Merge pull request #328 from bacchanalia/master

fix for: section producing incorrect results #322
diagrams · Mar 7, 2019 · 7ff9922 · 7ff9922
2 parents 9febf32 + c0da81d
commit 7ff9922
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diff --git a/src/Diagrams/Located.hs b/src/Diagrams/Located.hs
@@ -175,6 +175,8 @@ instance (InSpace v n a, Fractional n, Parametric a, Sectionable a, Codomain a ~
   splitAtParam (Loc x a) p = (Loc x a1, Loc (x .+^ (a `atParam` p)) a2)
     where (a1,a2) = splitAtParam a p
 
+  section (Loc x a) p1 p2 = Loc (x .+^ (a `atParam` p1)) (section a p1 p2)
+
   reverseDomain (Loc x a) = Loc (x .+^ y) (reverseDomain a)
     where y = a `atParam` domainUpper a
 

diff --git a/src/Diagrams/Trail.hs b/src/Diagrams/Trail.hs
@@ -520,6 +520,8 @@ instance (Metric v, OrderedField n, Real n)
     where
       (t1, t2) = splitAtParam t p
 
+  section (Line t) p1 p2 = Line (section t p1 p2)
+
   reverseDomain = reverseLine
 
 instance (Metric v, OrderedField n, Real n)
@@ -768,6 +770,8 @@ instance (Metric v, OrderedField n, Real n) => EndValues (Trail v n)
 instance (Metric v, OrderedField n, Real n) => Sectionable (Trail v n) where
   splitAtParam t p = withLine ((wrapLine *** wrapLine) . (`splitAtParam` p)) t
 
+  section t p1 p2 = withLine (wrapLine . (\l -> section l p1 p2)) t
+
   reverseDomain = reverseTrail
 
 instance (Metric v, OrderedField n, Real n)