From 7a442ba582abc30237d0361890f2755f83faea4b Mon Sep 17 00:00:00 2001
From: Simon Oberhammer <simon.oberhammer@orf.at>
Date: Thu, 18 Sep 2025 10:00:52 +0200
Subject: [PATCH] improve rivers by simplifying them later but then a bit more;
 show labels from 10 but only show them for water polygs of a certain size

---
 config.json | 8 ++++----
 process.lua | 8 ++++++--
 2 files changed, 10 insertions(+), 6 deletions(-)

diff --git a/config.json b/config.json
index e4b659e..9ac1600 100644
--- a/config.json
+++ b/config.json
@@ -32,7 +32,7 @@
             "combine_below": 15
         },
         "water_lines_labels": {
-            "minzoom": 4,
+            "minzoom": 13,
             "maxzoom": 14,
             "simplify_below": 14,
             "simplify_level": 0.0002,
@@ -140,8 +140,8 @@
         "water_polygons": {
             "minzoom": 4,
             "maxzoom": 14,
-            "simplify_below": 14,
-            "simplify_level": 0.0001,
+            "simplify_below": 12,
+            "simplify_level": 0.00015,
             "simplify_ratio": 2
         },
         "ocean": {
@@ -164,7 +164,7 @@
             "write_to": "ocean"
         },
         "water_polygons_labels": {
-            "minzoom": 14,
+            "minzoom": 10,
             "maxzoom": 14,
             "sort_z_level_ascending": false
         },
diff --git a/process.lua b/process.lua
index 9673d18..b00b93d 100644
--- a/process.lua
+++ b/process.lua
@@ -407,9 +407,13 @@ function process_water_polygons(way_area)
 		Attribute("kind", kind)
 		AttributeNumeric("way_area", way_area)
 		ZOrder(way_area)
-		if Holds("name") then
+		-- don't show river bodys and drop all small polygons always
+		if Holds("name") and not is_river and way_area > 2500000 then
+			-- show water poly labels only if they
+			-- are very big already
+			labelmz = math.max(mz, zmin_for_area(50, way_area))
 			LayerAsCentroid("water_polygons_labels")
-			MinZoom(14)
+			MinZoom(labelmz)
 			Attribute("kind", kind)
 			AttributeNumeric("way_area", way_area)
 			ZOrder(way_area)