#!/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 25.2418828 56.9840274 -gcp 43200.0 0.0 25.24623871 56.88767446 -gcp 43200.0 43332.0 25.07528543 56.88872935 -gcp 0.0 43332.0 25.07173419 56.97911646 GX825/GX_825_SK_frame_79.jpg GX_825_SK_frame_79.vrt

# Add cutline to VRT
gdalwarp -r $GDAL_SAMPLING_WARP -tps -dstalpha -cutline_srs EPSG:4326 \
  -cutline "POLYGON(($(echo -e "2016.0 4080.0\n1488.0 38508.0\n42480.0 39744.0\n42288.0 3456.0" | \
  gdaltransform -tps -output_xy GX_825_SK_frame_79.vrt | \
  awk 'NR==1{first=$0} {printf "%s %s,", $1,$2} END{print " " first}')))" \
  GX_825_SK_frame_79.vrt GX_825_SK_frame_79.cut.vrt

# Generate tiles
gdal2tiles.py -r $GDAL_SAMPLING_TILE --xyz -z $GDAL_TILE_ZOOMS -x --processes=$GDAL_TILE_PROCESSES GX_825_SK_frame_79.cut.vrt GX_825_SK_frame_79.xyz