[gdal-dev] C GDAL beginner

[deadpickle]

I'm trying to write a simple C program that creates and populates a
shapefile (have one done in python). I'm very new to C and GDAL both
and could use some help. I'm trying to apply coordinatetransformation
to my points but first I have to create the coordinatetransformation.
In python I can do this simply by:
coordtrans = osr.CoordinateTransformation(target, source)
but in C I cant seem to find the right call for this. Any ideas?

#include "ogr_api.h"
#include "ogr_srs_api.h"

int main()
{
        //~ variable declaration
        const char *format = "ESRI Shapefile", *name = "testc.shp", *source,
*target;
        const char *sprj = "+proj=lcc +lat_1=33.000000 +lat_2=45.000000
+lat_0=39.000000 +lon_0=-96.000000 +x_0=0.0 +y_0=0.0 +datum=NAD83";
        const char *tprj = "WGS84";
        OGRSFDriverH driver;
        OGRDataSourceH ds;
        OGRCoordinateTransformation ctrans;

        //~ get driver and create ds
        OGRRegisterAll();
        driver = OGRGetDriverByName(format);
        ds = OGR_Dr_CreateDataSource(driver, "testc.shp", NULL);

        //~ create spatrefs and trans
        OSRNewSpatialReference(source);
        OSRNewSpatialReference(target);
        OSRSetFromUserInput(source, sprj);
        OSRSetFromUserInput(target, tprj);
        ctrans = OGRCreateCoordinateTransformation(target, source);
}

[t...@updraft ~/Programs]$ gcc -o gdal_test_convert
gdal_test_convert.c
gdal_test_convert.c: In function ‘main’:
gdal_test_convert.c:12: error: ‘OGRCoordinateTransformation’
undeclared (first use in this function)
gdal_test_convert.c:12: error: (Each undeclared identifier is reported
only once
gdal_test_convert.c:12: error: for each function it appears in.)
gdal_test_convert.c:12: error: expected ‘;’ before ‘ctrans’
gdal_test_convert.c:22: warning: passing argument 1 of â
€˜OSRSetFromUserInput’ discards qualifiers from pointer target type
gdal_test_convert.c:23: warning: passing argument 1 of â
€˜OSRSetFromUserInput’ discards qualifiers from pointer target type
gdal_test_convert.c:24: error: ‘ctrans’ undeclared (first use in
this function)


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