Class: Geo3d::Plane

Inherits:
Object
  • Object
show all
Defined in:
lib/geo3d/plane.rb

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(*args) ⇒ Plane

Returns a new instance of Plane.



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# File 'lib/geo3d/plane.rb', line 9

def initialize *args
  @a = 0.0
  @b = 0.0
  @c = 0.0
  @d = 0.0
  @a = args[0].to_f if args.size > 0
  @b = args[1].to_f if args.size > 1
  @c = args[2].to_f if args.size > 2
  @d = args[3].to_f if args.size > 3
end

Instance Attribute Details

#a ⇒ Object Also known as: x

Returns the value of attribute a.



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# File 'lib/geo3d/plane.rb', line 3

def a
  @a
end

#b ⇒ Object Also known as: y

Returns the value of attribute b.



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# File 'lib/geo3d/plane.rb', line 3

def b
  @b
end

#c ⇒ Object Also known as: z

Returns the value of attribute c.



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# File 'lib/geo3d/plane.rb', line 3

def c
  @c
end

#d ⇒ Object Also known as: w

Returns the value of attribute d.



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# File 'lib/geo3d/plane.rb', line 3

def d
  @d
end

Class Method Details

.from_point_and_normal(point, normal) ⇒ Object 



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# File 'lib/geo3d/plane.rb', line 26

def self.from_point_and_normal point, normal
  point.w = 0
  self.new normal.x, normal.y, normal.z, -point.dot(normal)
end

.from_points(pv1, pv2, pv3) ⇒ Object 



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# File 'lib/geo3d/plane.rb', line 20

def self.from_points pv1, pv2, pv3
  edge1 = pv2 - pv1
  edge2 = pv3 - pv1
  from_point_and_normal pv1, edge1.cross(edge2).normalize
end

Instance Method Details

#!=(vec) ⇒ Object 



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# File 'lib/geo3d/plane.rb', line 39

def != vec
  !(self == vec)
end

#==(p) ⇒ Object 



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# File 'lib/geo3d/plane.rb', line 35

def == p
  Geo3d::Utils.float_cmp(a, p.a) && Geo3d::Utils.float_cmp(b, p.b) && Geo3d::Utils.float_cmp(c, p.c) && Geo3d::Utils.float_cmp(d, p.d)
end

#dot(v) ⇒ Object 



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# File 'lib/geo3d/plane.rb', line 43

def dot v
  a * v.x + b * v.y + c * v.z + d * v.w
end

#line_intersection(line_start, line_end) ⇒ Object 



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# File 'lib/geo3d/plane.rb', line 72

def line_intersection line_start, line_end
  direction = line_end - line_start

  normal_dot_direction = normal.dot direction

  if (normal_dot_direction.zero?)
    nil
  else
    temp = (d + normal.dot(line_start)) / normal_dot_direction
    line_start - direction * temp
  end
end

#normal ⇒ Object 



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# File 'lib/geo3d/plane.rb', line 68

def normal
  Vector.new a, b, c
end

#normalize ⇒ Object 



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# File 'lib/geo3d/plane.rb', line 62

def normalize
  p = self.class.new a, b, c, d
  p.normalize!
  p
end

#normalize! ⇒ Object 



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# File 'lib/geo3d/plane.rb', line 47

def normalize!
  norm = Math.sqrt(a*a + b*b + c*c)
  if norm.zero?
    @a = 0
    @b = 0
    @c = 0
    @d = 0
  else
    @a /= norm
    @b /= norm
    @c /= norm
    @d /= norm
  end
end

#to_a ⇒ Object 



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# File 'lib/geo3d/plane.rb', line 31

def to_a
  [a,b,c,d]
end

#transform(matrix, use_inverse_transpose = true) ⇒ Object 



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# File 'lib/geo3d/plane.rb', line 85

def transform matrix, use_inverse_transpose = true
  matrix = matrix.inverse.transpose if use_inverse_transpose
  p = self.class.new
  p.a = dot matrix.row(0)
  p.b = dot matrix.row(1)
  p.c = dot matrix.row(2)
  p.d = dot matrix.row(3)
  p
end