Class: Silicium::Geometry::Line2dCanon

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

Overview

Class represents a line as equation Ax + By + C = 0 in two-dimensional space

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(point1, point2) ⇒ Line2dCanon

Initializes with two objects of type Point

Raises:

  • (ArgumentError) 


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# File 'lib/geometry.rb', line 29

def initialize(point1, point2)
  raise ArgumentError, 'You need 2 different points' if point1.x.equal?(point2.x) && point1.y.equal?(point2.y)
  if point1.x.equal?(point2.x)
    @x_coefficient = 1
    @y_coefficient = 0
    @free_coefficient = - point1.x
  else
    slope_point = (point2.y - point1.y) / (point2.x - point1.x)
    @x_coefficient = -slope_point
    @y_coefficient = 1
    @free_coefficient = - point1.y + slope_point * point1.x
  end
end

Instance Attribute Details

#free_coefficient ⇒ Object (readonly)

Returns the value of attribute free_coefficient.



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# File 'lib/geometry.rb', line 25

def free_coefficient
  @free_coefficient
end

#x_coefficient ⇒ Object (readonly)

Returns the value of attribute x_coefficient.



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# File 'lib/geometry.rb', line 23

def x_coefficient
  @x_coefficient
end

#y_coefficient ⇒ Object (readonly)

Returns the value of attribute y_coefficient.



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# File 'lib/geometry.rb', line 24

def y_coefficient
  @y_coefficient
end

Instance Method Details

#array_of_points_is_on_line(array) ⇒ Object

Check if array of points is on the same line

Raises:

  • (ArgumentError) 


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# File 'lib/geometry.rb', line 112

def array_of_points_is_on_line(array)
  raise ArgumentError, 'Array is empty!' if array.length == 0
  res = Array.new
  for i in 0..array.size-1 do
    res.push(point_is_on_line?(array[i]))
  end
  res
end

#check_point_on_segment(point) ⇒ Object

Checking if the point is on a segment



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# File 'lib/geometry.rb', line 77

def check_point_on_segment(point)
  (@x_coefficient * point.x + @y_coefficient * point.y + @free_coefficient) - 0.0 <= 0.0001
end

#distance_between_parallel_lines(other_line) ⇒ Object

The distance between parallel lines

Raises:

  • (ArgumentError) 


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# File 'lib/geometry.rb', line 123

def distance_between_parallel_lines(other_line)
  raise ArgumentError, 'Lines are not parallel' if !parallel?(other_line)

  (other_line.free_coefficient - @free_coefficient).abs / Math.sqrt(@x_coefficient**2 + @y_coefficient**2)
end

#distance_point_to_line(point) ⇒ Object

The distance from a point to a line on a plane return 0 if the equation does not define a line.



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# File 'lib/geometry.rb', line 104

def distance_point_to_line(point)
  return 0 if @x_coefficient.eql?(0) && @y_coefficient.eql?(0)

  res = (@x_coefficient * point.x + @y_coefficient * point.y + @free_coefficient).abs
  res / Math.sqrt(@x_coefficient**2 + @y_coefficient**2).to_f
end

#distance_to_line(other_line) ⇒ Object

Returns distance between lines



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# File 'lib/geometry.rb', line 95

def distance_to_line(other_line)
  return 0 if intersecting?(other_line)

  (@free_coefficient - other_line.free_coefficient).abs / Math.sqrt(@x_coefficient**2 + @y_coefficient**2)
end

#initialize_with_coefficients(a, b, c) ⇒ Object

Initializes with coefficients

Raises:

  • (ArgumentError) 


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# File 'lib/geometry.rb', line 44

def initialize_with_coefficients(a, b, c)
  raise ArgumentError, 'All coefficients cannot be 0 ' if a.equal?(0) && b.equal?(0) && (c.equal?(0) || !c.equal?(0))

  @x_coefficient = a
  @y_coefficient = b
  @free_coefficient = c
end

#intersecting?(other_line) ⇒ Boolean

Checks if two lines are intersecting

Returns:

  • (Boolean) 


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# File 'lib/geometry.rb', line 65

def intersecting?(other_line)
  @x_coefficient != other_line.x_coefficient || @y_coefficient != other_line.y_coefficient
end

#intersection_point(other_line) ⇒ Object

Returns a point of intersection of two lines If not intersecting returns nil



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# File 'lib/geometry.rb', line 84

def intersection_point(other_line)
  return nil unless intersecting?(other_line)

  divisor = @x_coefficient * other_line.y_coefficient - other_line.x_coefficient * @y_coefficient
  x = (@y_coefficient * other_line.free_coefficient - other_line.y_coefficient * @free_coefficient) / divisor
  y = (@free_coefficient * other_line.x_coefficient - other_line.free_coefficient * @x_coefficient) / divisor
  Point.new(x, y)
end

#parallel?(other_line) ⇒ Boolean

Checks if two lines are parallel

Returns:

  • (Boolean) 


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# File 'lib/geometry.rb', line 59

def parallel?(other_line)
  @x_coefficient.equal?(other_line.x_coefficient) && @y_coefficient.equal?(other_line.y_coefficient)
end

#perpendicular?(other_line) ⇒ Boolean

Checks if two lines are perpendicular

Returns:

  • (Boolean) 


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# File 'lib/geometry.rb', line 71

def perpendicular?(other_line)
  (@x_coefficient * other_line.x_coefficient).equal?(- @y_coefficient * other_line.y_coefficient)
end

#point_is_on_line?(point) ⇒ Boolean

Checks the point lies on the line or not

Returns:

  • (Boolean) 


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# File 'lib/geometry.rb', line 54

def point_is_on_line?(point)
  ((@x_coefficient * point.x + @y_coefficient * point.y + @free_coefficient) - 0.0).abs < 0.0001
end