"
 COPYRIGHT (c) 1988 by Claus Gittinger
              All Rights Reserved

 This software is furnished under a license and may be used
 only in accordance with the terms of that license and with the
 inclusion of the above copyright notice.   This software may not
 be provided or otherwise made available to, or used by, any
 other person.  No title to or ownership of the software is
 hereby transferred.
"

Array subclass:#Polygon
       instanceVariableNames:''
       classVariableNames:''
       poolDictionaries:''
       category:'Graphics-Primitives'
!

Polygon comment:'
COPYRIGHT (c) 1988 by Claus Gittinger
              All Rights Reserved

$Header: /cvs/stx/stx/libbasic2/Polygon.st,v 1.7 1994-08-05 01:07:06 claus Exp $
'!

!Polygon class methodsFor: 'documentation'!

copyright
"
 COPYRIGHT (c) 1988 by Claus Gittinger
              All Rights Reserved

 This software is furnished under a license and may be used
 only in accordance with the terms of that license and with the
 inclusion of the above copyright notice.   This software may not
 be provided or otherwise made available to, or used by, any
 other person.  No title to or ownership of the software is
 hereby transferred.
"
!

version
"
$Header: /cvs/stx/stx/libbasic2/Polygon.st,v 1.7 1994-08-05 01:07:06 claus Exp $
"
!

documentation
"
    Polygon - an array of points
    Adds simple boundary checking methods to Array.
    (needs much more - such as inside check, area computation etc.)
"
! !

!Polygon methodsFor: 'accessing'!

top
    "return the top boundary of the polygon,
     that is the minimum y coordinate of all its points"

    |minY|

    (self size == 0) ifTrue: [^ nil].
    minY := (self at:1) y.
    self do:[:p |
        (p y < minY) ifTrue:[minY := p y].
        0 "stc hint"
    ].
    ^ minY
!

bottom
    "return the bottom boundary of the polygon,
     that is the maximum y coordinate of all its points"

    |maxY|

    (self size == 0) ifTrue: [^ nil].
    maxY := (self at:1) y.
    self do:[:p |
        (p y > maxY) ifTrue:[maxY := p y].
        0 "stc hint"
    ].
    ^ maxY
!

left
    "return the left boundary of the polygon,
     that is the minimum x coordinate of all its points"

    |minX|

    (self size == 0) ifTrue: [^ nil].
    minX := (self at:1) x.
    self do:[:p |
        (p x < minX) ifTrue:[minX := p x].
        0 "stc hint"
    ].
    ^ minX
!

right
    "return the right boundary of the polygon,
     that is the maximum y coordinate of all its points"

    |maxX|

    (self size == 0) ifTrue: [^ nil].
    maxX := (self at:1) x.
    self do:[:p |
        (p x > maxX) ifTrue:[maxX := p x].
        0 "stc hint"
    ].
    ^ maxX
! !