From 4aa3ce35dd6fa4f4000a72d172158e0be98fd2fb Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Motiejus=20Jak=C5=A1tys?= <motiejus@uber.com>
Date: Wed, 16 Dec 2020 08:52:18 +0200
Subject: [PATCH] README

---
 contours/Makefile  |  6 +++---
 contours/README.md | 34 +++++++++++++++++++++++-----------
 contours/config.mk |  8 ++++----
 3 files changed, 30 insertions(+), 18 deletions(-)

diff --git a/contours/Makefile b/contours/Makefile
index c0aceb9..e580c15 100644
--- a/contours/Makefile
+++ b/contours/Makefile
@@ -1,7 +1,7 @@
 include config.mk
 
 OUTSIZE = $(shell awk $(addprefix -v ,$(BOUNDS)) 'BEGIN{print ymax-ymin" "xmax-xmin}' /dev/null)
-XYZ = $(patsubst %.zip,%.xyz,$(wildcard 6*.zip))
+XYZ = $(patsubst %.zip,%.xyz,$(wildcard *.zip))
 SORT = sort -n -k2 -k1 -t,
 
 .PHONY: all
@@ -34,7 +34,7 @@ all.tif: all.vrt all.xyz
 		-outsize $(OUTSIZE)
 else
 ifeq ($(VARIANT),2017)
-all.tif: all.vrt all.xyz
+all.tif: all.xyz
 	gdal_translate $< $@ \
 		-ot Float32 -a_srs EPSG:3346 \
 		-co COMPRESS=DEFLATE -co PREDICTOR=2
@@ -50,7 +50,7 @@ all.xyz: $(XYZ)
 .INTERMEDIATE: $(XYZ)
 %.xyz: %.zip
 	unzip -qq -c $< $@ | \
-		./clip-2009.awk $(addprefix -v ,$(BOUNDS)) | \
+		./clip-$(VARIANT).awk $(addprefix -v ,$(BOUNDS)) | \
 		$(SORT) > $@
 
 db/.ready: managedb
diff --git a/contours/README.md b/contours/README.md
index eaaa98e..6fcea7d 100644
--- a/contours/README.md
+++ b/contours/README.md
@@ -1,27 +1,39 @@
 Countour line generator from LIDAR data
 ---------------------------------------
 
+This accepts two kinds of contour data:
+
+*2009 variant*: x, y, z, separated by one or more spaces:
+```
+ 501991.670  6150000.000  57.689
+```
+
+*Non-gridded*, therefore significantly slower (`gdal_grid` must be used before making contours, which is slow).
+
+
+*2017*: y, x, z, separated by commas:
+```
+6062999.75,584000.75,88.07
+```
+
+This is *gridded*, so quite fast.
+
 Usage:
 
-1. Download contour lines in format `6062999.75,584000.75,88.07`: coordinate
-   pair and height (in meters) to `DTM_XX_YY_N.zip` files.
-2. Adjust `BOUNDS` in the Makefile.
+1. Download contour lines to zip files in this directory.
+2. Adjust `BOUNDS` and `VARIANT` in `config.mk`.
 3. Run `make -j$(nproc) smooth_<X>.gpkg`. This will output a geo-package with
    contour lines every `X` meters. X can be fractional (e.g.
    `smooth_2.5.gpkg`).
 4. Optional: you may generate a raster image with `layer2img.py`.
 
-Dependencies:
+Dependencies for a Linux system:
 
-- postgis
+- docker
+- psql (client only)
 - gdal-bin
 - unzip
-
-TODO:
-
-1. Replace `managedb` stack with postgis-over-docker. This will lead to a less
-   fragile postgis setup.
-2. Accept `BOUNDS` in a way that does not require to change the Makefile.
+- awk
 
 Example
 -------
diff --git a/contours/config.mk b/contours/config.mk
index a5cf1f1..6083a1f 100644
--- a/contours/config.mk
+++ b/contours/config.mk
@@ -1,8 +1,8 @@
 #krekenava
 #BOUNDS = xmin=504440 ymin=6154741 xmax=507410 ymax=6158941
-BOUNDS = xmin=493674 ymin=6146103 xmax=518869 ymax=6171741
-VARIANT = 2009
+#BOUNDS = xmin=493674 ymin=6146103 xmax=518869 ymax=6171741
+#VARIANT = 2009
 
 #uzupis
-#BOUNDS = xmin=582700 ymin=6060750 xmax=584830 ymax=6062750
-#VARIANT=2017
+BOUNDS = xmin=582700 ymin=6060750 xmax=584830 ymax=6062750
+VARIANT = 2017