16 lines
396 B
Haskell
16 lines
396 B
Haskell
module Quaternion
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( rotateToZ
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)
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where
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import Geometry.Data
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import Geometry.Vector3D
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import qualified Linear.Quaternion as Q
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-- apply a rotation as if the z axis moves to the new point.
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rotateToZ :: Point3 -> Point3 -> Point3
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rotateToZ z1
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| cprod == V3 0 0 0 = id
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| otherwise = Q.rotate $ Q.axisAngle cprod (angleVV3 z1 (V3 0 0 1))
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where
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cprod = crossProd z1 (V3 0 0 1)
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