Class: Proj::Domain

Inherits:
Object
  • Object
show all
Defined in:
lib/proj/domain.rb

Overview

Represents a usage domain of a PjObject. Each domain has a scope describing the purpose and a geographic area of use. Objects can have multiple domains.

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(scope:, area_of_use:) ⇒ Domain

Returns a new instance of Domain.

Parameters:

  • scope (String) —

    The scope describing the purpose of this domain

  • area_of_use (Area) —

    The geographic area of use



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# File 'lib/proj/domain.rb', line 16

def initialize(scope:, area_of_use:)
  @scope = scope
  @area_of_use = area_of_use
end

Instance Attribute Details

#area_of_use ⇒ Area (readonly)

Returns The geographic area of use for this domain.

Returns:

  • (Area) —

    The geographic area of use for this domain



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# File 'lib/proj/domain.rb', line 12

def area_of_use
  @area_of_use
end

#scope ⇒ String (readonly)

Returns The scope of this domain.

Returns:

  • (String) —

    The scope of this domain



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# File 'lib/proj/domain.rb', line 9

def scope
  @scope
end

Class Method Details

.count(pj_object) ⇒ Integer

Returns the number of usage domains for an object. Requires PROJ 9.2+. Returns 1 on older versions for backward compatibility.

Parameters:

  • pj_object (PjObject) —

    The object to query

Returns:

  • (Integer)

See Also:



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# File 'lib/proj/domain.rb', line 29

def self.count(pj_object)
  if Api.method_defined?(:proj_get_domain_count)
    Api.proj_get_domain_count(pj_object)
  else
    1
  end
end

.domains(pj_object) ⇒ Array<Domain>

Returns all usage domains for an object. On PROJ < 9.2, falls back to Api.proj_get_scope and Api.proj_get_area_of_use and returns a single domain.

Parameters:

  • pj_object (PjObject) —

    The object to query

Returns:

See Also:



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# File 'lib/proj/domain.rb', line 47

def self.domains(pj_object)
  use_ex = Api.method_defined?(:proj_get_domain_count)
  domain_count = use_ex ? Api.proj_get_domain_count(pj_object) : 1

  domain_count.times.map do |index|
    scope = use_ex ? Api.proj_get_scope_ex(pj_object, index) : Api.proj_get_scope(pj_object)

    p_name = FFI::MemoryPointer.new(:pointer)
    p_west = FFI::MemoryPointer.new(:double)
    p_south = FFI::MemoryPointer.new(:double)
    p_east = FFI::MemoryPointer.new(:double)
    p_north = FFI::MemoryPointer.new(:double)

    if use_ex
      result = Api.proj_get_area_of_use_ex(pj_object.context, pj_object, index,
                                            p_west, p_south, p_east, p_north, p_name)
    else
      result = Api.proj_get_area_of_use(pj_object.context, pj_object,
                                         p_west, p_south, p_east, p_north, p_name)
    end
    unless result
      Error.check_object(pj_object)
    end

    name = p_name.read_pointer.read_string_to_null.force_encoding('utf-8')
    area = Area.new(west_lon_degree: p_west.read_double,
                    south_lat_degree: p_south.read_double,
                    east_lon_degree: p_east.read_double,
                    north_lat_degree: p_north.read_double,
                    name: name)

    new(scope: scope, area_of_use: area)
  end
end