-! Copyrigt (C) 2009 Doug Coleman.
+! Copyrigt (C) 2009 Doug Coleman, Keith Lazuka
! See http://factorcode.org/license.txt for BSD license.
-USING: accessors arrays combinators constructors destructors
-images images.loader io io.binary io.buffers
-io.encodings.binary io.encodings.string io.encodings.utf8
-io.files io.files.info io.ports io.streams.limited kernel make
-math math.bitwise math.functions multiline namespaces
-prettyprint sequences ;
+USING: accessors arrays combinators compression.lzw
+constructors destructors grouping images images.loader io
+io.binary io.buffers io.encodings.string io.encodings.utf8
+kernel make math math.bitwise namespaces sequences ;
IN: images.gif
SINGLETON: gif-image
ERROR: gif-unexpected-eof ;
TUPLE: graphics-control-extension
-label block-size raw-data
-packed delay-time color-index
-block-terminator ;
+flags delay-time transparent-color-index ;
TUPLE: image-descriptor
-separator left top width height flags ;
+left top width height flags first-code-size ;
TUPLE: plain-text-extension
introducer label block-size text-grid-left text-grid-top text-grid-width
TUPLE: trailer byte ;
CONSTRUCTOR: trailer ( byte -- obj ) ;
-CONSTANT: image-descriptor HEX: 2c
+CONSTANT: image-descriptor 0x2c
! Extensions
-CONSTANT: extension-identifier HEX: 21
-CONSTANT: plain-text-extension HEX: 01
-CONSTANT: graphic-control-extension HEX: f9
-CONSTANT: comment-extension HEX: fe
-CONSTANT: application-extension HEX: ff
-CONSTANT: trailer HEX: 3b
+CONSTANT: extension-identifier 0x21
+CONSTANT: plain-text-extension 0x01
+CONSTANT: graphic-control-extension 0xf9
+CONSTANT: comment-extension 0xfe
+CONSTANT: application-extension 0xff
+CONSTANT: trailer 0x3b
+CONSTANT: graphic-control-extension-block-size 0x04
+CONSTANT: block-terminator 0x00
: <loading-gif> ( -- loading-gif )
\ loading-gif new
V{ } clone >>comment-extensions
t >>loading? ;
-GENERIC: stream-peek1 ( stream -- byte )
-
-M: input-port stream-peek1
- dup check-disposed dup wait-to-read
- [ drop f ] [ buffer>> buffer-peek ] if ; inline
-
-: peek1 ( -- byte ) input-stream get stream-peek1 ;
-
: (read-sub-blocks) ( -- )
read1 [ read , (read-sub-blocks) ] unless-zero ;
: read-image-descriptor ( -- image-descriptor )
\ image-descriptor new
- 1 read le> >>separator
2 read le> >>left
2 read le> >>top
2 read le> >>width
2 read le> >>height
- 1 read le> >>flags ;
+ 1 read le> >>flags
+ 1 read le> 1 + >>first-code-size ;
: read-graphic-control-extension ( -- graphic-control-extension )
\ graphics-control-extension new
- 1 read le> [ >>block-size ] [ read ] bi
- >>raw-data
- 1 read le> >>block-terminator ;
+ 1 read le> graphic-control-extension-block-size assert=
+ 1 read le> >>flags
+ 2 read le> >>delay-time
+ 1 read le> >>transparent-color-index
+ 1 read le> block-terminator assert= ;
: read-plain-text-extension ( -- plain-text-extension )
\ plain-text-extension new
: interlaced? ( image -- ? ) flags>> 6 bit? ; inline
: sort? ( image -- ? ) flags>> 5 bit? ; inline
: color-table-size ( image -- ? ) flags>> 3 bits 1 + 2^ 3 * ; inline
+: transparency? ( image -- ? )
+ graphic-control-extensions>>
+ [ f ] [ first flags>> 0 bit? ] if-empty ; inline
: color-resolution ( image -- ? ) flags>> -4 shift 3 bits ; inline
: read-global-color-table ( loading-gif -- loading-gif )
dup color-table? [
- dup color-table-size read >>global-color-table
+ dup color-table-size read 3 group >>global-color-table
] when ;
: maybe-read-local-color-table ( loading-gif -- loading-gif )
} case
] with-input-stream ;
-: loading-gif>image ( loading-gif -- image )
- ;
+: decompress ( loading-gif -- indexes )
+ [ compressed-bytes>> ]
+ [ image-descriptor>> first-code-size>> ] bi
+ gif-lzw-uncompress ;
+
+: colorize ( index palette transparent-index/f -- seq )
+ pick = [ 2drop B{ 0 0 0 0 } ] [ nth 255 suffix ] if ;
+
+: apply-palette ( indexes palette transparent-index/f -- bitmap )
+ [ colorize ] 2curry V{ } map-as concat ;
+
+: dimensions ( loading-gif -- dim )
+ [ image-descriptor>> width>> ] [ image-descriptor>> height>> ] bi 2array ;
+
+: ?transparent-color-index ( loading-gif -- index/f )
+ dup transparency?
+ [ graphic-control-extensions>> first transparent-color-index>> ]
+ [ drop f ] if ;
+
+: gif>image ( loading-gif -- image )
+ [ <image> ] dip
+ [ dimensions >>dim ]
+ [ drop RGBA >>component-order ubyte-components >>component-type ]
+ [
+ [ decompress ] [ global-color-table>> ] [ ?transparent-color-index ] tri
+ apply-palette >>bitmap
+ ] tri ;
ERROR: loading-gif-error gif-image ;
dup loading?>> [ loading-gif-error ] when ;
M: gif-image stream>image ( path gif-image -- image )
- drop load-gif ensure-loaded loading-gif>image ;
+ drop load-gif ensure-loaded gif>image ;