#!/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 27.36790565 56.9161262 -gcp 21600.0 0.0 27.36524777 57.01284169 -gcp 21600.0 22038.0 27.53989908 57.00962825 -gcp 0.0 22038.0 27.5403964 56.92046644 GX825/GX_825_SK_frame_32.jpg GX_825_SK_frame_32.vrt

# Add cutline to VRT
gdalwarp -r $GDAL_SAMPLING_WARP -tps -dstalpha -cutline_srs EPSG:4326 \
  -cutline "POLYGON(($(echo -e "936.0 2328.0\n912.0 19440.0\n21288.0 19728.0\n21288.0 2112.0" | \
  gdaltransform -tps -output_xy GX_825_SK_frame_32.vrt | \
  awk 'NR==1{first=$0} {printf "%s %s,", $1,$2} END{print " " first}')))" \
  GX_825_SK_frame_32.vrt GX_825_SK_frame_32.cut.vrt

# Generate tiles
gdal2tiles.py -r $GDAL_SAMPLING_TILE --xyz -z $GDAL_TILE_ZOOMS -x --processes=$GDAL_TILE_PROCESSES GX_825_SK_frame_32.cut.vrt GX_825_SK_frame_32.xyz