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

        internal void MarkRectAsDirty(VirtScreen vs, int left, int right, int top, int bottom, int dirtybit = 0)
        {
            int lp, rp;

            if (left > right || top > bottom)
                return;
            if (top > vs.Height || bottom < 0)
                return;

            if (top < 0)
                top = 0;
            if (bottom > vs.Height)
                bottom = vs.Height;

            if (vs == MainVirtScreen && dirtybit != 0)
            {
                lp = left / 8 + _screenStartStrip;
                if (lp < 0)
                    lp = 0;

                rp = (right + vs.XStart) / 8;
                if (_game.Version >= 7)
                {
                    if (rp > 409)
                        rp = 409;
                }
                else
                {
                    if (rp >= 200)
                        rp = 200;
                }
                for (; lp <= rp; lp++)
                    Gdi.SetGfxUsageBit(lp, dirtybit);
            }

            // The following code used to be in the separate method setVirtscreenDirty
            lp = left / 8;
            rp = right / 8;

            if ((lp >= Gdi.NumStrips) || (rp < 0))
                return;
            if (lp < 0)
                lp = 0;
            if (rp >= Gdi.NumStrips)
                rp = Gdi.NumStrips - 1;

            while (lp <= rp)
            {
                if (top < vs.TDirty[lp])
                    vs.TDirty[lp] = top;
                if (bottom > vs.BDirty[lp])
                    vs.BDirty[lp] = bottom;
                lp++;
            }
        }