#!/bin/bash

GDAL_TILE_PROCESSES=16
GDAL_TILE_ZOOMS=8-14
GDAL_SAMPLING_WARP=cubic
GDAL_SAMPLING_TILE=antialias

# Create virtual dataset with coordinates
gdal_translate -of VRT -a_srs EPSG:4326 -outsize 300% 300% -gcp 2721.0 3186.0 25.833333333333332 56.583333333333336 -gcp 17196.0 3210.0 26 56.583333333333336 -gcp 17271.0 16689.0 26 56.5 -gcp 2742.0 16680.0 25.833333333333332 56.5 Latvijas_topografiskas_kartes_Krustpils_apkartne-6828_A1_L12_3_02.JPG Latvijas_topografiskas_kartes_Krustpils_apkartne-6828_A1_L12_3_02.vrt

# Add cutline to VRT
gdalwarp -r $GDAL_SAMPLING_WARP -tps -dstalpha -cutline_srs EPSG:4326 \
  -cutline "POLYGON(($(echo -e \"2721.0 3186.0\n17196.0 3210.0\n17271.0 16689.0\n2742.0 16680.0\" | \
  gdaltransform -tps -output_xy Latvijas_topografiskas_kartes_Krustpils_apkartne-6828_A1_L12_3_02.vrt | \
  awk 'NR==1{first=$0} {printf "%s %s,", $1,$2} END{print " " first}'))))" \
  Latvijas_topografiskas_kartes_Krustpils_apkartne-6828_A1_L12_3_02.vrt Latvijas_topografiskas_kartes_Krustpils_apkartne-6828_A1_L12_3_02.cut.vrt

# Generate tiles
gdal2tiles.py -r $GDAL_SAMPLING_TILE --xyz -z $GDAL_TILE_ZOOMS -x --processes=$GDAL_TILE_PROCESSES Latvijas_topografiskas_kartes_Krustpils_apkartne-6828_A1_L12_3_02.cut.vrt Latvijas_topografiskas_kartes_Krustpils_apkartne-6828_A1_L12_3_02.xyz