Catch out-of-bounds calls to value_at.

[spline3.git] / src / FunctionValues.hs

diff --git a/src/FunctionValues.hs b/src/FunctionValues.hs
index e9ff0647f413b3f530757725f3bab382ac33a730..e8bdcb8e2d1f294216d38fa24d3b56fcc4cba786 100644 (file)
--- a/src/FunctionValues.hs
+++ b/src/FunctionValues.hs
@@ -73,9 +73,15 @@ eval f (Difference x y) = (eval f x) - (eval f y)
 eval f (Product x y) = (eval f x) * (eval f y)
 eval f (Quotient x y) = (eval f x) / (eval f y)
 
-value_at :: [[[Double]]] -> Int -> Int -> Int -> Double            
-value_at values i j k =
-    ((values !! k) !! j) !! i
+value_at :: [[[Double]]] -> Int -> Int -> Int -> Double
+value_at values i j k
+         | i < 0 = 0
+         | j < 0 = 0
+         | k < 0 = 0
+         | length values <= k = 0
+         | length (values !! k) <= j = 0
+         | length ((values !! k) !! j) <= i = 0
+         | otherwise = ((values !! k) !! j) !! i
 
 make_values :: [[[Double]]] -> Int -> Int -> Int -> FunctionValues
 make_values values i j k =
@@ -106,3 +112,33 @@ make_values values i j k =
                    back_right_down = value_at values (i+1) (j+1) (k-1),
                    back_right_top = value_at values (i+1) (j+1) (k+1),
                    interior = value_at values i j k }
+
+rotate :: FunctionValues -> (Cardinal -> Cardinal) -> FunctionValues
+rotate fv rotation =
+    FunctionValues { front  = eval fv (rotation F),
+                     back   = eval fv (rotation B),
+                     left   = eval fv (rotation L),
+                     right  = eval fv (rotation R),
+                     down   = eval fv (rotation D),
+                     top    = eval fv (rotation T),
+                     front_left = eval fv (rotation FL),
+                     front_right = eval fv (rotation FR),
+                     front_down = eval fv (rotation FD),
+                     front_top = eval fv (rotation FT),
+                     back_left = eval fv (rotation BL),
+                     back_right = eval fv (rotation BR),
+                     back_down = eval fv (rotation BD),
+                     back_top = eval fv (rotation BT),
+                     left_down = eval fv (rotation LD),
+                     left_top = eval fv (rotation LT),
+                     right_down = eval fv (rotation RD),
+                     right_top = eval fv (rotation RT),
+                     front_left_down = eval fv (rotation FLD),
+                     front_left_top = eval fv (rotation FLT),
+                     front_right_down = eval fv (rotation FRD),
+                     front_right_top = eval fv (rotation FRT),
+                     back_left_down = eval fv (rotation BLD),
+                     back_left_top = eval fv (rotation BLT),
+                     back_right_down = eval fv (rotation BRD),
+                     back_right_top = eval fv (rotation BRT),
+                     interior = interior fv }