Adding better sanitization of NaN and Infinite

Fix #53

changelog

@@ -1,6 +1,12 @@
 Change log
 ==========
 
+v0.7.5 ??? 2019
+---------------
+
+ * Adding better sanitization of geometry in presence of NaN
+   and infinity.
+
 v0.7.4.3 May 2019
 -----------------
 

src/Graphics/Rasterific.hs

@@ -575,6 +575,14 @@ drawOrdersOfDrawing width height dpi background drawing =
     stupidDefaultTexture =
         SolidTexture $ colorMap (const clipBackground) background
 
+    orderOf ctxt method primitives = DrawOrder 
+        { _orderPrimitives = primitives
+        , _orderTexture    = textureOf ctxt
+        , _orderFillMethod = method
+        , _orderMask       = currentClip ctxt
+        , _orderDirect     = return ()
+        }
+
     go :: RenderContext px -> Free (DrawCommand px) () -> [DrawOrder px]
        -> [DrawOrder px]
     go _ (Pure ()) rest = rest
@@ -670,17 +678,12 @@ drawOrdersOfDrawing width height dpi background drawing =
 
     go ctxt (Free (Fill method prims next)) rest = order : after where
       after = go ctxt next rest
-      order = DrawOrder 
-            { _orderPrimitives = [geometryOf ctxt prims]
-            , _orderTexture    = textureOf ctxt
-            , _orderFillMethod = method
-            , _orderMask       = currentClip ctxt
-            , _orderDirect     = return ()
-            }
+      order = orderOf ctxt method [geometryOf ctxt prims >>= listOfContainer . sanitize]
 
-    go ctxt (Free (Stroke w j cap prims next)) rest =
-        go ctxt (Free $ Fill FillWinding prim' next) rest
-            where prim' = listOfContainer $ strokize w j cap prims
+    go ctxt (Free (Stroke w j cap prims next)) rest = order : after where
+      after = go ctxt next rest
+      order = orderOf ctxt FillWinding [prim']
+      prim' = listOfContainer $ strokize w j cap prims
 
     go ctxt (Free (SetTexture tx sub next)) rest =
         go (ctxt { currentTexture = tx }) (fromF sub) $

src/Graphics/Rasterific/Operators.hs

@@ -147,9 +147,13 @@ ifZero u v | nearZero u = v
 -- | Tell if two points are nearly indistinguishable.
 -- If indistinguishable, we can treat them as the same
 -- point.
+-- point with degenerate coordinates (Infinity/NaN) will be considered
+-- as nearby.
 isNearby :: Point -> Point -> Bool
 {-# INLINE isNearby #-}
-isNearby p1 p2 = squareDist < 0.1
+isNearby p1 p2 =
+    squareDist < 0.1 ||
+    isNaN squareDist || isInfinite squareDist -- degenerate case protection
   where vec = p1 ^-^ p2
         squareDist = vec `dot` vec
 

src/Graphics/Rasterific/StrokeInternal.hs

@@ -6,6 +6,7 @@ module Graphics.Rasterific.StrokeInternal
     , splitPrimitiveUntil
     , approximatePathLength
     , isPrimitivePoint
+    , sanitize
     )  where
 
 import Data.Monoid( (<>) )