#!/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 26.61798906 56.93304631 -gcp 21600.0 0.0 26.6326882 57.02942203 -gcp 21600.0 22038.0 26.80556084 57.01782897 -gcp 0.0 22038.0 26.79139578 56.92822549 GX825/GX_825_SK_frame_43.jpg GX_825_SK_frame_43.vrt

# Add cutline to VRT
gdalwarp -r $GDAL_SAMPLING_WARP -tps -dstalpha -cutline_srs EPSG:4326 \
  -cutline "POLYGON(($(echo -e "840.0 2640.0\n816.0 19632.0\n21024.0 19776.0\n21168.0 2376.0" | \
  gdaltransform -tps -output_xy GX_825_SK_frame_43.vrt | \
  awk 'NR==1{first=$0} {printf "%s %s,", $1,$2} END{print " " first}')))" \
  GX_825_SK_frame_43.vrt GX_825_SK_frame_43.cut.vrt

# Generate tiles
gdal2tiles.py -r $GDAL_SAMPLING_TILE --xyz -z $GDAL_TILE_ZOOMS -x --processes=$GDAL_TILE_PROCESSES GX_825_SK_frame_43.cut.vrt GX_825_SK_frame_43.xyz