60 lines
1.4 KiB
Go
60 lines
1.4 KiB
Go
package main
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import (
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"encoding/binary"
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"fmt"
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)
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const sridFlag = 0x20000000
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func wkbToEwkbWithSrid(geometry []byte, srid int) []byte {
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if len(geometry) < 5 {
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return geometry
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}
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var byteOrder binary.ByteOrder
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if geometry[0] == 0 {
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byteOrder = binary.BigEndian
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} else {
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byteOrder = binary.LittleEndian
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}
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wkbType := byteOrder.Uint32(geometry[1:5])
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if wkbType&sridFlag != 0 {
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return geometry
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}
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ewkbType := wkbType | sridFlag
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result := make([]byte, len(geometry)+4)
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result[0] = geometry[0]
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byteOrder.PutUint32(result[1:5], ewkbType)
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byteOrder.PutUint32(result[5:9], uint32(srid))
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copy(result[9:], geometry[5:])
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return result
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}
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func main() {
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shape := []byte{
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1, 3, 0, 0, 0, 1, 0, 0, 0, 5, 0, 0, 0, 217, 61, 121, 88, 168, 57, 83, 192,
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60, 78, 209, 145, 92, 222, 39, 192, 232, 106, 43, 246, 151, 57, 83, 192,
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60, 78, 209, 145, 92, 222, 39, 192, 232, 106, 43, 246, 151, 57, 83, 192,
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174, 182, 98, 127, 217, 221, 39, 192, 217, 61, 121, 88, 168, 57, 83, 192,
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174, 182, 98, 127, 217, 221, 39, 192, 217, 61, 121, 88, 168, 57, 83, 192,
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60, 78, 209, 145, 92, 222, 39, 192,
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}
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srid := 4326
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result := wkbToEwkbWithSrid(shape, srid)
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fmt.Printf("WKB Original (len): %d\n", len(shape))
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fmt.Printf("EWKB Result (len): %d\n", len(result))
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fmt.Printf("Primeros bytes (original): %v\n", shape[:10])
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fmt.Printf("Primeros bytes (resultado): %v\n", result[:10])
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}
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