#!/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 25.32404423 56.93270641 -gcp 21600.0 0.0 25.34580231 57.02793305 -gcp 21600.0 22347.0 25.51952362 57.01270194 -gcp 0.0 22347.0 25.49931049 56.92476767 GX825/GX_825_SK_frame_66.jpg GX_825_SK_frame_66.vrt

# Add cutline to VRT
gdalwarp -r $GDAL_SAMPLING_WARP -tps -dstalpha -cutline_srs EPSG:4326 \
  -cutline "POLYGON(($(echo -e "696.0 2910.0\n708.0 20034.0\n21192.0 20400.0\n21240.0 2688.0" | \
  gdaltransform -tps -output_xy GX_825_SK_frame_66.vrt | \
  awk 'NR==1{first=$0} {printf "%s %s,", $1,$2} END{print " " first}')))" \
  GX_825_SK_frame_66.vrt GX_825_SK_frame_66.cut.vrt

# Generate tiles
gdal2tiles.py -r $GDAL_SAMPLING_TILE --xyz -z $GDAL_TILE_ZOOMS -x --processes=$GDAL_TILE_PROCESSES GX_825_SK_frame_66.cut.vrt GX_825_SK_frame_66.xyz