Class: Bezier::Point

Inherits:
Object
  • Object
show all
Defined in:
lib/bezier/point.rb

Overview

Public: Stuff related to N-dimensional Points

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(*coordinates) ⇒ Point

Public: Construct an instance of Point.

*coordinates - N numbers describing an N-dimensional Point.

Examples

Bezier::Point.new(1, 2, 3)



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# File 'lib/bezier/point.rb', line 14

def initialize(*coordinates)
  self.coordinates = coordinates
end

Instance Attribute Details

#coordinates ⇒ Object

Public: Gets/Sets coordinates



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# File 'lib/bezier/point.rb', line 5

def coordinates
  @coordinates
end

Instance Method Details

#*(scalar) ⇒ Object

Public: Scalar multiplication

scalar - A number (instance of Numeric)

Examples

Bezier::Point.new(1, 2) * 2
=> (2, 4)

Bezier::Point.new(1, 2) * -1.2
=> (-1.2, -2.4)

Returns a Point if multiplication can be carried out, nil otherwise



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# File 'lib/bezier/point.rb', line 95

def *(scalar)
  if scalar.is_a? Numeric
    new_coordinates = coordinates.map { |x| scalar * x }
    self.class.new(*new_coordinates)
  else
    nil
  end
end

#+(another) ⇒ Object

Public: Vector addition.

another - Another instance of Point having the same dimension as the

current Point

Examples

Bezier::Point.new(1, 2, 3) + Bezier::Point.new(4, 5, 6)
=> (5, 7, 9)

Bezier::Point.new(1, 2) + Bezier::Point.new(1, 2, 3)
=> nil

Returns a new Point if addition can be carried out, nil otherwise



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# File 'lib/bezier/point.rb', line 53

def +(another)
  if another.respond_to?(:coordinates) && another.dimensions == dimensions
    new_coordinates = []
    coordinates.each_index do |i|
      new_coordinates << coordinates[i] + another.coordinates[i]
    end
    self.class.new(*new_coordinates)
  else
    nil
  end
end

#==(another) ⇒ Object

Public: Equality test

another - Another instance of Point to be tested for equality

Examples

Bezier::Point.new(1, 2) == Bezier::Point.new(1, 2)
=> true

Bezier::Point.new(1, 2) == Bezier::Point.new(1, 2, 3)
=> false

Returns a Boolean



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# File 'lib/bezier/point.rb', line 78

def ==(another)
  another.respond_to?(:coordinates) && coordinates == another.coordinates
end

#dimensions ⇒ Object

Public: Get the dimension.

Returns a number



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# File 'lib/bezier/point.rb', line 21

def dimensions
  coordinates.length
end

#distance(another) ⇒ Object

Public: Calculate the distance between two points

another - A Point

Examples

Bezier::Point.new(3, 4).distance Bezier::Point.new(0, 0)
=> 5

Returns a number if the distance is calculable, nil otherwise



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# File 'lib/bezier/point.rb', line 114

def distance(another)
  return nil unless another.respond_to?(:coordinates) && another.dimensions == dimensions

  square_diff = 0
  coordinates.each_index do |i|
    square_diff += (coordinates[i] - another.coordinates[i]) ** 2
  end
  ::Math.sqrt(square_diff)
end

#x ⇒ Object

Public: Get the first element of the coordinates

Returns a number



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# File 'lib/bezier/point.rb', line 28

def x
  coordinates.first
end

#y ⇒ Object

Public: Get the last element of the coordinates

Returns a number



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# File 'lib/bezier/point.rb', line 35

def y
  coordinates.last
end