[gdal-dev] Warping an image from C

[Even Rouault]

Le mercredi 04 mai 2011 16:52:02, Bborie Park a écrit :
> Hi,
> 
> I'm currently in the process of seeing what can be done to expose
> GDAL's C warp functions to PostGIS Raster and am wondering if I have
> hit a roadblock.
> 
> >From the docs for gdal_alg.h, it appears that the warp functionality
> 
> available is limited to GDALSimpleImageWarp and its limitations.  Is
> this conclusion correct?  I did take a look at gdalwarpsimple.c
> (https://svn.osgeo.org/gdal/trunk/gdal/apps/gdalwarpsimple.c) and it
> appears to confirm my initial thoughts.
> 
> Are there any plans to expand the C warp API?  If not, would anyone
> mind if I took a stab at it?

I was going to answer : no, indeed there isn't any C warp API for the "full 
warping mode" (i.e. for what would be needed by the gdalwarp utility), because 
I know that gdalwarp.cpp (the source code of gdalwarp utility) use a few C++ 
warp API, but I rechecked for confirmation and in alg/gdalwarper.h I can 
actually see :

GDALWarpOperationH CPL_DLL GDALCreateWarpOperation(const GDALWarpOptions* );
void CPL_DLL GDALDestroyWarpOperation( GDALWarpOperationH );
CPLErr CPL_DLL GDALChunkAndWarpImage( GDALWarpOperationH, int, int, int, int 
);
CPLErr CPL_DLL GDALChunkAndWarpMulti( GDALWarpOperationH, int, int, int, int 
);

So I believe you can accomplish from C code all what gdalwarp does currently 
do. Do you need something else ?

> 
> Thanks,
> Bborie