Add missing dependencies, fix arc rendering

src/Picture.hs

@@ -301,9 +301,9 @@ arc startA endA rad = thickArc startA endA rad 1
 thickArc :: Float -> Float -> Float -> Float -> Picture
 {-# INLINE thickArc #-}
 thickArc startA endA rad wdth
-    | endA - startA > pi = pictures 
-        [ thickArc (startA + pi) endA rad wdth
-        , thickArcHelp startA (startA + pi) r w
+    | endA - startA > (pi/ 2) = pictures 
+        [ thickArc (startA + pi/2) endA rad wdth
+        , thickArcHelp startA (startA + pi/2) r w
         ]
     | otherwise = thickArcHelp startA endA r w
   where
@@ -323,6 +323,7 @@ thickArcHelp startA endA rad wdth = map f
   where
     (V2 xa ya) = rotateV startA (V2 rad 0)
     (V2 xb yb) = rotateV (0.5 * (startA + endA)) (V2 (rad * sqrt 2) 0)
+    --(V2 xb yb) = rotateV (0.5 * (startA + endA)) (V2 (rad * 2) 0)
     (V2 xc yc) = rotateV endA (V2 rad 0)
     f (pos,col,V3 a b c) = Verx pos col [a,b,c] 0 arcNum