我正在构建一个基于2D方形网格的回合制HTML游戏。 每个网格方块可以跨越不同数量的移动点（即：道路为1 MP，草原为1.5 MP，森林为2 MP等）。 当用户单击一个单元时，我想使用该单元的分配移动点确定所有可能的可移动空间，以便我可以突出显示它们并使它们可单击。
有免费的图书馆可以做到这一点吗？ 我已经看到了一些路径算法，但没有关于确定可移动区域的算法。 其他游戏开发商如何处理这个问题？ 我对vanilla JS和JQuery解决方案都持开放态度。
好吧，我决定自己尝试攻击它。 我从来不擅长这类算法，所以我相信有一种比我所做的更有效的方法来处理它。 但是，就我而言，它运行得足够快，并且非常简单易懂。
如果它对其他希望这样做的人有帮助，我已经包含了下面的代码。 这是我原始答案的更新版本，我对其进行了修改以存储所采用的路径，以便您可以显示通过正确空间移动的单位。 这个答案在下面的例子中使用了JQuery，但只在少数地方;您可以轻松地将它们替换为香草JS。 包含实际路径/区域查找功能的第一个代码块是纯 JS。
<script>
var possibleMovementAreaArray = new Array(); // This array will hold our allowable movement tiles. Your other functions can access this after running possibleMovementArea().
function possibleMovementArea(unitIndex) {
// I'm storing each unit in my game in an array. So I pass in the index of the unit I want to determine the movement area for.
var x = unitList[unitIndex][10]; // x coordinate on the playgrid
var y = unitList[unitIndex][11]; // y coordinate on the playgrid
var mp = unitList[unitIndex][15]; // number of movement points
possibleMovementAreaArray.length = 0; // Clear our array so previous runs don't interfere.
findPossibleMovement(x, y, mp);
}
function findPossibleMovement(x, y, mp, prevStepX, prevStepY) {
// This is a recursive function; something I'm not normally too good at.
for (var d=1; d<=4; d++) {
// We run through each of the four cardinal directions. Bump this to 8 and add 4 more cases to include corners.
if (d == 1) {
// Check Up
var newX = x;
var newY = y - 1;
} else if (d == 2) {
// Check Down
var newX = x;
var newY = y + 1;
} else if (d == 3) {
// Check Left
var newX = x - 1;
var newY = y;
} else if (d == 4) {
// Check Right
var newX = x + 1;
var newY = y;
}
// Check to see if this square is occupied by another unit. Two units cannot occupy the same space.
spaceOccupied = false;
for (var j=1; j<=numUnits; j++) {
if (unitList[j][10] == newX && unitList[j][11] == newY)
spaceOccupied = true;
}
if (!spaceOccupied) {
// Modify this for loop as needed for your usage. I have a 2D array called mainMap that holds the ID of a type of terrain for each tile.
// I then have an array called terList that holds all the details for each type of terrain, such as movement points needed to get past.
// This for loop is just looking up the ID of the terrain for use later. Sort of like a "SELECT * FROM terrainInfo WHERE ID=terrainOfCurrentTile".
for (var j=1; j<=numTerrains; j++) {
if (newX > 0 && newX <= mapWidth && newY > 0 && newY <= mapHeight && terList[j][1] == mainMap[newX][newY])
break; // After finding the index of terList break out of the loop so j represents the correct index.
}
if (j <= numTerrains) { // Run if an actual terrain is found. No terrain is found if the search runs off the sides of the map.
var newMp = mp - terList[j][7]; // Decrement the movement points for this particular path.
if (newMp >= 0) { // Only continue if there were enough movement points to move to this square.
// Check to see if this square is already logged. For both efficiency and simplicity we only want each square logged once.
var newIndex = possibleMovementAreaArray.length
var alreadyLogged = false
if (possibleMovementAreaArray.length > 0) {
for (var j=0; j<possibleMovementAreaArray.length; j++) {
if (possibleMovementAreaArray[j][1] == newX && possibleMovementAreaArray[j][2] == newY) {
alreadyLogged = true;
var alreadyLoggedIndex = j;
}
}
}
if (!alreadyLogged) {
// This adds a row to the array and records the x and y coordinates of this tile as movable
possibleMovementAreaArray[newIndex] = new Array(6);
possibleMovementAreaArray[newIndex][1] = newX;
possibleMovementAreaArray[newIndex][2] = newY;
possibleMovementAreaArray[newIndex][3] = prevStepX; // This tracks the x coords of the steps taken so far to get here.
possibleMovementAreaArray[newIndex][4] = prevStepY; // This tracks the y coords of the steps taken so far to get here.
possibleMovementAreaArray[newIndex][5] = newMp; // Records remaining MP after the previous steps have been taken.
}
if (alreadyLogged && newMp > possibleMovementAreaArray[alreadyLoggedIndex][5]) {
// If this tile was already logged, but there was less MP remaining on that attempt, then this one is more efficient. Update the old path with this one.
possibleMovementAreaArray[alreadyLoggedIndex][3] = prevStepX;
possibleMovementAreaArray[alreadyLoggedIndex][4] = prevStepY;
possibleMovementAreaArray[alreadyLoggedIndex][5] = newMp;
}
if (newMp > 0) {
// Now update the list of previous steps to include this tile. This list will be passed along to the next call of this function, thus building a path.
if (prevStepX == '') {
var newPrevStepX = [newX];
var newPrevStepY = [newY];
} else {
// This code is required to make a full copy of the array holding the existing list of steps. If you use a simple equals then you just create a reference and
// subsequent calls are all updating the same array which creates a chaotic mess. This way we store a separate array for each possible path.
var newPrevStepX = prevStepX.slice();
newPrevStepX.push(newX);
var newPrevStepY = prevStepY.slice();
newPrevStepY.push(newY);
}
// If there are still movement points remaining, check and see where we could move next.
findPossibleMovement(newX, newY, newMp, newPrevStepX, newPrevStepY);
}
}
}
}
}
}
</script>
运行上述操作后，您可以遍历数组以查找所有可用的图块。 这是我是如何做到的：
<script>
// Shows the movement area based on the currently selected unit.
function showMovement() {
var newHTML = "";
curAction = "move";
possibleMovementArea(curUnit); // See above code
for (x=0; x<possibleMovementAreaArray.length; x++) {
// Loop over the array and do something with each tile. In this case I'm creating an overlay that I'll fade in and out.
var tileLeft = (possibleMovementAreaArray[x][1] - 1) * mapTileSize; // Figure out where to absolutely position this tile.
var tileTop = (possibleMovementAreaArray[x][2] - 1) * mapTileSize; // Figure out where to absolutely position this tile.
newHTML = newHTML + "<img id='path_" + possibleMovementAreaArray[x][1] + "_" + possibleMovementAreaArray[x][2] + "' onClick='mapClk(" + possibleMovementAreaArray[x][1] + ", " + possibleMovementAreaArray[x][2] + ", 0);' src='imgs/path.png' class='mapTile' style='left:" + tileLeft + "px; top:" + tileTop + "px;'>";
}
$("#movementDiv").html(newHTML); // Add all those images into a preexisting div.
$("#movementDiv").css("opacity", "0.5"); // Fade the div to 50%
$("#movementDiv").show(); // Make the div visible.
startFading(); // Run a routine to fade the div in and out.
}
</script>
由于我们确定了路径，因此我们也可以通过循环访问存储的信息来轻松显示运动：
<script>
for (j=0; j<possibleMovementAreaArray[areaIndex][3].length; j++) {
// This loop moves the unit img to each tile on its way to its destination. The final destination tile is not included.
var animSpeed = 150; // Time in ms that it takes to move each square.
var animEase = "linear"; // We want movement to remain a constant speed through each square in this case.
var targetLeft = (possibleMovementAreaArray[areaIndex][3][j]-1) * mapTileSize; // This looks at each step in the path array and multiplies it by tile size to determine the new horizonal position.
var targetTop = (possibleMovementAreaArray[areaIndex][4][j]-1) * mapTileSize; // This looks at each step in the path array and multiplies it by tile size to determine the new vertical position.
$("#char_"+curUnit).animate({"left":targetLeft, "top":targetTop}, animSpeed, animEase); // Do the animation. Subsequent animations get queued.
}
// Now we need to move to that last tile.
newLeft = (x-1) * mapTileSize;
newTop = (y-1) * mapTileSize;
$("#char_"+curUnit).animate({"left":newLeft, "top":newTop}, 400, "easeOutCubic"); // Slow unit at the end of journey for aesthetic purposes.
$("#char_"+curUnit).addClass("unitMoved", 250); // Turns the image grayscale so it can easily be seen that it has already moved.
</script>
希望这对其他人有帮助。