Avoid repeated resolutions caused by rounded zoom factors

ImagingDataCommons · Oct 31, 2023 · c01a6d4 · c01a6d4
1 parent bda0cfe
commit c01a6d4
Showing 1 changed file with 8 additions and 3 deletions.
diff --git 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)