Class: Geos::CoordinateSequence

Inherits:
Object
  • Object
show all
Includes:
Enumerable
Defined in:
lib/ffi-geos/coordinate_sequence.rb

Overview

A CoordinateSequence is a list of coordinates in a Geometry.

Defined Under Namespace

Classes: CoordinateAccessor, ParseError

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(*args) ⇒ CoordinateSequence

:call-seq:

new(ptr, auto_free = true)
new(size = 0, dimensions = 0)
new(options)
new(points)

The ptr version of the initializer is for internal use.

new(points) will try to glean the size and dimensions of your CoordinateSequence from an Array of points. The Array should contain uniform-sized Arrays which represent the [ x, y, z ] values of your coordinates.



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# File 'lib/ffi-geos/coordinate_sequence.rb', line 58

def initialize(*args)
  points = nil # forward declaration we can use later

  ptr, auto_free = if args.first.is_a?(FFI::Pointer)
    [ args.first, args[1] ]
  else
    size, dimensions = if args.first.is_a?(Array)
      points = if args.first.first.is_a?(Array)
        args.first
      else
        args
      end
      lengths = points.collect(&:length).uniq

      if lengths.empty?
        [ 0, 0 ]
      elsif lengths.length != 1
        raise ParseError.new("Different sized points found in Array")
      elsif !lengths.first.between?(1, 3)
        raise ParseError.new("Expected points to contain 1-3 elements")
      else
        [ points.length, points.first.length ]
      end
    elsif args.first.is_a?(Hash)
      args.first.values_at(:size, :dimensions)
    else
      if !args.length.between?(0, 2)
        raise ArgumentError.new("wrong number of arguments (#{args.length} for 0-2)")
      else
        [ args[0], args[1] ]
      end
    end

    size ||= 0
    dimensions ||= 0

    [ FFIGeos.GEOSCoordSeq_create_r(Geos.current_handle, size, dimensions), true ]
  end

  @ptr = FFI::AutoPointer.new(
    ptr,
    self.class.method(:release)
  )

  @ptr.autorelease = auto_free

  @x = CoordinateAccessor.new(self, 0)
  @y = CoordinateAccessor.new(self, 1)
  @z = CoordinateAccessor.new(self, 2)

  if points
    points.each_with_index do |point, idx|
      point.each_with_index do |val, dim|
        self.set_ordinate(idx, dim, val)
      end
    end
  end
end

Instance Attribute Details

#ptr ⇒ Object (readonly)

Returns the value of attribute ptr.



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# File 'lib/ffi-geos/coordinate_sequence.rb', line 44

def ptr
  @ptr
end

#x ⇒ Object (readonly)

Returns the value of attribute x.



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# File 'lib/ffi-geos/coordinate_sequence.rb', line 44

def x
  @x
end

#y ⇒ Object (readonly)

Returns the value of attribute y.



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# File 'lib/ffi-geos/coordinate_sequence.rb', line 44

def y
  @y
end

#z ⇒ Object (readonly)

Returns the value of attribute z.



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# File 'lib/ffi-geos/coordinate_sequence.rb', line 44

def z
  @z
end

Class Method Details

.release(ptr) ⇒ Object

:nodoc:



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# File 'lib/ffi-geos/coordinate_sequence.rb', line 128

def self.release(ptr) #:nodoc:
  FFIGeos.GEOSCoordSeq_destroy_r(Geos.current_handle, ptr)
end

Instance Method Details

#[](*args) ⇒ Object Also known as: slice 



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# File 'lib/ffi-geos/coordinate_sequence.rb', line 147

def [](*args)
  if args.length == 1 && args.first.is_a?(Numeric) && args.first >= 0
    i = args.first
    ary = [ self.get_x(i), self.get_y(i) ]
    ary << self.get_z(i) if self.has_z?
    ary
  else
    self.to_a[*args]
  end
end

#dimensions ⇒ Object 



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# File 'lib/ffi-geos/coordinate_sequence.rb', line 228

def dimensions
  if defined?(@dimensions)
    @dimensions
  else
    int_ptr = FFI::MemoryPointer.new(:int)
    FFIGeos.GEOSCoordSeq_getDimensions_r(Geos.current_handle, self.ptr, int_ptr)
    @dimensions = int_ptr.read_int
  end
end

#each ⇒ Object

Yields coordinates as [ x, y, z ]. The z coordinate may be omitted for 2-dimensional CoordinateSequences.



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# File 'lib/ffi-geos/coordinate_sequence.rb', line 134

def each
  if block_given?
    self.length.times do |n|
      yield self.build_coordinate(n)
    end
    self
  else
    self.length.times.collect { |n|
      self.build_coordinate(n)
    }.to_enum
  end
end

#empty? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/ffi-geos/coordinate_sequence.rb', line 224

def empty?
  self.length == 0
end

#get_ordinate(idx, dim) ⇒ Object 



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# File 'lib/ffi-geos/coordinate_sequence.rb', line 210

def get_ordinate(idx, dim)
  self.check_bounds(idx)
  double_ptr = FFI::MemoryPointer.new(:double)
  FFIGeos.GEOSCoordSeq_getOrdinate_r(Geos.current_handle, self.ptr, idx, dim, double_ptr)
  double_ptr.read_double
end

#get_x(idx) ⇒ Object

Gets the x value of a coordinate. Can also be retrieved via #x[].



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# File 'lib/ffi-geos/coordinate_sequence.rb', line 187

def get_x(idx)
  self.check_bounds(idx)
  double_ptr = FFI::MemoryPointer.new(:double)
  FFIGeos.GEOSCoordSeq_getX_r(Geos.current_handle, self.ptr, idx, double_ptr)
  double_ptr.read_double
end

#get_y(idx) ⇒ Object

Gets the y value of a coordinate. Can also be retrieved via #y[].



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# File 'lib/ffi-geos/coordinate_sequence.rb', line 195

def get_y(idx)
  self.check_bounds(idx)
  double_ptr = FFI::MemoryPointer.new(:double)
  FFIGeos.GEOSCoordSeq_getY_r(Geos.current_handle, self.ptr, idx, double_ptr)
  double_ptr.read_double
end

#get_z(idx) ⇒ Object

Gets the z value of a coordinate. Can also be retrieved via #z[].



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# File 'lib/ffi-geos/coordinate_sequence.rb', line 203

def get_z(idx)
  self.check_bounds(idx)
  double_ptr = FFI::MemoryPointer.new(:double)
  FFIGeos.GEOSCoordSeq_getZ_r(Geos.current_handle, self.ptr, idx, double_ptr)
  double_ptr.read_double
end

#has_z? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/ffi-geos/coordinate_sequence.rb', line 159

def has_z?
  self.dimensions == 3
end

#initialize_copy(source) ⇒ Object 



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# File 'lib/ffi-geos/coordinate_sequence.rb', line 117

def initialize_copy(source)
  @ptr = FFI::AutoPointer.new(
    FFIGeos.GEOSCoordSeq_clone_r(Geos.current_handle, source.ptr),
    self.class.method(:release)
  )

  @x = CoordinateAccessor.new(self, 0)
  @y = CoordinateAccessor.new(self, 1)
  @z = CoordinateAccessor.new(self, 2)
end

#length ⇒ Object Also known as: size 



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# File 'lib/ffi-geos/coordinate_sequence.rb', line 217

def length
  int_ptr = FFI::MemoryPointer.new(:int)
  FFIGeos.GEOSCoordSeq_getSize_r(Geos.current_handle, self.ptr, int_ptr)
  int_ptr.read_int
end

#set_ordinate(idx, dim, val) ⇒ Object 



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# File 'lib/ffi-geos/coordinate_sequence.rb', line 181

def set_ordinate(idx, dim, val)
  self.check_bounds(idx)
  FFIGeos.GEOSCoordSeq_setOrdinate_r(Geos.current_handle, self.ptr, idx, dim, val)
end

#set_x(idx, val) ⇒ Object

Sets the x value of a coordinate. Can also be set via #x[]=.



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# File 'lib/ffi-geos/coordinate_sequence.rb', line 164

def set_x(idx, val)
  self.check_bounds(idx)
  FFIGeos.GEOSCoordSeq_setX_r(Geos.current_handle, self.ptr, idx, val)
end

#set_y(idx, val) ⇒ Object

Sets the y value of a coordinate. Can also be set via #y[]=.



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# File 'lib/ffi-geos/coordinate_sequence.rb', line 170

def set_y(idx, val)
  self.check_bounds(idx)
  FFIGeos.GEOSCoordSeq_setY_r(Geos.current_handle, self.ptr, idx, val)
end

#set_z(idx, val) ⇒ Object

Sets the z value of a coordinate. Can also be set via #z[]=.



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# File 'lib/ffi-geos/coordinate_sequence.rb', line 176

def set_z(idx, val)
  self.check_bounds(idx)
  FFIGeos.GEOSCoordSeq_setZ_r(Geos.current_handle, self.ptr, idx, val)
end

#to_line_string(options = {}) ⇒ Object 



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# File 'lib/ffi-geos/coordinate_sequence.rb', line 246

def to_line_string(options = {})
  Geos.create_line_string(self, :srid => options[:srid])
end

#to_linear_ring(options = {}) ⇒ Object 



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# File 'lib/ffi-geos/coordinate_sequence.rb', line 242

def to_linear_ring(options = {})
  Geos.create_linear_ring(self, :srid => options[:srid])
end

#to_point(options = {}) ⇒ Object 



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# File 'lib/ffi-geos/coordinate_sequence.rb', line 238

def to_point(options = {})
  Geos.create_point(self, :srid => options[:srid])
end

#to_polygon(options = {}) ⇒ Object 



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# File 'lib/ffi-geos/coordinate_sequence.rb', line 250

def to_polygon(options = {})
  Geos.create_polygon(self, :srid => options[:srid])
end

#to_s ⇒ Object 



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# File 'lib/ffi-geos/coordinate_sequence.rb', line 254

def to_s
  self.entries.collect { |entry|
    entry.join(' ')
  }.join(', ')
end