fix(dcmjs): Store an optional second point for the arrow annotation

The point TID300 normally takes 1 point, but seems to be ok if an extra
one is added for the source of the indicator.

Author: wayfarer3130

src/adapters/Cornerstone/ArrowAnnotate.js

@@ -8,7 +8,6 @@ const CORNERSTONEFREETEXT = "CORNERSTONEFREETEXT";
 class ArrowAnnotate {
     constructor() {}
 
-    // TODO: this function is required for all Cornerstone Tool Adapters, since it is called by MeasurementReport.
     static getMeasurementData(MeasurementGroup) {
         const {
             defaultState,
@@ -31,11 +30,17 @@ class ArrowAnnotate {
                     highlight: true,
                     active: false
                 },
-                // TODO: How do we choose where the end goes?
-                // Just put it pointing from the bottom right for now?
+                // Use a generic offset if the stored data doesn't have the endpoint, otherwise
+                // use the actual endpoint.
                 end: {
-                    x: GraphicData[0] + 20,
-                    y: GraphicData[1] + 20,
+                    x:
+                        GraphicData.length == 4
+                            ? GraphicData[2]
+                            : GraphicData[0] + 20,
+                    y:
+                        GraphicData.length == 4
+                            ? GraphicData[3]
+                            : GraphicData[1] + 20,
                     highlight: true,
                     active: false
                 },
@@ -56,7 +61,7 @@ class ArrowAnnotate {
     }
 
     static getTID300RepresentationArguments(tool) {
-        const points = [tool.handles.start];
+        const points = [tool.handles.start, tool.handles.end];
 
         let { finding, findingSites } = tool;
 

src/utilities/TID300/Point.js

@@ -12,7 +12,12 @@ export default class Point extends TID300Measurement {
         const GraphicData = use3DSpatialCoordinates
             ? [points[0].x, points[0].y, points[0].z]
             : [points[0].x, points[0].y];
-
+        // Allow storing another point as part of an indicator showing a single point
+        if (points.length == 2) {
+            GraphicData.push(points[1].x);
+            GraphicData.push(points[1].y);
+            if (use3DSpatialCoordinates) GraphicData.push(points[1].z);
+        }
         return this.getMeasurement([
             {
                 RelationshipType: "CONTAINS",