module NSWTopo::Declination
Constants
- CREATE
- DEFAULTS
Public Instance Methods
get_features()
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# File lib/nswtopo/layer/declination.rb, line 17 def get_features @params["fill"] ||= @params["stroke"] declination = @angle || @map.declination col_spacing = 0.001 * @map.scale * @spacing row_spacing = 0.001 * @map.scale * @arrows * 0.5 col_offset = 0.001 * @map.scale * (@offset % @spacing) radius = 0.5 * @map.bounds.transpose.distance j_max = (radius / col_spacing).ceil i_max = (radius / row_spacing).ceil collection = GeoJSON::Collection.new(@map.projection) (-j_max..j_max).each do |j| x = j * col_spacing + col_offset coordinates = [[x, -radius], [x, radius]].map do |point| point.rotate_by_degrees(-declination).plus(@map.centre) end collection.add_linestring coordinates (-i_max..i_max).reject(&j.even? ? :even? : :odd?).map do |i| [x, i * row_spacing].rotate_by_degrees(-declination).plus(@map.centre) end.each do |coordinates| collection.add_point coordinates, "rotation" => declination end end collection end
to_s()
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# File lib/nswtopo/layer/declination.rb, line 44 def to_s lines = features.grep(GeoJSON::LineString) return @name if lines.none? line = lines.map(&:coordinates).max_by(&:distance) angle = 90 - 180 * Math::atan2(*line.difference.reverse) / Math::PI "%s: %i line%s at %.1f°%s" % [@name, lines.length, (?s unless lines.one?), angle.abs, angle > 0 ? ?E : angle < 0 ? ?W : nil] end