From c01a6d4a4fb82aebf854686ed9c1bc2d713c9054 Mon Sep 17 00:00:00 2001
From: Igor Octaviano <igoroctaviano@gmail.com>
Date: Tue, 31 Oct 2023 10:29:49 -0300
Subject: [PATCH] Avoid repeated resolutions caused by rounded zoom factors

---
 src/pyramid.js | 11 ++++++++---
 1 file changed, 8 insertions(+), 3 deletions(-)

diff --git a/src/pyramid.js b/src/pyramid.js
index 4ae2abba..36218c1d 100644
--- a/src/pyramid.js
+++ b/src/pyramid.js
@@ -204,13 +204,18 @@ function _computeImagePyramid ({ metadata }) {
       (totalPixelMatrixColumns * pixelSpacing[1]).toFixed(4),
       (totalPixelMatrixRows * pixelSpacing[0]).toFixed(4)
     ])
+    let zoomFactor = baseTotalPixelMatrixColumns / totalPixelMatrixColumns
+    const roundedZoomFactor = Math.round(zoomFactor)
     /*
     * Compute the resolution at each pyramid level, since the zoom
     * factor may not be the same between adjacent pyramid levels.
+    * 
+    * Round is conditional to avoid openlayers resolutions error.
+    * The resolutions array should be composed of unique values in descending order.
     */
-    const zoomFactor = Math.round(
-      baseTotalPixelMatrixColumns / totalPixelMatrixColumns
-    )
+    zoomFactor = pyramidResolutions.includes(roundedZoomFactor)
+      ? zoomFactor.toFixed(3)
+      : roundedZoomFactor
     pyramidResolutions.push(zoomFactor)
 
     pyramidOrigins.push(offset)