From: Michael Orlitzky <michael@orlitzky.com>
Date: Tue, 20 Sep 2011 16:38:30 +0000 (-0400)
Subject: Get rid of the chunk code, and recompute the grid within the zoom traverse.
X-Git-Tag: 0.0.1~129
X-Git-Url: https://gitweb.michael.orlitzky.com/?a=commitdiff_plain;h=3f0b6b7faecc561af0b7312a11c73a44a1b416f6;p=spline3.git

Get rid of the chunk code, and recompute the grid within the zoom traverse.
---

diff --git a/src/Grid.hs b/src/Grid.hs
index 5ff4aa2..647ec57 100644
--- a/src/Grid.hs
+++ b/src/Grid.hs
@@ -6,12 +6,10 @@ module Grid (
   grid_tests,
   make_grid,
   slow_tests,
-  zoom,
-  zoom_chunk
+  zoom
   )
 where
 
-import Data.Array (Array, array, (!))
 import qualified Data.Array.Repa as R
 import Test.HUnit
 import Test.Framework (Test, testGroup)
@@ -34,16 +32,12 @@ import ThreeDimensional
 import Values (Values3D, dims, empty3d, zoom_shape)
 
 
-type CubeGrid = Array (Int,Int,Int) Cube
-
-
 -- | Our problem is defined on a Grid. The grid size is given by the
 --   positive number h. The function values are the values of the
 --   function at the grid points, which are distance h from one
 --   another in each direction (x,y,z).
 data Grid = Grid { h :: Double, -- MUST BE GREATER THAN ZERO!
-                   function_values :: Values3D,
-                   cube_grid :: CubeGrid }
+                   function_values :: Values3D }
           deriving (Eq, Show)
 
 
@@ -59,29 +53,8 @@ instance Arbitrary Grid where
 make_grid :: Double -> Values3D -> Grid
 make_grid grid_size values
     | grid_size <= 0 = error "grid size must be positive"
-    | otherwise = Grid grid_size values (cubes grid_size values)
-
-
--- | Returns a three-dimensional array of cubes centered on the grid
---   points (h*i, h*j, h*k) with the appropriate 'FunctionValues'.
-cubes :: Double -> Values3D -> CubeGrid
-cubes delta fvs 
-  = array (lbounds, ubounds)
-           [ ((i,j,k), cube_ijk)
-                 | i <- [0..xmax],
-                   j <- [0..ymax],
-                   k <- [0..zmax],
-                   let tet_vol = (1/24)*(delta^(3::Int)),
-                   let fvs' = make_values fvs i j k,
-                   let cube_ijk =
-                         Cube delta i j k fvs' tet_vol]
-     where
-       xmax = xsize - 1
-       ymax = ysize - 1
-       zmax = zsize - 1
-       lbounds = (0, 0, 0)
-       ubounds = (xmax, ymax, zmax)
-       (xsize, ysize, zsize) = dims fvs
+    | otherwise = Grid grid_size values
+
 
 
 -- | Takes a grid and a position as an argument and returns the cube
@@ -95,10 +68,13 @@ cube_at g i j k
     | j >= ysize = error "j >= ysize in cube_at"
     | k < 0      = error "k < 0 in cube_at"
     | k >= zsize = error "k >= zsize in cube_at"
-    | otherwise = (cube_grid g) ! (i,j,k)
-      where
+    | otherwise = Cube delta i j k fvs' tet_vol
+      where        
         fvs = function_values g
         (xsize, ysize, zsize) = dims fvs
+        fvs' = make_values fvs i j k
+        delta = h g
+        tet_vol = (1/24)*(delta^(3::Int))
 
 --   The first cube along any axis covers (-h/2, h/2). The second
 --   covers (h/2, 3h/2).  The third, (3h/2, 5h/2), and so on.
@@ -134,16 +110,17 @@ 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 :: Values3D -> ScaleFactor -> a -> (R.DIM3 -> Double)
+zoom_lookup v3d scale_factor _ =
+    zoom_result v3d scale_factor
 
 
 {-# INLINE zoom_result #-}
-zoom_result :: Grid -> ScaleFactor -> R.DIM3 -> Double
-zoom_result g (sfx, sfy, sfz) (R.Z R.:. m R.:. n R.:. o) =
+zoom_result :: Values3D -> ScaleFactor -> R.DIM3 -> Double
+zoom_result v3d (sfx, sfy, sfz) (R.Z R.:. m R.:. n R.:. o) =
   f p
   where
+    g = make_grid 1 v3d
     offset = (h g)/2
     m' = (fromIntegral m) / (fromIntegral sfx) - offset
     n' = (fromIntegral n) / (fromIntegral sfy) - offset
@@ -154,52 +131,13 @@ zoom_result g (sfx, sfy, sfz) (R.Z R.:. m R.:. n R.:. o) =
     f = polynomial t
 
 
-zoom :: Grid -> ScaleFactor -> Values3D
-zoom g scale_factor
-    | xsize == 0 || ysize == 0 || zsize == 0 = empty3d
-    | otherwise =
-        R.force $ R.unsafeTraverse arr transExtent (zoom_lookup g scale_factor)
-          where
-            arr = function_values g
-            (xsize, ysize, zsize) = dims arr
-            transExtent = zoom_shape scale_factor
-
-
-
-
-{-# INLINE zoom_chunk_lookup #-}
-zoom_chunk_lookup :: Grid -> ScaleFactor -> a -> (R.DIM3 -> Double)
-zoom_chunk_lookup g scale_factor _ =
-    zoom_chunk_result g scale_factor
-
-
-{-# INLINE zoom_chunk_result #-}
-zoom_chunk_result :: Grid -> ScaleFactor -> R.DIM3 -> Double
-zoom_chunk_result g (sfx, sfy, sfz) (R.Z R.:. m R.:. n R.:. o)
-  | m /= 1 = 0 -- We're going to drop these anyway.
-  | otherwise = f p
-    where
-      offset = (h g)/2
-      sfx' = fromIntegral sfx
-      sfy' = fromIntegral sfy
-      sfz' = fromIntegral sfz
-      m' = (fromIntegral m) / sfx' - offset
-      n' = (fromIntegral n) / sfy' - offset
-      o' = (fromIntegral o) / sfz' - offset
-      p  = (m', n', o') :: Point
-      cube = find_containing_cube g p
-      t = find_containing_tetrahedron cube p
-      f = polynomial t
-
-
-zoom_chunk :: Grid -> ScaleFactor -> Values3D
-zoom_chunk g scale_factor
+zoom :: Values3D -> ScaleFactor -> Values3D
+zoom v3d scale_factor
     | xsize == 0 || ysize == 0 || zsize == 0 = empty3d
     | otherwise =
-        R.force $ R.unsafeTraverse arr transExtent (zoom_chunk_lookup g scale_factor)
+        R.force $ R.unsafeTraverse v3d transExtent (zoom_lookup v3d scale_factor)
           where
-            arr = function_values g
-            (xsize, ysize, zsize) = dims arr
+            (xsize, ysize, zsize) = dims v3d
             transExtent = zoom_shape scale_factor
 
 
diff --git a/src/MRI.hs b/src/MRI.hs
index 5f2ceea..8e2b0ac 100644
--- a/src/MRI.hs
+++ b/src/MRI.hs
@@ -170,13 +170,3 @@ write_values_slice_to_bitmap v3d path =
     routput = R.map (\(red, _,     _)    -> red)   colors
     goutput = R.map (\(_,   green, _)    -> green) colors
     boutput = R.map (\(_,   _,     blue) -> blue)  colors
-
-
-write_values_chunk_to_bitmap :: Values3D -> FilePath -> IO ()
-write_values_chunk_to_bitmap v3d path
-  | zdim /= 3 = error "not a 3xMxN chunk"
-  | otherwise = write_values_slice_to_bitmap target_slice path
-  where
-    (Z :. zdim :. _ :. _) = extent v3d
-    target_slice = z_slice 1 v3d
-
diff --git a/src/Main.hs b/src/Main.hs
index b65cc4b..e577351 100644
--- a/src/Main.hs
+++ b/src/Main.hs
@@ -4,7 +4,7 @@ where
 import qualified Data.Array.Repa as R
 import System.Environment (getArgs)
 
-import Grid (make_grid, zoom, zoom_chunk)
+import Grid (zoom)
 import MRI
 
 
@@ -13,24 +13,7 @@ in_file = "./data/mri.bin"
 
 
 main :: IO ()
-main = main2d_chunk
-
-
-main2d_chunk :: IO ()
-main2d_chunk = do
-  (s:_) <- getArgs
-  let scale = read s :: Int
-  let zoom_factor = (1, scale, scale)
-  let out_file = "output.bmp"
-  arr <- read_word16s in_file
-  let arr' = swap_bytes arr
-  let arrInv   = flip_x $ flip_y arr'
-  let arrSlice = z_slice3 50 arrInv
-  let dbl_data = R.map fromIntegral arrSlice
-  let g = make_grid 1 dbl_data
-  let output = zoom_chunk g zoom_factor
-  write_values_chunk_to_bitmap output out_file
-
+main = main3d
 
 
 main3d :: IO ()
@@ -41,11 +24,9 @@ main3d = do
   let out_file = "output.bin"
   arr <- read_word16s in_file
   let arr' = swap_bytes arr
---  let arrInv   = flip_x $ flip_y arr'
   let arrMRI = R.reshape mri_shape arr'
   let dbl_data = R.force $ R.map fromIntegral arrMRI
-  let g = make_grid 1 dbl_data
-  let output = zoom g zoom_factor
+  let output = zoom dbl_data zoom_factor
   let word16_output = bracket_array output
   write_word16s out_file word16_output
 
@@ -62,6 +43,5 @@ main2d = do
   let arrSlice = z_slice 50 arrInv
   let arrSlice' = R.reshape mri_slice3d arrSlice
   let dbl_data = R.map fromIntegral arrSlice'
-  let g = make_grid 1 dbl_data
-  let output = zoom g zoom_factor
+  let output = zoom dbl_data zoom_factor
   write_values_slice_to_bitmap (z_slice 0 output) out_file