#!/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 25.27451992 56.8687035 -gcp 43200.0 0.0 25.29589176 56.96341493 -gcp 43200.0 43455.0 25.46480656 56.94814582 -gcp 0.0 43455.0 25.44291973 56.85908539 GX825/GX_825_SK_frame_155.jpg GX_825_SK_frame_155.vrt

# Add cutline to VRT
gdalwarp -r $GDAL_SAMPLING_WARP -tps -dstalpha -cutline_srs EPSG:4326 \
  -cutline "POLYGON(($(echo -e "1500.0 4752.0\n1932.0 38940.0\n42396.0 39456.0\n42720.0 4308.0" | \
  gdaltransform -tps -output_xy GX_825_SK_frame_155.vrt | \
  awk 'NR==1{first=$0} {printf "%s %s,", $1,$2} END{print " " first}')))" \
  GX_825_SK_frame_155.vrt GX_825_SK_frame_155.cut.vrt

# Generate tiles
gdal2tiles.py -r $GDAL_SAMPLING_TILE --xyz -z $GDAL_TILE_ZOOMS -x --processes=$GDAL_TILE_PROCESSES GX_825_SK_frame_155.cut.vrt GX_825_SK_frame_155.xyz