AGS.Editor.RoomSettingsEditor.ExtendCanvasSizeOf8BitBitmap C# (CSharp) Метод

        private Bitmap ExtendCanvasSizeOf8BitBitmap(Bitmap source, int newWidth, int newHeight)
        {
            if (source.PixelFormat != PixelFormat.Format8bppIndexed)
            {
                throw new AGSEditorException("This function only works with 8-bit images; use built-in .net routines for higher colour depths");
            }
            int bytesPerPixel = 1;
            Bitmap paddedBmp = new Bitmap(newWidth, newHeight, source.PixelFormat);
            Rectangle sourceRect = new Rectangle(0, 0, source.Width, source.Height);
            BitmapData sourceData = source.LockBits(sourceRect, ImageLockMode.ReadOnly, source.PixelFormat);
            Rectangle destRect = new Rectangle(0, 0, paddedBmp.Width, paddedBmp.Height);
            BitmapData bmpData = paddedBmp.LockBits(destRect, ImageLockMode.WriteOnly, paddedBmp.PixelFormat);
            int srcMemoryAddress = sourceData.Scan0.ToInt32();
            int memoryAddress = bmpData.Scan0.ToInt32();
            for (int y = 0; y < newHeight; y++)
            {
                byte[] line = new byte[bmpData.Stride];
                Array.Clear(line, 0, line.Length);
                if (y < source.Height)
                {
                    Marshal.Copy(new IntPtr(srcMemoryAddress), line, 0, source.Width * bytesPerPixel);
                }
                Marshal.Copy(line, 0, new IntPtr(memoryAddress), line.Length);

                srcMemoryAddress += sourceData.Stride;
                memoryAddress += bmpData.Stride;
            }
            paddedBmp.UnlockBits(bmpData);
            source.UnlockBits(sourceData);

            ColorPalette sourcePalette = source.Palette;
            ColorPalette destPalette = paddedBmp.Palette;
            for (int i = 0; i < sourcePalette.Entries.Length; i++)
            {
                destPalette.Entries[i] = sourcePalette.Entries[i];
            }
            // The palette needs to be re-set onto the bitmap to force it
            // to update its internal storage of the colours
            paddedBmp.Palette = destPalette;

            source.Dispose();
            return paddedBmp;
        }