Class: Three::Quaternion

Inherits:
Object
  • Object
show all
Includes:
Enumerable
Defined in:
lib/three/math/quaternion.rb

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(x = 0, y = 0, z = 0, w = 1) ⇒ Quaternion

Returns a new instance of Quaternion.



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# File 'lib/three/math/quaternion.rb', line 11

def initialize(x = 0, y = 0, z = 0, w = 1)
  @x = x
  @y = y
  @z = z
  @w = w
  @on_change_callback = proc {}
end

Instance Attribute Details

#w ⇒ Object

Returns the value of attribute w.



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# File 'lib/three/math/quaternion.rb', line 9

def w
  @w
end

#x ⇒ Object

Returns the value of attribute x.



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# File 'lib/three/math/quaternion.rb', line 9

def x
  @x
end

#y ⇒ Object

Returns the value of attribute y.



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# File 'lib/three/math/quaternion.rb', line 9

def y
  @y
end

#z ⇒ Object

Returns the value of attribute z.



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# File 'lib/three/math/quaternion.rb', line 9

def z
  @z
end

Instance Method Details

#==(other) ⇒ Object 



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# File 'lib/three/math/quaternion.rb', line 239

def ==(other)
  other.is_a?(self.class) && equals?(other)
end

#clone ⇒ Object 



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# File 'lib/three/math/quaternion.rb', line 52

def clone
  self.class.new(@x, @y, @z, @w)
end

#conjugate ⇒ Object 



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# File 'lib/three/math/quaternion.rb', line 188

def conjugate
  @x *= -1
  @y *= -1
  @z *= -1
  changed!
  self
end

#copy(quaternion, update: true) ⇒ Object 



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# File 'lib/three/math/quaternion.rb', line 56

def copy(quaternion, update: true)
  set(quaternion.x, quaternion.y, quaternion.z, quaternion.w, update: update)
end

#deconstruct ⇒ Object 



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# File 'lib/three/math/quaternion.rb', line 263

def deconstruct
  to_a
end

#dot(quaternion) ⇒ Object 



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# File 'lib/three/math/quaternion.rb', line 200

def dot(quaternion)
  @x * quaternion.x + @y * quaternion.y + @z * quaternion.z + @w * quaternion.w
end

#each {|@x| ... } ⇒ Object

Yields:

  • (@x) 


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# File 'lib/three/math/quaternion.rb', line 250

def each
  return enum_for(:each) unless block_given?

  yield @x
  yield @y
  yield @z
  yield @w
end

#equals?(quaternion, epsilon: 0.0) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/three/math/quaternion.rb', line 232

def equals?(quaternion, epsilon: 0.0)
  (@x - quaternion.x).abs <= epsilon &&
    (@y - quaternion.y).abs <= epsilon &&
    (@z - quaternion.z).abs <= epsilon &&
    (@w - quaternion.w).abs <= epsilon
end

#identity(update: true) ⇒ Object 



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# File 'lib/three/math/quaternion.rb', line 48

def identity(update: true)
  set(0, 0, 0, 1, update: update)
end

#inspect ⇒ Object 



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# File 'lib/three/math/quaternion.rb', line 267

def inspect
  "#<#{self.class} x=#{@x.inspect} y=#{@y.inspect} z=#{@z.inspect} w=#{@w.inspect}>"
end

#invert ⇒ Object 



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# File 'lib/three/math/quaternion.rb', line 196

def invert
  conjugate
end

#length ⇒ Object 



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# File 'lib/three/math/quaternion.rb', line 208

def length
  Math.sqrt(length_sq)
end

#length_sq ⇒ Object 



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# File 'lib/three/math/quaternion.rb', line 204

def length_sq
  dot(self)
end

#multiply(quaternion) ⇒ Object 



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# File 'lib/three/math/quaternion.rb', line 162

def multiply(quaternion)
  multiply_quaternions(self, quaternion)
end

#multiply_quaternions(a, b) ⇒ Object 



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# File 'lib/three/math/quaternion.rb', line 170

def multiply_quaternions(a, b)
  qax = a.x
  qay = a.y
  qaz = a.z
  qaw = a.w
  qbx = b.x
  qby = b.y
  qbz = b.z
  qbw = b.w

  @x = qax * qbw + qaw * qbx + qay * qbz - qaz * qby
  @y = qay * qbw + qaw * qby + qaz * qbx - qax * qbz
  @z = qaz * qbw + qaw * qbz + qax * qby - qay * qbx
  @w = qaw * qbw - qax * qbx - qay * qby - qaz * qbz
  changed!
  self
end

#normalize ⇒ Object 



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# File 'lib/three/math/quaternion.rb', line 212

def normalize
  current_length = length

  if current_length.zero?
    @x = 0
    @y = 0
    @z = 0
    @w = 1
  else
    scale = 1.0 / current_length
    @x *= scale
    @y *= scale
    @z *= scale
    @w *= scale
  end

  changed!
  self
end

#on_change(&callback) ⇒ Object Also known as: _on_change 



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# File 'lib/three/math/quaternion.rb', line 243

def on_change(&callback)
  @on_change_callback = callback || proc {}
  self
end

#premultiply(quaternion) ⇒ Object 



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# File 'lib/three/math/quaternion.rb', line 166

def premultiply(quaternion)
  multiply_quaternions(quaternion, self)
end

#set(x, y, z, w, update: true) ⇒ Object 



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# File 'lib/three/math/quaternion.rb', line 39

def set(x, y, z, w, update: true)
  @x = x
  @y = y
  @z = z
  @w = w
  changed! if update
  self
end

#set_from_axis_angle(axis, angle, update: true) ⇒ Object 



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# File 'lib/three/math/quaternion.rb', line 107

def set_from_axis_angle(axis, angle, update: true)
  half_angle = angle / 2.0
  s = Math.sin(half_angle)

  @x = axis.x * s
  @y = axis.y * s
  @z = axis.z * s
  @w = Math.cos(half_angle)
  changed! if update
  self
end

#set_from_euler(euler, update: true) ⇒ Object 



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# File 'lib/three/math/quaternion.rb', line 60

def set_from_euler(euler, update: true)
  c1 = Math.cos(euler.x / 2.0)
  c2 = Math.cos(euler.y / 2.0)
  c3 = Math.cos(euler.z / 2.0)
  s1 = Math.sin(euler.x / 2.0)
  s2 = Math.sin(euler.y / 2.0)
  s3 = Math.sin(euler.z / 2.0)

  case euler.order
  when "XYZ"
    @x = s1 * c2 * c3 + c1 * s2 * s3
    @y = c1 * s2 * c3 - s1 * c2 * s3
    @z = c1 * c2 * s3 + s1 * s2 * c3
    @w = c1 * c2 * c3 - s1 * s2 * s3
  when "YXZ"
    @x = s1 * c2 * c3 + c1 * s2 * s3
    @y = c1 * s2 * c3 - s1 * c2 * s3
    @z = c1 * c2 * s3 - s1 * s2 * c3
    @w = c1 * c2 * c3 + s1 * s2 * s3
  when "ZXY"
    @x = s1 * c2 * c3 - c1 * s2 * s3
    @y = c1 * s2 * c3 + s1 * c2 * s3
    @z = c1 * c2 * s3 + s1 * s2 * c3
    @w = c1 * c2 * c3 - s1 * s2 * s3
  when "ZYX"
    @x = s1 * c2 * c3 - c1 * s2 * s3
    @y = c1 * s2 * c3 + s1 * c2 * s3
    @z = c1 * c2 * s3 - s1 * s2 * c3
    @w = c1 * c2 * c3 + s1 * s2 * s3
  when "YZX"
    @x = s1 * c2 * c3 + c1 * s2 * s3
    @y = c1 * s2 * c3 + s1 * c2 * s3
    @z = c1 * c2 * s3 - s1 * s2 * c3
    @w = c1 * c2 * c3 - s1 * s2 * s3
  when "XZY"
    @x = s1 * c2 * c3 - c1 * s2 * s3
    @y = c1 * s2 * c3 - s1 * c2 * s3
    @z = c1 * c2 * s3 + s1 * s2 * c3
    @w = c1 * c2 * c3 + s1 * s2 * s3
  else
    raise ArgumentError, "unknown Euler order: #{euler.order}"
  end

  changed! if update
  self
end

#set_from_rotation_matrix(matrix, update: true) ⇒ Object 



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# File 'lib/three/math/quaternion.rb', line 119

def set_from_rotation_matrix(matrix, update: true)
  elements = matrix.elements
  m11 = elements[0]
  m12 = elements[4]
  m13 = elements[8]
  m21 = elements[1]
  m22 = elements[5]
  m23 = elements[9]
  m31 = elements[2]
  m32 = elements[6]
  m33 = elements[10]
  trace = m11 + m22 + m33

  if trace.positive?
    s = 0.5 / Math.sqrt(trace + 1.0)
    @w = 0.25 / s
    @x = (m32 - m23) * s
    @y = (m13 - m31) * s
    @z = (m21 - m12) * s
  elsif m11 > m22 && m11 > m33
    s = 2.0 * Math.sqrt(1.0 + m11 - m22 - m33)
    @w = (m32 - m23) / s
    @x = 0.25 * s
    @y = (m12 + m21) / s
    @z = (m13 + m31) / s
  elsif m22 > m33
    s = 2.0 * Math.sqrt(1.0 + m22 - m11 - m33)
    @w = (m13 - m31) / s
    @x = (m12 + m21) / s
    @y = 0.25 * s
    @z = (m23 + m32) / s
  else
    s = 2.0 * Math.sqrt(1.0 + m33 - m11 - m22)
    @w = (m21 - m12) / s
    @x = (m13 + m31) / s
    @y = (m23 + m32) / s
    @z = 0.25 * s
  end

  changed! if update
  self
end

#to_a ⇒ Object 



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# File 'lib/three/math/quaternion.rb', line 259

def to_a
  [@x, @y, @z, @w]
end