Use local font "Ubuntu Regular" for rendering tests

Set local font for all rendering tests including
TextStyles to enhance comparability on different
systems.

rendering/cases/layer-vector-decluttering/main.js

@@ -90,7 +90,7 @@ layer2.setStyle(function(feature) {
   return new Style({
     text: new Text({
       text: feature.get('text'),
-      font: '12px sans-serif'
+      font: '12px "Ubuntu Regular", sans-serif'
     })
   });
 });
@@ -119,7 +119,7 @@ layer3.setStyle(function(feature) {
     }),
     text: new Text({
       text: feature.get('text'),
-      font: '12px sans-serif',
+      font: '12px "Ubuntu Regular", sans-serif',
       textBaseline: 'bottom',
       offsetY: -5
     })
@@ -151,7 +151,7 @@ line.setStyle(new Style({
   text: new Text({
     placement: 'line',
     text: 'east-west',
-    font: '12px sans-serif'
+    font: '12px "Ubuntu Regular", sans-serif'
   })
 }));
 source4.addFeature(point);

rendering/cases/text-style-linestring-nice/main.js

@@ -23,6 +23,7 @@ feature1.setStyle(new Style({
   stroke: new Stroke({color: 'blue'}),
   text: new Text({
     text: 'Hello world',
+    font: '"Ubuntu Regular", sans-serif',
     placement: 'line'
   })
 }));
@@ -39,7 +40,7 @@ feature2.setStyle(new Style({
     textBaseline: 'bottom',
     textAlign: 'right',
     placement: 'line',
-    font: 'bold italic 0.8em serif'
+    font: 'bold italic 0.8em "Ubuntu Regular", sans-serif'
   })
 }));
 vectorSource.addFeature(feature2);
@@ -50,10 +51,11 @@ const feature3 = new Feature({geometry: lineString3});
 feature3.setStyle(new Style({
   stroke: new Stroke({color: 'blue'}),
   text: new Text({
+    font: '"Ubuntu Regular", sans-serif',
     text: 'Set properties'
   })
 }));
-feature3.getStyle().getText().setFont('bold italic 1.2em monospace');
+feature3.getStyle().getText().setFont('bold italic 1.2em "Ubuntu Regular", sans-serif');
 feature3.getStyle().getText().setTextAlign('left');
 feature3.getStyle().getText().setOffsetX(10);
 feature3.getStyle().getText().setOffsetY(-10);
@@ -71,6 +73,7 @@ feature4.setStyle(new Style({
   stroke: new Stroke({color: 'blue'}),
   text: new Text({
     text: 'negative offsetX',
+    font: '"Ubuntu Regular", sans-serif',
     offsetX: -10,
     textAlign: 'start',
     textBaseline: 'top',
@@ -86,6 +89,7 @@ feature5.setStyle(new Style({
   stroke: new Stroke({color: 'blue'}),
   text: new Text({
     text: 'Small text',
+    font: '"Ubuntu Regular", sans-serif',
     offsetY: 5,
     scale: 0.7,
     textAlign: 'end',
@@ -101,6 +105,7 @@ feature6.setStyle(new Style({
   stroke: new Stroke({color: 'blue'}),
   text: new Text({
     text: 'FILL AND STROKE',
+    font: '"Ubuntu Regular", sans-serif',
     placement: 'line',
     fill: new Fill({color: '#FFC0CB'}),
     stroke: new Stroke({

rendering/cases/text-style-linestring-ugly/main.js

@@ -20,6 +20,7 @@ feature1.setStyle(new Style({
   stroke: new Stroke({color: 'blue'}),
   text: new Text({
     text: 'Hello world',
+    font: '"Ubuntu Regular", sans-serif',
     placement: 'line',
     overflow: true
   })
@@ -37,7 +38,7 @@ feature2.setStyle(new Style({
     textBaseline: 'bottom',
     textAlign: 'right',
     placement: 'line',
-    font: 'bold italic 0.8em serif',
+    font: 'bold italic 0.8em "Ubuntu Regular", sans-serif',
     overflow: true
   })
 }));
@@ -72,6 +73,7 @@ feature4.setStyle(new Style({
   stroke: new Stroke({color: 'red'}),
   text: new Text({
     text: 'PLEASE OMIT ME IM UGLY',
+    font: '"Ubuntu Regular", sans-serif',
     offsetX: -10,
     textAlign: 'start',
     textBaseline: 'top',
@@ -88,6 +90,7 @@ feature5.setStyle(new Style({
   stroke: new Stroke({color: 'blue'}),
   text: new Text({
     text: 'Small text',
+    font: '"Ubuntu Regular", sans-serif',
     offsetY: 5,
     scale: 0.7,
     rotation: 4,
@@ -106,6 +109,7 @@ feature6.setStyle(new Style({
   stroke: new Stroke({color: 'blue'}),
   text: new Text({
     text: 'FILL AND STROKE',
+    font: '"Ubuntu Regular", sans-serif',
     placement: 'line',
     overflow: true,
     fill: new Fill({color: '#FFC0CB'}),

rendering/cases/text-style-overlap/main.js

@@ -19,6 +19,7 @@ const vectorSource = new VectorSource();
 const pointStyle = new Style({
   text: new Text({
     text: 'Point Label',
+    font: '"Ubuntu Regular", sans-serif',
     fill: new Fill({
       color: 'red'
     }),
@@ -31,6 +32,7 @@ const lineStyle = new Style({
   stroke: new Stroke({color: 'blue'}),
   text: new Text({
     text: 'Line Label',
+    font: '"Ubuntu Regular", sans-serif',
     fill: new Fill({
       color: 'red'
     }),

rendering/cases/text-style/main.js

@@ -20,7 +20,7 @@ feature = new Feature({
 feature.setStyle(new Style({
   text: new Text({
     text: 'hello',
-    font: '14px sans-serif',
+    font: '14px "Ubuntu Regular", sans-serif',
     scale: 2,
     fill: new Fill({
       color: 'red'
@@ -39,7 +39,7 @@ feature = new Feature({
 feature.setStyle(new Style({
   text: new Text({
     text: 'upside down',
-    font: '14px sans-serif',
+    font: '14px "Ubuntu Regular", sans-serif',
     rotation: Math.PI,
     stroke: new Stroke({
       color: 'red',
@@ -55,6 +55,7 @@ feature = new Feature({
 });
 feature.setStyle(new Style({
   text: new Text({
+    font: '"Ubuntu Regular", sans-serif',
     text: 'rotateWithView',
     rotateWithView: true,
     stroke: new Stroke({
@@ -71,7 +72,7 @@ feature = new Feature({
 feature.setStyle(new Style({
   text: new Text({
     text: 'hello',
-    font: '14px sans-serif',
+    font: '14px "Ubuntu Regular", sans-serif',
     padding: [1, 2, 3, 5],
     backgroundFill: new Fill({
       color: 'rgba(55, 55, 55, 0.25)'
@@ -91,7 +92,7 @@ feature = new Feature({
 feature.setStyle(new Style({
   text: new Text({
     text: 'hello',
-    font: '14px sans-serif',
+    font: '14px "Ubuntu Regular", sans-serif',
     padding: [1, 2, 3, 5],
     backgroundFill: new Fill({
       color: 'rgba(55, 55, 55, 0.25)'