Module: Matrix3d

Defined in:
lib/ext/projector/matrix3d.rb

Class Method Summary collapse

Class Method Details

.frustum(left, right, bottom, top, znear, zfar) ⇒ Object 



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# File 'lib/ext/projector/matrix3d.rb', line 10

def frustum(left, right, bottom, top, znear, zfar)
  x = 2.0 * znear / (right - left)
  y = 2.0 * znear / (top - bottom)
  a = (right + left) / (right - left)
  b = (top + bottom) / (top - bottom)
  c = -(zfar + znear) / (zfar - znear)
  d = -2.0 * zfar * znear / (zfar - znear)
  Matrix[
      [x,   0.0, a,    0.0],
      [0.0, y,   b,    0.0],
      [0.0, 0.0, c,    d],
      [0.0, 0.0, -1.0, 0.0]
  ]
end

.identity ⇒ Object 



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# File 'lib/ext/projector/matrix3d.rb', line 8

def identity() Matrix.identity(4) end

.perspective(fov, aspect, znear, zfar) ⇒ Object 



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# File 'lib/ext/projector/matrix3d.rb', line 25

def perspective(fov, aspect, znear, zfar)
  yhi = znear * Math.tan(fov * Math::PI / 360.0)
  ylo = -yhi
  xlo = ylo * aspect
  xhi = yhi * aspect
  frustum(xlo, xhi, ylo, yhi, znear, zfar)
end

.rotate(theta, axis) ⇒ Object 



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# File 'lib/ext/projector/matrix3d.rb', line 53

def rotate(theta, axis)
  axis.size >= 3 or raise 'axis vector size >= 3.'
  theta = Math::PI / 180.0 * theta
  axis = Vector[axis[0], axis[1], axis[2]]
  axis_r = axis.r
  axis_r > axis_r * Float::EPSILON or raise 'r must not be zero vector.'
  x = axis[0] / axis_r
  y = axis[1] / axis_r
  z = axis[2] / axis_r
  s = Math.sin(theta)
  c = Math.cos(theta)
  cc = 1.0 - c
  Matrix[
    [cc * x * x + c,     cc * y * x - s * z, cc * z * x + s * y, 0.0],
    [cc * x * y + s * z, cc * y * y + c,     cc * z * y - s * x, 0.0],
    [cc * x * z - s * y, cc * y * z + s * x, cc * z * z + c,     0.0],
    [0.0, 0.0, 0.0, 1.0]
  ]
end

.scale(v) ⇒ Object 



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# File 'lib/ext/projector/matrix3d.rb', line 43

def scale(v)
  v.size >= 3 or raise 'vector size >= 3.'
  Matrix[
    [v[0], 0.0, 0.0, 0.0],
    [0.0, v[1], 0.0, 0.0],
    [0.0, 0.0, v[2], 0.0],
    [0.0, 0.0, 0.0, 1.0]
  ]
end

.translate(v) ⇒ Object 



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# File 'lib/ext/projector/matrix3d.rb', line 33

def translate(v)
  v.size >= 3 or raise 'vector size >= 3.'
  Matrix[
    [1.0, 0.0, 0.0, v[0]],
    [0.0, 1.0, 0.0, v[1]],
    [0.0, 0.0, 1.0, v[2]],
    [0.0, 0.0, 0.0, 1.0]
  ]
end