我有一个世界地图,它将被放置在popovers/modals中(遵循本教程)当使用时,它需要放大到给定的国家。我制作了一个参考地图,隐藏了它,复制了它的内容,创建了一个新的(本地化的)地图。问题是:我无法更新新地图上的投影比例。它在原始地图上工作,遵循这个答案中的说明。
我是第一次来这里寻求帮助的。非常感谢。我确信这不是最佳实践,但重新绘制一个新svg的加载时间是一个性能问题。
var width = 280, height = width/2, scale = 50;
var projection, path, svg, g, countries, country, content;
projection = d3.geo.mercator()
.translate([(width/2), (height/2)])
.scale( width / 2 / Math.PI);
path = d3.geo.path().projection(projection);
svg = d3.select("#referenceMap").append("svg")
.attr("width", width)
.attr("height", height);
g = svg.append("g");
d3.json("data/world-topo-min.json", function(error, world) {
countries = topojson.feature(world, world.objects.countries).features;
country = g.selectAll(".country").data(topo);
country.enter().insert("path")
.attr("class", "country")
.attr("d", path)
.attr("id", function(d,i) { return d.id; })
.attr("title", function(d,i) { return d.properties.name; })
.style("fill", function(d, i) { return d.properties.color; });
content = d3.select('#referenceMap').html(); // -- copy the SVG
});
function copyMap(element, countryName) {
var countryPath = countries.filter(function(d) {
return d.properties.name == countryName;
})[0];
var div = d3.select(element).html(content); // -- 'paste' the SVG
g = d3.select(element).select('g');
.attr("fill", 'rgb(102, 106, 79)'); // -- this works fine as well
// Issue Area: Update the projection to pan and zoom on the given country
var bounds = path.bounds(countryPath);
var hscale = scale*width / (bounds[1][0] - bounds[0][0]);
var vscale = scale*height / (bounds[1][1] - bounds[0][1]);
scale = (hscale < vscale) ? hscale : vscale;
var offset = [width - (bounds[0][0] + bounds[1][0])/2,
height - (bounds[0][1] + bounds[1][1])/2];
// new projection
projection = d3.geo.mercator().center(d3.geo.centroid(countryPath))
.scale(scale).translate(offset);
path = path.projection(projection);
}
完成投影后。比例尺(600);我需要添加g.selectAll("路径").attr("d",路径);。不幸的是,这只是让加载速度对我的popover来说太长了。
// new projection
projection = d3.geo.mercator().center(d3.geo.centroid(countryPath))
.scale(scale).translate(offset);
path = path.projection(projection);
g.selectAll("path").attr("d", path); // <-- Added this line to fix the issue.