#!/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 25.16691746 56.93372186 -gcp 21600.0 0.0 25.18878926 57.02935498 -gcp 21600.0 21666.0 25.35748518 57.0137974 -gcp 0.0 21666.0 25.33677491 56.9257988 GX825/GX_825_SK_frame_69.jpg GX_825_SK_frame_69.vrt

# Add cutline to VRT
gdalwarp -r $GDAL_SAMPLING_WARP -tps -dstalpha -cutline_srs EPSG:4326 \
  -cutline "POLYGON(($(echo -e "642.0 2328.0\n582.0 19530.0\n21120.0 19224.0\n21024.0 2112.0" | \
  gdaltransform -tps -output_xy GX_825_SK_frame_69.vrt | \
  awk 'NR==1{first=$0} {printf "%s %s,", $1,$2} END{print " " first}')))" \
  GX_825_SK_frame_69.vrt GX_825_SK_frame_69.cut.vrt

# Generate tiles
gdal2tiles.py -r $GDAL_SAMPLING_TILE --xyz -z $GDAL_TILE_ZOOMS -x --processes=$GDAL_TILE_PROCESSES GX_825_SK_frame_69.cut.vrt GX_825_SK_frame_69.xyz