factor/extra/quadtrees/quadtrees.factor

200 lines
5.8 KiB
Factor

! (c) 2009 Joe Groff, see BSD license
USING: assocs kernel math.rectangles combinators accessors locals
math.vectors vectors sequences math combinators.short-circuit arrays fry ;
IN: quadtrees
TUPLE: quadtree { bounds rect } point value ll lr ul ur leaf? ;
: <quadtree> ( bounds -- quadtree )
quadtree new
swap >>bounds
t >>leaf? ;
: rect-ll ( rect -- point ) loc>> ;
: rect-lr ( rect -- point ) [ loc>> ] [ dim>> { 1 0 } v* ] bi v+ ;
: rect-ul ( rect -- point ) [ loc>> ] [ dim>> { 0 1 } v* ] bi v+ ;
: rect-ur ( rect -- point ) [ loc>> ] [ dim>> ] bi v+ ;
: rect-center ( rect -- point ) [ loc>> ] [ dim>> 0.5 v*n ] bi v+ ; inline
: (quadrant) ( pt node -- quadrant )
swap [ first 0.0 < ] [ second 0.0 < ] bi
[ [ ll>> ] [ lr>> ] if ]
[ [ ul>> ] [ ur>> ] if ] if ;
: quadrant ( pt node -- quadrant )
[ bounds>> rect-center v- ] keep (quadrant) ;
: descend ( pt node -- pt subnode )
[ drop ] [ quadrant ] 2bi ; inline
: each-quadrant ( node quot -- )
{
[ [ ll>> ] [ call ] bi* ]
[ [ lr>> ] [ call ] bi* ]
[ [ ul>> ] [ call ] bi* ]
[ [ ur>> ] [ call ] bi* ]
} 2cleave ; inline
: map-quadrant ( node quot: ( child-node -- x ) -- array )
each-quadrant 4array ; inline
<PRIVATE
DEFER: (prune)
DEFER: insert
DEFER: erase
DEFER: at-point
DEFER: quadtree>alist
DEFER: quadtree-size
DEFER: node-insert
DEFER: in-rect*
: child-dim ( rect -- dim/2 ) dim>> 0.5 v*n ; inline
: ll-bounds ( rect -- rect' )
[ loc>> ] [ child-dim ] bi <rect> ;
: lr-bounds ( rect -- rect' )
[ [ loc>> ] [ dim>> { 0.5 0.0 } v* ] bi v+ ] [ child-dim ] bi <rect> ;
: ul-bounds ( rect -- rect' )
[ [ loc>> ] [ dim>> { 0.0 0.5 } v* ] bi v+ ] [ child-dim ] bi <rect> ;
: ur-bounds ( rect -- rect' )
[ [ loc>> ] [ dim>> { 0.5 0.5 } v* ] bi v+ ] [ child-dim ] bi <rect> ;
: {quadrants} ( node -- quadrants )
{ [ ll>> ] [ lr>> ] [ ul>> ] [ ur>> ] } cleave 4array ;
: add-subnodes ( node -- node )
dup bounds>> {
[ ll-bounds <quadtree> >>ll ]
[ lr-bounds <quadtree> >>lr ]
[ ul-bounds <quadtree> >>ul ]
[ ur-bounds <quadtree> >>ur ]
} cleave
f >>leaf? ;
: split-leaf ( value point leaf -- )
add-subnodes
[ value>> ] [ point>> ] [ ] tri
[ node-insert ] [ node-insert ] bi ;
: leaf-replaceable? ( pt leaf -- ? ) point>> { [ nip not ] [ = ] } 2|| ;
: leaf-insert ( value point leaf -- )
2dup leaf-replaceable?
[ [ (>>point) ] [ (>>value) ] bi ]
[ split-leaf ] if ;
: node-insert ( value point node -- )
descend insert ;
: insert ( value point tree -- )
dup leaf?>> [ leaf-insert ] [ node-insert ] if ;
:: leaf-at-point ( point leaf -- value/f ? )
point leaf point>> =
[ leaf value>> t ] [ f f ] if ;
: node-at-point ( point node -- value/f ? )
descend at-point ;
: at-point ( point tree -- value/f ? )
dup leaf?>> [ leaf-at-point ] [ node-at-point ] if ;
: (node-in-rect*) ( values rect node -- values )
2dup bounds>> contains-rect? [ in-rect* ] [ 2drop ] if ;
: node-in-rect* ( values rect node -- values )
[ (node-in-rect*) ] with each-quadrant ;
:: leaf-in-rect* ( values rect leaf -- values )
{ [ leaf point>> ] [ leaf point>> rect contains-point? ] } 0&&
[ values leaf value>> suffix! ] [ values ] if ;
: in-rect* ( values rect tree -- values )
dup leaf?>> [ leaf-in-rect* ] [ node-in-rect* ] if ;
:: leaf-erase ( point leaf -- )
point leaf point>> = [ leaf f >>point f >>value drop ] when ;
: node-erase ( point node -- )
descend erase ;
: erase ( point tree -- )
dup leaf?>> [ leaf-erase ] [ node-erase ] if ;
: (?leaf) ( quadrant -- {point,value}/f )
dup point>> [ swap value>> 2array ] [ drop f ] if* ;
: ?leaf ( quadrants -- {point,value}/f )
[ (?leaf) ] map sift dup length {
{ 1 [ first ] }
{ 0 [ drop { f f } ] }
[ 2drop f ]
} case ;
: collapseable? ( node -- {point,value}/f )
{quadrants} { [ [ leaf?>> ] all? ] [ ?leaf ] } 1&& ;
: remove-subnodes ( node -- leaf ) f >>ll f >>lr f >>ul f >>ur t >>leaf? ;
: collapse ( node {point,value} -- )
first2 [ >>point ] [ >>value ] bi* remove-subnodes drop ;
: node-prune ( node -- )
[ [ (prune) ] each-quadrant ] [ ] [ collapseable? ] tri
[ collapse ] [ drop ] if* ;
: (prune) ( tree -- )
dup leaf?>> [ drop ] [ node-prune ] if ;
: leaf>alist ( leaf -- alist )
dup point>> [ [ point>> ] [ value>> ] bi 2array 1array ] [ drop { } ] if ;
: node>alist ( node -- alist ) [ quadtree>alist ] map-quadrant concat ;
: quadtree>alist ( tree -- assoc )
dup leaf?>> [ leaf>alist ] [ node>alist ] if ;
: leaf-size ( leaf -- count )
point>> [ 1 ] [ 0 ] if ;
: node-size ( node -- count )
0 swap [ quadtree-size + ] each-quadrant ;
: quadtree-size ( tree -- count )
dup leaf?>> [ leaf-size ] [ node-size ] if ;
: leaf= ( a b -- ? ) [ [ point>> ] [ value>> ] bi 2array ] bi@ = ;
: node= ( a b -- ? ) [ {quadrants} ] bi@ = ;
: (tree=) ( a b -- ? ) dup leaf?>> [ leaf= ] [ node= ] if ;
: tree= ( a b -- ? )
2dup [ leaf?>> ] bi@ = [ (tree=) ] [ 2drop f ] if ;
PRIVATE>
: prune-quadtree ( tree -- tree ) [ (prune) ] keep ;
: in-rect ( tree rect -- values )
[ 16 <vector> ] 2dip in-rect* ;
M: quadtree equal? ( a b -- ? )
over quadtree? [ tree= ] [ 2drop f ] if ;
INSTANCE: quadtree assoc
M: quadtree at* ( key assoc -- value/f ? ) at-point ;
M: quadtree assoc-size ( assoc -- n ) quadtree-size ;
M: quadtree >alist ( assoc -- alist ) quadtree>alist ;
M: quadtree set-at ( value key assoc -- ) insert ;
M: quadtree delete-at ( key assoc -- ) erase ;
M: quadtree clear-assoc ( assoc -- )
t >>leaf?
f >>point
f >>value
drop ;
: swizzle ( sequence quot -- sequence' )
[ dup ] dip map
[ zip ] [ rect-containing <quadtree> ] bi
[ '[ first2 _ set-at ] each ] [ values ] bi ; inline