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fix stupid error in quadratic solver
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sheaf
parent
2983943363
commit
570a593f4f
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@ -41,7 +41,7 @@ import Data.Foldable
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import Data.List.NonEmpty
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( unzip )
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import Data.Maybe
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( fromMaybe, isJust, mapMaybe )
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( fromMaybe, isJust, listToMaybe, mapMaybe )
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import GHC.Exts
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( newMutVar#, runRW# )
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import GHC.STRef
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@ -212,7 +212,7 @@ computeStrokeOutline fitParams ptParams brushFn spline@( Spline { splineStart =
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endTgtBwd = (-1) *^ snd ( lastOutlineBwd 0 )
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startBrush, endBrush :: SplinePts Closed
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startBrush = brushShape spt0
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endBrush = brushShape endPt
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endBrush = brushShape endPt
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-- Computation of which brush segment to use for the end caps.
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startTgt, endTgt :: Vector2D Double
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@ -229,24 +229,24 @@ computeStrokeOutline fitParams ptParams brushFn spline@( Spline { splineStart =
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stx, sty, etx, ety :: Double
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Vector2D stx sty = startTgt
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Vector2D etx ety = endTgt
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startCap, endCap :: SplinePts Open
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startCap
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| isJust $ between brushOrientation startTgtBwd startTgtFwd startTestTgt
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= fmap ( MkVector2D ( coords spt0 ) • )
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$ joinWithBrush ( withTangent startTgtBwd startBrush ) ( withTangent startTgtFwd startBrush ) startBrush
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$ joinWithBrush startBrush startTgtBwd startTgtFwd
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| otherwise
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= fmap ( MkVector2D ( coords spt0 ) • )
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. reverseSpline
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$ joinWithBrush ( withTangent startTgtFwd startBrush ) ( withTangent startTgtBwd startBrush )startBrush
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$ joinWithBrush startBrush startTgtFwd startTgtBwd
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endCap
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| not . isJust $ between brushOrientation endTgtBwd endTgtFwd endTestTgt
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= fmap ( MkVector2D ( coords endPt ) • )
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. reverseSpline
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$ joinWithBrush ( withTangent endTgtBwd endBrush ) ( withTangent endTgtFwd endBrush ) endBrush
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$ joinWithBrush endBrush endTgtBwd endTgtFwd
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| otherwise
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= fmap ( MkVector2D ( coords endPt ) • )
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$ joinWithBrush ( withTangent endTgtFwd endBrush ) ( withTangent endTgtBwd endBrush ) endBrush
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$ joinWithBrush endBrush endTgtFwd endTgtBwd
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-> do
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TwoSided ( fwdPts, fwdFits ) ( bwdPts, bwdFits ) <- updateSpline ( startTgtFwd, startTgtBwd )
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pure
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@ -373,21 +373,21 @@ computeStrokeOutline fitParams ptParams brushFn spline@( Spline { splineStart =
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= Spline { splineStart = coords sp0, splineCurves = OpenCurves Empty }
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| brushOrientation == convexOrientation [ prevTgtFwd, tgtFwd ]
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= fmap ( ptOffset • )
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$ joinWithBrush ( withTangent prevTgtFwd brush0 ) ( withTangent tgtFwd brush0 ) brush0
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$ joinWithBrush brush0 prevTgtFwd tgtFwd
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| otherwise
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= fmap ( ptOffset • )
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. reverseSpline
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$ joinWithBrush ( withTangent tgtFwd brush0 ) ( withTangent prevTgtFwd brush0 ) brush0
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$ joinWithBrush brush0 tgtFwd prevTgtFwd
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bwdJoin
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| tgtBwd `strictlyParallel` prevTgtBwd
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= Spline { splineStart = coords sp0, splineCurves = OpenCurves Empty }
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| brushOrientation == convexOrientation [ tgtBwd, prevTgtBwd ]
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= fmap ( ptOffset • )
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$ joinWithBrush ( withTangent tgtBwd brush0 ) ( withTangent prevTgtBwd brush0 ) brush0
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$ joinWithBrush brush0 tgtBwd prevTgtBwd
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| otherwise
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= fmap ( ptOffset • )
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. reverseSpline
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$ joinWithBrush ( withTangent prevTgtBwd brush0 ) ( withTangent tgtBwd brush0 ) brush0
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$ joinWithBrush brush0 prevTgtBwd tgtBwd
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brushJoin :: OutlineData
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brushJoin = TwoSided ( fwdJoin, Empty ) ( bwdJoin, Empty )
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@ -499,7 +499,6 @@ outlineFunctions ptParams brushFn sp0 crv =
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-- used in the "stroke" function.
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-----
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startTangent, endTangent :: ( SplineTypeI clo, HasType ( Point2D Double ) ptData ) => ptData -> ptData -> Curve clo crvData ptData -> Vector2D Double
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startTangent sp p0 ( LineTo mp1 _ ) = coords p0 --> coords ( fromNextPoint sp mp1 )
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startTangent _ p0 ( Bezier2To p1 _ _ ) = coords p0 --> coords p1
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@ -516,11 +515,27 @@ lastTangent ( Spline { splineStart, splineCurves = ClosedCurves ( _ :|> prev ) l
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--------------------------------------------------------------------------------
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-- | Compute the join at a point of discontinuity of the tangent vector direction (G1 discontinuity).
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joinWithBrush :: forall crvData ptData. HasType ( Point2D Double ) ptData => Offset -> Offset -> Spline Closed crvData ptData -> SplinePts Open
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joinWithBrush
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:: ( HasType ( Point2D Double ) ptData
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-- debugging
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, Show ptData, Show crvData
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)
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=> Spline Closed crvData ptData
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-> Vector2D Double
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-> Vector2D Double
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-> SplinePts Open
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joinWithBrush brush startTgt endTgt = joinBetweenOffsets brush startOffset endOffset
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where
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startOffset, endOffset :: Offset
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startOffset = withTangent startTgt brush
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endOffset = withTangent endTgt brush
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-- | Select the section of a spline in between two offsets.
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joinBetweenOffsets :: forall crvData ptData. HasType ( Point2D Double ) ptData => Spline Closed crvData ptData -> Offset -> Offset -> SplinePts Open
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joinBetweenOffsets
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spline
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( Offset { offsetIndex = i1, offsetParameter = mb_t1 } )
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( Offset { offsetIndex = i2, offsetParameter = mb_t2 } )
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spline
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| i2 > i1
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= let
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pcs, lastAndRest :: Maybe ( SplinePts Open )
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@ -746,10 +761,9 @@ withTangent tgt_wanted spline@( Spline { splineStart } ) = case lastTangent spli
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in
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let
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mbParam :: Maybe Double
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mbParam =
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case mapMaybe correctTangentParam $ solveQuadratic c01 ( 2 * ( c12 - c01 ) ) ( c01 + c23 - 2 * c12 ) of
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( t : _ ) -> Just t
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_ -> between ori tgt0 tgt2 tgt_wanted -- fallback in case we couldn't solve the quadratic for some reason
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mbParam = listToMaybe
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. mapMaybe correctTangentParam
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$ solveQuadratic c01 ( 2 * ( c12 - c01 ) ) ( c01 + c23 - 2 * c12 )
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in for_ mbParam \ t ->
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throwE $
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Offset
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@ -69,8 +69,8 @@ solveQuadratic a0 a1 a2
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r =
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if a1 >= 0
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then 2 * a0 / ( - a1 - sqrt disc )
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else 0.5 * ( - a1 + sqrt disc) / a2
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in [ r, -r - a1 ]
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else 0.5 * ( - a1 + sqrt disc ) / a2
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in [ r, -r - a1 / a2 ]
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where
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disc :: a
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disc = a1 * a1 - 4 * a0 * a2
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