31 lines
691 B
Go
31 lines
691 B
Go
package proj
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import (
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"github.com/omniscale/imposm3/element"
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"math"
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)
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const pole = 6378137 * math.Pi // 20037508.342789244
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func WgsToMerc(long, lat float64) (x, y float64) {
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x = long * pole / 180.0
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y = math.Log(math.Tan((90.0+lat)*math.Pi/360.0)) / math.Pi * pole
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return x, y
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}
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func MercToWgs(x, y float64) (long, lat float64) {
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long = 180.0 * x / pole
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lat = 180.0 / math.Pi * (2*math.Atan(math.Exp((y/pole)*math.Pi)) - math.Pi/2)
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return long, lat
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}
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func NodesToMerc(nodes []element.Node) {
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for i, nd := range nodes {
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nodes[i].Long, nodes[i].Lat = WgsToMerc(nd.Long, nd.Lat)
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}
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}
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func NodeToMerc(node *element.Node) {
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node.Long, node.Lat = WgsToMerc(node.Long, node.Lat)
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}
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