tweaks in support of better rendering

robot.go

@@ -23,10 +23,11 @@ type Robot struct {
 // This is the subset of data we send to players about robots
 // that are not theirs.
 type OtherRobot struct {
-	Id       string    `json:"id"`
-	Name     string    `json:"name"`
-	Position v.Point2d `json:"position"`
-	Health   int       `json:"health"`
+	Id       string     `json:"id"`
+	Name     string     `json:"name"`
+	Position v.Point2d  `json:"position"`
+	Heading  v.Vector2d `json:"heading"`
+	Health   int        `json:"health"`
 }
 
 func (r Robot) GetTruncatedDetails() OtherRobot {
@@ -34,6 +35,7 @@ func (r Robot) GetTruncatedDetails() OtherRobot {
 		Id:       r.Id,
 		Name:     r.Name,
 		Position: r.Position,
+		Heading:  r.Heading,
 		Health:   r.Health,
 	}
 }