Class: Mittsu::Matrix3

Inherits:
Object
  • Object
show all
Defined in:
lib/mittsu/math/matrix3.rb

Constant Summary collapse

DIMENSIONS = 
3

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize ⇒ Matrix3

Returns a new instance of Matrix3.



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# File 'lib/mittsu/math/matrix3.rb', line 7

def initialize()
  @elements = [
    1.0, 0.0, 0.0,
    0.0, 1.0, 0.0,
    0.0, 0.0, 1.0
  ]
end

Instance Attribute Details

#elements ⇒ Object

Returns the value of attribute elements.



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# File 'lib/mittsu/math/matrix3.rb', line 3

def elements
  @elements
end

Instance Method Details

#==(other) ⇒ Object 



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# File 'lib/mittsu/math/matrix3.rb', line 145

def ==(other)
  other.elements == @elements
end

#apply_to_vector3_array(array, offset = 0, length = array.length) ⇒ Object 



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# File 'lib/mittsu/math/matrix3.rb', line 42

def apply_to_vector3_array(array, offset = 0, length = array.length)
  v1 = Mittsu::Vector3.new
  i, j = 0, offset
  while i < length
    v1.x = array[j]
    v1.y = array[j + 1]
    v1.z = array[j + 2]
    v1.apply_matrix3(self)
    array[j]     = v1.x
    array[j + 1] = v1.y
    array[j + 2] = v1.z
    i += 3
    j += 3
  end
  array
end

#clone ⇒ Object 



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# File 'lib/mittsu/math/matrix3.rb', line 163

def clone
  Mittsu::Matrix3.new.from_array(self.elements)
end

#copy(m) ⇒ Object 



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# File 'lib/mittsu/math/matrix3.rb', line 32

def copy(m)
  me = m.elements
  self.set(
    me[0], me[3], me[6],
    me[1], me[4], me[7],
    me[2], me[5], me[8]
  )
  self
end

#determinant ⇒ Object 



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# File 'lib/mittsu/math/matrix3.rb', line 67

def determinant
  a, b, c, d, e, f, g, h, i = *self.elements
  a * e * i - a * f * h - b * d * i + b * f * g + c * d * h - c * e * g
end

#flatten_to_array_offset(array, offset) ⇒ Object 



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# File 'lib/mittsu/math/matrix3.rb', line 111

def flatten_to_array_offset(array, offset)
  te = self.elements
  array[offset    ] = te[0]
  array[offset + 1] = te[1]
  array[offset + 2] = te[2]
  array[offset + 3] = te[3]
  array[offset + 4] = te[4]
  array[offset + 5] = te[5]
  array[offset + 6] = te[6]
  array[offset + 7] = te[7]
  array[offset + 8]  = te[8]
  array
end

#from_array(array) ⇒ Object 



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# File 'lib/mittsu/math/matrix3.rb', line 149

def from_array(array)
  self.elements[0..array.length] = (array)
  self
end

#identity ⇒ Object 



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# File 'lib/mittsu/math/matrix3.rb', line 23

def identity
  self.set(
    1.0, 0.0, 0.0,
    0.0, 1.0, 0.0,
    0.0, 0.0, 1.0
  )
  self
end

#inverse(matrix, throw_on_invertible = false) ⇒ Object 



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# File 'lib/mittsu/math/matrix3.rb', line 72

def inverse(matrix, throw_on_invertible = false)
  # input: Mittsu::Matrix4
  # (based on http:#code.google.com/p/webgl-mjs/)
  me = matrix.elements
  te = self.elements
  te[0] =   me[10] * me[5] - me[6] * me[9]
  te[1] = - me[10] * me[1] + me[2] * me[9]
  te[2] =   me[6] * me[1] - me[2] * me[5]
  te[3] = - me[10] * me[4] + me[6] * me[8]
  te[4] =   me[10] * me[0] - me[2] * me[8]
  te[5] = - me[6] * me[0] + me[2] * me[4]
  te[6] =   me[9] * me[4] - me[5] * me[8]
  te[7] = - me[9] * me[0] + me[1] * me[8]
  te[8] =   me[5] * me[0] - me[1] * me[4]
  det = me[0] * te[0] + me[1] * te[3] + me[2] * te[6]
  # no inverse
  if det.zero?
    msg = "Mittsu::Matrix3#inverse: can't invert matrix, determinant is 0"
    if throw_on_invertible
      raise Error.new(msg)
    else
      puts "WARNING: #{msg}"
      # THREE.warn(msg)
    end
    self.identity
    return self
  end
  self.multiply_scalar(1.0 / det)
  self
end

#multiply_scalar(s) ⇒ Object 



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# File 'lib/mittsu/math/matrix3.rb', line 59

def multiply_scalar(s)
  te = self.elements
  te[0] *= s; te[3] *= s; te[6] *= s
  te[1] *= s; te[4] *= s; te[7] *= s
  te[2] *= s; te[5] *= s; te[8] *= s
  self
end

#normal_matrix(m) ⇒ Object 



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# File 'lib/mittsu/math/matrix3.rb', line 125

def normal_matrix(m)
  # input: THREE.Matrix4
  self.inverse(m).transpose
  self
end

#set(n11, n12, n13, n21, n22, n23, n31, n32, n33) ⇒ Object 



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# File 'lib/mittsu/math/matrix3.rb', line 15

def set(n11, n12, n13, n21, n22, n23, n31, n32, n33)
  te = self.elements
  te[0] = n11.to_f; te[3] = n12.to_f; te[6] = n13.to_f
  te[1] = n21.to_f; te[4] = n22.to_f; te[7] = n23.to_f
  te[2] = n31.to_f; te[5] = n32.to_f; te[8] = n33.to_f
  self
end

#to_a ⇒ Object 



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# File 'lib/mittsu/math/matrix3.rb', line 154

def to_a
  te = self.elements
  [
    te[0], te[1], te[2],
    te[3], te[4], te[5],
    te[6], te[7], te[8]
  ]
end

#transpose ⇒ Object 



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# File 'lib/mittsu/math/matrix3.rb', line 103

def transpose
  m = self.elements
  tmp = m[1]; m[1] = m[3]; m[3] = tmp
  tmp = m[2]; m[2] = m[6]; m[6] = tmp
  tmp = m[5]; m[5] = m[7]; m[7] = tmp
  self
end

#transpose_into_array(r) ⇒ Object 



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# File 'lib/mittsu/math/matrix3.rb', line 131

def transpose_into_array(r)
  m = self.elements
  r[0] = m[0]
  r[1] = m[3]
  r[2] = m[6]
  r[3] = m[1]
  r[4] = m[4]
  r[5] = m[7]
  r[6] = m[2]
  r[7] = m[5]
  r[8] = m[8]
  self
end