From 148d56c2fe981b2fbf43dc317a62f5dad941d767 Mon Sep 17 00:00:00 2001
From: Andreas Hocevar <andreas.hocevar@gmail.com>
Date: Fri, 29 Mar 2024 10:33:37 +0100
Subject: [PATCH] Use point resolution for hillshade calculation

---
 src/apply.js | 14 +++++++++++---
 1 file changed, 11 insertions(+), 3 deletions(-)

diff --git a/src/apply.js b/src/apply.js
index ca3b3ead..b5cf5313 100644
--- a/src/apply.js
+++ b/src/apply.js
@@ -45,11 +45,12 @@ import {
 import {
   equivalent,
   fromLonLat,
+  getPointResolution,
   get as getProjection,
   getUserProjection,
 } from 'ol/proj.js';
+import {getCenter, getTopLeft} from 'ol/extent.js';
 import {getFonts} from './text.js';
-import {getTopLeft} from 'ol/extent.js';
 import {hillshade} from './shaders.js';
 import {
   normalizeSourceUrl,
@@ -907,9 +908,16 @@ export function setupLayer(glStyle, styleUrl, glLayer, options) {
   } else if (glSource.type == 'raster-dem' && glLayer.type == 'hillshade') {
     const hillshadeLayer = setupHillshadeLayer(glSource, styleUrl, options);
     layer = hillshadeLayer;
-    hillshadeLayer.getSource().on('beforeoperations', function (event) {
+    const source = hillshadeLayer.getSource();
+    source.on('beforeoperations', function (event) {
       const data = event.data;
-      data.resolution = event.resolution;
+      data.resolution = getPointResolution(
+        options.projection || 'EPSG:3857',
+        event.resolution,
+        getCenter(event.extent),
+        'm',
+      );
+      console.log(options);
       const zoom = getZoomForResolution(
         event.resolution,
         options.resolutions || defaultResolutions,