What is “di:waypoint ” in BPMN?

[blertadhimitri]

Hi everyone!
I've been reading on the XML structure of BPMN files and I have understood everything expect the use of di:waypoint . Can anyone explain me what it is used for? Here is a small xml of a bpmn file:
<code>
<?xml version="1.0" encoding="UTF-8"?>
    <definitions id="Definition">
      <process processType="Private" isExecutable="true" id="Minimal" name="Minimal Process" >
      
     <!– nodes –>
        <startEvent id="_1" name="StartProcess" />
        <scriptTask id="_2" name="Hello" >
          <script>System.out.println("Hello World");</script>
        </scriptTask>
        <endEvent id="_3" name="EndProcess" >
            <terminateEventDefinition/>
        </endEvent>
   
        <!– connections –>
        <sequenceFlow id="_1-_2" sourceRef="_1" targetRef="_2" />
        <sequenceFlow id="_2-_3" sourceRef="_2" targetRef="_3" />
   
      </process>
   
      <bpmndi:BPMNDiagram>
        <bpmndi:BPMNPlane bpmnElement="Minimal" >
          <bpmndi:BPMNShape bpmnElement="_1" >
            <dc:Bounds x="15" y="91" width="48" height="48" />
          </bpmndi:BPMNShape>
          <bpmndi:BPMNShape bpmnElement="_2" >
            <dc:Bounds x="95" y="88" width="83" height="48" />
          </bpmndi:BPMNShape>
          <bpmndi:BPMNShape bpmnElement="_3" >
            <dc:Bounds x="258" y="86" width="48" height="48" />
          </bpmndi:BPMNShape>
          <bpmndi:BPMNEdge bpmnElement="_1-_2" >
            <di:waypoint x="39" y="115" />
            <di:waypoint x="75" y="46" />
            <di:waypoint x="136" y="112" />
          </bpmndi:BPMNEdge>
          <bpmndi:BPMNEdge bpmnElement="_2-_3" >
            <di:waypoint x="136" y="112" />
            <di:waypoint x="240" y="240" />
            <di:waypoint x="282" y="110" />
          </bpmndi:BPMNEdge>
        </bpmndi:BPMNPlane>
      </bpmndi:BPMNDiagram>
   
    </definitions>

[frederikherema1]

These are the points that are part of a sequenceflow, for example:


An edge is often depicted as a line with 2 or more points (i.e., one or more connected line segments) in the coordinate system, called waypoints. The first point typically intersects with the edge’s source, while the last point typically intersects with the edge’s target. Any points in between establish a route for the line to traverse in the diagram.

Having 3 waypoints mean the sequence-flow will be bent/curved in the middle somewhere.