在Web前端基于CAD图实现等值线在线分析 - ToB企服应用市场:ToB评测及商务社交产业平台

//生成测试数据
let dataMinValue = 10; // 数据最小值
let dataMaxValue = 500; // 数据最大值
let dataset = {
"type" : "FeatureCollection",
"features" : []
};
// 区间颜色值
let colors = ["#006837", "#1a9850", "#66bd63", "#a6d96a", "#d9ef8b", "#ffffbf","#fee08b",
"#fdae61", "#f46d43", "#d73027", "#a50026"];
for (let i = 0; i < 100; i++) {
let feature={
"type" : "Feature",
"properties" : {
"value" : vjmap.randInt(dataMinValue, dataMaxValue) // 在最大值最小值范围内随机生成一个测试数据
},
"geometry" : {
"type" : "Point",
"coordinates" : map.toLngLat(mapBounds.randomPoint())
}
};
dataset.features.push(feature);
}
let contoursSize = 20; // 等值面分级区间数，这里设置为20，可以自行设置
const createContour = async (dataset, contoursSize, propField, colors, dataMinValue, dataMaxValue, maxHeight, model) => {
let contours = [];
for(let i = 0; i < contoursSize; i++) {
contours.push(dataMinValue + (dataMaxValue - dataMinValue) * i / (contoursSize - 1));
}
let interpolateInput = [], interpolateOutput = [];
for(let i = 0; i < colors.length; i++) {
interpolateInput.push(i / (colors.length - 1)); // 插值输入值，这里输入0-1之间的比例
interpolateOutput.push(colors[i]) // 插值输出值，这里输入0-1之间的比例对应的颜色值
}
// 启动webworker计算函数
let createContourWorker = vjmap.WorkerProxy(vjmap.vectorContour);
let { grid, contour } = await createContourWorker(dataset, propField, contours, {
model: model || 'exponential',
sigma2:0,
alpha:100
});
// 根据比例插值颜色
const mapProgressToValues = value => vjmap.interpolate(
interpolateInput,
interpolateOutput,
{ ease: vjmap.linear }
)(value)
// 把原数据的颜色也设置下，绘制marker需要
dataset.features.forEach(f => f.properties.color = mapProgressToValues((f.properties.value - dataMinValue) / (dataMaxValue - dataMinValue)))
let h = maxHeight; // 设置最大值要拉伸的高度
for(let i = 0; i < contour.features.length; i++) {
let prop = contour.features[i].properties;
let r = (prop.value - dataMinValue) / (dataMaxValue - dataMinValue);
prop.color = mapProgressToValues(r); // 插值出颜色值
prop.height = h * r; // 插值出要拉伸的高度值
}
return contour;
}
let maxHeight = map.pixelToHeight(100, map.getZoom()); // 设置最大值要拉伸的高度
let contour = await createContour(dataset, contoursSize, "value" /*geojson的哪个属性值用于计算*/, colors, dataMinValue, dataMaxValue, maxHeight);
（3）绘制原始数据和生成好的等值线
let markers = null;
const addMarkers = ()=> {
if (markers) return;
markers = dataset.features.map(f => {
// 再随机生成不同样式的
let _marker = new vjmap.DiffusedApertureMarker({
lngLat: f.geometry.coordinates,
text: f.properties.value.toFixed(0)
}, {
// 可以给不同的属性，如宽度，颜色，字体
width: 10,
colors: [f.properties.color, vjmap.randomColor()],
textFontSize: 14,
textColor: f.properties.color
}).createMarker();
_marker.addTo(map)
return _marker
})
}
const removeMarkers = ()=> {
if (!markers) return;
for(let i = markers.length - 1; i >= 0; i--) {
markers[i].remove();
}
markers = null;
}
let polyline = null;
const addPolyline = ()=> {
if (polyline) return;
polyline = new vjmap.Polyline({
data: contour,
lineColor: ['case', ['to-boolean', ['feature-state', 'hover']], '#00ffff', ['get', 'color']],
isHoverPointer: true,
isHoverFeatureState: true
});
polyline.addTo(map);
polyline.clickPopup(f => `<h3>值: ${f.properties.value.toFixed(2)}</h3>Color: ${f.properties.color}`, { anchor: 'bottom' });
}
const removePolyline = ()=> {
if (!polyline) return;
polyline.remove();
polyline = null;
}

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let polygon = null;
const addPolygon = ()=> {
if (polygon) return;
polygon = new vjmap.Polygon({
data: contour,
fillColor: ['case', ['to-boolean', ['feature-state', 'hover']], '#00ffff', ['get', 'color']],
fillOpacity: 0.9,
isHoverPointer: true,
isHoverFeatureState: true
});
polygon.addTo(map);
polygon.clickPopup(f => `<h3>值: ${f.properties.value.toFixed(2)}</h3>Color: ${f.properties.color}`, { anchor: 'bottom' });
}
const removePolygon = ()=> {
if (!polygon) return;
polygon.remove();
polygon = null;
}

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let fillExtrusions = null;
const addFillExtrusion = ()=> {
if (fillExtrusions) return;
fillExtrusions = new vjmap.FillExtrusion({
data: contour,
fillExtrusionColor: ['case', ['to-boolean', ['feature-state', 'hover']], '#00ffff', ['get', 'color']],
fillExtrusionOpacity: 0.9,
fillExtrusionHeight: ['get', 'height'],
fillExtrusionBase:0,
isHoverPointer: true,
isHoverFeatureState: true
});
fillExtrusions.addTo(map);
fillExtrusions.clickPopup(f => `<h3>值: ${f.properties.value.toFixed(2)}</h3>Color: ${f.properties.color}`, { anchor: 'bottom' });
}
const removeFillExtrusion = ()=> {
if (!fillExtrusions) return;
fillExtrusions.remove();
fillExtrusions = null;
}

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