mirror of https://github.com/tidwall/tile38.git
64 lines
1.7 KiB
Go
64 lines
1.7 KiB
Go
package bing
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import "errors"
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// LatLongToQuad iterates through all of the quads parts until levelOfDetail is reached.
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func LatLongToQuad(latitude, longitude float64, levelOfDetail uint64, iterator func(part int) bool) {
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pixelX, pixelY := LatLongToPixelXY(latitude, longitude, levelOfDetail)
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tileX, tileY := PixelXYToTileXY(pixelX, pixelY)
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for i := levelOfDetail; i > 0; i-- {
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if !iterator(partForTileXY(tileX, tileY, i)) {
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break
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}
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}
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}
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func partForTileXY(tileX, tileY int64, levelOfDetail uint64) int {
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mask := int64(1 << (levelOfDetail - 1))
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if (tileX & mask) != 0 {
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if (tileY & mask) != 0 {
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return 3
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}
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return 1
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} else if (tileY & mask) != 0 {
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return 2
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}
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return 0
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}
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// TileXYToBounds returns the bounds around a tile.
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func TileXYToBounds(tileX, tileY int64, levelOfDetail uint64) (minLat, minLon, maxLat, maxLon float64) {
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size := int64(1 << levelOfDetail)
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pixelX, pixelY := TileXYToPixelXY(tileX, tileY)
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maxLat, minLon = PixelXYToLatLong(pixelX, pixelY, levelOfDetail)
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pixelX, pixelY = TileXYToPixelXY(tileX+1, tileY+1)
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minLat, maxLon = PixelXYToLatLong(pixelX, pixelY, levelOfDetail)
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if size == 0 || tileX%size == 0 {
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minLon = MinLongitude
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}
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if size == 0 || tileX%size == size-1 {
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maxLon = MaxLongitude
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}
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if tileY <= 0 {
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maxLat = MaxLatitude
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}
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if tileY >= size-1 {
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minLat = MinLatitude
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}
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return
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}
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// QuadKeyToBounds converts a quadkey to bounds
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func QuadKeyToBounds(quadkey string) (minLat, minLon, maxLat, maxLon float64, err error) {
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for i := 0; i < len(quadkey); i++ {
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switch quadkey[i] {
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case '0', '1', '2', '3':
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default:
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err = errors.New("invalid quadkey")
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return
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}
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}
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minLat, minLon, maxLat, maxLon = TileXYToBounds(QuadKeyToTileXY(quadkey))
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return
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}
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