NScumm.Scumm.ScummEngine.GetNextBox C# (CSharp) Метод

        internal int GetNextBox(byte from, byte to)
        {
            byte i;
            int numOfBoxes = GetNumBoxes();
            int dest = -1;

            if (from == to)
                return to;

            if (to == InvalidBox)
                return -1;

            if (from == InvalidBox)
                return to;

            if (from >= numOfBoxes)
                throw new ArgumentOutOfRangeException("from");
            if (to >= numOfBoxes)
                throw new ArgumentOutOfRangeException("to");

            var boxm = _boxMatrix;

            if (Game.Version == 0)
            {
                // calculate shortest paths
                var itineraryMatrix = CalcItineraryMatrix(numOfBoxes);

                dest = to;
                do
                {
                    dest = itineraryMatrix[from, dest];
                } while (dest != InvalidBox && !AreBoxesNeighbors(from, (byte)dest));

                if (dest == InvalidBox)
                    dest = -1;

                return dest;
            }
            else if (Game.Version <= 2)
            {
                // The v2 box matrix is a real matrix with numOfBoxes rows and columns.
                // The first numOfBoxes bytes contain indices to the start of the corresponding
                // row (although that seems unnecessary to me - the value is easily computable.
                return (sbyte)boxm[numOfBoxes + boxm[from] + to];
            }

            // WORKAROUND #1: It seems that in some cases, the box matrix is corrupt
            // (more precisely, is too short) in the datafiles already. In
            // particular this seems to be the case in room 46 of Indy3 EGA (see
            // also bug #770690). This didn't cause problems in the original
            // engine, because there, the memory layout is different. After the
            // walkbox would follow the rest of the room file, thus the program
            // always behaved the same (and by chance, correct). Not so for us,
            // since random data may follow after the resource in ScummVM.
            //
            // As a workaround, we add a check for the end of the box matrix
            // resource, and abort the search once we reach the end.

            int boxmIndex = _boxMatrix[0] == 0xFF ? 1 : 0;
            // Skip up to the matrix data for box 'from'
            for (i = 0; i < from && boxmIndex < boxm.Count; i++)
            {
                while (boxmIndex < boxm.Count && boxm[boxmIndex] != 0xFF)
                    boxmIndex += 3;
                boxmIndex++;
            }

            // Now search for the entry for box 'to'
            while (boxmIndex < boxm.Count && boxm[boxmIndex] != 0xFF)
            {
                if (boxm[boxmIndex] <= to && to <= boxm[boxmIndex + 1])
                    dest = (sbyte)boxm[boxmIndex + 2];
                boxmIndex += 3;
            }

            //if (boxm >= boxm.Count)
            //    debug(0, "The box matrix apparently is truncated (room %d)", _roomResource);

            return dest;
        }