Merge pull request #1418 from fredj/vector-api-lineCap

[vector-api] Set default canvas lineJoin and lineCap to 'round'

src/ol/render/canvas/canvas.js

@@ -18,7 +18,7 @@ ol.render.canvas.defaultFillStyle = ol.color.fromString('black');
 /**
  * @const {string}
  */
-ol.render.canvas.defaultLineCap = 'butt';
+ol.render.canvas.defaultLineCap = 'round';
 
 
 /**
@@ -30,7 +30,7 @@ ol.render.canvas.defaultLineDash = [];
 /**
  * @const {string}
  */
-ol.render.canvas.defaultLineJoin = 'miter';
+ol.render.canvas.defaultLineJoin = 'round';
 
 
 /**