#!/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 25.33648968 56.86914916 -gcp 43200.0 0.0 25.35773277 56.96407016 -gcp 43200.0 43086.0 25.5267334 56.94775962 -gcp 0.0 43086.0 25.50046921 56.85838153 GX825/GX_825_SK_frame_154.jpg GX_825_SK_frame_154.vrt

# Add cutline to VRT
gdalwarp -r $GDAL_SAMPLING_WARP -tps -dstalpha -cutline_srs EPSG:4326 \
  -cutline "POLYGON(($(echo -e "1872.0 3960.0\n1920.0 38160.0\n42768.0 38400.0\n42528.0 3456.0" | \
  gdaltransform -tps -output_xy GX_825_SK_frame_154.vrt | \
  awk 'NR==1{first=$0} {printf "%s %s,", $1,$2} END{print " " first}')))" \
  GX_825_SK_frame_154.vrt GX_825_SK_frame_154.cut.vrt

# Generate tiles
gdal2tiles.py -r $GDAL_SAMPLING_TILE --xyz -z $GDAL_TILE_ZOOMS -x --processes=$GDAL_TILE_PROCESSES GX_825_SK_frame_154.cut.vrt GX_825_SK_frame_154.xyz