Merge pull request #814 from tschaub/814-min-resolution

Fix vector rendering for projections that do not specify units

externs/proj4js.js

@@ -76,6 +76,12 @@ Proj4js.Proj.prototype.units;
 Proj4js.Proj.prototype.srsCode;
 
 
+/**
+ * @type {number}
+ */
+Proj4js.Proj.prototype.to_meter;
+
+
 /**
  * @nosideeffects
  * @param {Proj4js.Proj} source

src/ol/proj/proj.js

@@ -143,7 +143,15 @@ ol.Projection.prototype.getUnits = function() {
  * @return {number} Meters.
  */
 ol.Projection.prototype.getMetersPerUnit = function() {
-  return ol.METERS_PER_UNIT[this.units_];
+  var metersPerUnit;
+  if (!goog.isNull(this.units_)) {
+    metersPerUnit = ol.METERS_PER_UNIT[this.units_];
+  } else {
+    if (this instanceof ol.Proj4jsProjection_) {
+      metersPerUnit = this.getProj4jsProj().to_meter;
+    }
+  }
+  return metersPerUnit;
 };
 
 

src/ol/renderer/canvas/canvasvectorlayerrenderer.js

@@ -159,7 +159,7 @@ ol.renderer.canvas.VectorLayer = function(mapRenderer, layer) {
    * @private
    * @type {ol.TileRange}
    */
-  this.tileRange_ = null;
+  this.tileRange_ = new ol.TileRange(NaN, NaN, NaN, NaN);
 
   /**
    * @private
@@ -332,9 +332,12 @@ ol.renderer.canvas.VectorLayer.prototype.renderFrame =
   // lazy tile grid creation
   if (idle) {
     // avoid rendering issues for very high zoom levels
-    var gridResolution = Math.max(resolution,
+    var minResolution = ol.renderer.canvas.MIN_RESOLUTION;
-        ol.renderer.canvas.MIN_RESOLUTION /
+    var metersPerUnit = projection.getMetersPerUnit();
-        ol.METERS_PER_UNIT[projection.getUnits()]);
+    if (metersPerUnit) {
+      minResolution = minResolution / metersPerUnit;
+    }
+    var gridResolution = Math.max(resolution, minResolution);
     if (gridResolution !== this.renderedResolution_) {
       tileGrid = new ol.tilegrid.TileGrid({
         origin: [0, 0],
@@ -357,8 +360,8 @@ ol.renderer.canvas.VectorLayer.prototype.renderFrame =
   // set up transform for the layer canvas to be drawn to the map canvas
   var tileResolution = tileGrid.getResolution(0);
   if (idle) {
-    this.tileRange_ = tileGrid.getTileRangeForExtentAndResolution(
+    tileGrid.getTileRangeForExtentAndResolution(
-        extent, tileResolution);
+        extent, tileResolution, this.tileRange_);
   }
   var transform = this.transform_,
       tileRange = this.tileRange_,

test/spec/ol/proj/proj.test.js

@@ -313,11 +313,31 @@ describe('ol.proj', function() {
 
   describe('ol.Projection.prototype.getMetersPerUnit()', function() {
 
+    beforeEach(function() {
+      Proj4js.defs['EPSG:26782'] =
+          '+proj=lcc +lat_1=29.3 +lat_2=30.7 +lat_0=28.66666666666667 ' +
+          '+lon_0=-91.33333333333333 +x_0=609601.2192024384 +y_0=0 ' +
+          '+ellps=clrk66 +datum=NAD27 +to_meter=0.3048006096012192 +no_defs';
+      ol.proj.configureProj4jsProjection({
+        code: 'EPSG:26782'
+      });
+    });
+
+    afterEach(function() {
+      ol.proj.proj4jsProjections_ = {};
+      delete Proj4js.defs['EPSG:26782'];
+    });
+
     it('returns value in meters', function() {
       var epsg4326 = ol.proj.get('EPSG:4326');
       expect(epsg4326.getMetersPerUnit()).to.eql(111194.87428468118);
     });
 
+    it('works for proj4js projections without units', function() {
+      var epsg26782 = ol.proj.get('EPSG:26782');
+      expect(epsg26782.getMetersPerUnit()).to.eql(0.3048006096012192);
+    });
+
   });
 
   describe('ol.proj.configureProj4jsProjection()', function() {