Merge pull request #12731 from ahocevar/user-resolution

Handle resolution and tile loadingstrategy with user projection

src/ol/loadingstrategy.js

@@ -2,6 +2,8 @@
  * @module ol/loadingstrategy
  */
 
+import {fromUserExtent, fromUserResolution, toUserExtent} from './proj.js';
+
 /**
  * Strategy function for loading all features with a single request.
  * @param {import("./extent.js").Extent} extent Extent.
@@ -28,7 +30,7 @@ export function bbox(extent, resolution) {
 /**
  * Creates a strategy function for loading features based on a tile grid.
  * @param {import("./tilegrid/TileGrid.js").default} tileGrid Tile grid.
- * @return {function(import("./extent.js").Extent, number): Array<import("./extent.js").Extent>} Loading strategy.
+ * @return {function(import("./extent.js").Extent, number, import("./proj.js").Projection): Array<import("./extent.js").Extent>} Loading strategy.
  * @api
  */
 export function tile(tileGrid) {
@@ -36,11 +38,17 @@ export function tile(tileGrid) {
     /**
      * @param {import("./extent.js").Extent} extent Extent.
      * @param {number} resolution Resolution.
+     * @param {import("./proj.js").Projection} projection Projection.
      * @return {Array<import("./extent.js").Extent>} Extents.
      */
-    function (extent, resolution) {
-      const z = tileGrid.getZForResolution(resolution);
-      const tileRange = tileGrid.getTileRangeForExtentAndZ(extent, z);
+    function (extent, resolution, projection) {
+      const z = tileGrid.getZForResolution(
+        fromUserResolution(resolution, projection)
+      );
+      const tileRange = tileGrid.getTileRangeForExtentAndZ(
+        fromUserExtent(extent, projection),
+        z
+      );
       /** @type {Array<import("./extent.js").Extent>} */
       const extents = [];
       /** @type {import("./tilecoord.js").TileCoord} */
@@ -55,7 +63,9 @@ export function tile(tileGrid) {
           tileCoord[2] <= tileRange.maxY;
           ++tileCoord[2]
         ) {
-          extents.push(tileGrid.getTileCoordExtent(tileCoord));
+          extents.push(
+            toUserExtent(tileGrid.getTileCoordExtent(tileCoord), projection)
+          );
         }
       }
       return extents;

src/ol/proj.js

@@ -631,6 +631,44 @@ export function fromUserExtent(extent, destProjection) {
   return transformExtent(extent, userProjection, destProjection);
 }
 
+/**
+ * Return the resolution in user projection units per pixel. If no user projection
+ * is set, or source or user projection are missing units, the original resolution
+ * is returned.
+ * @param {number} resolution Resolution in input projection units per pixel.
+ * @param {ProjectionLike} sourceProjection The input projection.
+ * @return {number} Resolution in user projection units per pixel.
+ */
+export function toUserResolution(resolution, sourceProjection) {
+  if (!userProjection) {
+    return resolution;
+  }
+  const sourceUnits = get(sourceProjection).getUnits();
+  const userUnits = userProjection.getUnits();
+  return sourceUnits && userUnits
+    ? (resolution * METERS_PER_UNIT[sourceUnits]) / METERS_PER_UNIT[userUnits]
+    : resolution;
+}
+
+/**
+ * Return the resolution in user projection units per pixel. If no user projection
+ * is set, or source or user projection are missing units, the original resolution
+ * is returned.
+ * @param {number} resolution Resolution in user projection units per pixel.
+ * @param {ProjectionLike} destProjection The destination projection.
+ * @return {number} Resolution in destination projection units per pixel.
+ */
+export function fromUserResolution(resolution, destProjection) {
+  if (!userProjection) {
+    return resolution;
+  }
+  const sourceUnits = get(destProjection).getUnits();
+  const userUnits = userProjection.getUnits();
+  return sourceUnits && userUnits
+    ? (resolution * METERS_PER_UNIT[userUnits]) / METERS_PER_UNIT[sourceUnits]
+    : resolution;
+}
+
 /**
  * Creates a safe coordinate transform function from a coordinate transform function.
  * "Safe" means that it can handle wrapping of x-coordinates for global projections,

src/ol/renderer/canvas/VectorLayer.js

@@ -36,6 +36,7 @@ import {
   getTransformFromProjections,
   getUserProjection,
   toUserExtent,
+  toUserResolution,
 } from '../../proj.js';
 import {getUid} from '../../util.js';
 import {wrapX as wrapCoordinateX} from '../../coordinate.js';
@@ -642,9 +643,11 @@ class CanvasVectorLayerRenderer extends CanvasLayerRenderer {
     let userTransform;
     if (userProjection) {
       for (let i = 0, ii = loadExtents.length; i < ii; ++i) {
+        const extent = loadExtents[i];
+        const userExtent = toUserExtent(extent, projection);
         vectorSource.loadFeatures(
-          toUserExtent(loadExtents[i], projection),
-          resolution,
+          userExtent,
+          toUserResolution(resolution, projection),
           userProjection
         );
       }

src/ol/source/Vector.js

@@ -26,7 +26,7 @@ import {xhr} from '../featureloader.js';
  * returns an array of {@link module:ol/extent~Extent} with the extents to load. Usually this
  * is one of the standard {@link module:ol/loadingstrategy} strategies.
  *
- * @typedef {function(import("../extent.js").Extent, number): Array<import("../extent.js").Extent>} LoadingStrategy
+ * @typedef {function(import("../extent.js").Extent, number, import("../proj/Projection.js").default): Array<import("../extent.js").Extent>} LoadingStrategy
  * @api
  */
 
@@ -939,7 +939,7 @@ class VectorSource extends Source {
    */
   loadFeatures(extent, resolution, projection) {
     const loadedExtentsRtree = this.loadedExtentsRtree_;
-    const extentsToLoad = this.strategy_(extent, resolution);
+    const extentsToLoad = this.strategy_(extent, resolution, projection);
     for (let i = 0, ii = extentsToLoad.length; i < ii; ++i) {
       const extentToLoad = extentsToLoad[i];
       const alreadyLoaded = loadedExtentsRtree.forEachInExtent(