Merge pull request #1201 from DavidHudlow/FixComplexTriangulationFailure

Tolerate (but don't fully render) complex polygons

CHANGES.md

@@ -73,6 +73,7 @@ Beta Releases
   becomes
 
         return primitives.add(new Primitive(/* ... */));
+* Fixed bug in triangulation that fails on complex polygons. Instead, it makes a "best effort" to render what it can.
 
 ### b20 - 2013-09-03
 

Source/Core/GeometryPipeline.js

@@ -635,6 +635,11 @@ define([
 
         for ( var i = 0; i < values3D.length; i += 3) {
             var value = Cartesian3.fromArray(values3D, i, scratchProjectTo2DCartesian3);
+
+            if (Cartesian3.equals(value, Cartesian3.ZERO)) {
+                continue;
+            }
+
             var lonLat = ellipsoid.cartesianToCartographic(value, scratchProjectTo2DCartographic);
             var projectedLonLat = projection.project(lonLat, scratchProjectTo2DCartesian3);
 

Source/Core/PolygonGeometry.js

@@ -102,6 +102,10 @@ define([
         }
 
         var indices = PolygonPipeline.triangulate(positions2D);
+        /* If polygon is completely unrenderable, just use the first three vertices */
+        if (indices.length < 3) {
+            indices = [0, 1, 2];
+        }
         return new GeometryInstance({
             geometry : PolygonPipeline.computeSubdivision(positions, indices, granularity)
         });

Source/Core/PolygonPipeline.js

@@ -708,7 +708,6 @@ define([
      * @returns {Array} Index array representing triangles that fill the polygon
      *
      * @exception {DeveloperError} Invalid polygon: must have at least three vertices.
-     * @exception {DeveloperERror} Tried x times to find a vild cut and couldn't.
      *
      * @private
      */
@@ -736,7 +735,8 @@ define([
             // Make sure we don't go into an endless loop
             var maxTries = nodeArray.length * 10;
             if (tries > maxTries) {
-                throw new DeveloperError('Tried ' + maxTries + ' times to find a valid cut and couldn\'t.');
+                // Hopefully that part of the polygon isn't important
+                return [];
             }
             tries++;