Class: CTioga2::Graphics::Line

Inherits:
Object
  • Object
show all
Defined in:
lib/ctioga2/graphics/geometry.rb

Overview

A geometry line, ie something that has a starting point and a direction. It is infinite

Direct Known Subclasses

Segment

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(x, y, dx, dy) ⇒ Line

Returns a new instance of Line.



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# File 'lib/ctioga2/graphics/geometry.rb', line 35

def initialize(x, y, dx, dy)
  @x = x.to_f
  @y = y.to_f
  @dx = dx.to_f
  @dy = dy.to_f
end

Instance Attribute Details

#dx ⇒ Object

Returns the value of attribute dx.



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# File 'lib/ctioga2/graphics/geometry.rb', line 33

def dx
  @dx
end

#dy ⇒ Object

Returns the value of attribute dy.



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# File 'lib/ctioga2/graphics/geometry.rb', line 33

def dy
  @dy
end

#x ⇒ Object

Returns the value of attribute x.



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# File 'lib/ctioga2/graphics/geometry.rb', line 33

def x
  @x
end

#y ⇒ Object

Returns the value of attribute y.



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# File 'lib/ctioga2/graphics/geometry.rb', line 33

def y
  @y
end

Instance Method Details

#intersection(line) ⇒ Object

Returns the X and Y positions of the intersection with the given Line, or false should there be none.



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# File 'lib/ctioga2/graphics/geometry.rb', line 44

def intersection(line)
  fact = @dx * line.dy - line.dx * @dy
  rhs =  @dy * (line.x - @x) - @dx * (line.y - @y)
  if fact != 0            # There is a unique intersection
    beta = rhs/fact
    nx = line.x + beta * line.dx
    ny = line.y + beta * line.dy
  # elsif rhs == 0
  #   # Infinite, we return 
  #   return 
  else
    return false
  end
  return [nx, ny] if (within_bounds?(nx, ny) and 
                      line.within_bounds?(nx, ny))
  return false
end

#within_bounds?(x, y) ⇒ Boolean

Checks if within the bounds of the line (but not necessarily ON the line)

Returns:

  • (Boolean) 


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# File 'lib/ctioga2/graphics/geometry.rb', line 29

def within_bounds?(x, y)
  return true
end