void generate( GDALDataset  *ds)
{
    int tcount = (1 + abs(tmaxx - tminx))*(1 + abs(tmaxy - tminy));
    GDALDriver* jpegDriver = GetGDALDriverManager()->GetDriverByName("PNG");
    int tz = tmaxz;
    for (int ty = tmaxy; ty >= tminy; ty--)
    {
        #pragma omp parallel for schedule(dynamic, 1)
        for (int tx = tminx; tx <= tmaxx; tx++){

            // TODO tilefilename is exits
            int googleY = (pow(2, tz) - 1) - ty;
            string tileDir = "D:\test2\" + to_string(tz) + "\" + to_string(tx);
            string tilefilename = tileDir + "\" +to_string(googleY) + "." + tileext;
            create_dir(tileDir.c_str());
            Envelope b = mercator->TileBounds(tx, ty, tz);
            int * rwxy;
            rwxy = geo_query(b,querysize);
            int rx, ry, rxsize, rysize, wx, wy, wxsize, wysize;
            rx = *(rwxy+0);
            ry = *(rwxy + 1);
            rxsize = *(rwxy + 2);
            rysize = *(rwxy + 3);
            wx = *(rwxy + 4);
            wy = *(rwxy + 5);
            wxsize = *(rwxy + 6);
            wysize = *(rwxy + 7);

            GDALDataset *dstile;
            char **papszOptions = NULL;
            dstile = mem_drv->Create("temp", tilesize, tilesize, 3, GDT_Byte, papszOptions);

            int bandNum;
            bandNum = ds->GetRasterCount();    //波段数
            bandNum = 3;
            int depth = GDALGetDataTypeSize(ds->GetRasterBand(1)->GetRasterDataType());//8;    //图像深度
            size_t imgBufNum = (size_t)wxsize * wysize * bandNum*depth;
            GByte *data = new GByte[imgBufNum];

            ds->RasterIO(GF_Read, rx, ry, rxsize, rysize, data, wxsize, wysize,
                GDT_Byte, bandNum, nullptr, bandNum*depth, wxsize*bandNum*depth, depth);
            if (tilesize == querysize)
            {
                //写入
                dstile->RasterIO(GF_Write, wx, wy, wxsize, wysize, data, wxsize, wysize,
                GDT_Byte, bandNum, nullptr, bandNum*depth, wxsize*bandNum*depth, depth);
                dstile->GetRasterBand(4)->SetNoDataValue(0);
            }
            else
            {


                GDALDataset *dsquery;
                dsquery = mem_drv->Create("temp", querysize, querysize, 3, GDT_Byte, papszOptions);
                dsquery->RasterIO(GF_Write, wx, wy, wxsize, wysize, data, wxsize, wysize,
                    GDT_Byte, bandNum, nullptr, bandNum*depth, wxsize*bandNum*depth, depth);
                scale_query_to_tile(dsquery, dstile);
                GDALClose((GDALDatasetH)dsquery);


            }

            delete[] data;
            data = NULL;
            clock_t start, finish;
            start = clock();
            GDALDataset *poDstDS;
            poDstDS = jpegDriver->CreateCopy(tilefilename.c_str(), dstile, FALSE, NULL, NULL, NULL);
            //Once we're done, close properly the dataset */
            if (poDstDS != NULL)
                GDALClose((GDALDatasetH)poDstDS);
            GDALClose((GDALDatasetH)dstile);
        }
    }
    //GetLocalTime(&st);
    }