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

        protected void DrawBoxCore(int x, int y, int x2, int y2, int color)
        {
            VirtScreen vs;

            if ((vs = FindVirtScreen(y)) == null)
                return;

            if (x > x2)
                ScummHelper.Swap(ref x, ref x2);

            if (y > y2)
                ScummHelper.Swap(ref y, ref y2);

            x2++;
            y2++;

            // Adjust for the topline of the VirtScreen
            y -= vs.TopLine;
            y2 -= vs.TopLine;

            // Clip the coordinates
            if (x < 0)
                x = 0;
            else if (x >= vs.Width)
                return;

            if (x2 < 0)
                return;
            if (x2 > vs.Width)
                x2 = vs.Width;

            if (y < 0)
                y = 0;
            else if (y > vs.Height)
                return;

            if (y2 < 0)
                return;

            if (y2 > vs.Height)
                y2 = vs.Height;

            int width = x2 - x;
            int height = y2 - y;

            // This will happen in the Sam & Max intro - see bug #1039162 - where
            // it would trigger an assertion in blit().

            if (width <= 0 || height <= 0)
                return;

            MarkRectAsDirty(vs, x, x2, y, y2);

            var backbuff = new PixelNavigator(vs.Surfaces[0]);
            backbuff.GoTo(vs.XStart + x, y);

            // A check for -1 might be wrong in all cases since o5_drawBox() in its current form
            // is definitely not capable of passing a parameter of -1 (color range is 0 - 255).
            // Just to make sure I don't break anything I restrict the code change to FM-Towns
            // version 5 games where this change is necessary to fix certain long standing bugs.
            if (color == -1 || (color >= 254 && Game.Platform == Platform.FMTowns && (Game.GameId == GameId.Monkey2 || Game.GameId == GameId.Indy4)))
            {
                if (_game.Platform == Platform.FMTowns)
                {
                    if (color == 254)
                        TownsSetupPalCycleField(x, y, x2, y2);
                }
                else
                {
                    if (vs != MainVirtScreen)
                        Debug.WriteLine("can only copy bg to main window");

                    var bgbuff = new PixelNavigator(vs.Surfaces[1]);
                    bgbuff.GoTo(vs.XStart + x, y);

                    Gdi.Blit(backbuff, bgbuff, width, height);
                    if (_charset.HasMask)
                    {
                        var mask = new PixelNavigator(_textSurface);
                        mask.GoToIgnoreBytesByPixel(x * _textSurfaceMultiplier, (y - ScreenTop) * _textSurfaceMultiplier);
                        Gdi.Fill(mask, CharsetMaskTransparency, width * _textSurfaceMultiplier, height * _textSurfaceMultiplier);
                    }
                }
            }
            else
            {
                if (_game.Features.HasFlag(GameFeatures.Is16BitColor))
                {
                    Gdi.Fill(backbuff, _16BitPalette[color], width, height);
                }
                else
                {
                    if (_game.Platform == Platform.FMTowns)
                    {
                        color = ((color & 0x0f) << 4) | (color & 0x0f);
                        var mask = new PixelNavigator(_textSurface);
                        mask.GoTo(x * _textSurfaceMultiplier, (y - ScreenTop + vs.TopLine) * _textSurfaceMultiplier);
                        Gdi.Fill(mask, (byte)color, width * _textSurfaceMultiplier, height * _textSurfaceMultiplier);

                        if (Game.GameId == GameId.Monkey2 || Game.GameId == GameId.Indy4 || ((Game.GameId == GameId.Indy3 || Game.GameId == GameId.Zak)
                            && vs != TextVirtScreen) || (_game.GameId == GameId.Loom && vs == MainVirtScreen))
                            return;
                    }

                    Gdi.Fill(backbuff, (byte)color, width, height);
                }
            }
        }