#!/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 25.10474389 56.86903572 -gcp 43200.0 0.0 25.12719897 56.96466558 -gcp 43200.0 41844.0 25.28955656 56.94959602 -gcp 0.0 41844.0 25.26810401 56.8603452 GX825/GX_825_SK_frame_158.jpg GX_825_SK_frame_158.vrt

# Add cutline to VRT
gdalwarp -r $GDAL_SAMPLING_WARP -tps -dstalpha -cutline_srs EPSG:4326 \
  -cutline "POLYGON(($(echo -e "1860.0 3024.0\n1824.0 37308.0\n42576.0 37632.0\n42528.0 2832.0" | \
  gdaltransform -tps -output_xy GX_825_SK_frame_158.vrt | \
  awk 'NR==1{first=$0} {printf "%s %s,", $1,$2} END{print " " first}')))" \
  GX_825_SK_frame_158.vrt GX_825_SK_frame_158.cut.vrt

# Generate tiles
gdal2tiles.py -r $GDAL_SAMPLING_TILE --xyz -z $GDAL_TILE_ZOOMS -x --processes=$GDAL_TILE_PROCESSES GX_825_SK_frame_158.cut.vrt GX_825_SK_frame_158.xyz