72 lines
1.1 KiB
Ruby
72 lines
1.1 KiB
Ruby
class BoundingBox
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def initialize(min_lon, min_lat, max_lon, max_lat)
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@bbox = [min_lon.to_f, min_lat.to_f, max_lon.to_f, max_lat.to_f]
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end
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def self.from_s(s)
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BoundingBox.new(*s.split(/,/))
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end
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def min_lon
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@bbox[0]
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end
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def min_lon=(min_lon)
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@bbox[0] = min_lon
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end
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def min_lat
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@bbox[1]
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end
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def min_lat=(min_lat)
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@bbox[1] = min_lat
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end
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def max_lon
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@bbox[2]
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end
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def max_lon=(max_lon)
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@bbox[2] = max_lon
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end
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def max_lat
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@bbox[3]
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end
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def max_lat=(max_lat)
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@bbox[3] = max_lat
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end
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def centre_lon
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(@bbox[0] + @bbox[2]) / 2.0
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end
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def centre_lat
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(@bbox[1] + @bbox[3]) / 2.0
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end
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def width
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@bbox[2] - @bbox[0]
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end
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def height
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@bbox[3] - @bbox[1]
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end
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def slippy_width(zoom)
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width * 256.0 * 2.0 ** zoom / 360.0
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end
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def slippy_height(zoom)
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min = min_lat * Math::PI / 180.0
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max = max_lat * Math::PI / 180.0
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Math.log((Math.tan(max) + 1.0 / Math.cos(max)) / (Math.tan(min) + 1.0 / Math.cos(min))) * 128.0 * 2.0 ** zoom / Math::PI
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end
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def to_s
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return @bbox.join(",")
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end
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end
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