Implement point buffers for simple_spherical and simple_cartesian fac…

…tories

History.rdoc

@@ -1,3 +1,9 @@
+=== 0.3.13 / 2012-05-04
+
+* The spherical factory and the simple cartesian factory now support buffers around points (but not around other types). Accordingly, those factories now take the :buffer_resolution property argument.
+* The :uses_lenient_assertions and parser/generator arguments to RGeo::Geographic.spherical_factory did not have their advertised effect. Fixed.
+* The parser/generator arguments to projected geographic factories did not have their advertised effect. Fixed.
+
 === 0.3.12 / 2012-04-24
 
 * Geos::FFIFactory collection constructors sometimes modified arguments in place, which caused problems for the ZMFactory among other things. Fixed.

Version

@@ -1 +1 @@
-0.3.12
+0.3.13

ext/geos_c_impl/extconf.rb

@@ -71,7 +71,7 @@
   header_dirs_, lib_dirs_ = dir_config('geos', header_dirs_, lib_dirs_)
   if have_header('geos_c.h')
     $libs << ' -lgeos -lgeos_c'
-    if have_func('initGEOS_r', 'geos_c.h')
+    if have_func('GEOSSetSRID_r', 'geos_c.h')
       found_geos_ = true
     else
       $libs.gsub!(' -lgeos -lgeos_c', '')

ext/geos_c_impl/preface.h

@@ -36,7 +36,7 @@
 
 
 #ifdef HAVE_GEOS_C_H
-#ifdef HAVE_INITGEOS_R
+#ifdef HAVE_GEOSSETSRID_R
 #define RGEO_GEOS_SUPPORTED
 #endif
 #endif

lib/rgeo/cartesian/factory.rb

@@ -77,6 +77,8 @@ def initialize(opts_={})
         srid_ ||= @coord_sys.authority_code if @coord_sys
         @srid = srid_.to_i
         @lenient_assertions = opts_[:uses_lenient_assertions] ? true : false
+        @buffer_resolution = opts_[:buffer_resolution].to_i
+        @buffer_resolution = 1 if @buffer_resolution < 1
 
         wkt_generator_ = opts_[:wkt_generator]
         case wkt_generator_
@@ -129,6 +131,7 @@ def marshal_dump  # :nodoc:
           'wktp' => @wkt_parser._properties,
           'wkbp' => @wkb_parser._properties,
           'lena' => @lenient_assertions,
+          'bufr' => @buffer_resolution,
         }
         hash_['proj4'] = @proj4.marshal_dump if @proj4
         hash_['cs'] = @coord_sys.to_wkt if @coord_sys
@@ -156,6 +159,7 @@ def marshal_load(data_)  # :nodoc:
           :wkt_parser => ImplHelper::Utils.symbolize_hash(data_['wktp']),
           :wkb_parser => ImplHelper::Utils.symbolize_hash(data_['wkbp']),
           :uses_lenient_assertions => data_['lena'],
+          :buffer_resolution => data_['bufr'],
           :proj4 => proj4_,
           :coord_sys => coord_sys_
         )
@@ -169,6 +173,7 @@ def encode_with(coder_)  # :nodoc:
         coder_['has_m_coordinate'] = @has_m
         coder_['srid'] = @srid
         coder_['lenient_assertions'] = @lenient_assertions
+        coder_['buffer_resolution'] = @buffer_resolution
         coder_['wkt_generator'] = @wkt_generator._properties
         coder_['wkb_generator'] = @wkb_generator._properties
         coder_['wkt_parser'] = @wkt_parser._properties
@@ -204,6 +209,7 @@ def init_with(coder_)  # :nodoc:
           :wkt_parser => ImplHelper::Utils.symbolize_hash(coder_['wkt_parser']),
           :wkb_parser => ImplHelper::Utils.symbolize_hash(coder_['wkb_parser']),
           :uses_lenient_assertions => coder_['lenient_assertions'],
+          :buffer_resolution => coder_['buffer_resolution'],
           :proj4 => proj4_,
           :coord_sys => coord_sys_
         )
@@ -227,6 +233,8 @@ def property(name_)
           @has_m
         when :uses_lenient_assertions
           @lenient_assertions
+        when :buffer_resolution
+          @buffer_resolution
         when :is_cartesian
           true
         else

lib/rgeo/cartesian/feature_methods.rb

@@ -71,6 +71,17 @@ def distance(rhs_)
       end
 
 
+      def buffer(distance_)
+        point_count_ = factory.property(:buffer_resolution) * 4
+        angle_ = -::Math::PI * 2.0 / point_count_
+        points_ = (0...point_count_).map do |i_|
+          r_ = angle_ * i_
+          factory.point(@x + distance_ * ::Math.cos(r_), @y + distance_ * ::Math.sin(r_))
+        end
+        factory.polygon(factory.linear_ring(points_))
+      end
+
+
     end
 
 

lib/rgeo/geographic/factory.rb

@@ -75,6 +75,8 @@ def initialize(impl_prefix_, opts_={})  # :nodoc:
           @coord_sys = CoordSys::CS.create_from_wkt(@coord_sys) rescue nil
         end
         @lenient_assertions = opts_[:uses_lenient_assertions] ? true : false
+        @buffer_resolution = opts_[:buffer_resolution].to_i
+        @buffer_resolution = 1 if @buffer_resolution < 1
 
         wkt_generator_ = opts_[:wkt_generator]
         case wkt_generator_
@@ -138,6 +140,7 @@ def marshal_dump  # :nodoc:
           'wktp' => @wkt_parser._properties,
           'wkbp' => @wkb_parser._properties,
           'lena' => @lenient_assertions,
+          'bufr' => @buffer_resolution,
         }
         hash_['proj4'] = @proj4.marshal_dump if @proj4
         hash_['cs'] = @coord_sys.to_wkt if @coord_sys
@@ -169,6 +172,7 @@ def marshal_load(data_)  # :nodoc:
           :wkt_parser => ImplHelper::Utils.symbolize_hash(data_['wktp']),
           :wkb_parser => ImplHelper::Utils.symbolize_hash(data_['wkbp']),
           :uses_lenient_assertions => data_['lena'],
+          :buffer_resolution => data_['bufr'],
           :proj4 => proj4_,
           :coord_sys => coord_sys_
         )
@@ -195,6 +199,7 @@ def encode_with(coder_)  # :nodoc:
         coder_['wkt_parser'] = @wkt_parser._properties
         coder_['wkb_parser'] = @wkb_parser._properties
         coder_['lenient_assertions'] = @lenient_assertions
+        coder_['buffer_resolution'] = @buffer_resolution
         if @proj4
           str_ = @proj4.original_str || @proj4.canonical_str
           coder_['proj4'] = @proj4.radians? ? {'proj4' => str_, 'radians' => true} : str_
@@ -230,6 +235,7 @@ def init_with(coder_)  # :nodoc:
           :wkt_parser => ImplHelper::Utils.symbolize_hash(coder_['wkt_parser']),
           :wkb_parser => ImplHelper::Utils.symbolize_hash(coder_['wkb_parser']),
           :uses_lenient_assertions => coder_['lenient_assertions'],
+          :buffer_resolution => coder_['buffer_resolution'],
           :proj4 => proj4_,
           :coord_sys => coord_sys_
         )
@@ -334,6 +340,8 @@ def property(name_)
           @support_m
         when :uses_lenient_assertions
           @lenient_assertions
+        when :buffer_resolution
+          @buffer_resolution
         when :is_geographic
           true
         else

lib/rgeo/geographic/interface.rb

@@ -92,6 +92,16 @@ class << self
       #   Polygon and MultiPolygon. This may speed up creation of certain
       #   objects, at the expense of not doing the proper checking for
       #   OGC compliance. Default is false.
+      # [<tt>:buffer_resolution</tt>]
+      #   The resolution of buffers around geometries created by this
+      #   factory. This controls the number of line segments used to
+      #   approximate curves. The default is 1, which causes, for
+      #   example, the buffer around a point to be approximated by a
+      #   4-sided polygon. A resolution of 2 would cause that buffer
+      #   to be approximated by an 8-sided polygon. The exact behavior
+      #   for different kinds of buffers is not specified precisely,
+      #   but in general the value is taken as the number of segments
+      #   per 90-degree curve.
       # [<tt>:proj4</tt>]
       #   Provide the coordinate system in Proj4 format. You may pass
       #   either an RGeo::CoordSys::Proj4 object, or a string or hash
@@ -153,6 +163,12 @@ def spherical_factory(opts_={})
           :has_m_coordinate => opts_[:has_m_coordinate],
           :proj4 => proj4_ || _proj4_4055,
           :coord_sys => coord_sys_ || _coordsys_4055,
+          :uses_lenient_assertions => opts_[:uses_lenient_assertions],
+          :buffer_resolution => opts_[:buffer_resolution],
+          :wkt_parser => opts_[:wkt_parser],
+          :wkb_parser => opts_[:wkb_parser],
+          :wkt_generator => opts_[:wkt_generator],
+          :wkb_generator => opts_[:wkb_generator],
           :srid => (srid_ || 4055).to_i)
       end
 
@@ -234,6 +250,10 @@ def simple_mercator_factory(opts_={})
           :proj4 => _proj4_4326,
           :coord_sys => _coordsys_4326,
           :srid => 4326,
+          :wkt_parser => opts_[:wkt_parser],
+          :wkb_parser => opts_[:wkb_parser],
+          :wkt_generator => opts_[:wkt_generator],
+          :wkb_generator => opts_[:wkb_generator],
           :has_z_coordinate => opts_[:has_z_coordinate],
           :has_m_coordinate => opts_[:has_m_coordinate])
         projector_ = Geographic::SimpleMercatorProjector.new(factory_,

lib/rgeo/geographic/spherical_feature_classes.rb

@@ -96,6 +96,26 @@ def equals?(rhs_)
       end
 
 
+      def buffer(distance_)
+        radius_ = distance_ / SphericalMath::RADIUS
+        radius_ = 1.5 if radius_ > 1.5
+        cos_ = ::Math.cos(radius_)
+        sin_ = ::Math.sin(radius_)
+        point_count_ = factory.property(:buffer_resolution) * 4
+        p0_ = _xyz
+        p1_ = p0_.create_perpendicular
+        p2_ = p1_ % p0_
+        angle_ = ::Math::PI * 2.0 / point_count_
+        points_ = (0...point_count_).map do |i_|
+          r_ = angle_ * i_
+          pi_ = SphericalMath::PointXYZ.weighted_combination(p1_, ::Math.cos(r_), p2_, ::Math.sin(r_))
+          p_ = SphericalMath::PointXYZ.weighted_combination(p0_, cos_, pi_, sin_)
+          factory.point(*p_.lonlat)
+        end
+        factory.polygon(factory.linear_ring(points_))
+      end
+
+
       alias_method :longitude, :x
       alias_method :lon, :x
       alias_method :latitude, :y

lib/rgeo/geographic/spherical_math.rb

@@ -90,6 +90,14 @@ def latlon
         end
 
 
+        def lonlat
+          lat_rad_ = ::Math.asin(@z)
+          lon_rad_ = ::Math.atan2(@y, @x) rescue 0.0
+          rpd_ = ImplHelper::Math::RADIANS_PER_DEGREE
+          [lon_rad_ / rpd_, lat_rad_ / rpd_]
+        end
+
+
         def *(rhs_)
           val_ = @x * rhs_.x + @y * rhs_.y + @z * rhs_.z
           val_ = 1.0 if val_ > 1.0
@@ -119,6 +127,17 @@ def dist_to_point(rhs_)
         end
 
 
+        # Creates some point that is perpendicular to this point
+
+        def create_perpendicular
+          p1dot_ = self * P1
+          p2dot_ = self * P2
+          p1dot_ = -p1dot_ if p1dot_ < 0
+          p2dot_ = -p2dot_ if p2dot_ < 0
+          p1dot_ < p2dot_ ? (self % P1) : (self % P2)
+        end
+
+
         def self.from_latlon(lat_, lon_)
           rpd_ = ImplHelper::Math::RADIANS_PER_DEGREE
           lat_rad_ = rpd_ * lat_
@@ -130,6 +149,15 @@ def self.from_latlon(lat_, lon_)
           new(x_, y_, z_)
         end
 
+
+        def self.weighted_combination(p1_, w1_, p2_, w2_)
+          new(p1_.x * w1_ + p2_.x * w2_, p1_.y * w1_ + p2_.y * w2_, p1_.z * w1_ + p2_.z * w2_)
+        end
+
+
+        P1 = new(1, 0, 0)
+        P2 = new(0, 1, 0)
+
       end
 
 

test/common/point_tests.rb

@@ -286,6 +286,7 @@ def test_buffer
           point_ = @factory.point(11, 12)
           buffer_ = point_.buffer(4)
           assert_equal(::RGeo::Feature::Polygon, buffer_.geometry_type)
+          assert_equal(33, buffer_.exterior_ring.num_points)
         end
 
 

test/geos_capi/tc_point.rb

@@ -48,7 +48,7 @@ class TestPoint < ::Test::Unit::TestCase  # :nodoc:
 
 
         def setup
-          @factory = ::RGeo::Geos.factory
+          @factory = ::RGeo::Geos.factory(:buffer_resolution => 8)
           @zfactory = ::RGeo::Geos.factory(:has_z_coordinate => true)
           @mfactory = ::RGeo::Geos.factory(:has_m_coordinate => true)
           @zmfactory = ::RGeo::Geos.factory(:has_z_coordinate => true, :has_m_coordinate => true)

test/geos_ffi/tc_point.rb

@@ -48,7 +48,7 @@ class TestPoint < ::Test::Unit::TestCase  # :nodoc:
 
 
         def setup
-          @factory = ::RGeo::Geos.factory(:native_interface => :ffi)
+          @factory = ::RGeo::Geos.factory(:native_interface => :ffi, :buffer_resolution => 8)
           @zfactory = ::RGeo::Geos.factory(:has_z_coordinate => true, :native_interface => :ffi)
           @mfactory = ::RGeo::Geos.factory(:has_m_coordinate => true, :native_interface => :ffi)
           @zmfactory = ::RGeo::Geos.factory(:has_z_coordinate => true, :has_m_coordinate => true,

test/projected_geographic/tc_point.rb

@@ -48,7 +48,7 @@ class TestPoint < ::Test::Unit::TestCase  # :nodoc:
 
 
         def setup
-          @factory = ::RGeo::Geographic.projected_factory(:projection_proj4 => '+proj=merc +a=6378137 +b=6378137 +lat_ts=0.0 +lon_0=0.0 +x_0=0.0 +y_0=0 +k=1.0 +units=m +nadgrids=@null +wktext +no_defs', :projection_srid => 3857)
+          @factory = ::RGeo::Geographic.projected_factory(:buffer_resolution => 8, :projection_proj4 => '+proj=merc +a=6378137 +b=6378137 +lat_ts=0.0 +lon_0=0.0 +x_0=0.0 +y_0=0 +k=1.0 +units=m +nadgrids=@null +wktext +no_defs', :projection_srid => 3857)
           @zfactory = ::RGeo::Geographic.projected_factory(:has_z_coordinate => true, :projection_proj4 => '+proj=merc +a=6378137 +b=6378137 +lat_ts=0.0 +lon_0=0.0 +x_0=0.0 +y_0=0 +k=1.0 +units=m +nadgrids=@null +wktext +no_defs', :projection_srid => 3857)
           @mfactory = ::RGeo::Geographic.projected_factory(:has_m_coordinate => true, :projection_proj4 => '+proj=merc +a=6378137 +b=6378137 +lat_ts=0.0 +lon_0=0.0 +x_0=0.0 +y_0=0 +k=1.0 +units=m +nadgrids=@null +wktext +no_defs', :projection_srid => 3857)
           @zmfactory = ::RGeo::Geographic.projected_factory(:has_z_coordinate => true, :has_m_coordinate => true, :projection_proj4 => '+proj=merc +a=6378137 +b=6378137 +lat_ts=0.0 +lon_0=0.0 +x_0=0.0 +y_0=0 +k=1.0 +units=m +nadgrids=@null +wktext +no_defs', :projection_srid => 3857)

test/simple_cartesian/tc_point.rb

@@ -48,7 +48,7 @@ class TestPoint < ::Test::Unit::TestCase  # :nodoc:
 
 
         def setup
-          @factory = ::RGeo::Cartesian.simple_factory(:srid => 1)
+          @factory = ::RGeo::Cartesian.simple_factory(:srid => 1, :buffer_resolution => 8)
           @zfactory = ::RGeo::Cartesian.simple_factory(:srid => 1, :has_z_coordinate => true)
           @mfactory = ::RGeo::Cartesian.simple_factory(:srid => 1, :has_m_coordinate => true)
           @zmfactory = ::RGeo::Cartesian.simple_factory(:srid => 1, :has_z_coordinate => true, :has_m_coordinate => true)
@@ -82,7 +82,6 @@ def test_distance
         undef_method :test_union
         undef_method :test_difference
         undef_method :test_sym_difference
-        undef_method :test_buffer
 
 
       end

test/simple_mercator/tc_point.rb

@@ -48,7 +48,7 @@ class TestPoint < ::Test::Unit::TestCase  # :nodoc:
 
 
         def setup
-          @factory = ::RGeo::Geographic.simple_mercator_factory
+          @factory = ::RGeo::Geographic.simple_mercator_factory(:buffer_resolution => 8)
           @zfactory = ::RGeo::Geographic.simple_mercator_factory(:has_z_coordinate => true)
           @mfactory = ::RGeo::Geographic.simple_mercator_factory(:has_m_coordinate => true)
           @zmfactory = ::RGeo::Geographic.simple_mercator_factory(:has_z_coordinate => true, :has_m_coordinate => true)

test/spherical_geographic/tc_point.rb

@@ -48,7 +48,7 @@ class TestPoint < ::Test::Unit::TestCase  # :nodoc:
 
 
         def setup
-          @factory = ::RGeo::Geographic.spherical_factory
+          @factory = ::RGeo::Geographic.spherical_factory(:buffer_resolution => 8)
           @zfactory = ::RGeo::Geographic.spherical_factory(:has_z_coordinate => true)
           @mfactory = ::RGeo::Geographic.spherical_factory(:has_m_coordinate => true)
           @zmfactory = ::RGeo::Geographic.spherical_factory(:has_z_coordinate => true, :has_m_coordinate => true)
@@ -100,7 +100,6 @@ def test_floating_point_perturbation
         undef_method :test_union
         undef_method :test_difference
         undef_method :test_sym_difference
-        undef_method :test_buffer
 
 
       end

test/tc_oneoff.rb

@@ -46,10 +46,10 @@ class TestOneOff < ::Test::Unit::TestCase  # :nodoc:
 
       def setup
         # @mercator_factory = ::RGeo::Geographic.simple_mercator_factory
-        # @spherical_factory = ::RGeo::Geographic.spherical_factory(:has_z_coordinate => true)
+        # @spherical_factory = ::RGeo::Geographic.spherical_factory(:buffer_resolution => 2)
         # @projected_factory = ::RGeo::Geographic.projected_factory(:projection_proj4 => '+proj=merc +a=6378137 +b=6378137 +lat_ts=0.0 +lon_0=0.0 +x_0=0.0 +y_0=0 +k=1.0 +units=m +nadgrids=@null +wktext +no_defs', :projection_srid => 3857, :has_z_coordinate => true)
-        # @geos_factory = ::RGeo::Geos.factory(:buffer_resolution => 8)
-        # @cartesian_factory = ::RGeo::Cartesian.simple_factory(:srid => 1, :has_z_coordinate => true)
+        # @geos_factory = ::RGeo::Geos.factory(:buffer_resolution => 2)
+        # @cartesian_factory = ::RGeo::Cartesian.simple_factory(:buffer_resolution => 2)
       end