19 lines
529 B
Haskell
19 lines
529 B
Haskell
module Bound where
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import Geometry
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import Control.Lens
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import Streaming
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import qualified Streaming.Prelude as S
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import qualified Control.Foldl as L
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boundPoints :: Stream (Of Point2) Identity () -> Maybe (Float,Float,Float,Float)
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{-# INLINE boundPoints #-}
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boundPoints = f . runIdentity . L.purely S.fold_ ((,,,)
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<$> L.premap (^?! _2) L.maximum
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<*> L.premap (^?! _2) L.minimum
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<*> L.premap (^?! _1) L.maximum
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<*> L.premap (^?! _1) L.minimum
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)
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where
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f (mn,ms,me,mw) = (,,,) <$> mn <*> ms <*> me <*> mw
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