Testing Reprojection Nodata

warp_test.rs

use std::ffi::CString;
use std::process::exit;
use std::ptr;

use gdal::errors::Result;
use gdal::spatial_ref::SpatialRef;
use gdal::Dataset;
use gdal_sys::{
    CPLErr, CSLSetNameValue, GDALCreateWarpOptions, GDALDestroyWarpOptions, GDALResampleAlg,
    GDALWarpInitDefaultBandMapping, GDALWarpInitDstNoDataReal,
};

fn main() -> Result<()> {
    // Implement the following:
    //  gdalwarp -overwrite -t_srs EPSG:4269 -dstnodata 255 -r near fixtures/labels.tif target/labels-reprojected.tif
    let ds = Dataset::open("fixtures/labels.tif")?;
    let dest_file = CString::new("target/labels-reprojected.tif")?;
    let dest_srs = CString::new(SpatialRef::from_epsg(4269)?.to_wkt()?)?;

    let rv: CPLErr::Type;
    unsafe {
        let opts = GDALCreateWarpOptions();

        GDALWarpInitDefaultBandMapping(opts, 1);

        GDALWarpInitDstNoDataReal(opts, 255.0);

        (*opts).papszWarpOptions = CSLSetNameValue(
            ptr::null_mut(),
            CString::new("INIT_DEST")?.as_ptr(),
            CString::new("NO_DATA")?.as_ptr(),
        );

        rv = gdal_sys::GDALCreateAndReprojectImage(
            ds.c_dataset(),
            ptr::null(),
            dest_file.as_ptr(),
            dest_srs.as_ptr(),
            ds.driver().c_driver(),
            ptr::null_mut(),
            GDALResampleAlg::GRA_NearestNeighbour,
            0.0,
            0.0,
            None,
            ptr::null_mut(),
            opts,
        );

        GDALDestroyWarpOptions(opts);
    };

    if rv != CPLErr::CE_None {
        exit(1);
    } else {
        Ok(())
    }
}