#!/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 0.0 0.0 25.27100086 56.93169952 -gcp 21600.0 0.0 25.2926302 57.0273258 -gcp 21600.0 22161.0 25.464077 57.01232809 -gcp 0.0 22161.0 25.44532299 56.92453346 GX825/GX_825_SK_frame_67.jpg GX_825_SK_frame_67.vrt

# Add cutline to VRT
gdalwarp -r $GDAL_SAMPLING_WARP -tps -dstalpha -cutline_srs EPSG:4326 \
  -cutline "POLYGON(($(echo -e "888.0 2568.0\n816.0 19656.0\n21360.0 19800.0\n21168.0 2280.0" | \
  gdaltransform -tps -output_xy GX_825_SK_frame_67.vrt | \
  awk 'NR==1{first=$0} {printf "%s %s,", $1,$2} END{print " " first}')))" \
  GX_825_SK_frame_67.vrt GX_825_SK_frame_67.cut.vrt

# Generate tiles
gdal2tiles.py -r $GDAL_SAMPLING_TILE --xyz -z $GDAL_TILE_ZOOMS -x --processes=$GDAL_TILE_PROCESSES GX_825_SK_frame_67.cut.vrt GX_825_SK_frame_67.xyz