26 lines
735 B
Haskell
26 lines
735 B
Haskell
module Quaternion
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( rotateToZ
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, vToQuat
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, module Linear.Quaternion
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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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import Linear.Quaternion
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-- apply a rotation as if the z axis moves to the new point.
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-- i think this may instead do as if the new point moves to be on z axis
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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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vToQuat :: Point3 -> Point3 -> Q.Quaternion Float
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vToQuat a b
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| cprod == V3 0 0 0 = Q.axisAngle (V3 0 0 1) 0
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| otherwise = Q.axisAngle cprod (angleVV3 a b)
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where
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cprod = crossProd a b
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