#!/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 1980.0 3174.0 24.5 56.333333333333336 -gcp 12924.0 3165.0 25 56.333333333333336 -gcp 13023.0 16686.0 25 56 -gcp 1992.0 16695.0 24.5 56 LVVA/Latvijas-Lietuvas_rep_un_Vitebskas_apg-Birzi_un_apkartne_6828_A1_L34_25_02.JPG Latvijas-Lietuvas_rep_un_Vitebskas_apg-Birzi_un_apkartne_6828_A1_L34_25_02.vrt

# Add cutline to VRT
gdalwarp -r $GDAL_SAMPLING_WARP -tps -dstalpha -cutline_srs EPSG:4326 \
  -cutline "POLYGON(($(echo -e "1980.0 3174.0\n12924.0 3165.0\n13023.0 16686.0\n1992.0 16695.0" | \
  gdaltransform -tps -output_xy Latvijas-Lietuvas_rep_un_Vitebskas_apg-Birzi_un_apkartne_6828_A1_L34_25_02.vrt | \
  awk 'NR==1{first=$0} {printf "%s %s,", $1,$2} END{print " " first}')))" \
  Latvijas-Lietuvas_rep_un_Vitebskas_apg-Birzi_un_apkartne_6828_A1_L34_25_02.vrt Latvijas-Lietuvas_rep_un_Vitebskas_apg-Birzi_un_apkartne_6828_A1_L34_25_02.cut.vrt

# Generate tiles
gdal2tiles.py -r $GDAL_SAMPLING_TILE --xyz -z $GDAL_TILE_ZOOMS -x --processes=$GDAL_TILE_PROCESSES Latvijas-Lietuvas_rep_un_Vitebskas_apg-Birzi_un_apkartne_6828_A1_L34_25_02.cut.vrt Latvijas-Lietuvas_rep_un_Vitebskas_apg-Birzi_un_apkartne_6828_A1_L34_25_02.xyz