Merge pull request #4055 from fgravin/graticulePerf

Improve graticule perf

examples/sphere-mollweide.js

@@ -16,7 +16,7 @@ var sphereMollweideProjection = new ol.proj.Projection({
   code: 'ESRI:53009',
   extent: [-9009954.605703328, -9009954.605703328,
     9009954.605703328, 9009954.605703328],
-  worldExtent: [-179, -90, 179, 90]
+  worldExtent: [-179, -89.99, 179, 89.99]
 });
 
 var map = new ol.Map({

src/ol/graticule.js

@@ -58,6 +58,30 @@ ol.Graticule = function(opt_options) {
    */
   this.minLon_ = -Infinity;
 
+  /**
+   * @type {number}
+   * @private
+   */
+  this.maxLatP_ = Infinity;
+
+  /**
+   * @type {number}
+   * @private
+   */
+  this.maxLonP_ = Infinity;
+
+  /**
+   * @type {number}
+   * @private
+   */
+  this.minLatP_ = -Infinity;
+
+  /**
+   * @type {number}
+   * @private
+   */
+  this.minLonP_ = -Infinity;
+
   /**
    * @type {number}
    * @private
@@ -135,6 +159,8 @@ ol.Graticule.intervals_ = [90, 45, 30, 20, 10, 5, 2, 1, 0.5, 0.2, 0.1, 0.05,
 
 /**
  * @param {number} lon Longitude.
+ * @param {number} minLat Minimal latitude.
+ * @param {number} maxLat Maximal latitude.
  * @param {number} squaredTolerance Squared tolerance.
  * @param {ol.Extent} extent Extent.
  * @param {number} index Index.
@@ -142,8 +168,9 @@ ol.Graticule.intervals_ = [90, 45, 30, 20, 10, 5, 2, 1, 0.5, 0.2, 0.1, 0.05,
  * @private
  */
 ol.Graticule.prototype.addMeridian_ =
-    function(lon, squaredTolerance, extent, index) {
+    function(lon, minLat, maxLat, squaredTolerance, extent, index) {
-  var lineString = this.getMeridian_(lon, squaredTolerance, index);
+  var lineString = this.getMeridian_(lon, minLat, maxLat,
+      squaredTolerance, index);
   if (ol.extent.intersects(lineString.getExtent(), extent)) {
     this.meridians_[index++] = lineString;
   }
@@ -153,6 +180,8 @@ ol.Graticule.prototype.addMeridian_ =
 
 /**
  * @param {number} lat Latitude.
+ * @param {number} minLon Minimal longitude.
+ * @param {number} maxLon Maximal longitude.
  * @param {number} squaredTolerance Squared tolerance.
  * @param {ol.Extent} extent Extent.
  * @param {number} index Index.
@@ -160,8 +189,9 @@ ol.Graticule.prototype.addMeridian_ =
  * @private
  */
 ol.Graticule.prototype.addParallel_ =
-    function(lat, squaredTolerance, extent, index) {
+    function(lat, minLon, maxLon, squaredTolerance, extent, index) {
-  var lineString = this.getParallel_(lat, squaredTolerance, index);
+  var lineString = this.getParallel_(lat, minLon, maxLon, squaredTolerance,
+      index);
   if (ol.extent.intersects(lineString.getExtent(), extent)) {
     this.parallels_[index++] = lineString;
   }
@@ -191,17 +221,31 @@ ol.Graticule.prototype.createGraticule_ =
   var maxLines = this.maxLines_;
   var cnt, idx, lat, lon;
 
+  var validExtent = [
+    Math.max(extent[0], this.minLonP_),
+    Math.max(extent[1], this.minLatP_),
+    Math.min(extent[2], this.maxLonP_),
+    Math.min(extent[3], this.maxLatP_)
+  ];
+
+  validExtent = ol.proj.transformExtent(validExtent, this.projection_,
+      'EPSG:4326');
+  var maxLat = validExtent[3];
+  var maxLon = validExtent[2];
+  var minLat = validExtent[1];
+  var minLon = validExtent[0];
+
   // Create meridians
 
   centerLon = Math.floor(centerLon / interval) * interval;
   lon = goog.math.clamp(centerLon, this.minLon_, this.maxLon_);
 
-  idx = this.addMeridian_(lon, squaredTolerance, extent, 0);
+  idx = this.addMeridian_(lon, minLat, maxLat, squaredTolerance, extent, 0);
 
   cnt = 0;
   while (lon != this.minLon_ && cnt++ < maxLines) {
     lon = Math.max(lon - interval, this.minLon_);
-    idx = this.addMeridian_(lon, squaredTolerance, extent, idx);
+    idx = this.addMeridian_(lon, minLat, maxLat, squaredTolerance, extent, idx);
   }
 
   lon = goog.math.clamp(centerLon, this.minLon_, this.maxLon_);
@@ -209,7 +253,7 @@ ol.Graticule.prototype.createGraticule_ =
   cnt = 0;
   while (lon != this.maxLon_ && cnt++ < maxLines) {
     lon = Math.min(lon + interval, this.maxLon_);
-    idx = this.addMeridian_(lon, squaredTolerance, extent, idx);
+    idx = this.addMeridian_(lon, minLat, maxLat, squaredTolerance, extent, idx);
   }
 
   this.meridians_.length = idx;
@@ -219,12 +263,12 @@ ol.Graticule.prototype.createGraticule_ =
   centerLat = Math.floor(centerLat / interval) * interval;
   lat = goog.math.clamp(centerLat, this.minLat_, this.maxLat_);
 
-  idx = this.addParallel_(lat, squaredTolerance, extent, 0);
+  idx = this.addParallel_(lat, minLon, maxLon, squaredTolerance, extent, 0);
 
   cnt = 0;
   while (lat != this.minLat_ && cnt++ < maxLines) {
     lat = Math.max(lat - interval, this.minLat_);
-    idx = this.addParallel_(lat, squaredTolerance, extent, idx);
+    idx = this.addParallel_(lat, minLon, maxLon, squaredTolerance, extent, idx);
   }
 
   lat = goog.math.clamp(centerLat, this.minLat_, this.maxLat_);
@@ -232,7 +276,7 @@ ol.Graticule.prototype.createGraticule_ =
   cnt = 0;
   while (lat != this.maxLat_ && cnt++ < maxLines) {
     lat = Math.min(lat + interval, this.maxLat_);
-    idx = this.addParallel_(lat, squaredTolerance, extent, idx);
+    idx = this.addParallel_(lat, minLon, maxLon, squaredTolerance, extent, idx);
   }
 
   this.parallels_.length = idx;
@@ -285,18 +329,21 @@ ol.Graticule.prototype.getMap = function() {
 
 /**
  * @param {number} lon Longitude.
+ * @param {number} minLat Minimal latitude.
+ * @param {number} maxLat Maximal latitude.
  * @param {number} squaredTolerance Squared tolerance.
  * @return {ol.geom.LineString} The meridian line string.
  * @param {number} index Index.
  * @private
  */
-ol.Graticule.prototype.getMeridian_ = function(lon, squaredTolerance, index) {
+ol.Graticule.prototype.getMeridian_ = function(lon, minLat, maxLat,
+                                               squaredTolerance, index) {
   goog.asserts.assert(lon >= this.minLon_,
       'lon should be larger than or equal to this.minLon_');
   goog.asserts.assert(lon <= this.maxLon_,
       'lon should be smaller than or equal to this.maxLon_');
   var flatCoordinates = ol.geom.flat.geodesic.meridian(lon,
-      this.minLat_, this.maxLat_, this.projection_, squaredTolerance);
+      minLat, maxLat, this.projection_, squaredTolerance);
   goog.asserts.assert(flatCoordinates.length > 0,
       'flatCoordinates cannot be empty');
   var lineString = goog.isDef(this.meridians_[index]) ?
@@ -318,12 +365,15 @@ ol.Graticule.prototype.getMeridians = function() {
 
 /**
  * @param {number} lat Latitude.
+ * @param {number} minLon Minimal longitude.
+ * @param {number} maxLon Maximal longitude.
  * @param {number} squaredTolerance Squared tolerance.
  * @return {ol.geom.LineString} The parallel line string.
  * @param {number} index Index.
  * @private
  */
-ol.Graticule.prototype.getParallel_ = function(lat, squaredTolerance, index) {
+ol.Graticule.prototype.getParallel_ = function(lat, minLon, maxLon,
+                                               squaredTolerance, index) {
   goog.asserts.assert(lat >= this.minLat_,
       'lat should be larger than or equal to this.minLat_');
   goog.asserts.assert(lat <= this.maxLat_,
@@ -395,25 +445,48 @@ ol.Graticule.prototype.handlePostCompose_ = function(e) {
 ol.Graticule.prototype.updateProjectionInfo_ = function(projection) {
   goog.asserts.assert(!goog.isNull(projection), 'projection cannot be null');
 
+  var epsg4326Projection = ol.proj.get('EPSG:4326');
+
   var extent = projection.getExtent();
   var worldExtent = projection.getWorldExtent();
+  var worldExtentP = ol.proj.transformExtent(worldExtent,
+      epsg4326Projection, projection);
+
   var maxLat = worldExtent[3];
   var maxLon = worldExtent[2];
   var minLat = worldExtent[1];
   var minLon = worldExtent[0];
 
+  var maxLatP = worldExtentP[3];
+  var maxLonP = worldExtentP[2];
+  var minLatP = worldExtentP[1];
+  var minLonP = worldExtentP[0];
+
   goog.asserts.assert(!goog.isNull(extent), 'extent cannot be null');
   goog.asserts.assert(goog.isDef(maxLat), 'maxLat should be defined');
   goog.asserts.assert(goog.isDef(maxLon), 'maxLon should be defined');
   goog.asserts.assert(goog.isDef(minLat), 'minLat should be defined');
   goog.asserts.assert(goog.isDef(minLon), 'minLon should be defined');
 
+  goog.asserts.assert(goog.isDef(maxLatP),
+      'projected maxLat should be defined');
+  goog.asserts.assert(goog.isDef(maxLonP),
+      'projected maxLon should be defined');
+  goog.asserts.assert(goog.isDef(minLatP),
+      'projected minLat should be defined');
+  goog.asserts.assert(goog.isDef(minLonP),
+      'projected minLon should be defined');
+
   this.maxLat_ = maxLat;
   this.maxLon_ = maxLon;
   this.minLat_ = minLat;
   this.minLon_ = minLon;
 
-  var epsg4326Projection = ol.proj.get('EPSG:4326');
+  this.maxLatP_ = maxLatP;
+  this.maxLonP_ = maxLonP;
+  this.minLatP_ = minLatP;
+  this.minLonP_ = minLonP;
+
 
   this.fromLonLatTransform_ = ol.proj.getTransform(
       epsg4326Projection, projection);