Class: Geokit::Bounds

Inherits:
Object show all
Defined in:
lib/geokit/bounds.rb

Overview

Bounds represents a rectangular bounds, defined by the SW and NE corners

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(sw, ne) ⇒ Bounds

provide sw and ne to instantiate a new Bounds instance


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# File 'lib/geokit/bounds.rb', line 8

def initialize(sw, ne)
  unless sw.is_a?(Geokit::LatLng) && ne.is_a?(Geokit::LatLng)
    raise ArgumentError
  end
  @sw, @ne = sw, ne
end

Instance Attribute Details

#neObject

sw and ne are LatLng objects


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# File 'lib/geokit/bounds.rb', line 5

def ne
  @ne
end

#swObject

sw and ne are LatLng objects


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# File 'lib/geokit/bounds.rb', line 5

def sw
  @sw
end

Class Method Details

.from_point_and_radius(point, radius, options = {}) ⇒ Object

returns an instance of bounds which completely encompases the given circle


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# File 'lib/geokit/bounds.rb', line 69

def from_point_and_radius(point, radius, options = {})
  point = LatLng.normalize(point)
  p0 = point.endpoint(0, radius, options)
  p90 = point.endpoint(90, radius, options)
  p180 = point.endpoint(180, radius, options)
  p270 = point.endpoint(270, radius, options)
  sw = Geokit::LatLng.new(p180.lat, p270.lng)
  ne = Geokit::LatLng.new(p0.lat, p90.lng)
  Geokit::Bounds.new(sw, ne)
end

.normalize(thing, other = nil) ⇒ Object

Takes two main combinations of arguments to create a bounds: point,point (this is the only one which takes two arguments

point,point

. . . where a point is anything LatLng#normalize can handle

(which is quite a lot)

NOTE: everything combination is assumed to pass points in the order sw, ne


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# File 'lib/geokit/bounds.rb', line 88

def normalize(thing, other = nil)
  # maybe this will be simple -- an actual bounds object is passed, and
  # we can all go home
  return thing if thing.is_a? Bounds

  # no? OK, if there's no "other," the thing better be a two-element array
  thing, other = thing if !other && thing.is_a?(Array) && thing.size == 2

  # Now that we're set with a thing and another thing, let LatLng do the
  # heavy lifting.
  # Exceptions may be thrown
  thing_ll = Geokit::LatLng.normalize(thing)
  other_ll = Geokit::LatLng.normalize(other)
  Bounds.new(thing_ll, other_ll)
end

Instance Method Details

#==(other) ⇒ Object

Returns true if the candidate object is logically equal. Logical equivalence is true if the lat and lng attributes are the same for both objects.


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# File 'lib/geokit/bounds.rb', line 51

def ==(other)
  return false unless other.is_a?(Bounds)
  sw == other.sw && ne == other.ne
end

#centerObject

returns the a single point which is the center of the rectangular bounds


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# File 'lib/geokit/bounds.rb', line 16

def center
  @sw.midpoint_to(@ne)
end

#contains?(point) ⇒ Boolean

Returns true if the bounds contain the passed point. allows for bounds which cross the meridian


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# File 'lib/geokit/bounds.rb', line 32

def contains?(point)
  point = Geokit::LatLng.normalize(point)
  res = point.lat > @sw.lat && point.lat < @ne.lat
  if crosses_meridian?
    res &= point.lng < @ne.lng || point.lng > @sw.lng
  else
    res &= point.lng < @ne.lng && point.lng > @sw.lng
  end
  res
end

#crosses_meridian?Boolean

returns true if the bounds crosses the international dateline


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# File 'lib/geokit/bounds.rb', line 44

def crosses_meridian?
  @sw.lng > @ne.lng
end

#to_aObject

a two-element array of two-element arrays: sw,ne


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# File 'lib/geokit/bounds.rb', line 26

def to_a
  [@sw.to_a, @ne.to_a]
end

#to_sObject

a simple string representation:sw,ne


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# File 'lib/geokit/bounds.rb', line 21

def to_s
  "#{@sw},#{@ne}"
end

#to_spanObject

Equivalent to Google Maps API's .toSpan() method on GLatLng's.

Returns a LatLng object, whose coordinates represent the size of a rectangle defined by these bounds.


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# File 'lib/geokit/bounds.rb', line 60

def to_span
  lat_span = @ne.lat - @sw.lat
  lng_span = crosses_meridian? ? 360 + @ne.lng - @sw.lng : @ne.lng - @sw.lng
  Geokit::LatLng.new(lat_span.abs, lng_span.abs)
end