#!/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 25.6120491 56.97291278 -gcp 43200.0 0.0 25.63101768 56.87833087 -gcp 43200.0 43086.0 25.46633005 56.86918438 -gcp 0.0 43086.0 25.44289827 56.95824416 GX825/GX_825_SK_frame_85.jpg GX_825_SK_frame_85.vrt

# Add cutline to VRT
gdalwarp -r $GDAL_SAMPLING_WARP -tps -dstalpha -cutline_srs EPSG:4326 \
  -cutline "POLYGON(($(echo -e "1536.0 4320.0\n1632.0 38832.0\n42480.0 39888.0\n42336.0 3840.0" | \
  gdaltransform -tps -output_xy GX_825_SK_frame_85.vrt | \
  awk 'NR==1{first=$0} {printf "%s %s,", $1,$2} END{print " " first}')))" \
  GX_825_SK_frame_85.vrt GX_825_SK_frame_85.cut.vrt

# Generate tiles
gdal2tiles.py -r $GDAL_SAMPLING_TILE --xyz -z $GDAL_TILE_ZOOMS -x --processes=$GDAL_TILE_PROCESSES GX_825_SK_frame_85.cut.vrt GX_825_SK_frame_85.xyz