Changeset discussions

[rails.git] / lib / bounding_box.rb

diff --git a/lib/bounding_box.rb b/lib/bounding_box.rb
index 30bbebb8d928ed056f591a5361b56c613363248e..38b994d26a6e11233983adcf6cbd730e5198af70 100644 (file)
--- a/lib/bounding_box.rb
+++ b/lib/bounding_box.rb
@@ -1,58 +1,120 @@
 class BoundingBox
 class BoundingBox

-  def initialize(min_lon, min_lat, max_lon, max_lat)
-    @bbox = [min_lon.to_f, min_lat.to_f, max_lon.to_f, max_lat.to_f]
-  end
-
-  def self.from_s(s)
-    BoundingBox.new(*s.split(/,/))
-  end
-
-  def min_lon
-    @bbox[0]
-  end
-
-  def min_lon=(min_lon)
-    @bbox[0] = min_lon
-  end
-
-  def min_lat
-    @bbox[1]
-  end
-
-  def min_lat=(min_lat)
-    @bbox[1] = min_lat
-  end
+  attr_reader :min_lon, :min_lat, :max_lon, :max_lat

 
 

-  def max_lon
-    @bbox[2]
-  end
-
-  def max_lon=(max_lon)
-    @bbox[2] = max_lon
-  end
+private
+  LON_LIMIT = 180.0
+  LAT_LIMIT = 90.0
+  SCALED_LON_LIMIT = LON_LIMIT *  GeoRecord::SCALE
+  SCALED_LAT_LIMIT = LAT_LIMIT *  GeoRecord::SCALE

 
 

-  def max_lat
-    @bbox[3]
+public
+  def initialize(min_lon, min_lat, max_lon, max_lat)
+    @min_lon = min_lon.to_f unless min_lon.nil?
+    @min_lat = min_lat.to_f unless min_lat.nil?
+    @max_lon = max_lon.to_f unless max_lon.nil?
+    @max_lat = max_lat.to_f unless max_lat.nil?

   end
 
   end
 

-  def max_lat=(max_lat)
-    @bbox[3] = max_lat
+  def self.from_s(s)
+    if s.count(',') == 3
+      BoundingBox.new(*s.split(/,/))
+    else
+      nil
+    end
+  end
+
+  def self.from_bbox_params(params)
+    if params[:bbox] and params[:bbox].count(',') == 3
+      bbox_array = params[:bbox].split(',')
+    end
+    from_bbox_array(bbox_array)
+  end
+
+  def self.from_lon_lat_params(params)
+    if params[:minlon] and params[:minlat] and params[:maxlon] and params[:maxlat]
+      bbox_array = [params[:minlon], params[:minlat], params[:maxlon], params[:maxlat]]
+    end
+    from_bbox_array(bbox_array)
+  end
+
+  def self.from_lrbt_params(params)
+    if params[:l] and params[:b] and params[:t] and params[:t]
+      bbox_array = [params[:l], params[:b], params[:r], params[:t]]
+    end
+    from_bbox_array(bbox_array)
+  end
+
+  def expand!(bbox, margin = 0)
+    update!(bbox) unless complete?
+    # only try to expand the bbox if there is a value for every coordinate
+    # which there will be from the previous line as long as array does not contain a nil
+    if bbox.complete?
+      @min_lon = [-SCALED_LON_LIMIT,
+                  bbox.min_lon + margin * (min_lon - max_lon)].max if bbox.min_lon < min_lon
+      @min_lat = [-SCALED_LAT_LIMIT,
+                  bbox.min_lat + margin * (min_lat - max_lat)].max if bbox.min_lat < min_lat
+      @max_lon = [+SCALED_LON_LIMIT,
+                  bbox.max_lon + margin * (max_lon - min_lon)].min if bbox.max_lon > max_lon
+      @max_lat = [+SCALED_LAT_LIMIT,
+                  bbox.max_lat + margin * (max_lat - min_lat)].min if bbox.max_lat > max_lat
+    end
+    self
+  end
+
+  def check_boundaries
+    # check the bbox is sane
+    if min_lon > max_lon
+      raise OSM::APIBadBoundingBox.new(
+        "The minimum longitude must be less than the maximum longitude, but it wasn't")
+    end
+    if min_lat > max_lat
+      raise OSM::APIBadBoundingBox.new(
+        "The minimum latitude must be less than the maximum latitude, but it wasn't")
+    end
+    if min_lon < -LON_LIMIT || min_lat < -LAT_LIMIT || max_lon > +LON_LIMIT || max_lat > +LAT_LIMIT
+      raise OSM::APIBadBoundingBox.new("The latitudes must be between #{-LAT_LIMIT} and #{LAT_LIMIT}," +
+                                       " and longitudes between #{-LON_LIMIT} and #{LON_LIMIT}")
+    end
+    self
+  end
+
+  def check_size(max_area = MAX_REQUEST_AREA)
+    # check the bbox isn't too large
+    if area > max_area
+      raise OSM::APIBadBoundingBox.new("The maximum bbox size is " + max_area.to_s +
+        ", and your request was too large. Either request a smaller area, or use planet.osm")
+    end
+    self
+  end
+
+  ##
+  # returns area of the bbox as a rough comparative quantity
+  def area
+    if complete?
+      (max_lon - min_lon) * (max_lat - min_lat)
+    else
+      0
+    end
+  end
+
+  def complete?
+    not to_a.include?(nil)

   end
 
   def centre_lon
   end
 
   def centre_lon

-    (@bbox[0] + @bbox[2]) / 2.0
+    (min_lon + max_lon) / 2.0

   end
 
   def centre_lat
   end
 
   def centre_lat

-    (@bbox[1] + @bbox[3]) / 2.0
+    (min_lat + max_lat) / 2.0

   end
 
   def width
   end
 
   def width

-    @bbox[2] - @bbox[0]
+    max_lon - min_lon

   end
 
   def height
   end
 
   def height

-    @bbox[3] - @bbox[1]
+    max_lat - min_lat

   end
 
   def slippy_width(zoom)
   end
 
   def slippy_width(zoom)


@@ -63,10 +125,64 @@ class BoundingBox
     min = min_lat * Math::PI / 180.0
     max = max_lat * Math::PI / 180.0
 
     min = min_lat * Math::PI / 180.0
     max = max_lat * Math::PI / 180.0
 

-    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
+    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)
+  end
+
+  # there are two forms used for bounds with and without an underscore,
+  # cater for both forms eg minlon and min_lon
+  def add_bounds_to(hash, underscore = "")
+    hash["min#{underscore}lat"] = min_lat.to_s
+    hash["min#{underscore}lon"] = min_lon.to_s
+    hash["max#{underscore}lat"] = max_lat.to_s
+    hash["max#{underscore}lon"] = max_lon.to_s
+    hash
+  end
+
+  def to_scaled
+    BoundingBox.new((min_lon * GeoRecord::SCALE),
+                    (min_lat * GeoRecord::SCALE),
+                    (max_lon * GeoRecord::SCALE),
+                    (max_lat * GeoRecord::SCALE))
+  end
+
+  def to_unscaled
+    BoundingBox.new((min_lon / GeoRecord::SCALE),
+                    (min_lat / GeoRecord::SCALE),
+                    (max_lon / GeoRecord::SCALE),
+                    (max_lat / GeoRecord::SCALE))
+  end
+
+  def to_a
+    [min_lon, min_lat, max_lon, max_lat]

   end
 
   def to_s
   end
 
   def to_s

-    return @bbox.join(",")
+    "#{min_lon},#{min_lat},#{max_lon},#{max_lat}"
+  end
+
+  private
+  def self.from_bbox_array(bbox_array)
+    unless bbox_array
+      raise OSM::APIBadUserInput.new(
+        "The parameter bbox is required, and must be of the form min_lon,min_lat,max_lon,max_lat")
+    end
+    # Take an array of length 4, create a bounding box with min_lon, min_lat, max_lon and
+    # max_lat within their respective boundaries.
+    min_lon = [[bbox_array[0].to_f, -LON_LIMIT].max, +LON_LIMIT].min
+    min_lat = [[bbox_array[1].to_f, -LAT_LIMIT].max, +LAT_LIMIT].min
+    max_lon = [[bbox_array[2].to_f, +LON_LIMIT].min, -LON_LIMIT].max
+    max_lat = [[bbox_array[3].to_f, +LAT_LIMIT].min, -LAT_LIMIT].max
+    BoundingBox.new(min_lon, min_lat, max_lon, max_lat)
+  end
+
+  def update!(bbox)
+    # ensure that bbox has no nils in it. if there are any
+    # nils, just use the bounding box update to write over them.
+    @min_lon = bbox.min_lon if min_lon.nil?
+    @min_lat = bbox.min_lat if min_lat.nil?
+    @max_lon = bbox.max_lon if max_lon.nil?
+    @max_lat = bbox.max_lat if max_lat.nil?

   end
 end
   end
 end