factor/extra/rosetta-code/bitmap/bitmap.factor

! Copyright (c) 2012 Anonymous
! See http://factorcode.org/license.txt for BSD license.
USING: arrays fry kernel math.matrices sequences ;
IN: rosetta-code.bitmap

! http://rosettacode.org/wiki/Basic_bitmap_storage

! Show a basic storage type to handle a simple RGB raster
! graphics image, and some primitive associated functions.

! If possible provide a function to allocate an uninitialised
! image, given its width and height, and provide 3 additional
! functions:

! * one to fill an image with a plain RGB color,
! * one to set a given pixel with a color,
! * one to get the color of a pixel.

! (If there are specificities about the storage or the
! allocation, explain those.)

! Various utilities
: meach ( matrix quot -- ) [ each ] curry each ; inline
: meach-index ( matrix quot -- )
    [ swap 2array ] prepose
    [ curry each-index ] curry each-index ; inline
: mmap ( matrix quot -- matrix' ) [ map ] curry map ; inline
: mmap! ( matrix quot -- matrix' ) [ map! ] curry map! ; inline
: mmap-index ( matrix quot -- matrix' )
    [ swap 2array ] prepose
    [ curry map-index ] curry map-index ; inline

: matrix-dim ( matrix -- i j ) [ length ] [ first length ] bi ;
: set-Mi,j ( elt {i,j} matrix -- ) [ first2 swap ] dip nth set-nth ;
: Mi,j ( {i,j} matrix -- elt ) [ first2 swap ] dip nth nth ;

! The storage functions
: <raster-image> ( width height -- image )
    zero-matrix [ drop { 0 0 0 } ] mmap ;
: fill-image ( {R,G,B} image -- image )
    swap '[ drop _ ] mmap! ;
: set-pixel ( {R,G,B} {i,j} image -- ) set-Mi,j ; inline
: get-pixel ( {i,j} image -- pixel ) Mi,j ; inline