Class: MySQLPoint::Coordinate

Inherits:
Object
  • Object
show all
Defined in:
lib/mysql_point/coordinate.rb

Overview

A struct for latitude/longitude coordinates, with serializers and deserializers for the standard WKT and WKB formats.

# WKT

‘POINT(<longitude> <latitude>)`

# WKB

  • byte 0: byte order (little endian is 01)

  • bytes 1-4: WKB type (point is 01)

  • bytes 5-12: X coordinate (longitude)

  • bytes 13-21: Y coordinate (latitude)

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(longitude:, latitude:) ⇒ Coordinate

Returns a new instance of Coordinate.



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# File 'lib/mysql_point/coordinate.rb', line 34

def initialize(longitude:, latitude:)
  @longitude = longitude.to_f if longitude
  @latitude = latitude.to_f if latitude
end

Instance Attribute Details

#latitude ⇒ Object (readonly)

Returns the value of attribute latitude.



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# File 'lib/mysql_point/coordinate.rb', line 32

def latitude
  @latitude
end

#longitude ⇒ Object (readonly)

Returns the value of attribute longitude.



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# File 'lib/mysql_point/coordinate.rb', line 31

def longitude
  @longitude
end

Class Method Details

.from_wkb(binstr) ⇒ Object 



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# File 'lib/mysql_point/coordinate.rb', line 21

def self.from_wkb(binstr)
  type = binstr[1, 4].unpack(binstr[0] == "\x01" ? 'V' : 'N').first
  return unless type == 1

  x = binstr[5, 8].unpack('D').first
  y = binstr[13, 8].unpack('D').first

  new(longitude: x, latitude: y)
end

.from_wkt(str) ⇒ Object

POINT(<longitude> <latitude>)



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# File 'lib/mysql_point/coordinate.rb', line 16

def self.from_wkt(str)
  md = str.match(/\APOINT\((-?[0-9.]*) (-?[0-9.]*)\)\z/)
  new(longitude: md[1], latitude: md[2]) if md
end

Instance Method Details

#to_wkb ⇒ Object 



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# File 'lib/mysql_point/coordinate.rb', line 43

def to_wkb
  "\x01" + [1].pack('L') + [longitude, latitude].pack('D*')
end

#to_wkt ⇒ Object 



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# File 'lib/mysql_point/coordinate.rb', line 39

def to_wkt
  "POINT(#{format('%.7f', longitude)} #{format('%.7f', latitude)})"
end