creating a demo to render a lower envelope

hgeometry-examples/hgeometry-examples.cabal

@@ -280,3 +280,14 @@ executable hgeometry-draw
   main-is:        Main.hs
   -- other-modules:
   --       Options
+
+
+--------------------------------------------------------------------------------
+
+-- Renders a 3D model of the lower envelope of a set of planes
+executable hgeometry-lowerEnv
+  import:         setup, miso-setup
+  hs-source-dirs: lowerEnv
+  main-is:        Main.hs
+  -- other-modules:
+  --       Options

hgeometry-examples/lowerEnv/Main.hs

@@ -0,0 +1,41 @@
+{-# LANGUAGE QuasiQuotes #-}
+module Main(main) where
+
+import           Control.Lens
+import qualified Data.List.NonEmpty as NonEmpty
+import           HGeometry.Ext
+import           HGeometry.Number.Real.Rational
+import           HGeometry.Plane.LowerEnvelope
+import           HGeometry.PlaneGraph
+import           HGeometry.PlaneGraph.Instances
+import           HGeometry.Point
+import           HGeometry.VoronoiDiagram.ViaLowerEnvelope
+import           Ipe
+import           PLY.Writer
+import           System.OsPath
+import           Test.QuickCheck
+
+--------------------------------------------------------------------------------
+
+type R = RealNumber 5
+
+
+myPlanes = NonEmpty.fromList $ zipWith (\i p -> pointToPlane p :+ (i,p)) [0..]
+           [ Point2 16 80
+           , Point2 64 48
+           , Point2 208 128
+           , Point2 176 48
+           , Point2 96 112
+           , Point2 128 80
+           , Point2 48 144
+           ]
+
+verticesOf = \case
+  ParallelStrips _      -> undefined
+  ConnectedEnvelope env -> undefined
+
+trianglesOf env = []
+
+main :: IO ()
+main = renderOutputToFile [osp|myLowerEnv|] (verticesOf $ lowerEnvelope myPlanes)
+                                            (trianglesOf $ lowerEnvelope myPlanes)