[Gdal-dev] C# Bindings

[Tamas Szekeres]

>
> Fair enough. My initial thought was to suggest a signature like:
>
>   public void ReadRaster(int xOff, int yOff, int xSize, int ySize, byte*
> buffer, int bufXSize, int bufYSize, int pixelSpace, int lineSpace)
>
> and similarly for other data types (short, ushort, int, uint, long,
> ulong, float, double). Using a pointer rather than an array for the
> buffer allows the method to be used to fill Bitmaps without having to
> copy into an intermediate array.
>
> So, that would be 9 methods, and that's not even including signed bytes
> or complex data types...
>
> It would also be nice not to have to specify all the arguments in common
> cases. Since we don't have default arguments in C#, we could use two
> more overloads for each of the above with signatures like:
>
>   // bufXSize == xSize, bufYSize == ySize, pixelSpace ==
> sizeof(datatype), lineSpace == sizeof(datatype) * bufXSize
>   public void ReadRaster(int xOff, int yOff, int xSize, int ySize, byte*
> buffer)
>
>   // pixelSpace == sizeof(datatype), lineSpace == sizeof(datatype) *
> bufXSize
>   public void ReadRaster(int xOff, int yOff, int xSize, int ySize, byte*
> buffer, int bufXSize, int bufYSize)
>
>
> So we're up to 27 different methods...
>
> And then all over again for WriteRaster(). Making a grand total of 54
> different method signatures for reading and writing data - not covering
> all the possible data types! Hmmm...
>
>
>
> OK, if that's way too many, how about this as an alternative: we follow
> the GDAL pattern and pass an IntPtr buffer, along with an enum argument
> that specifies the data type. We can probably also drop one of the above
> overloads, since this is a low level API. In that case, we would have a
> grand total of 4 signatures:
>
>   public void ReadRaster(int xOff, int yOff, int xSize, int ySize,
> IntPtr buffer, int bufXSize, int bufYSize, GDALDataType type)
>
>  public void ReadRaster(int xOff, int yOff, int xSize, int ySize, IntPtr
> buffer, int bufXSize, int bufYSize, GDALDataType type, int pixelSpace,
> int lineSpace)
>
>   public void WriteRaster(int xOff, int yOff, int xSize, int ySize,
> IntPtr buffer, int bufXSize, int bufYSize, GDALDataType type)
>
>  public void WriteRaster(int xOff, int yOff, int xSize, int ySize,
> IntPtr buffer, int bufXSize, int bufYSize, GDALDataType type, int
> pixelSpace, int lineSpace)
>
>
> How does that sound? Maybe at some point in the future when generics are
> the norm, we can add templated versions to get a  modicum of type safety
> and avoid having to specify a data type explicitly.
>
>
>
> Cheers!
>
> Sy
>
> P.S. I've just checked in my manifest embedding changes to makefile.vc
>
>
>