[fpc-pascal] How to emulate SetDIBits and GetDIBits in Linux

[fpclist at silvermono.co.za]

Hi guys

In MS Windows I use the following API functions: 

1/
SetDIBits(bmap.Canvas.Handle, bmap.Handle, 0, bmap.Height, data,
            PBitmapInfo(bitmapInfop)^, DIB_RGB_COLORS);    

To set the pixels in a bitmap (bmap) using the colour data found in the 
specified device-independent bitmap (data)

and 

2/
GetDIBits(bmap.Canvas.Handle, bmap.Handle, 0, bmap.Height, data,
            PBitmapInfo(bitmapInfop)^, DIB_RGB_COLORS);  

To retrieve the bits of the specified compatible bitmap (bmap) and write same 
into a buffer (data)

//--------------------------------------------------------
where
  DIB_RGB_COLORS = 0  // colour table in RGBs

and

  PRGBQuad = ^TRGBQuad;
  tagRGBQUAD = packed record
    rgbBlue     : Byte;
    rgbGreen    : Byte;
    rgbRed      : Byte;
    rgbReserved : Byte;
  end;
  TRGBQuad = tagRGBQUAD;     

  PBitmapInfo = ^TBitmapInfo;
  tagBITMAPINFO = packed record
    bmiHeader : TBitMapInfoHeader;
    bmicolors : array[0..0] of TRGBQuad;
  end;
  TBitmapInfo = tagBITMAPINFO;      
//--------------------------------------------------------

Does anyone know how to do the same in Linux using FPC. Code must not bound 
only to the LCL, i.e. must function in GUI and console apps. I can do 
everything else, I'm not able to create the bitmap from the RGB data.

Thanks
Nino