#!/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 25.66772226 56.8682918 -gcp 21600.0 0.0 25.68917509 56.96338746 -gcp 21600.0 21789.0 25.85749969 56.94802267 -gcp 0.0 21789.0 25.83623489 56.86072628 GX825/GX_825_SK_frame_148.jpg GX_825_SK_frame_148.vrt

# Add cutline to VRT
gdalwarp -r $GDAL_SAMPLING_WARP -tps -dstalpha -cutline_srs EPSG:4326 \
  -cutline "POLYGON(($(echo -e "1032.0 2616.0\n1320.0 19776.0\n21504.0 19584.0\n21576.0 2088.0" | \
  gdaltransform -tps -output_xy GX_825_SK_frame_148.vrt | \
  awk 'NR==1{first=$0} {printf "%s %s,", $1,$2} END{print " " first}')))" \
  GX_825_SK_frame_148.vrt GX_825_SK_frame_148.cut.vrt

# Generate tiles
gdal2tiles.py -r $GDAL_SAMPLING_TILE --xyz -z $GDAL_TILE_ZOOMS -x --processes=$GDAL_TILE_PROCESSES GX_825_SK_frame_148.cut.vrt GX_825_SK_frame_148.xyz