feat(renderer): Add support for direct arc-based segments

lib/renderer/renderedsegment.js

@@ -2,7 +2,7 @@ import d3 from 'd3'
 import { forEach } from 'lodash'
 
 import interpolateLine from '../util/interpolate-line'
-
+import { distance } from '../util'
 /**
  * RenderedSegment
  */
@@ -85,6 +85,19 @@ export default class RenderedSegment {
       })
     }
 
+    // Check if this segment is to be drawn as an arc; if so replace render data
+    if (this.pathSegment.journeySegment && this.pathSegment.journeySegment.arc) {
+      const first = this.renderData[0]
+      const last = this.renderData[this.renderData.length - 1]
+      const arc = {
+        x: last.x,
+        y: last.y,
+        arc: -45,
+        radius: distance(first.x, first.y, last.x, last.y)
+      }
+      this.renderData = [first, arc, last]
+    }
+
     var lineData = this.line(this.renderData)
     this.lineGraph.attr('d', lineData)
     this.lineGraphFront.attr('d', lineData)