Copying and Pasting cs Code

In cs, like in almost any computer programming language, reading data from a file can be tricky. You add extra lines of code to tell the computer what to do. Sometimes you can copy and paste these lines from other peoples’ code.

For example, you can follow the pattern in this listing:

   public static bool Conv3x3(Bitmap b, ConvMatrix m)
   {
    // Avoid divide by zero errors
    if (0 == m.Factor) return false;

    Bitmap bSrc = (Bitmap)b.Clone();

    // GDI+ still lies to us - the return format is BGR, NOT RGB.
    BitmapData bmData = b.LockBits(new Rectangle(0, 0, b.Width, b.Height), ImageLockMode.ReadWrite, PixelFormat.Format24bppRgb);
    BitmapData bmSrc = bSrc.LockBits(new Rectangle(0, 0, bSrc.Width, bSrc.Height), ImageLockMode.ReadWrite, PixelFormat.Format24bppRgb);

    int stride = bmData.Stride;
    int stride2 = stride * 2;
    System.IntPtr Scan0 = bmData.Scan0;
    System.IntPtr SrcScan0 = bmSrc.Scan0;

    unsafe
    {
     byte * p = (byte *)(void *)Scan0;
     byte * pSrc = (byte *)(void *)SrcScan0;

     int nOffset = stride + 6 - b.Width*3;
     int nWidth = b.Width - 2;
     int nHeight = b.Height - 2;

     int nPixel;

     for(int y=0;y < nHeight;++y)
     {
      for(int x=0; x < nWidth; ++x )
      {
       nPixel = ( ( ( (pSrc[2] * m.TopLeft) + (pSrc[5] * m.TopMid) + (pSrc[8] * m.TopRight) +
        (pSrc[2 + stride] * m.MidLeft) + (pSrc[5 + stride] * m.Pixel) + (pSrc[8 + stride] * m.MidRight) +
        (pSrc[2 + stride2] * m.BottomLeft) + (pSrc[5 + stride2] * m.BottomMid) + (pSrc[8 + stride2] * m.BottomRight)) / m.Factor) + m.Offset);

       if (nPixel < 0) nPixel = 0;
       if (nPixel > 255) nPixel = 255;

       p[5 + stride]= (byte)nPixel;

       nPixel = ( ( ( (pSrc[1] * m.TopLeft) + (pSrc[4] * m.TopMid) + (pSrc[7] * m.TopRight) +
        (pSrc[1 + stride] * m.MidLeft) + (pSrc[4 + stride] * m.Pixel) + (pSrc[7 + stride] * m.MidRight) +
        (pSrc[1 + stride2] * m.BottomLeft) + (pSrc[4 + stride2] * m.BottomMid) + (pSrc[7 + stride2] * m.BottomRight)) / m.Factor) + m.Offset);

       if (nPixel < 0) nPixel = 0;
       if (nPixel > 255) nPixel = 255;

       p[4 + stride] = (byte)nPixel;

       nPixel = ( ( ( (pSrc[0] * m.TopLeft) + (pSrc[3] * m.TopMid) + (pSrc[6] * m.TopRight) +
        (pSrc[0 + stride] * m.MidLeft) + (pSrc[3 + stride] * m.Pixel) + (pSrc[6 + stride] * m.MidRight) +
        (pSrc[0 + stride2] * m.BottomLeft) + (pSrc[3 + stride2] * m.BottomMid) + (pSrc[6 + stride2] * m.BottomRight)) / m.Factor) + m.Offset);

       if (nPixel < 0) nPixel = 0;
       if (nPixel > 255) nPixel = 255;

       p[3 + stride] = (byte)nPixel;

       p += 3;
       pSrc += 3;
      }

      p += nOffset;
      pSrc += nOffset;
     }
    }

    b.UnlockBits(bmData);
    bSrc.UnlockBits(bmSrc);

    return true;
   }