factor/extra/tetris/board/board.factor

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1.7 KiB
Factor

! Copyright (C) 2006, 2007, 2008 Alex Chapman
! See http://factorcode.org/license.txt for BSD license.
USING: accessors arrays combinators.short-circuit fry kernel
math sequences tetris.piece ;
IN: tetris.board
TUPLE: board
{ width integer }
{ height integer }
{ rows array } ;
: make-rows ( width height -- rows )
swap '[ _ f <array> ] replicate ;
: <board> ( width height -- board )
2dup make-rows board boa ;
! A block is simply an array of form { x y } where { 0 0 } is
! the top-left of the tetris board, and { 9 19 } is the bottom
! right on a 10x20 board.
: board@block ( board block -- n row )
[ second swap rows>> nth ] keep first swap ;
: set-block ( board block colour -- ) -rot board@block set-nth ;
: block ( board block -- colour ) board@block nth ;
: block-free? ( board block -- ? ) block not ;
: block-in-bounds? ( board block -- ? )
[ first swap width>> <iota> bounds-check? ]
[ second swap height>> <iota> bounds-check? ] 2bi and ;
: location-valid? ( board block -- ? )
{ [ block-in-bounds? ] [ block-free? ] } 2&& ;
: piece-valid? ( board piece -- ? )
piece-blocks [ location-valid? ] with all? ;
: row-not-full? ( row -- ? ) f swap member? ;
: add-row ( board -- board )
dup rows>> over width>> f <array> prefix >>rows ;
: top-up-rows ( board -- )
dup height>> over rows>> length = [
drop
] [
add-row top-up-rows
] if ;
: remove-full-rows ( board -- board )
[ [ row-not-full? ] filter ] change-rows ;
: check-rows ( board -- n )
! remove full rows, then add blank ones at the top,
! returning the number of rows removed (and added)
remove-full-rows dup height>> over rows>> length - swap top-up-rows ;