#!/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 26.65900137 56.85743358 -gcp 21600.0 0.0 26.67351496 56.95400033 -gcp 21600.0 21666.0 26.84369369 56.94266308 -gcp 0.0 21666.0 26.83010383 56.85308497 GX825/GX_825_SK_frame_131.jpg GX_825_SK_frame_131.vrt

# Add cutline to VRT
gdalwarp -r $GDAL_SAMPLING_WARP -tps -dstalpha -cutline_srs EPSG:4326 \
  -cutline "POLYGON(($(echo -e "792.0 1848.0\n816.0 18912.0\n21024.0 19248.0\n21216.0 1632.0" | \
  gdaltransform -tps -output_xy GX_825_SK_frame_131.vrt | \
  awk 'NR==1{first=$0} {printf "%s %s,", $1,$2} END{print " " first}')))" \
  GX_825_SK_frame_131.vrt GX_825_SK_frame_131.cut.vrt

# Generate tiles
gdal2tiles.py -r $GDAL_SAMPLING_TILE --xyz -z $GDAL_TILE_ZOOMS -x --processes=$GDAL_TILE_PROCESSES GX_825_SK_frame_131.cut.vrt GX_825_SK_frame_131.xyz