#!/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 27.23547608 56.91569419 -gcp 21600.0 0.0 27.2347101 57.01112653 -gcp 21600.0 22038.0 27.40687353 57.00897755 -gcp 0.0 22038.0 27.40854003 56.91910311 GX825/GX_825_SK_frame_34.jpg GX_825_SK_frame_34.vrt

# Add cutline to VRT
gdalwarp -r $GDAL_SAMPLING_WARP -tps -dstalpha -cutline_srs EPSG:4326 \
  -cutline "POLYGON(($(echo -e "864.0 2424.0\n744.0 19680.0\n21168.0 19608.0\n21216.0 2424.0" | \
  gdaltransform -tps -output_xy GX_825_SK_frame_34.vrt | \
  awk 'NR==1{first=$0} {printf "%s %s,", $1,$2} END{print " " first}')))" \
  GX_825_SK_frame_34.vrt GX_825_SK_frame_34.cut.vrt

# Generate tiles
gdal2tiles.py -r $GDAL_SAMPLING_TILE --xyz -z $GDAL_TILE_ZOOMS -x --processes=$GDAL_TILE_PROCESSES GX_825_SK_frame_34.cut.vrt GX_825_SK_frame_34.xyz