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Create bitmap from pixels

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25 Jan 2011CPOL 43.1K   10   2
Create a bitmap from an array of pixels
C++
static HBITMAP Create8bppBitmap(HDC hdc, int width, int height, LPVOID pBits = NULL)
{
    BITMAPINFO *bmi = (BITMAPINFO *)malloc(sizeof(BITMAPINFOHEADER) + sizeof(RGBQUAD) * 256);
    BITMAPINFOHEADER &bih(bmi->bmiHeader);
    bih.biSize = sizeof (BITMAPINFOHEADER);
    bih.biWidth         = width;
    bih.biHeight        = -height;
    bih.biPlanes        = 1;
    bih.biBitCount      = 8;
    bih.biCompression   = BI_RGB;
    bih.biSizeImage     = 0;
    bih.biXPelsPerMeter = 14173;
    bih.biYPelsPerMeter = 14173;
    bih.biClrUsed       = 0;
    bih.biClrImportant  = 0;
    for (int I = 0; I <= 255; I++)
    {
        bmi->bmiColors[I].rgbBlue = bmi->bmiColors[I].rgbGreen = bmi->bmiColors[I].rgbRed = (BYTE)I;
        bmi->bmiColors[I].rgbReserved = 0;
    }

    void *Pixels = NULL;
    HBITMAP hbmp = CreateDIBSection(hdc, bmi, DIB_RGB_COLORS, &Pixels, NULL, 0);

    if(pBits != NULL)
    {
        //fill the bitmap
        BYTE* pbBits = (BYTE*)pBits;
        BYTE *Pix = (BYTE *)Pixels;
        memcpy(Pix, pbBits, width * height);
    }

    free(bmi);

    return hbmp;
}

static HBITMAP CreateBitmapFromPixels( HDC hDC, UINT uWidth, UINT uHeight, UINT uBitsPerPixel, LPVOID pBits)
    {
           if(uBitsPerPixel < 8) // NOT IMPLEMENTED YET
              return NULL;

          if(uBitsPerPixel == 8)
              return Create8bppBitmap(hDC, uWidth, uHeight, pBits);

          HBITMAP hBitmap = 0;
          if ( !uWidth || !uHeight || !uBitsPerPixel )
             return hBitmap;
          LONG lBmpSize = uWidth * uHeight * (uBitsPerPixel/8) ;
          BITMAPINFO bmpInfo = { 0 };
          bmpInfo.bmiHeader.biBitCount = uBitsPerPixel;
          bmpInfo.bmiHeader.biHeight = uHeight;
          bmpInfo.bmiHeader.biWidth = uWidth;
          bmpInfo.bmiHeader.biPlanes = 1;
          bmpInfo.bmiHeader.biSize = sizeof(BITMAPINFOHEADER);
               // Pointer to access the pixels of bitmap
          UINT * pPixels = 0;
          hBitmap = CreateDIBSection( hDC, (BITMAPINFO *)&
                                      bmpInfo, DIB_RGB_COLORS, (void **)&
                                      pPixels , NULL, 0);

          if ( !hBitmap )
              return hBitmap; // return if invalid bitmaps

          //SetBitmapBits( hBitmap, lBmpSize, pBits);
          // Directly Write
          memcpy(pPixels, pBits, lBmpSize );

          return hBitmap;
    }

License

This article, along with any associated source code and files, is licensed under The Code Project Open License (CPOL)


Written By
Technical Lead Kotha Technologies
Bangladesh Bangladesh
If you are not in - you are out !
- Chapter 1

Comments and Discussions

 
GeneralMy vote of 5 Pin
mOOmOOn_1-Aug-13 22:40
mOOmOOn_1-Aug-13 22:40 
GeneralYes, I know these are all in the internet.. but, when u post... Pin
Mukit, Ataul25-Jan-11 0:25
Mukit, Ataul25-Jan-11 0:25 
Yes, I know these are all in the internet.. but, when u post a tip, it's readily available without going through much surfing..

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