userrect.cpp

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// $Id: userrect.cpp 1282 2006-06-09 09:46:49Z alex $
/* @@tag:xara-cn@@ DO NOT MODIFY THIS LINE
================================XARAHEADERSTART===========================
 
               Xara LX, a vector drawing and manipulation program.
                    Copyright (C) 1993-2006 Xara Group Ltd.
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              respective authors. See AUTHORS file for details.

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----------------------------------

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 */


#include "camtypes.h"
#include "userrect.h"
//#include "ensure.h" - in camtypes.h [AUTOMATICALLY REMOVED]

DECLARE_SOURCE("$Revision: 1282 $");

/*
  $Log: rect.ctt $
Revision 1.20  1995/07/07  11:35:00  Jason
Fixed ABS macro definitions to be safe

Revision 1.19  1994/06/28  16:57:47  Rik
Added some code that shows how the hell the IsAdjacent function works

Revision 1.18  1994/03/03  11:38:12  Tim
Added a MakeEmpty function.

Revision 1.17  1994/01/20  17:09:23  Simon
Default constructor now creates an empty recatngle

Revision 1.16  1994/01/12  17:30:17  Rik
Improved region merging and region joining

Revision 1.15  1993/11/05  14:56:03  Rik
Blobs work, fixed DocRect probs, selecting blobs work

Revision 1.14  1993/08/12  11:17:48  Will
Global CheckIn for new UserCoord system.

Revision 1.13  1993/07/29  11:10:02  Will
Fixed problem with fuzzy adjacent test.

Revision 1.12  1993/07/21  21:08:29  Will
Split rect function was splitting the wrong rect.

Revision 1.11  1993/07/19  17:02:42  Will
Added some comments.
Added Fuzzy limit passed during IsAdjacent().

Revision 1.10  1993/07/15  17:04:10  Will
Added SplitRect function for BG rendering.

Revision 1.9  1993/07/14  17:34:25  Will
Added IsAdjacent function for region merging.

Revision 1.8  1993/07/12  12:58:11  Tim
Added a ContainsRect function.

Revision 1.7  1993/06/18  11:06:28  Tim
Made rectangle classes usable by tools by using the CAMAPI macro in the
class declaration.

Revision 1.6  1993/06/15  16:49:28  Tim
Altered Intersection and Union to return objects rather than object refs.

Revision 1.5  1993/06/10  10:29:35  Tim
Improved links for ADC generated help file.

Revision 1.4  1993/06/09  16:40:02  Tim
Moved class comment from .cpp file to .h file to conform to style guide.

Revision 1.3  1993/06/09  13:52:40  Tim
Revised use and meaning of empty/invalid rectangles.
Expanded comment headers to explain this.

Revision 1.2  1993/06/08  14:12:06  Tim
Added comments about non-re-entrancy of Union and Intersection.

*/


/**********************************************************************************************

>    BOOL UserRect::IsAdjacent() const

     Author:    Will_Cowling (Xara Group Ltd) <camelotdev@xara.com>
     Created:   14/7/93
     Inputs:    The Fuzzy limit in MILLIPOINTS.  
     Outputs:   - 
     
     Returns:   TRUE if the rectangles are adjacent within a Fuzzy limit.
                
     Purpose:   To check for adjacent rectangles.

     Errors:    

**********************************************************************************************/  

BOOL UserRect::IsAdjacent(const UserRect& Rect, MILLIPOINT Fuzzy) const
{
    // Check for an an empty rectangle
    if (IsEmpty())
        return FALSE;

    // Detect an invalid rectangle
    ENSURE(IsValid(), "UserRect::IsAdjacent() was called on\nan invalid rectangle.");  

#if 0
    // This is the expansion of the rampant return statement below

    // Near top or bottom
    BOOL NearBot = (ABS(Rect.hi.y - lo.y)) <= Fuzzy;
    BOOL NearTop = (ABS(Rect.lo.y - hi.y)) <= Fuzzy;

    // Near left or right
    BOOL NearLeft  = (ABS(Rect.hi.x - lo.x)) <= Fuzzy;
    BOOL NearRight = (ABS(Rect.lo.x - hi.x)) <= Fuzzy;

    // Overlaps
    BOOL OverLeft  = (ABS(Rect.lo.x - lo.x)) <= Fuzzy;
    BOOL OverRight = (ABS(Rect.hi.x - hi.x)) <= Fuzzy;
    BOOL OverTop   = (ABS(Rect.hi.y - hi.y)) <= Fuzzy;
    BOOL OverBot   = (ABS(Rect.lo.y - lo.y)) <= Fuzzy;

    // Adjacent to the top or bottom?
    BOOL TopOrBot    = (NearTop || NearBot) && OverLeft && OverRight;
    BOOL LeftOrRight = (NearLeft || NearRight) && OverTop && OverBot;

    return (TopOrBot || LeftOrRight);
#endif

    // This is explained more carefully in the section above that is excluded from the build
    return (( ((ABS(Rect.lo.x - lo.x))<=Fuzzy) && ((ABS(Rect.hi.x - hi.x))<=Fuzzy) &&
             (((ABS(Rect.hi.y - lo.y))<=Fuzzy) || ((ABS(Rect.lo.y - hi.y))<=Fuzzy)) ) ||
            ( ((ABS(Rect.lo.y - lo.y))<=Fuzzy) && ((ABS(Rect.hi.y - hi.y))<=Fuzzy) &&
             (((ABS(Rect.hi.x - lo.x))<=Fuzzy) || ((ABS(Rect.lo.x - hi.x))<=Fuzzy)) ));
}



/*********************************************************************************************

>    UserRect UserRect::Union(const UserRect& R)

     Author:    Tim_Browse (Xara Group Ltd) <camelotdev@xara.com>
     Created:   17/5/93
     Inputs:    R - the rectangle to join with the object.
     Outputs:   - 
     
     Returns:   The simple union (bounding box).
                
     Purpose:   Compute union of two rectangles.
                
                If one of the rectangles involved is invalid, the other is returned as the
                result.  In the case of both being invalid, one of the invalid rectangles
                is returned as the result.  It is undefined which rectangle is returned in
                this case.

     Errors:    None.

**********************************************************************************************/  

UserRect UserRect::Union(const UserRect& R) const
{
    // Special cases for invalid rectangles...
    if (!IsValid()  ||  IsEmpty())
        return R;
    if (!R.IsValid()  ||  R.IsEmpty())
        return *this;
        
    // Return the result
    UserRect U;
    U.lo.x = min(lo.x, R.lo.x);
    U.lo.y = min(lo.y, R.lo.y);
    U.hi.x = max(hi.x, R.hi.x);
    U.hi.y = max(hi.y, R.hi.y);
    return U;
}



/*********************************************************************************************

>    UserRect UserRect::Intersection(const UserRect& R)

     Author:    Tim_Browse (Xara Group Ltd) <camelotdev@xara.com>
     Created:   17/5/93
     Inputs:    R - the rectangle to intersect with.
     Outputs:   - 
     
     Returns:   The intersection.
                
     Purpose:   Compute intersection of two rectangles.

                If one of the rectangles involved is invalid, the other is returned as the
                result.  In the case of both being invalid, one of the invalid rectangles
                is returned as the result.  It is undefined which rectangle is returned in
                this case.

     Errors:    None.

**********************************************************************************************/  

UserRect UserRect::Intersection(const UserRect& R) const
{
    // Special cases for invalid rectangles...
    if (!IsValid())
        return R;
    if (!R.IsValid())
        return *this;
    
    // Special cases when empty rectangles
    if (IsEmpty())
        return *this;
    if (R.IsEmpty())
        return R;

    // Return the result
    UserRect I;
    I.lo.x = max(lo.x, R.lo.x);
    I.lo.y = max(lo.y, R.lo.y);
    I.hi.x = min(hi.x, R.hi.x);
    I.hi.y = min(hi.y, R.hi.y);
    return I;
}



/*********************************************************************************************

>    INT32 UserRect::SplitRect(const UserRect& R, UserRect* SubRects)

     Author:    Will_Cowling (Xara Group Ltd) <camelotdev@xara.com>
     Created:   14/7/93
     Inputs:    R is the rectangle to intersect with, SubRects is an array of UserRect to fill.  
     Outputs:   Puts any sub-rects into SubRects. 
     
     Returns:   The number of subrectangles found. 0 for no intersection.
                
     Purpose:   Splits a rectangle into sub-rectangles which all exclude the interecting
                rectangle R.  The number of sub-rects generated depends on how the rectangles
                intersect.
                     _______________________         ___________________
                    |                       |       |                   |
                    | *this    A            |       | *this    A        |
                    |_ _ _  ________  _ _ _ |       |_ _ _ _ _  ________|__________
                    |      |        |       |       |          |        |          |
                    |  B   |   R    |   C   |       |    B     |        |          |
                    |_ _ _ |________| _ _ _ |       |__________|________| R        |
                    |                       |                  |                   |
                    |          D    Index=4 |                  |           Index=2 |
                    |_______________________|                  |___________________|
     Errors:    

**********************************************************************************************/  

INT32 UserRect::SplitRect(const UserRect& R, UserRect* SubRects)
{
    if (!this->IsIntersectedWith(R))
        return 0;   // No intersection  

    INT32 Index = 0;

    if (R.hi.y < hi.y)
        SubRects[Index++] = UserRect(lo.x, R.hi.y, hi.x, hi.y); // Sub-Rect A
        
    if (R.lo.y > lo.y)
        SubRects[Index++] = UserRect(lo.x, lo.y, hi.x, R.lo.y); // Sub-Rect D

    INT32 Ry0 = max(R.lo.y, lo.y);
    INT32 Ry1 = min(R.hi.y, hi.y);
    
    if (R.lo.x > lo.x)
        SubRects[Index++] = UserRect(lo.x, Ry0, R.lo.x, Ry1);           // Sub-Rect B       

    if (R.hi.x < hi.x)
        SubRects[Index++] = UserRect(R.hi.x, Ry0, hi.x, Ry1);           // Sub-Rect C       

    return Index;
}



/***********************************************************************************************

>   void UserRect::IncludePoint(const UserCoord& Point)

    Author:     Tim_Browse (Xara Group Ltd) <camelotdev@xara.com>
    Created:    27/5/93
    Inputs:     Point - coordinate to include into this rectangle.
    Outputs:    -
    Returns:    -
    Purpose:    Expand a rectangle so that it includes the given point.
    Errors:     An assertion failure if the rectangle is invalid.
    SeeAlso:    -

***********************************************************************************************/

void UserRect::IncludePoint(const UserCoord& Point)
{
    // Detect an invalid rectangle
    ENSURE(IsValid(), "UserRect::IncludePoint() was called on an \ninvalid rectangle.");  

    // Extend lower corner to include point if necessary
    lo.x = min(lo.x, Point.x);
    lo.y = min(lo.y, Point.y);
    
    // Extend upper corner to include point if necessary
    // (remember upper corner is exclusive)
    hi.x = max(hi.x, (INT32)(Point.x + 1L));
    hi.y = max(hi.y, (INT32)(Point.y + 1L));
}

// extra functions specific to the DocRect class

/*
$Log: userrect.def $
Revision 1.1  1995/09/12  17:11:49  Ed
Initial revision

*/

DECLARE_SOURCE("$Revision: 1282 $");

//#include "docrect.h" - in camtypes.h [AUTOMATICALLY REMOVED]

/********************************************************************************************
>   DocRect UserRect::ToSpread(Spread* pSpread)

    Author:     Ed_Cornes (Xara Group Ltd) <camelotdev@xara.com>
    Created:    6/9/95
    Inputs:     pSpread - 
    Returns:    SpreadRect
    Purpose:    Convert a UserRect to a SpreadRect (AKA DocRect)
********************************************************************************************/

DocRect UserRect::ToSpread(Spread* pSpread)
{
    return DocRect( this->lo.ToSpread(pSpread), this->hi.ToSpread(pSpread) );
}

---