module PixelDistance

Constants

OFFSET
RADIUS
VERSION
ZOOM

Public Class Methods

from_coords(lat1,lon1,lat2,lon2,zoom = nil) click to toggle source

# File lib/pixeldistance.rb, line 8
def from_coords(lat1,lon1,lat2,lon2,zoom = nil)
  zoom ||= ZOOM

  x1 = lon_to_x(lon1)
  y1 = lat_to_y(lat1)
  x2 = lon_to_x(lon2)
  y2 = lat_to_y(lat2)

  Math.sqrt((x1-x2)**2 + (y1-y2)**2).to_i >> (21 - zoom)
end

lat_to_y(lat) click to toggle source

# File lib/pixeldistance.rb, line 23
def lat_to_y(lat)
  (OFFSET + RADIUS *
      Math.log((1 + Math.sin(lat * Math::PI / 180)) /
                   (1 - Math.sin(lat * Math::PI / 180))) / 2)
end

lon_to_x(lon) click to toggle source

# File lib/pixeldistance.rb, line 19
def lon_to_x(lon)
  (OFFSET + RADIUS * lon * Math::PI / 180).to_i
end

Private Instance Methods

from_coords(lat1,lon1,lat2,lon2,zoom = nil) click to toggle source

# File lib/pixeldistance.rb, line 8
def from_coords(lat1,lon1,lat2,lon2,zoom = nil)
  zoom ||= ZOOM

  x1 = lon_to_x(lon1)
  y1 = lat_to_y(lat1)
  x2 = lon_to_x(lon2)
  y2 = lat_to_y(lat2)

  Math.sqrt((x1-x2)**2 + (y1-y2)**2).to_i >> (21 - zoom)
end

lat_to_y(lat) click to toggle source

# File lib/pixeldistance.rb, line 23
def lat_to_y(lat)
  (OFFSET + RADIUS *
      Math.log((1 + Math.sin(lat * Math::PI / 180)) /
                   (1 - Math.sin(lat * Math::PI / 180))) / 2)
end

lon_to_x(lon) click to toggle source

# File lib/pixeldistance.rb, line 19
def lon_to_x(lon)
  (OFFSET + RADIUS * lon * Math::PI / 180).to_i
end