instance.startY = startY; + instance.endX = endX; + instance.endY = endY; + instance.callback = callbackWrapper; + + instance.openList.insert(coordinateToNode(instance, instance.startX, + instance.startY, null, STRAIGHT_COST)); + + instances.push(instance); + }; + + /** + * This method steps through the A* Algorithm in an attempt to + * find your path(s). It will search 4-8 tiles (depending on diagonals) for every calculation. + * You can change the number of calculations done in a call by using + * easystar.setIteratonsPerCalculation(). + **/ + this.calculate = function() { + if (instances.length === 0 || collisionGrid === undefined || acceptableTiles === undefined) { + return; + } + for (iterationsSoFar = 0; iterationsSoFar < iterationsPerCalculation; iterationsSoFar++) { + if (instances.length === 0) { + return; + } + + if (syncEnabled) { + // If this is a sync instance, we want to make sure that it calculates synchronously. + iterationsSoFar = 0; + } + + // Couldn't find a path. + if (instances[0].openList.length === 0) { + var ic = instances[0]; + ic.callback(null); + instances.shift(); + continue; + } + + var searchNode = instances[0].openList.shiftHighestPriorityElement(); + + var tilesToSearch = []; + searchNode.list = EasyStar.Node.CLOSED_LIST; + + if (searchNode.y > 0) { + tilesToSearch.push({ + instance: instances[0], + searchNode: searchNode, + x: 0, + y: -1, + cost: STRAIGHT_COST * getTileCost(searchNode.x, searchNode.y - 1) + }); + } + if (searchNode.x < collisionGrid[0].length - 1) { + tilesToSearch.push({ + instance: instances[0], + searchNode: searchNode, + x: 1, + y: 0, + cost: STRAIGHT_COST * getTileCost(searchNode.x + 1, searchNode.y) + }); + } + if (searchNode.y < collisionGrid.length - 1) { + tilesToSearch.push({ + instance: instances[0], + searchNode: searchNode, + x: 0, + y: 1, + cost: STRAIGHT_COST * getTileCost(searchNode.x, searchNode.y + 1) + }); + } + if (searchNode.x > 0) { + tilesToSearch.push({ + instance: instances[0], + searchNode: searchNode, + x: -1, + y: 0, + cost: STRAIGHT_COST * getTileCost(searchNode.x - 1, searchNode.y) + }); + } + if (diagonalsEnabled) { + if (searchNode.x > 0 && searchNode.y > 0) { + + if (allowCornerCutting || + (isTileWalkable(collisionGrid, acceptableTiles, searchNode.x, searchNode.y - 1) && + isTileWalkable(collisionGrid, acceptableTiles, searchNode.x - 1, searchNode.y))) { + + tilesToSearch.push({ + instance: instances[0], + searchNode: searchNode, + x: -1, + y: -1, + cost: DIAGONAL_COST * getTileCost(searchNode.x - 1, searchNode.y - 1) + }); + } + } + if (searchNode.x < collisionGrid[0].length - 1 && searchNode.y < collisionGrid.length - 1) { + + if (allowCornerCutting || + (isTileWalkable(collisionGrid, acceptableTiles, searchNode.x, searchNode.y + 1) && + isTileWalkable(collisionGrid, acceptableTiles, searchNode.x + 1, searchNode.y))) { + + tilesToSearch.push({ + instance: instances[0], + searchNode: searchNode, + x: 1, + y: 1, + cost: DIAGONAL_COST * getTileCost(searchNode.x + 1, searchNode.y + 1) + }); + } + } + if (searchNode.x < collisionGrid[0].length - 1 && searchNode.y > 0) { + + if (allowCornerCutting || + (isTileWalkable(collisionGrid, acceptableTiles, searchNode.x, searchNode.y - 1) && + isTileWalkable(collisionGrid, acceptableTiles, searchNode.x + 1, searchNode.y))) { + + + tilesToSearch.push({ + instance: instances[0], + searchNode: searchNode, + x: 1, + y: -1, + cost: DIAGONAL_COST * getTileCost(searchNode.x + 1, searchNode.y - 1) + }); + } + } + if (searchNode.x > 0 && searchNode.y < collisionGrid.length - 1) { + + if (allowCornerCutting || + (isTileWalkable(collisionGrid, acceptableTiles, searchNode.x, searchNode.y + 1) && + isTileWalkable(collisionGrid, acceptableTiles, searchNode.x - 1, searchNode.y))) { + + + tilesToSearch.push({ + instance: instances[0], + searchNode: searchNode, + x: -1, + y: 1, + cost: DIAGONAL_COST * getTileCost(searchNode.x - 1, searchNode.y + 1) + }); + } + } + } + + // First sort all of the potential nodes we could search by their cost + heuristic distance. + tilesToSearch.sort(function(a, b) { + var aCost = a.cost + getDistance(searchNode.x + a.x, searchNode.y + a.y, instances[0].endX, instances[0].endY) + var bCost = b.cost + getDistance(searchNode.x + b.x, searchNode.y + b.y, instances[0].endX, instances[0].endY) + if (aCost < bCost) { + return -1; + } else if (aCost === bCost) { + return 0; + } else { + return 1; + } + }); + + var isDoneCalculating = false; + + // Search all of the surrounding nodes + for (var i = 0; i < tilesToSearch.length; i++) { + checkAdjacentNode(tilesToSearch[i].instance, tilesToSearch[i].searchNode, + tilesToSearch[i].x, tilesToSearch[i].y, tilesToSearch[i].cost); + if (tilesToSearch[i].instance.isDoneCalculating === true) { + isDoneCalculating = true; + break; + } + } + + if (isDoneCalculating) { + instances.shift(); + continue; + } + + } + }; + + // Private methods follow + var checkAdjacentNode = function(instance, searchNode, x, y, cost) { + var adjacentCoordinateX = searchNode.x + x; + var adjacentCoordinateY = searchNode.y + y; + + if (pointsToAvoid[adjacentCoordinateX + "_" + adjacentCoordinateY] === undefined) { + // Handles the case where we have found the destination + if (instance.endX === adjacentCoordinateX && instance.endY === adjacentCoordinateY) { + instance.isDoneCalculating = true; + var path = []; + var pathLen = 0; + path[pathLen] = { + x: adjacentCoordinateX, + y: adjacentCoordinateY + }; + pathLen++; + path[pathLen] = { + x: searchNode.x, + y: searchNode.y + }; + pathLen++; + var parent = searchNode.parent; + while (parent != null) { + path[pathLen] = { + x: parent.x, + y: parent.y + }; + pathLen++; + parent = parent.parent; + } + path.reverse(); + var ic = instance; + var ip = path; + ic.callback(ip); + return + } + + if (isTileWalkable(collisionGrid, acceptableTiles, adjacentCoordinateX, adjacentCoordinateY)) { + var node = coordinateToNode(instance, adjacentCoordinateX, + adjacentCoordinateY, searchNode, cost); + + if (node.list === undefined) { + node.list = EasyStar.Node.OPEN_LIST; + instance.openList.insert(node); + } else if (node.list === EasyStar.Node.OPEN_LIST) { + if (searchNode.costSoFar + cost < node.costSoFar) { + node.costSoFar = searchNode.costSoFar + cost; + node.parent = searchNode; + } + } + } + } + }; + + // Helpers + var isTileWalkable = function(collisionGrid, acceptableTiles, x, y) { + for (var i = 0; i < acceptableTiles.length; i++) { + if (collisionGrid[y][x] === acceptableTiles[i]) { + return true; + } + } + + return false; + }; + + var getTileCost = function(x, y) { + return pointsToCost[x + '_' + y] || costMap[collisionGrid[y][x]] + }; + + var coordinateToNode = function(instance, x, y, parent, cost) { + if (instance.nodeHash[x + "_" + y] !== undefined) { + return instance.nodeHash[x + "_" + y]; + } + var simpleDistanceToTarget = getDistance(x, y, instance.endX, instance.endY); + if (parent !== null) { + var costSoFar = parent.costSoFar + cost; + } else { + costSoFar = simpleDistanceToTarget; + } + var node = new EasyStar.Node(parent, x, y, costSoFar, simpleDistanceToTarget); + instance.nodeHash[x + "_" + y] = node; + return node; + }; + + var getDistance = function(x1, y1, x2, y2) { + return Math.sqrt((x2 -= x1) * x2 + (y2 -= y1) * y2); + }; + } + return EasyStar +} \ No newline at end of file diff --git a/examples/libraries/easyStarExample.js b/examples/libraries/easyStarExample.js new file mode 100644 index 0000000000..3e28fb571e --- /dev/null +++ b/examples/libraries/easyStarExample.js @@ -0,0 +1,30 @@ +Script.include('easyStar.js'); +var easystar = loadEasyStar(); + +var grid = [ + [0, 0, 1, 0, 0], + [0, 0, 1, 0, 0], + [0, 0, 1, 0, 0], + [0, 0, 1, 0, 0], + [0, 0, 0, 0, 0] +]; + +easystar.setGrid(grid); + +easystar.setAcceptableTiles([0]); + +easystar.findPath(0, 0, 4, 0, function(path) { + if (path === null) { + print("Path was not found."); + Script.update.disconnect(tickEasyStar) + } else { + print("Path was found. The first Point is " + path[0].x + " " + path[0].y); + Script.update.disconnect(tickEasyStar) + } +}); + +var tickEasyStar = function() { + easystar.calculate(); +} + +Script.update.connect(tickEasyStar); \ No newline at end of file