根据坐标为某些网格切片上色 [英] Color certain grid tiles based on coordinates
本文介绍了根据坐标为某些网格切片上色的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！
问题描述
我想根据某些网格磁贴的坐标为其上色。
我创建了以下网格：
数据-lang="js"数据-隐藏="假"数据-控制台="真"数据-巴贝尔="假"><!DOCTYPE html>
<html>
<head>
<title>Color Tiles</title>
<meta charset="utf-8" />
<link href="https://cdn.jsdelivr.net/npm/bootstrap@5.1.3/dist/css/bootstrap.min.css" rel="stylesheet" integrity="sha384-1BmE4kWBq78iYhFldvKuhfTAU6auU8tT94WrHftjDbrCEXSU1oBoqyl2QvZ6jIW3" crossorigin="anonymous">
<link rel="stylesheet" href="https://unpkg.com/leaflet@1.0.1/dist/leaflet.css" />
<style>
body {
padding: 0;
margin: 0;
}
html,
body,
#map {
height: 100%;
width: 100%;
}
</style>
</head>
<body>
<div id="map"></div>
<script src="https://cdn.jsdelivr.net/npm/bootstrap@5.1.3/dist/js/bootstrap.bundle.min.js" integrity="sha384-ka7Sk0Gln4gmtz2MlQnikT1wXgYsOg+OMhuP+IlRH9sENBO0LRn5q+8nbTov4+1p" crossorigin="anonymous"></script>
<script src="https://unpkg.com/leaflet@1.0.1/dist/leaflet.js"></script>
<!-- Make sure you put this AFtER leaflet.js, when using with leaflet
<script src="https://unpkg.com/leaflet-geosearch@3.0.0/dist/geosearch.umd.js"></script>
-->
<script>
var map = new L.Map('map', { center: [10, 0], zoom: 2 });
let zoomLevel = map.getZoom()
console.log("zoomLevel " + zoomLevel)
// if(zoomLevel === 1) {
var tiles = new L.GridLayer();
tiles.createTile = function (coords) {
var tile = L.DomUtil.create('canvas', 'leaflet-tile');
var ctx = tile.getContext('2d');
var size = this.getTileSize()
// console.log("size: " + size.toString())
tile.width = size.x
tile.height = size.y
// calculate projection coordinates of top left tile pixel
var nwPoint = coords.scaleBy(size)
// calculate geographic coordinates of top left tile pixel
var nw = map.unproject(nwPoint, coords.z)
ctx.fillStyle = 'white';
ctx.fillRect(0, 0, size.x, 50);
ctx.fillStyle = 'black';
ctx.fillText('x: ' + coords.x + ', y: ' + coords.y + ', zoom: ' + coords.z, 20, 20);
ctx.fillText('lat: ' + nw.lat + ', lon: ' + nw.lng, 20, 40);
ctx.strokeStyle = 'black';
ctx.beginPath();
ctx.moveTo(0, 0);
ctx.lineTo(size.x - 1, 0);
ctx.lineTo(size.x - 1, size.y - 1);
ctx.lineTo(0, size.y - 1);
ctx.closePath();
ctx.stroke();
return tile;
}
L.tileLayer('http://{s}.tile.openstreetmap.org/{z}/{x}/{y}.png', {
attribution: 'Map data © <a href="http://www.osm.org">OpenStreetMap</a>',
}).addTo(map)
tiles.addTo(map)
</script>
</body>
</html>我想要以下物品：
我尝试通过css直接设置样式，这似乎很管用。但是，我想根据提供的坐标设置样式。
有什么建议如何做到这一点吗？
推荐答案
什么类型的坐标？
查看您在回合游戏中使用地图的另一个问题，对于坐标的含义可能有些模棱两可。您可能指的是地理坐标(即纬度和经度)，表示地图或地球仪上的点。另一方面，您可能表示表示地图或地球上某个区域的磁贴(例如，第4行、第5列，位于特定磁贴集的缩放级别3)的坐标。我会仔细检查两种情况下的处理方法。地理坐标
let内置了通过使用LatLngBounds.contains method检测特定LatLng coordinates是否在范围内的方法。
首先您可以定义一个按键坐标数组，然后根据它们创建传单LatLng objects：
var keyCoordinates = [
[ -5.9, -123.9 ],
[ -12, -28.5 ]
];
var leafletKeyCoordinates = keyCoordinates.map(function (c) {
return new L.LatLng(c[0], c[1]);
});
要确定特定瓷砖的边界，可以计算瓷砖的西南角。此部分：
// calculate projection coordinates of top left tile pixel
var nwPoint = coords.scaleBy(size)
// calculate geographic coordinates of top left tile pixel
var nw = map.unproject(nwPoint, coords.z);
添加：
// calculate projection coordinates of bottom right tile pixel
var sePoint = nwPoint.add(size);
// calculate geographic coordinates of bottom right tile pixel
var se = map.unproject(sePoint, coords.z);
var bounds = new L.LatLngBounds(nw, se);
从那里，您可以使用每个平铺的边界来确定是否应该对其进行着色。您可以通过在画布上绘制或将类应用于平铺来完成此操作。对于使用画布的示例，在createTile的底部添加：
// if it contains any coordinates, it should be filled
var shouldShade = leafletKeyCoordinates.some(function (a) {
return bounds.contains(a);
});
if (shouldShade) {
ctx.fillStyle = 'rgba(0, 0, 240, 0.3)';
ctx.fillRect(0, 0, size.x, size.y);
}
全部：
数据-lang="js"数据-隐藏="假"数据-控制台="真"数据-巴贝尔="假"><!DOCTYPE html>
<html>
<head>
<title>Color Tiles</title>
<meta charset="utf-8" />
<link href="https://cdn.jsdelivr.net/npm/bootstrap@5.1.3/dist/css/bootstrap.min.css" rel="stylesheet" integrity="sha384-1BmE4kWBq78iYhFldvKuhfTAU6auU8tT94WrHftjDbrCEXSU1oBoqyl2QvZ6jIW3" crossorigin="anonymous">
<link rel="stylesheet" href="https://unpkg.com/leaflet@1.0.1/dist/leaflet.css" />
<style>
body {
padding: 0;
margin: 0;
}
html,
body,
#map {
height: 100%;
width: 100%;
}
</style>
</head>
<body>
<div id="map"></div>
<script src="https://cdn.jsdelivr.net/npm/bootstrap@5.1.3/dist/js/bootstrap.bundle.min.js" integrity="sha384-ka7Sk0Gln4gmtz2MlQnikT1wXgYsOg+OMhuP+IlRH9sENBO0LRn5q+8nbTov4+1p" crossorigin="anonymous"></script>
<script src="https://unpkg.com/leaflet@1.0.1/dist/leaflet.js"></script>
<!-- Make sure you put this AFtER leaflet.js, when using with leaflet
<script src="https://unpkg.com/leaflet-geosearch@3.0.0/dist/geosearch.umd.js"></script>
-->
<script>
var map = new L.Map('map', { center: [10, 0], zoom: 2 });
let zoomLevel = map.getZoom()
console.log("zoomLevel " + zoomLevel)
var keyCoordinates = [
[ -5.9, -123.9 ],
[ -12, -28.5 ]
];
var leafletKeyCoordinates = keyCoordinates.map(function (c) {
return new L.LatLng(c[0], c[1]);
});
// if(zoomLevel === 1) {
var tiles = new L.GridLayer();
tiles.createTile = function (coords) {
var tile = L.DomUtil.create('canvas', 'leaflet-tile');
var ctx = tile.getContext('2d');
var size = this.getTileSize()
// console.log("size: " + size.toString())
tile.width = size.x
tile.height = size.y
// calculate projection coordinates of top left tile pixel
var nwPoint = coords.scaleBy(size)
// calculate geographic coordinates of top left tile pixel
var nw = map.unproject(nwPoint, coords.z)
// calculate projection coordinates of bottom right tile pixel
var sePoint = nwPoint.add(size);
// calculate geographic coordinates of bottom right tile pixel
var se = map.unproject(sePoint, coords.z);
var bounds = new L.LatLngBounds(nw, se);
ctx.fillStyle = 'white';
ctx.fillRect(0, 0, size.x, 50);
ctx.fillStyle = 'black';
ctx.fillText('x: ' + coords.x + ', y: ' + coords.y + ', zoom: ' + coords.z, 20, 20);
ctx.fillText('lat: ' + nw.lat + ', lon: ' + nw.lng, 20, 40);
ctx.strokeStyle = 'black';
ctx.beginPath();
ctx.moveTo(0, 0);
ctx.lineTo(size.x - 1, 0);
ctx.lineTo(size.x - 1, size.y - 1);
ctx.lineTo(0, size.y - 1);
ctx.closePath();
ctx.stroke();
// if it contains any coordinates, it should be filled
var shouldShade = leafletKeyCoordinates.some(function (a) {
return bounds.contains(a);
});
if (shouldShade) {
ctx.fillStyle = 'rgba(0, 0, 240, 0.3)';
ctx.fillRect(0, 0, size.x, size.y);
}
return tile;
}
L.tileLayer('http://{s}.tile.openstreetmap.org/{z}/{x}/{y}.png', {
attribution: 'Map data © <a href="http://www.osm.org">OpenStreetMap</a>',
}).addTo(map)
tiles.addTo(map)
</script>
</body>
</html>平铺坐标
对于平铺，您可以直接查看列和行的coords.x和coords.y，以及缩放级别的coords.z。这种情况的棘手之处在于，如果存在不同的缩放级别，您的用户的缩放比例可能与您标识的磁贴的缩放比例不同。
var tileCoordinates = [
[0, 3, 3], // x, y, and zoom of tile
[28, 6, 5]
];
Math.pow(2, targetZoom - coords.z)或Math.pow(2, coords.z - targetZoom)来确定要乘以的因子。
var { x, y, z } = coords;
var shouldShade = tileCoordinates.some(function (c) {
let [ tx, ty, tz] = c, multiple, sx, sy;
if (z < tz) {
// map is zoomed out from the target
// you may just want to `return false;` here
multiple = Math.pow(2, tz - z);
sx = Math.floor(tx / multiple);
sy = Math.floor(ty / multiple);
return sx === x && sy === y;
} else if (z > tz) {
// map is zoomed in from the target
multiple = Math.pow(2, z - tz);
sx = Math.floor(x / multiple);
sy = Math.floor(y / multiple);
return sx === tx && sy === ty;
}
return tx === x && ty === y;
});
加在一起：
<!DOCTYPE html>
<html>
<head>
<title>Color Tiles</title>
<meta charset="utf-8" />
<link href="https://cdn.jsdelivr.net/npm/bootstrap@5.1.3/dist/css/bootstrap.min.css" rel="stylesheet" integrity="sha384-1BmE4kWBq78iYhFldvKuhfTAU6auU8tT94WrHftjDbrCEXSU1oBoqyl2QvZ6jIW3" crossorigin="anonymous">
<link rel="stylesheet" href="https://unpkg.com/leaflet@1.0.1/dist/leaflet.css" />
<style>
body {
padding: 0;
margin: 0;
}
html,
body,
#map {
height: 100%;
width: 100%;
}
</style>
</head>
<body>
<div id="map"></div>
<script src="https://cdn.jsdelivr.net/npm/bootstrap@5.1.3/dist/js/bootstrap.bundle.min.js" integrity="sha384-ka7Sk0Gln4gmtz2MlQnikT1wXgYsOg+OMhuP+IlRH9sENBO0LRn5q+8nbTov4+1p" crossorigin="anonymous"></script>
<script src="https://unpkg.com/leaflet@1.0.1/dist/leaflet.js"></script>
<!-- Make sure you put this AFtER leaflet.js, when using with leaflet
<script src="https://unpkg.com/leaflet-geosearch@3.0.0/dist/geosearch.umd.js"></script>
-->
<script>
var map = new L.Map('map', { center: [10, 0], zoom: 2 });
let zoomLevel = map.getZoom()
console.log("zoomLevel " + zoomLevel)
var tileCoordinates = [
[0, 3, 3],
[28, 6, 5]
];
// if(zoomLevel === 1) {
var tiles = new L.GridLayer();
tiles.createTile = function (coords) {
var tile = L.DomUtil.create('canvas', 'leaflet-tile');
var ctx = tile.getContext('2d');
var size = this.getTileSize()
// console.log("size: " + size.toString())
tile.width = size.x
tile.height = size.y
// calculate projection coordinates of top left tile pixel
var nwPoint = coords.scaleBy(size)
// calculate geographic coordinates of top left tile pixel
var nw = map.unproject(nwPoint, coords.z)
// calculate projection coordinates of bottom right tile pixel
var sePoint = nwPoint.add(size);
// calculate geographic coordinates of bottom right tile pixel
var se = map.unproject(sePoint, coords.z);
var bounds = new L.LatLngBounds(nw, se);
ctx.fillStyle = 'white';
ctx.fillRect(0, 0, size.x, 50);
ctx.fillStyle = 'black';
ctx.fillText('x: ' + coords.x + ', y: ' + coords.y + ', zoom: ' + coords.z, 20, 20);
ctx.fillText('lat: ' + nw.lat + ', lon: ' + nw.lng, 20, 40);
ctx.strokeStyle = 'black';
ctx.beginPath();
ctx.moveTo(0, 0);
ctx.lineTo(size.x - 1, 0);
ctx.lineTo(size.x - 1, size.y - 1);
ctx.lineTo(0, size.y - 1);
ctx.closePath();
ctx.stroke();
var { x, y, z } = coords;
var shouldShade = tileCoordinates.some(function (c) {
let [ tx, ty, tz] = c, multiple, sx, sy;
if (z < tz) {
// map is zoomed out from the target
// you may just want to `return false;` here
multiple = Math.pow(2, tz - z);
sx = Math.floor(tx / multiple);
sy = Math.floor(ty / multiple);
return sx === x && sy === y;
} else if (z > tz) {
// map is zoomed in from the target
multiple = Math.pow(2, z - tz);
sx = Math.floor(x / multiple);
sy = Math.floor(y / multiple);
return sx === tx && sy === ty;
}
return tx === x && ty === y;
});
if (shouldShade) {
ctx.fillStyle = 'rgba(0, 0, 240, 0.3)';
ctx.fillRect(0, 0, size.x, size.y);
}
return tile;
}
L.tileLayer('http://{s}.tile.openstreetmap.org/{z}/{x}/{y}.png', {
attribution: 'Map data © <a href="http://www.osm.org">OpenStreetMap</a>',
}).addTo(map)
tiles.addTo(map)
</script>
</body>
</html>这篇关于根据坐标为某些网格切片上色的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！
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