#!/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 25.16115904 56.86972374 -gcp 43200.0 0.0 25.18597484 56.96529844 -gcp 43200.0 41844.0 25.34627438 56.94902353 -gcp 0.0 41844.0 25.32513857 56.86066904 GX825/GX_825_SK_frame_157.jpg GX_825_SK_frame_157.vrt

# Add cutline to VRT
gdalwarp -r $GDAL_SAMPLING_WARP -tps -dstalpha -cutline_srs EPSG:4326 \
  -cutline "POLYGON(($(echo -e "672.0 3408.0\n1200.0 37392.0\n42096.0 37824.0\n41568.0 3072.0" | \
  gdaltransform -tps -output_xy GX_825_SK_frame_157.vrt | \
  awk 'NR==1{first=$0} {printf "%s %s,", $1,$2} END{print " " first}')))" \
  GX_825_SK_frame_157.vrt GX_825_SK_frame_157.cut.vrt

# Generate tiles
gdal2tiles.py -r $GDAL_SAMPLING_TILE --xyz -z $GDAL_TILE_ZOOMS -x --processes=$GDAL_TILE_PROCESSES GX_825_SK_frame_157.cut.vrt GX_825_SK_frame_157.xyz