nicely drawing halfplanes :)

noinia · Mar 2, 2025 · aaa6c34 · aaa6c34
1 parent 3191cb7
commit aaa6c34
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Showing 3 changed files with 52 additions and 10 deletions.
diff --git a/hgeometry/data/test-with-ipe/Polygon/Simple/convexHalfspaceIntersection.out.ipe b/hgeometry/data/test-with-ipe/Polygon/Simple/convexHalfspaceIntersection.out.ipe
@@ -1,5 +1,15 @@
 <?xml version="1.0" encoding="UTF-8"?>
-<ipe version="70005" creator="HGeometry"><ipestyle name="basic">
+<ipe version="70005" creator="HGeometry"><ipestyle name="opacities">
+<opacity name="10%" value="0.1"/>
+<opacity name="20%" value="0.2"/>
+<opacity name="30%" value="0.3"/>
+<opacity name="40%" value="0.4"/>
+<opacity name="50%" value="0.5"/>
+<opacity name="60%" value="0.6"/>
+<opacity name="70%" value="0.7"/>
+<opacity name="80%" value="0.8"/>
+<opacity name="90%" value="0.9"/>
+</ipestyle><ipestyle name="basic">
 <color name="red" value="1 0 0"/>
 <color name="green" value="0 1 0"/>
 <color name="blue" value="0 0 1"/>
@@ -140,7 +150,12 @@
 160.000000000000 208.000000000000 l
 112.000000000000 176.000000000000 l
 h
-</path><group><path>-708.800000000000 -1000.000000000000 m
+</path><group><path fill="gray" opacity="20%">757.866666666666 1000.000000000000 m
+-708.800000000000 -1000.000000000000 l
+-1000.000000000000 -1000.000000000000 l
+-1000.000000000000 1000.000000000000 l
+h
+</path><path>-708.800000000000 -1000.000000000000 m
 757.866666666666 1000.000000000000 l
 </path></group><group><path fill="red">103.255813953488 107.348837209302 m
 172.487804878048 201.756097560975 l

diff --git a/hgeometry/data/test-with-ipe/Polygon/Simple/polygonHalfspaceIntersection.out.ipe b/hgeometry/data/test-with-ipe/Polygon/Simple/polygonHalfspaceIntersection.out.ipe
@@ -1,5 +1,15 @@
 <?xml version="1.0" encoding="UTF-8"?>
-<ipe version="70005" creator="HGeometry"><ipestyle name="basic">
+<ipe version="70005" creator="HGeometry"><ipestyle name="opacities">
+<opacity name="10%" value="0.1"/>
+<opacity name="20%" value="0.2"/>
+<opacity name="30%" value="0.3"/>
+<opacity name="40%" value="0.4"/>
+<opacity name="50%" value="0.5"/>
+<opacity name="60%" value="0.6"/>
+<opacity name="70%" value="0.7"/>
+<opacity name="80%" value="0.8"/>
+<opacity name="90%" value="0.9"/>
+</ipestyle><ipestyle name="basic">
 <color name="red" value="1 0 0"/>
 <color name="green" value="0 1 0"/>
 <color name="blue" value="0 0 1"/>
@@ -140,7 +150,12 @@
 336.000000000000 112.000000000000 l
 224.000000000000 208.000000000000 l
 h
-</path><group><path>-1000.000000000000 520.066070397942 m
+</path><group><path fill="gray" opacity="20%">1000.000000000000 -174.493340015153 m
+-1000.000000000000 520.066070397942 l
+-1000.000000000000 1000.000000000000 l
+1000.000000000000 1000.000000000000 l
+h
+</path><path>-1000.000000000000 520.066070397942 m
 1000.000000000000 -174.493340015153 l
 </path></group><group><path fill="red">96.464620234993 139.286160313325 m
 258.606691901969 82.977509463238 l

diff --git a/hgeometry/test-with-ipe/test/Polygon/Simple/IntersectHalfplaneSpec.hs b/hgeometry/test-with-ipe/test/Polygon/Simple/IntersectHalfplaneSpec.hs
@@ -12,6 +12,7 @@ import           Data.Functor.Contravariant (phantom)
 import           Data.List.NonEmpty (NonEmpty(..))
 import qualified Data.List.NonEmpty as NonEmpty
 import           Data.Maybe (isJust, mapMaybe, maybeToList)
+import qualified Data.Text as Text
 import           Data.Traversable
 import           Data.Vector.NonEmpty (NonEmptyVector)
 import           Golden
@@ -526,9 +527,8 @@ testIpe inFp outFp = describe (show inFp) $ do
                          ]
     describe "compute intersection" $
       goldenWith [osp|data/test-with-ipe/Polygon/Simple/|]
-                 (ipeContentGolden { name = outFp })
-                 content'
-    pure ()
+                 (ipeFileGolden { name = outFp })
+                   (addStyleSheet opacitiesStyle $ singlePageFromContent content')
 
 
 renderComponent :: forall vertex f r.
@@ -556,11 +556,23 @@ instance (Fractional r, Ord r, Show r) => HasDefaultIpeOut (HalfSpaceF (LinePV 2
   type DefaultIpeOut (HalfSpaceF (LinePV 2 r)) = Group
   defIO = ipeHalfPlane
 
+-- | Default rendering of halfplanes
 ipeHalfPlane :: (Show r, Fractional r, Ord r) => IpeOut (HalfSpaceF (LinePV 2 r)) Group r
 ipeHalfPlane = ipeHalfPlaneIn defaultBox
 
+-- | Draw a halfplane in the given rectangle.
+--
+-- We draw both the border (in black) and the interior (20% transparant gray) of the halfpace
 ipeHalfPlaneIn          :: (Ord r, Fractional r, Show r)
                         => Rectangle (Point 2 r) -> IpeOut (HalfSpaceF (LinePV 2 r)) Group r
-ipeHalfPlaneIn rect' hl = ipeGroup [ iO $ ipeLineIn rect' (hl^.boundingHyperPlane)
-                                   ]
-  -- TDOO: I think we also want to display the interior
+ipeHalfPlaneIn rect' hl = case hl `intersect` rect' of
+    Nothing -> ipeGroup [] -- this should not really happen I guess?
+    Just is -> case is of
+      ActualPolygon interior -> ipeGroup [ iO $ ipeSimplePolygon interior
+                                              ! attr SFill gray
+                                              ! attr SOpacity (Text.pack "20%")
+                                         , boundary
+                                         ]
+      _                      -> ipeGroup [ boundary ]
+  where
+    boundary = iO $ ipeLineIn rect' (hl^.boundingHyperPlane)