#!/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 4254.0 1698.0 22.333333333333332 57 -gcp 23430.0 1719.0 24.333333333333332 57 -gcp 23661.0 19257.0 24.333333333333332 56 -gcp 3969.0 19248.0 22.333333333333332 56 1944_Osteuropa_S57_Riga_comp.jpg 1944_Osteuropa_S57_Riga_comp.vrt

# Add cutline to VRT
gdalwarp -r $GDAL_SAMPLING_WARP -tps -dstalpha -cutline_srs EPSG:4326 \
  -cutline "POLYGON(($(echo -e "4254.0 1698.0\n23430.0 1719.0\n23661.0 19257.0\n3969.0 19248.0" | \
  gdaltransform -tps -output_xy 1944_Osteuropa_S57_Riga_comp.vrt | \
  awk 'NR==1{first=$0} {printf "%s %s,", $1,$2} END{print " " first}')))" \
  1944_Osteuropa_S57_Riga_comp.vrt 1944_Osteuropa_S57_Riga_comp.cut.vrt

# Generate tiles
gdal2tiles.py -r $GDAL_SAMPLING_TILE --xyz -z $GDAL_TILE_ZOOMS -x --processes=$GDAL_TILE_PROCESSES 1944_Osteuropa_S57_Riga_comp.cut.vrt 1944_Osteuropa_S57_Riga_comp.xyz