gdal3.js/src/allJsFunctions/application/gdal_translate.js

gdal3.js is a port of Gdal applications (**gdal_translate**, **ogr2ogr**, **gdal_rasterize**, **gdalwarp**, **gdaltransform**) to Webassembly. It allows you to convert raster and vector geospatial data to various formats and coordinate systems.

/* eslint-disable camelcase */
import { GDALFunctions } from '../../allCFunctions';
import { getGdalError } from '../helper/error';
import { drivers } from '../helper/drivers';
import { getOptions, clearOptions } from '../helper/options';
import { OUTPUTPATH, getRealOutputPath } from '../helper/const';
import { getFileListFromDataset } from '../helper/getFileList';

/**
    * gdal_translate function can be used to convert raster data between different formats,
    * potentially performing some operations like subsettings, resampling,
    * and rescaling pixels in the process.
    *
    * {@link https://gdal.org/programs/gdal_translate.html}
    *
    * @module a/gdal_translate
    * @async
    * @param {TypeDefs.Dataset} dataset Dataset to be converted.
    * @param {Array} [options] Options ({@link https://gdal.org/programs/gdal_translate.html#description})
    * @param {string} [outputName] Destination file name without extension.
    * @return {Promise<TypeDefs.FilePath>} "Promise" returns paths of created files.
    * @example
    * const Gdal = await initGdalJs();
    * const dataset = (await Gdal.open('data.tif')).datasets[0];
    * const options = [
    *   '-of', 'PNG'
    * ];
    * const filePath = await Gdal.gdal_translate(dataset, options);
    *
*/
export default function gdal_translate(dataset, options = [], outputName = null) {
    return new Promise((resolve, reject) => {
        const optStr = getOptions(options);
        const config = optStr.config;
        Object.entries(config).forEach(([key, value]) => {
            GDALFunctions.CPLSetConfigOption(key, value);
        });
        const translateOptionsPtr = GDALFunctions.GDALTranslateOptionsNew(optStr.ptr, null);

        const driverIndex = options.indexOf('-of') + 1;
        let ext = 'unknown';
        if (driverIndex !== 0) {
            const driverName = options[driverIndex];
            const driver = drivers.raster[driverName];
            if (driver) ext = driver.extension;
        }

        const finalOutputName = outputName || dataset.path.split('.', 1)[0];
        const filePath = `${OUTPUTPATH}/${finalOutputName}.${ext}`;
        const datasetPtr = GDALFunctions.GDALTranslate(filePath, dataset.pointer, translateOptionsPtr, null);
        const outputFiles = getFileListFromDataset(datasetPtr);
        GDALFunctions.GDALTranslateOptionsFree(translateOptionsPtr);
        clearOptions(optStr);
        GDALFunctions.GDALClose(datasetPtr);

        if (GDALFunctions.CPLGetLastErrorNo() >= 3) {
            const error = getGdalError();
            reject(error);
        } else {
            resolve({
                local: filePath,
                real: `${getRealOutputPath()}/${finalOutputName}.${ext}`,
                all: outputFiles.map((file) => ({
                    local: file,
                    real: file.replace(`${OUTPUTPATH}/`, `${getRealOutputPath()}/`),
                })),
            });
        }
    });
}