From aed1b3cc557b67aca7d8b3259f44715078db94ae Mon Sep 17 00:00:00 2001
From: Michael Orlitzky <michael@orlitzky.com>
Date: Sun, 4 Sep 2011 09:03:47 -0400
Subject: [PATCH] Memoize the zoom function via PolynomialArray.

---
 src/Grid.hs | 45 ++++++++++++++++++++++++---------------------
 src/Main.hs | 19 +++++++++++++++++--
 2 files changed, 41 insertions(+), 23 deletions(-)

diff --git a/src/Grid.hs b/src/Grid.hs
index 2cf56ba..d31ffab 100644
--- a/src/Grid.hs
+++ b/src/Grid.hs
@@ -2,6 +2,7 @@
 --   for it. We hide the main Grid constructor because we don't want
 --   to allow instantiation of a grid with h <= 0.
 module Grid (
+  cube_at,
   grid_tests,
   make_grid,
   slow_tests,
@@ -22,13 +23,13 @@ import Comparisons
 import Cube (Cube(Cube),
              find_containing_tetrahedron,
              tetrahedra,
-             tetrahedron0,
-             tetrahedron15)
+             tetrahedron)
 import Examples
 import FunctionValues
 import Point (Point)
+import PolynomialArray (PolynomialArray)
 import ScaleFactor
-import Tetrahedron (c, polynomial, v0, v1, v2, v3)
+import Tetrahedron (Tetrahedron, c, number, polynomial, v0, v1, v2, v3)
 import ThreeDimensional
 import Values (Values3D, dims, empty3d, zoom_shape)
 
@@ -132,30 +133,32 @@ find_containing_cube g p =
 
 
 {-# INLINE zoom_lookup #-}
-zoom_lookup :: Grid -> ScaleFactor -> a -> (R.DIM3 -> Double)
-zoom_lookup g scale_factor _ = zoom_result g scale_factor
+zoom_lookup :: Grid -> PolynomialArray -> ScaleFactor -> a -> (R.DIM3 -> Double)
+zoom_lookup g polynomials scale_factor _ =
+    zoom_result g polynomials scale_factor
 
 
 {-# INLINE zoom_result #-}
-zoom_result :: Grid -> ScaleFactor -> R.DIM3 -> Double
-zoom_result g (sfx, sfy, sfz) (R.Z R.:. i R.:. j R.:. k) =
-  f p
+zoom_result :: Grid -> PolynomialArray -> ScaleFactor -> R.DIM3 -> Double
+zoom_result g polynomials (sfx, sfy, sfz) (R.Z R.:. m R.:. n R.:. o) =
+  (polynomials ! (i, j, k, (number t))) p
   where
     offset = (h g)/2
-    i' = (fromIntegral i) / (fromIntegral sfx) - offset
-    j' = (fromIntegral j) / (fromIntegral sfy) - offset
-    k' = (fromIntegral k) / (fromIntegral sfz) - offset
-    p  = (i', j', k') :: Point
+    m' = (fromIntegral m) / (fromIntegral sfx) - offset
+    n' = (fromIntegral n) / (fromIntegral sfy) - offset
+    o' = (fromIntegral o) / (fromIntegral sfz) - offset
+    p  = (m', n', o') :: Point
     cube = find_containing_cube g p
+    -- Figure out i,j,k without importing those functions.
+    Cube _ i j k _ _ = cube
     t = find_containing_tetrahedron cube p
-    f = polynomial t
 
-
-zoom :: Grid -> ScaleFactor -> Values3D
-zoom g scale_factor
+    
+zoom :: Grid -> PolynomialArray -> ScaleFactor -> Values3D
+zoom g polynomials scale_factor
     | xsize == 0 || ysize == 0 || zsize == 0 = empty3d
     | otherwise =
-        R.force $ R.traverse arr transExtent (zoom_lookup g scale_factor)
+        R.force $ R.traverse arr transExtent (zoom_lookup g polynomials scale_factor)
           where
             arr = function_values g
             (xsize, ysize, zsize) = dims arr
@@ -205,7 +208,7 @@ trilinear_c0_t0_tests =
   where
     g = make_grid 1 trilinear
     cube = cube_at g 1 1 1
-    t = tetrahedron0 cube
+    t = tetrahedron cube 0
 
     test_trilinear_c0030 :: Assertion
     test_trilinear_c0030 =
@@ -334,7 +337,7 @@ test_zeros_reproduced =
     where
       g = make_grid 1 zeros
       c0 = cube_at g 1 1 1
-      t0 = tetrahedron0 c0
+      t0 = tetrahedron c0 0
       p = polynomial t0
 
 
@@ -362,7 +365,7 @@ test_trilinear9x9x9_reproduced =
 --
 --   Example from before the fix:
 --
---   > b0 (tetrahedron15 c) p
+--   > b0 (tetrahedron c 15) p
 --   -3.4694469519536365e-18
 --
 test_tetrahedra_collision_sensitivity :: Assertion
@@ -373,7 +376,7 @@ test_tetrahedra_collision_sensitivity =
     g = make_grid 1 naturals_1d
     cube = cube_at g 0 17 1
     p = (0, 16.75, 0.5) :: Point
-    t15 = tetrahedron15 cube
+    t15 = tetrahedron cube 15
 
 
 prop_cube_indices_never_go_out_of_bounds :: Grid -> Gen Bool
diff --git a/src/Main.hs b/src/Main.hs
index c8ba345..4040276 100644
--- a/src/Main.hs
+++ b/src/Main.hs
@@ -9,12 +9,18 @@ import Data.Array.Repa (
 
 import System.Environment (getArgs)
 
+import Cube (tetrahedron)
+import Grid (cube_at, make_grid, zoom)
+import PolynomialArray (make_polynomial_array)
+import Tetrahedron (polynomial)
 import Values (read_values_3d, write_values_1d)
-import Grid (make_grid, zoom)
 
 mri_shape :: DIM3
 mri_shape = (Z :. 256 :. 256 :. 1)
 
+
+
+
 main :: IO ()
 main = do
   args <- getArgs
@@ -22,6 +28,15 @@ main = do
   let in_file  = "./data/MRbrain.40." ++ color
   let out_file = "MRbrain.40." ++ color ++ ".out"
   mridata <- read_values_3d mri_shape in_file
+
   let g = make_grid 1 mridata
-  let output = zoom g (8,8,1)
+  let polynomials = make_polynomial_array (255,255,0,23)
+        [ ((i,j,k,tet), polynomial t) | i <- [0..255],
+                                        j <- [0..255],
+                                        k <- [0],
+                                        tet <- [0..23],
+                                        let c = cube_at g i j k,
+                                        let t = tetrahedron c tet ]
+
+  let output = zoom g polynomials (8,8,1)
   write_values_1d output out_file
-- 
2.43.2