MARKUS

using System;

using System.Collections.Generic;

using System.Linq;

using System.Text;

using System.Collections.ObjectModel;

using System.Windows;

namespace ImageFields

{

    internal class RectCollection

    {

        // Fields

        private bool dirty;

        private Collection<Int32Rect> rects = new Collection<Int32Rect>();

        // Methods

        public void Add(ref Int32Rect toAdd)

        {

            Merge(this.rects, toAdd);

            this.dirty = true;

        }

        private static void Merge(Collection<Int32Rect> rects, Int32Rect rectToAdd)

        {

            foreach (Int32Rect rect in rects)

            {

                Int32Rect b = rect;

                UnionRects(ref rectToAdd, ref b);

                if (rect != b)

                {

                    rects.Remove(rect);

                    if (b.Width != 0)

                    {

                        rects.Add(b);

                    }

                    break;

                }

                if (rectToAdd.Width == 0)

                {

                    break;

                }

            }

            if (rectToAdd.Width != 0)

            {

                rects.Add(rectToAdd);

            }

        }

        private static Collection<Int32Rect> MergeCollections(Collection<Int32Rect> oldRects)

        {

            Collection<Int32Rect> collection;

            Collection<Int32Rect> rects = oldRects;

            do

            {

                collection = rects;

                rects = new Collection<Int32Rect>();

                foreach (Int32Rect rect in collection)

                {

                    Merge(rects, rect);

                }

            }

            while (rects.Count != collection.Count);

            return collection;

        }

        private static Int32Rect MergeRects(ref Int32Rect a, Int32Rect b)

        {

            if ((((a.X >= b.X) && (a.Y >= b.Y)) && ((a.X + a.Width) <= (b.X + b.Width))) && ((a.Y + a.Height) <= (b.Y + b.Height)))

            {

                return b;

            }

            if ((((a.X <= b.X) && (a.Y <= b.Y)) && ((a.X + a.Width) >= (b.X + b.Width))) && ((a.Y + a.Height) >= (b.Y + b.Height)))

            {

                return a;

            }

            if ((((a.X == b.X) && (a.Width == b.Width)) && ((a.Y + a.Height) >= b.Y)) && (a.Y <= b.Y))

            {

                return new Int32Rect(a.X, a.Y, a.Width, (b.Y + b.Height) - a.Y);

            }

            if ((((a.X == b.X) && (a.Width == b.Width)) && ((b.Y + b.Height) >= a.Y)) && (b.Y <= a.Y))

            {

                return new Int32Rect(a.X, b.Y, a.Width, (a.Y + a.Height) - b.Y);

            }

            if ((((a.Y == b.Y) && (a.Height == b.Height)) && ((a.X + a.Width) >= b.X)) && (a.X <= b.X))

            {

                return new Int32Rect(a.X, a.Y, (b.X + b.Width) - a.X, a.Height);

            }

            if ((((a.Y == b.Y) && (a.Height == b.Height)) && ((b.X + b.Width) >= a.X)) && (b.X <= a.X))

            {

                return new Int32Rect(b.X, a.Y, (a.X + a.Width) - b.X, a.Height);

            }

            return Int32Rect.Empty;

        }

        private static void UnionRects(ref Int32Rect a, ref Int32Rect b)

        {

            if (((((b.X + b.Width) >= a.X) && (b.X <= (a.X + a.Width))) && ((b.Y + b.Height) >= a.Y)) && (b.Y <= (a.Y + a.Height)))

            {

                if ((((a.X >= b.X) && (a.Y >= b.Y)) && ((a.X + a.Width) <= (b.X + b.Width))) && ((a.Y + a.Height) <= (b.Y + b.Height)))

                {

                    a.Width = 0;

                }

                else if ((((a.X <= b.X) && (a.Y <= b.Y)) && ((a.X + a.Width) >= (b.X + b.Width))) && ((a.Y + a.Height) >= (b.Y + b.Height)))

                {

                    b.Width = 0;

                }

                else if ((((a.X == b.X) && (a.Width == b.Width)) && ((a.Y + a.Height) >= b.Y)) && (a.Y <= b.Y))

                {

                    a.Height = (b.Y + b.Height) - a.Y;

                    b.Width = 0;

                }

                else if ((((a.X == b.X) && (a.Width == b.Width)) && ((b.Y + b.Height) >= a.Y)) && (b.Y <= a.Y))

                {

                    b.Height = (a.Y + a.Height) - b.Y;

                    a.Width = 0;

                }

                else if ((((a.Y == b.Y) && (a.Height == b.Height)) && ((a.X + a.Width) >= b.X)) && (a.X <= b.X))

                {

                    a.Width = (b.X + b.Width) - a.X;

                    b.Width = 0;

                }

                else if ((((a.Y == b.Y) && (a.Height == b.Height)) && ((b.X + b.Width) >= a.X)) && (b.X <= a.X))

                {

                    b.Width = (a.X + a.Width) - b.X;

                    a.Width = 0;

                }

                else if ((((a.X <= b.X) && (a.Y <= b.Y)) && (((a.X + a.Width) >= b.X) && ((a.Y + a.Height) >= (b.Y + b.Height)))) && ((a.X + a.Width) <= (b.X + b.Width)))

                {

                    b.Width = ((b.X + b.Width) - a.X) - a.Width;

                    b.X = a.X + a.Width;

                }

                else if ((((b.X <= a.X) && (b.Y <= a.Y)) && (((b.X + b.Width) >= a.X) && ((b.Y + b.Height) >= (a.Y + a.Height)))) && ((b.X + b.Width) <= (a.X + a.Width)))

                {

                    a.Width = ((a.X + a.Width) - b.X) - b.Width;

                    a.X = b.X + b.Width;

                }

                else if ((((a.Y <= b.Y) && (a.X <= b.X)) && (((a.Y + a.Height) >= b.Y) && ((a.X + a.Width) >= (b.X + b.Width)))) && ((a.Y + a.Height) <= (b.Y + b.Height)))

                {

                    b.Height = ((b.Y + b.Height) - a.Y) - a.Height;

                    b.Y = a.Y + a.Height;

                }

                else if ((((b.Y <= a.Y) && (b.X <= a.X)) && (((b.Y + b.Height) >= a.Y) && ((b.X + b.Width) >= (a.X + a.Width)))) && ((b.Y + b.Height) <= (a.Y + a.Height)))

                {

                    a.Height = ((a.Y + a.Height) - b.Y) - b.Height;

                    a.Y = b.Y + b.Height;

                }

                else if ((((a.X <= b.X) && (a.Y >= b.Y)) && (((a.X + a.Width) >= b.X) && ((a.Y + a.Height) <= (b.Y + b.Height)))) && ((a.X + a.Width) <= (b.X + b.Width)))

                {

                    a.Width = b.X - a.X;

                }

                else if ((((b.X <= a.X) && (b.Y >= a.Y)) && (((b.X + b.Width) >= a.X) && ((b.Y + b.Height) <= (a.Y + a.Height)))) && ((b.X + b.Width) <= (a.X + a.Width)))

                {

                    b.Width = a.X - b.X;

                }

                else if ((((a.Y <= b.Y) && (a.X >= b.X)) && (((a.Y + a.Height) >= b.Y) && ((a.X + a.Width) <= (b.X + b.Width)))) && ((a.Y + a.Height) <= (b.Y + b.Height)))

                {

                    a.Height = b.Y - a.Y;

                }

                else if ((((b.Y <= a.Y) && (b.X >= a.X)) && (((b.Y + b.Height) >= a.Y) && ((b.X + b.Width) <= (a.X + a.Width)))) && ((b.Y + b.Height) <= (a.Y + a.Height)))

                {

                    b.Height = a.Y - b.Y;

                }

            }

        }

        // Properties

        public Collection<Int32Rect> Rects

        {

            get

            {

                if (this.dirty)

                {

                    this.rects = MergeCollections(this.rects);

                    this.dirty = false;

                }

                return this.rects;

            }

        }

    }

}