"

 COPYRIGHT (c) 1989 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.

"

Object subclass:#Rectangle

       instanceVariableNames:'left top width height'

       classVariableNames:''

       poolDictionaries:''

       category:'Graphics-Primitives'

!

Rectangle comment:'

COPYRIGHT (c) 1989 by Claus Gittinger

              All Rights Reserved

'!

!Rectangle class methodsFor:'documentation'!

copyright

"

 COPYRIGHT (c) 1989 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/libbasic/Rectangle.st,v 1.9 1994-06-02 16:21:44 claus Exp $

"

!

documentation

"

    Rectangles represent a rectangular area in 2D space.

    notice, my implementation does not use origin/corner as instance objects

    but left/top/width/height to save space and allocations. This means, that my

    Rectangles cannot be used to represent Rectangles in a higher than 2D

    space. (i.e. only valid if origin/corner are 2D Points)

    (aside from that, you will not see any difference from the outside)

    Instance variables:

        left           <Number>        the left coordinate (i.e origin x)

        top            <Number>        the top coordinate (i.e origin y)

        width          <Number>        the width of the rectangle

        height         <Number>        the height of the rectangle

    I am not certain, if implementing Rectangle different was a good idea - 

    subclasses may expect things to be different ...

    Therefore, this may change.

"

! !

!Rectangle class methodsFor:'instance creation'!

origin:origin corner:corner

    "create and return a new Rectangle giving top-left and bottom-right points"

    ^ (self basicNew) origin:origin corner:corner

!

origin:origin extent:extent

    "create and return a new Rectangle giving top-left point and extent point"

%{  /* NOCONTEXT */

    REGISTER OBJ newRect;

    REGISTER struct point *p;

    extern OBJ Point;

    /* short cut - rectangles are created so often ... */

    if (_CanDoQuickNew(OHDR_SIZE + 4*sizeof(OBJ))) {

        if (self == Rectangle) {

            if (__isPoint(origin) && __isPoint(extent)) {

                _qCheckedAlignedNew(newRect, OHDR_SIZE + 4*sizeof(OBJ));

                _InstPtr(newRect)->o_class = Rectangle;

                p = _PointInstPtr(origin);

                _InstPtr(newRect)->i_instvars[0] = p->p_x;

                _InstPtr(newRect)->i_instvars[1] = p->p_y;

                __STORE(newRect, p->p_x);

                __STORE(newRect, p->p_y);

                p = _PointInstPtr(extent);

                _InstPtr(newRect)->i_instvars[2] = p->p_x;

                _InstPtr(newRect)->i_instvars[3] = p->p_y;

                __STORE(newRect, p->p_x);

                __STORE(newRect, p->p_y);

                RETURN ( newRect );

            }

        }

    }

%}

.

    ^ (self basicNew) origin:origin extent:extent

!

left:left top:top width:w height:h

    "create and return a new Rectangle giving left and top coordinates

     and width, height"

%{  /* NOCONTEXT */

    REGISTER OBJ newRect;

    if (_CanDoQuickNew(OHDR_SIZE + 4*sizeof(OBJ))) {

        /* short cut - rectangles are created so often ... */

        if (self == Rectangle) {

            _qCheckedAlignedNew(newRect, OHDR_SIZE + 4*sizeof(OBJ));

            _InstPtr(newRect)->o_class = Rectangle;

            _InstPtr(newRect)->i_instvars[0] = left;

            _InstPtr(newRect)->i_instvars[1] = top;

            _InstPtr(newRect)->i_instvars[2] = w;

            _InstPtr(newRect)->i_instvars[3] = h;

            __STORE(newRect, _InstPtr(newRect)->i_instvars[0]);

            __STORE(newRect, _InstPtr(newRect)->i_instvars[1]);

            __STORE(newRect, _InstPtr(newRect)->i_instvars[2]);

            __STORE(newRect, _InstPtr(newRect)->i_instvars[3]);

            RETURN ( newRect );

        }

    }

%}

.

    ^ (self basicNew) left:left top:top width:w height:h

!

left:left right:right top:top bottom:bottom

    "create and return a new Rectangle giving left, top, right and bottom coordinates"

    ^ (self basicNew) left:left right:right top:top bottom:bottom

!

left:left top:top right:right bottom:bottom

    "create and return a new Rectangle giving left, top, right and bottom coordinates"

    ^ (self basicNew) left:left top:top right:right bottom:bottom

!

fromUser

    "let user specify a rectangle on the screen, return it"

    ^ Display rectangleFromUser

    "Rectangle fromUser"

! !

!Rectangle methodsFor:'accessing'!

left:newLeft right:right top:newTop bottom:bottom

    "set the rectangle given left, top, right and bottom coordinates."

    left := newLeft.

    top := newTop.

    width := right - left.

    height := bottom - top

!

left:newLeft top:newTop right:right bottom:bottom

    "set the rectangle given left, top, right and bottom coordinates"

    left := newLeft.

    top := newTop.

    width := right - left.

    height := bottom - top

!

left:newLeft top:newTop width:newWidth height:newHeight

    "set the rectangle given left, top coordinates and width, height"

    left := newLeft.

    top := newTop.

    width := newWidth.

    height := newHeight

!

origin:aPoint

    "set the top-left origin. The corner remains unchanged."

    |newTop newLeft|

    newTop := aPoint y.

    newLeft := aPoint x.

    height := height + (top - newTop).

    width := width + (left - newLeft).

    left := newLeft.

    top := newTop

!

corner:aPoint

    "set the bottom-right corner"

    width := aPoint x - left.

    height := aPoint y - top

!

top:aNumber

    "set the top edge"

    height := height + (top - aNumber).

    top := aNumber

!

bottom:aNumber

    "set the bottom edge"

    height := aNumber - top

!

left:aNumber

    "set the left edge"

    width := width + (left - aNumber).

    left := aNumber

!

right:aNumber

    "set the right edge"

    width := aNumber - left

!

topLeft:aPoint

    "Set the top and left edges.

     The bottom right remains unchanged."

    |newTop|

    newTop := aPoint y.

    height := height + (top - newTop).

    top := newTop.

    width := aPoint x - left

!

topRight:aPoint

    "Set the top and right edges. 

     The bottom left remains unchanged."

    |newTop|

    newTop := aPoint y.

    height := height + (top - newTop).

    top := newTop.

    width := aPoint x - left

!

origin:origin corner:corner

    "set both origin and corner"

    left := origin x.

    top := origin y.

    width := corner x - left.

    height := corner y - top

!

extent:aPoint

    "set the extent from the argument, aPoint with width taken from aPoint x

     and height taken from aPoint y"

    width := aPoint x.

    height := aPoint y

!

origin:origin extent:extent

    "set both origin and extent"

    left := origin x.

    top := origin y.

    width := extent x.

    height := extent y

!

origin

    "return the origin"

    ^ left @ top

!

corner

    "return the corner"

    ^ (left + width) @ (top + height)

!

width

    "return the width of the rectangle"

    ^ width

!

height

    "return the height of the rectangle"

    ^ height

!

extent

    "return the extent"

    ^ width @ height

!

left

    "return the x-coordinate of the top-left origin"

    ^ left

!

leftCenter

    "return the left center point"

    ^ left @ (top + (height // 2))

!

top

    "return the y-coordinate of the top-left"

    ^ top

!

topLeft

    "return the top-left point - the same as origin"

    ^ left @ top

!

topRight

    "return the top-right point"

    ^ (left + width) @ top

!

topCenter

    "return the top center point"

    ^ (left + (width // 2)) @ top

!

bottom

    "return the y coordinate of the bottom"

    ^ (top + height)

!

bottomLeft

    "return the bottom-left point"

    ^ left @ (top + height)

!

bottomRight

    "return the bottom-right point"

    ^ (left + width) @ (top + height)

!

bottomCenter

    "return the bottom center point"

    ^ (left + (width // 2)) @ (top + height)

!

right

    "return the x coordinate of the right"

    ^ (left + width)

!

rightCenter

    "return the right center point"

    ^ (left + width) @ (top + (height // 2))

!

center

    "return the point in the center of the receiver"

    ^ (left + (width // 2)) @ (top + (height // 2))

!

area

    "return the area 

     - for screen Rectangles this is the number of pixels"

    ^ width * height

! !

!Rectangle methodsFor:'comparing'!

= aRectangle

    "return true, if the argument aRectangle represents the same

     rectangle as the receiver"

%{  /* NOCONTEXT */

    REGISTER struct instance *mySelf, *other;

    /*

     * handle the common case quickly

     */

    if (_isNonNilObject(aRectangle) 

     && _qClass(aRectangle) == Rectangle) {

        mySelf = _InstPtr(self);

        other = _InstPtr(aRectangle);

        if ((mySelf->i_instvars[0] == other->i_instvars[0])

         && (mySelf->i_instvars[1] == other->i_instvars[1])

         && (mySelf->i_instvars[2] == other->i_instvars[2])

         && (mySelf->i_instvars[3] == other->i_instvars[3])) {

            RETURN ( true );

        }

    }

%}

.

    (aRectangle isKindOf:Rectangle) ifFalse:[^ false].

    left = aRectangle left ifFalse:[^ false].

    top = aRectangle top ifFalse:[^ false].

    width = aRectangle width ifFalse:[^ false].

    height = aRectangle height ifFalse:[^ false].

    ^ true

!

hash

    "return an integer useful for hashing -

     redefined since = is redefined here"

    ^ ((left hash bitShift:16) bitXor:(top hash bitShift:16))

      + ((width hash) bitXor:(height hash))

! !

!Rectangle methodsFor:'queries'!

isRectangle

    "return true, if the receiver is some kind of rectangle"

    ^ true

! !

!Rectangle methodsFor:'testing'!

containsPoint:aPoint

    "return true, if the argument, aPoint is contained in the receiver"

    |px py|

    px := aPoint x.

    (px < left)           ifTrue:[^ false].

    (px > (left + width)) ifTrue:[^ false].

    py := aPoint y.

    (py < top)            ifTrue:[^ false].

    (py > (top + height)) ifTrue:[^ false].

    ^ true

!

intersects:aRectangle

    "return true, if the intersection between the argument, aRectangle

     and the receiver is not empty"

    |b r|

    (aRectangle right)  < left ifTrue:[^ false].

    (aRectangle bottom) < top  ifTrue:[^ false].

    r := left + width.

    (aRectangle left)   > r    ifTrue:[^ false].

    b := top + height.

    (aRectangle top)    > b    ifTrue:[^ false].

    ^ true

!

contains:aRectangle

    "return true, if the argument, aRectangle is equal to or

     is contained fully within the receiver"

    (left <= aRectangle left) ifTrue:[

      ((left + width) >= aRectangle right) ifTrue:[

        (top <= aRectangle top) ifTrue:[

          ((top + height) >= aRectangle bottom) ifTrue:[

            ^ true

          ]

        ]

      ]

    ].

    ^ false

!

isContainedIn:aRectangle

    "return true, if the receiver is fully contained within 

     the argument, aRectangle"

    (aRectangle left <= left) ifTrue:[

      (aRectangle right >= (left + width)) ifTrue:[

        (aRectangle top <= top) ifTrue:[

          (aRectangle bottom >= (top + height)) ifTrue:[

            ^ true