Class: Mittsu::Frustum

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

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(p0 = nil, p1 = nil, p2 = nil, p3 = nil, p4 = nil, p5 = nil) ⇒ Frustum

Returns a new instance of Frustum.



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# File 'lib/mittsu/math/frustum.rb', line 5

def initialize(p0 = nil, p1 = nil, p2 = nil, p3 = nil, p4 = nil, p5 = nil)
  @planes = [
    p0 || Mittsu::Plane.new,
    p1 || Mittsu::Plane.new,
    p2 || Mittsu::Plane.new,
    p3 || Mittsu::Plane.new,
    p4 || Mittsu::Plane.new,
    p5 || Mittsu::Plane.new
  ]
end

Instance Attribute Details

#planes ⇒ Object

Returns the value of attribute planes.



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

def planes
  @planes
end

Instance Method Details

#clone ⇒ Object 



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# File 'lib/mittsu/math/frustum.rb', line 99

def clone
  Mittsu::Frustum.new.copy(self)
end

#contains_point?(point) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/mittsu/math/frustum.rb', line 91

def contains_point?(point)
  planes = self.planes
  6.times do |i|
    return false if planes[i].distance_to_point(point) < 0
  end
  true
end

#copy(frustum) ⇒ Object 



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# File 'lib/mittsu/math/frustum.rb', line 27

def copy(frustum)
  planes = self.planes
  6.times do |i|
    planes[i].copy(frustum.planes[i])
  end
  self
end

#intersects_box?(box) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/mittsu/math/frustum.rb', line 71

def intersects_box?(box)
  p1 = Mittsu::Vector3.new
  p2 = Mittsu::Vector3.new
  planes = self.planes
  6.times do |i|
    plane = planes[i]
    p1.x = plane.normal.x > 0 ? box.min.x : box.max.x
    p2.x = plane.normal.x > 0 ? box.max.x : box.min.x
    p1.y = plane.normal.y > 0 ? box.min.y : box.max.y
    p2.y = plane.normal.y > 0 ? box.max.y : box.min.y
    p1.z = plane.normal.z > 0 ? box.min.z : box.max.z
    p2.z = plane.normal.z > 0 ? box.max.z : box.min.z
    d1 = plane.distance_to_point(p1)
    d2 = plane.distance_to_point(p2)
    # if both outside plane, no intersection
    return false if d1 < 0 && d2 < 0
  end
  true
end

#intersects_object?(object) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/mittsu/math/frustum.rb', line 51

def intersects_object?(object)
  sphere = Mittsu::Sphere.new
  geometry = object.geometry
  geometry.compute_bounding_sphere if geometry.bounding_sphere.nil?
  sphere.copy(geometry.bounding_sphere)
  sphere.apply_matrix4(object.matrix_world)
  self.intersects_sphere?(sphere)
end

#intersects_sphere?(sphere) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/mittsu/math/frustum.rb', line 60

def intersects_sphere?(sphere)
  planes = self.planes
  center = sphere.center
  negRadius = -sphere.radius
  6.times do |i|
    distance = planes[i].distance_to_point(center)
    return false if distance < negRadius
  end
  true
end

#set(p0, p1, p2, p3, p4, p5) ⇒ Object 



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# File 'lib/mittsu/math/frustum.rb', line 16

def set(p0, p1, p2, p3, p4, p5)
  planes = self.planes
  planes[0].copy(p0)
  planes[1].copy(p1)
  planes[2].copy(p2)
  planes[3].copy(p3)
  planes[4].copy(p4)
  planes[5].copy(p5)
  self
end

#set_from_matrix(m) ⇒ Object 



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# File 'lib/mittsu/math/frustum.rb', line 35

def set_from_matrix(m)
  planes = self.planes
  me = m.elements
  me0 = me[0]; me1 = me[1]; me2 = me[2]; me3 = me[3]
  me4 = me[4]; me5 = me[5]; me6 = me[6]; me7 = me[7]
  me8 = me[8]; me9 = me[9]; me10 = me[10]; me11 = me[11]
  me12 = me[12]; me13 = me[13]; me14 = me[14]; me15 = me[15]
  planes[0].set_components(me3 - me0, me7 - me4, me11 - me8, me15 - me12).normalize
  planes[1].set_components(me3 + me0, me7 + me4, me11 + me8, me15 + me12).normalize
  planes[2].set_components(me3 + me1, me7 + me5, me11 + me9, me15 + me13).normalize
  planes[3].set_components(me3 - me1, me7 - me5, me11 - me9, me15 - me13).normalize
  planes[4].set_components(me3 - me2, me7 - me6, me11 - me10, me15 - me14).normalize
  planes[5].set_components(me3 + me2, me7 + me6, me11 + me10, me15 + me14).normalize
  self
end