X-Git-Url: https://gitweb.michael.orlitzky.com/?a=blobdiff_plain;f=src%2FTetrahedron.hs;h=1f7c22b355c0392f26988a1d9c315e63fee2d68e;hb=b2e1c440b9b1bb99ae564d6600230bbd1f7d204c;hp=95233e008bfa0efe4fb69f20a4485b52f8e53b20;hpb=c0ea15048f7c0285213e30c82b458504be10da91;p=spline3.git

diff --git a/src/Tetrahedron.hs b/src/Tetrahedron.hs
index 95233e0..1f7c22b 100644
--- a/src/Tetrahedron.hs
+++ b/src/Tetrahedron.hs
@@ -17,7 +17,8 @@ data Tetrahedron = Tetrahedron { fv :: FunctionValues,
                                  v0 :: Point,
                                  v1 :: Point,
                                  v2 :: Point,
-                                 v3 :: Point }
+                                 v3 :: Point,
+                                 precomputed_volume :: Double }
                    deriving (Eq)
 
 
@@ -28,7 +29,11 @@ instance Arbitrary Tetrahedron where
       rnd_v2 <- arbitrary :: Gen Point
       rnd_v3 <- arbitrary :: Gen Point
       rnd_fv <- arbitrary :: Gen FunctionValues
-      return (Tetrahedron rnd_fv rnd_v0 rnd_v1 rnd_v2 rnd_v3)
+      -- We can't assign an incorrect precomputed volume,
+      -- so we have to calculate the correct one here.
+      let t' = Tetrahedron rnd_fv rnd_v0 rnd_v1 rnd_v2 rnd_v3 0
+      let vol = volume t'
+      return (Tetrahedron rnd_fv rnd_v0 rnd_v1 rnd_v2 rnd_v3 vol)
 
 
 instance Show Tetrahedron where
@@ -265,27 +270,27 @@ volume t
 
 -- | The barycentric coordinates of a point with respect to v0.
 b0 :: Tetrahedron -> (RealFunction Point)
-b0 t point = (volume inner_tetrahedron) / (volume t)
+b0 t point = (volume inner_tetrahedron) / (precomputed_volume t)
              where
                inner_tetrahedron = t { v0 = point }
 
 
 -- | The barycentric coordinates of a point with respect to v1.
 b1 :: Tetrahedron -> (RealFunction Point)
-b1 t point = (volume inner_tetrahedron) / (volume t)
+b1 t point = (volume inner_tetrahedron) / (precomputed_volume t)
              where
                inner_tetrahedron = t { v1 = point }
 
 
 -- | The barycentric coordinates of a point with respect to v2.
 b2 :: Tetrahedron -> (RealFunction Point)
-b2 t point = (volume inner_tetrahedron) / (volume t)
+b2 t point = (volume inner_tetrahedron) / (precomputed_volume t)
              where
                inner_tetrahedron = t { v2 = point }
 
 
 -- | The barycentric coordinates of a point with respect to v3.
 b3 :: Tetrahedron -> (RealFunction Point)
-b3 t point = (volume inner_tetrahedron) / (volume t)
+b3 t point = (volume inner_tetrahedron) / (precomputed_volume t)
              where
                inner_tetrahedron = t { v3 = point }