From 030351ef876dd8571d2cb596f149c2c70b39bcaa Mon Sep 17 00:00:00 2001
From: Doug Coleman <doug.coleman@gmail.com>
Date: Sat, 26 Sep 2009 20:09:16 -0500
Subject: [PATCH] move the png filtering code to images.png

---
 basis/compression/inflate/inflate.factor | 42 +++---------------------
 basis/images/png/png.factor              | 35 +++++++++++++++++---
 2 files changed, 35 insertions(+), 42 deletions(-)

diff --git a/basis/compression/inflate/inflate.factor b/basis/compression/inflate/inflate.factor
index fa3f4d1284..26b851cc1e 100644
--- a/basis/compression/inflate/inflate.factor
+++ b/basis/compression/inflate/inflate.factor
@@ -1,10 +1,9 @@
 ! Copyright (C) 2009 Marc Fauconneau.
 ! See http://factorcode.org/license.txt for BSD license.
-USING: accessors arrays assocs byte-arrays
-byte-vectors combinators fry grouping hashtables
-compression.huffman images io.binary kernel locals
-math math.bitwise math.order math.ranges multiline sequences
-sorting ;
+USING: accessors arrays assocs byte-vectors combinators
+compression.huffman fry hashtables io.binary kernel locals math
+math.bitwise math.order math.ranges sequences sorting ;
+QUALIFIED-WITH: bitstreams bs
 IN: compression.inflate
 
 QUALIFIED-WITH: bitstreams bs
@@ -177,42 +176,9 @@ CONSTANT: dist-table
         case
     ]
     [ produce ] keep call suffix concat ;
-    
-  !  [ produce ] keep dip swap suffix
-
-:: paeth ( a b c -- p ) 
-    a b + c - { a b c } [ [ - abs ] keep 2array ] with map 
-    sort-keys first second ;
-    
-:: png-unfilter-line ( prev curr filter -- curr' )
-    prev :> c
-    prev 3 tail-slice :> b
-    curr :> a
-    curr 3 tail-slice :> x
-    x length [0,b)
-    filter {
-        { 0 [ drop ] }
-        { 1 [ [| n | n x nth n a nth + 256 wrap n x set-nth ] each ] }
-        { 2 [ [| n | n x nth n b nth + 256 wrap n x set-nth ] each ] }
-        { 3 [ [| n | n x nth n a nth n b nth + 2/ + 256 wrap n x set-nth ] each ] }
-        { 4 [ [| n | n x nth n a nth n b nth n c nth paeth + 256 wrap n x set-nth ] each ] }
-    } case 
-    curr 3 tail ;
 
 PRIVATE>
 
-: reverse-png-filter' ( lines -- byte-array )
-    [ first ] [ 1 tail ] [ map ] bi-curry@ bi nip
-    concat [ 128 + ] B{ } map-as ;
-
-: reverse-png-filter ( lines -- byte-array )
-    dup first length 0 <array> prefix
-    [ { 0 0 } prepend ] map
-    2 clump [
-        first2 dup [ third ] [ [ 0 2 ] dip set-nth ] bi
-        png-unfilter-line
-    ] map B{ } concat-as ;
-
 : zlib-inflate ( bytes -- bytes )
     bs:<lsb0-bit-reader>
     [ check-zlib-header ] [ inflate-loop ] bi
diff --git a/basis/images/png/png.factor b/basis/images/png/png.factor
index 8dde02687d..d0a001f3f6 100755
--- a/basis/images/png/png.factor
+++ b/basis/images/png/png.factor
@@ -1,9 +1,9 @@
 ! Copyright (C) 2009 Doug Coleman.
 ! See http://factorcode.org/license.txt for BSD license.
-USING: accessors images io io.binary io.encodings.ascii
-io.encodings.binary io.encodings.string io.files io.files.info kernel
-sequences io.streams.limited fry combinators arrays math checksums
-checksums.crc32 compression.inflate grouping byte-arrays images.loader ;
+USING: accessors arrays checksums checksums.crc32 combinators
+compression.inflate fry grouping images images.loader io
+io.binary io.encodings.ascii io.encodings.string kernel locals
+math math.bitwise math.ranges sequences sorting ;
 IN: images.png
 
 SINGLETON: png-image
@@ -90,6 +90,33 @@ ERROR: unknown-filter-method image ;
         [ unknown-color-type ]
     } case ;
 
+:: paeth ( a b c -- p ) 
+    a b + c - { a b c } [ [ - abs ] keep 2array ] with map 
+    sort-keys first second ;
+    
+:: png-unfilter-line ( prev curr filter -- curr' )
+    prev :> c
+    prev 3 tail-slice :> b
+    curr :> a
+    curr 3 tail-slice :> x
+    x length [0,b)
+    filter {
+        { filter-none [ drop ] }
+        { filter-sub [ [| n | n x nth n a nth + 256 wrap n x set-nth ] each ] }
+        { filter-up [ [| n | n x nth n b nth + 256 wrap n x set-nth ] each ] }
+        { filter-average [ [| n | n x nth n a nth n b nth + 2/ + 256 wrap n x set-nth ] each ] }
+        { filter-paeth [ [| n | n x nth n a nth n b nth n c nth paeth + 256 wrap n x set-nth ] each ] }
+    } case 
+    curr 3 tail ;
+
+: reverse-png-filter ( lines -- byte-array )
+    dup first length 0 <array> prefix
+    [ { 0 0 } prepend ] map
+    2 clump [
+        first2 dup [ third ] [ [ 0 2 ] dip set-nth ] bi
+        png-unfilter-line
+    ] map B{ } concat-as ;
+
 : filter-png ( groups loading-png -- byte-array )
     filter-method>> {
         { filter-none [ reverse-png-filter ] }