rect_placement.h

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// --------------------------------------------------------------------------------
// Name        : rect_placement.h
// Description : A class that allocates subrectangles into power-of-2 rectangles
// (C) Copyright 2000-2002 by Javier Arevalo
// This code is free to use and modify for all purposes
// --------------------------------------------------------------------------------

#ifndef _RECT_PLACEMENT_H_
#define _RECT_PLACEMENT_H_

#include <vector>

// --------------------------------------------------------------------------------
// --------------------------------------------------------------------------------

class CRectPlacement
{
public:

    // Helper classes
    struct TPos
    {
        int x, y;

        TPos() : x( 0 ), y( 0 ) { }
        TPos( int _x, int _y ) : x( _x ), y( _y ) { }

        bool operator ==( const TPos& p ) const { return x == p.x && y == p.y; }
    };

    struct TRect : public TPos
    {
        int w, h;

        TRect() : w( 0 ), h( 0 ) { }
        TRect( int _x, int _y, int _w, int _h ) : TPos( _x, _y ), w( _w > 0 ? _w : 0 ), h(
                _h > 0 ? _h : 0 ) { }

        bool Contains( const TPos& p )  const
        {
            return p.x >= x && p.y >= y && p.x < (x + w) && p.y < (y + h);
        }
        bool Contains( const TRect& r ) const
        {
            return r.x >= x && r.y >= y &&
                   (r.x + r.w) <= (x + w) && (r.y + r.h) <= (y + h);
        }
        bool Intersects( const TRect& r ) const
        {
            return w > 0 && h > 0 && r.w > 0 && r.h > 0
                   && ( (r.x + r.w) > x && r.x < (x + w) && (r.y + r.h) > y && r.y < (y + h) );
        }

        // static bool Greater(const TRect &a, const TRect &b)
        //  { return a.w*a.h > b.w*b.h; }
        // Greater rect area. Not as good as the next heuristic:
        // Greater size in at least one dim.
        static bool Greater( const TRect&   a, const TRect&   b )
        {
            return (a.w > b.w && a.w > b.h) || (a.h > b.w && a.h > b.h);
        }
    };

    // ---------------------

    typedef std::vector<TPos>   CPosArray;
    typedef std::vector<TRect>  CRectArray;

    // ---------------------

    CRectPlacement()                    { Init(); }
    ~CRectPlacement()                   { End(); }

    void    Init( int w = 1, int h = 1 );
    void    End();

    bool      IsOk() const { return m_size.w > 0; }

    int       GetW() const { return m_size.w; }
    int       GetH() const { return m_size.h; }
    double    GetArea() const { return m_area; }
    double    GetTotalArea() const { return (double)m_size.w * m_size.h; }

    bool AddAtEmptySpotAutoGrow( TRect* pRect, int maxW, int maxH );

private:
    TRect       m_size;
    CRectArray  m_vRects;
    CPosArray   m_vPositions;
    double      m_area;

    // ---------------------

    bool    IsFree( const TRect& r ) const;
    void    AddPosition( const TPos& p );
    void    AddRect( const TRect& r );
    bool    AddAtEmptySpot( TRect& r );
};

#endif    // _RECT_PLACEMENT_H_