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point.st
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1992-02-15
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"=====================================================================
|
| Point Class Definitions
|
====================================================================="
"======================================================================
|
| Copyright (C) 1990, 1991, 1992 Free Software Foundation, Inc.
| By Doug McCallum <uunet!ico.isc.com!dougm>
| Additions by sbb@eng.sun.com (Steve Byrne)
|
| This file is part of GNU Smalltalk.
|
| GNU Smalltalk is free software; you can redistribute it and/or modify it
| under the terms of the GNU General Public License as published by the Free
| Software Foundation; either version 1, or (at your option) any later version.
|
| GNU Smalltalk is distributed in the hope that it will be useful, but WITHOUT
| ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
| FOR A PARTICULAR PURPOSE. See the GNU General Public License for more
| details.
|
| You should have received a copy of the GNU General Public License along with
| GNU Smalltalk; see the file COPYING. If not, write to the Free Software
| Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
|
======================================================================"
"
| Change Log
| ============================================================================
| Author Date Change
| sbb 10 Jul 91 Added = for Points (= from Object isn't right)
|
| dougm 16 Apr 90 Created basic Point class.
|
"
Object subclass: #Point
instanceVariableNames: 'x y'
classVariableNames: ''
poolDictionaries: ''
category: nil
!
Point comment:
'Beginning of a Point class for simple display manipulation. Has not been
exhaustively tested but appears to work for the basic primitives and for
the needs of the Rectangle class.' !
!Number methodsFor: 'point creation'!
@ y
^ Point x: self y: y
!
asPoint
^Point x: self y: self
!!
!Point class methodsFor: 'instance creation'!
x: xInteger y: yInteger
^self new x: xInteger y: yInteger
!!
!Point methodsFor: 'printing'!
printOn: aStream
aStream print: x;
nextPut: $@;
print: y
!!
!Point methodsFor: 'storing'!
storeOn: aStream
aStream store: x;
nextPut: $@;
store: y
!!
!Point methodsFor: 'accessing'!
x
^x
!
y
^y
!
x: aNumber
x _ aNumber
!
y: aNumber
y _ aNumber
!
x: anXNumber y: aYNumber
x _ anXNumber.
y _ aYNumber
!!
!Point methodsFor: 'converting'!
asPoint
^self "But I already AM a point!"
!
hash
^(x abs + y abs) truncated
!!
!Point methodsFor: 'arithmetic'!
+ delta
delta _ delta asPoint.
^Point x: (x + delta x) y: (y + delta y)
!
- delta
delta _ delta asPoint.
^Point x: (x - delta x) y: (y - delta y)
!
* scale
scale _ scale asPoint.
^Point x: (x * scale x) y: (y * scale y)
!
/ scale
scale _ scale asPoint.
^Point x: (x / scale x) y: (y / scale y)
!
// scale
scale _ scale asPoint.
^Point x: (x // scale x) y: (y // scale y)
!
abs
^Point x: (x abs) y: (y abs)
!!
!Point methodsFor: 'truncation and round off'!
rounded
^Point x: (x rounded) y: (y rounded)
!
truncateTo: grid
^Point x: (x truncateTo: grid) y: (y truncateTo: grid)
!!
!Point methodsFor: 'comparing'!
= aPoint
^(x = aPoint x) and: [ y = aPoint y ]
!
< aPoint
^(x < aPoint x) and: [ (y < aPoint y) ]
!
> aPoint
^(x > aPoint x) and: [ (y > aPoint y) ]
!
<= aPoint
^(self > aPoint) not "unverified"
!
>= aPoint
^(self < aPoint) not "unverified"
!
max: aPoint
(self >aPoint )
ifTrue: [ ^self ]
ifFalse:[ ^aPoint ]
!
min: aPoint
(self < aPoint)
ifTrue: [^ self ]
ifFalse:[^ aPoint ]
!!
!Point methodsFor: 'point functions'!
dist: aPoint
| a b |
a _ x - (aPoint x).
b _ y - (aPoint y).
^((a squared) + (b squared)) sqrt
!
dotProduct: aPoint
^(x * aPoint x) + (y * aPoint y)
!
grid: aPoint
^Point x: (x roundTo: (aPoint x)) y: (y roundTo: (aPoint y))
!
normal
"rotate the Point 90degrees clockwise and get the unit vector"
|len|
len _ ((x squared) + (y squared)) sqrt.
^Point x: ((y asFloat negated)/len) y: (x/len)
!
transpose
^Point x: y y: x
!
truncatedGrid: aPoint
^Point x: (x truncateTo: (aPoint x)) y: (y truncateTo: (aPoint y))
!!