Class: WindingPolygon::Point

Inherits:
Object
  • Object
show all
Defined in:
lib/winding-polygon/point.rb

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(x, y) ⇒ Point

Returns a new instance of Point.



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# File 'lib/winding-polygon/point.rb', line 7

def initialize(x,y)
  @x=x
  @y=y
end

Instance Attribute Details

#x ⇒ Object

Returns the value of attribute x.



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# File 'lib/winding-polygon/point.rb', line 4

def x
  @x
end

#y ⇒ Object

Returns the value of attribute y.



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# File 'lib/winding-polygon/point.rb', line 5

def y
  @y
end

Instance Method Details

#<(other_point) ⇒ Object 



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# File 'lib/winding-polygon/point.rb', line 45

def < (other_point)
  return true if @x < other_point.x
  return true if @x == other_point.x && @y < other_point.y
  return false
end

#<=>(other_point) ⇒ Object

Raises:

  • (Exception) 


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# File 'lib/winding-polygon/point.rb', line 27

def <=> other_point
  raise Exception.new("Self is x=#{@x},y=#{@y}, the other_point is nil") if other_point.nil?
  # x-coord first
  return  1 if @x > other_point.x
  return -1 if @x < other_point.x

  # y-coord second
  return  1 if @y > other_point.y
  return -1 if @y < other_point.y

  # they are the same point
  return 0
end

#==(other_point) ⇒ Object 



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# File 'lib/winding-polygon/point.rb', line 41

def == (other_point)
  @x==other_point.x && @y==other_point.y
end

#>(other_point) ⇒ Object 



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# File 'lib/winding-polygon/point.rb', line 51

def > (other_point)
  return true if @x > other_point.x
  return true if @x == other_point.x && @y > other_point.y
  return false
end

#compare(other_point) ⇒ Object

Determines the xy lexicographical order of two points

Raises:

  • (Exception) 


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# File 'lib/winding-polygon/point.rb', line 13

def compare other_point
  raise Exception.new("Self is x=#{@x},y=#{@y}, the other_point is nil") if other_point.nil?
  # x-coord first
  return  1 if @x > other_point.x
  return -1 if @x < other_point.x

  # y-coord second
  return  1 if @y > other_point.y
  return -1 if @y < other_point.y

  # they are the same point
  return 0
end

#is_left(p0, p1) ⇒ Object

tests if point is Left|On|Right of the line P0 to P1.

returns:

>0 for left of the line
0 for on the line
<0 for right of the line



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# File 'lib/winding-polygon/point.rb', line 63

def is_left p0, p1
  return (p1.x - p0.x) * (@y - p0.y) - (@x - p0.x) * (p1.y - p0.y)
end