#!/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 3075.0 2982.0 25.5 56.25 -gcp 17670.0 3069.0 25.666666666666668 56.25 -gcp 17649.0 16563.0 25.666666666666668 56.166666666666664 -gcp 3024.0 16467.0 25.5 56.166666666666664 Latvijas_topografiskas_kartes_Saukas_Rites_Elksnu_un-6828_A1_L12_13_02.JPG Latvijas_topografiskas_kartes_Saukas_Rites_Elksnu_un-6828_A1_L12_13_02.vrt

# Add cutline to VRT
gdalwarp -r $GDAL_SAMPLING_WARP -tps -dstalpha -cutline_srs EPSG:4326 \
  -cutline "POLYGON(($(echo -e \"3075.0 2982.0\n17670.0 3069.0\n17649.0 16563.0\n3024.0 16467.0\" | \
  gdaltransform -tps -output_xy Latvijas_topografiskas_kartes_Saukas_Rites_Elksnu_un-6828_A1_L12_13_02.vrt | \
  awk 'NR==1{first=$0} {printf "%s %s,", $1,$2} END{print " " first}'))))" \
  Latvijas_topografiskas_kartes_Saukas_Rites_Elksnu_un-6828_A1_L12_13_02.vrt Latvijas_topografiskas_kartes_Saukas_Rites_Elksnu_un-6828_A1_L12_13_02.cut.vrt

# Generate tiles
gdal2tiles.py -r $GDAL_SAMPLING_TILE --xyz -z $GDAL_TILE_ZOOMS -x --processes=$GDAL_TILE_PROCESSES Latvijas_topografiskas_kartes_Saukas_Rites_Elksnu_un-6828_A1_L12_13_02.cut.vrt Latvijas_topografiskas_kartes_Saukas_Rites_Elksnu_un-6828_A1_L12_13_02.xyz