Fix NPEs with tracker data

Author: g3force

internal/app/engine/common.go

@@ -73,7 +73,7 @@ func addDur(duration *duration.Duration, delta time.Duration) {
 }
 
 func (e *Engine) ballSteady() bool {
-	if e.gcState.TrackerStateGc.Ball.Vel == nil {
+	if e.gcState.TrackerStateGc.Ball == nil || e.gcState.TrackerStateGc.Ball.Vel == nil {
 		return true
 	}
 	return e.gcState.TrackerStateGc.Ball.Vel.ToVector2().Length() < ballSteadyThreshold

internal/app/engine/consume_tracker.go

@@ -15,6 +15,8 @@ func (e *Engine) ProcessTrackerFrame(wrapperFrame *tracker.TrackerWrapperPacket)
 		Robots:     convertRobots(wrapperFrame.TrackedFrame.Robots),
 	}
 
+	readyToContinue := e.readyToContinue()
+
 	e.UpdateGcState(func(gcState *GcState) {
 		gcState.TrackerState[*wrapperFrame.Uuid] = &state
 
@@ -24,7 +26,7 @@ func (e *Engine) ProcessTrackerFrame(wrapperFrame *tracker.TrackerWrapperPacket)
 		if e.gcState.ReadyToContinue == nil {
 			e.gcState.ReadyToContinue = new(bool)
 		}
-		*e.gcState.ReadyToContinue = e.readyToContinue()
+		*e.gcState.ReadyToContinue = readyToContinue
 	})
 }
 
@@ -51,7 +53,8 @@ func convertBalls(balls []*tracker.TrackedBall) *Ball {
 
 func (e *Engine) readyToContinue() bool {
 	radius := e.gameConfig.DistanceToBallInStop + robotRadius + distanceThreshold
-	if !e.ballSteady() ||
+	if e.gcState.TrackerStateGc.Ball == nil ||
+		!e.ballSteady() ||
 		e.robotsInsideRadius(e.gcState.TrackerStateGc.Robots, e.gcState.TrackerStateGc.Ball.Pos.ToVector2(), radius) {
 		return false
 	}

internal/app/engine/engine.go

@@ -48,6 +48,7 @@ func NewEngine(gameConfig config.Game) (e *Engine) {
 		state.Team_BLUE.String():   new(GcStateTeam),
 	}
 	e.gcState.AutoRefState = map[string]*GcStateAutoRef{}
+	e.gcState.TrackerState = map[string]*GcStateTracker{}
 	e.gcState.TrackerStateGc = new(GcStateTracker)
 	e.noProgressDetector = NoProgressDetector{gcEngine: e}
 	e.ballPlacementCoordinator = BallPlacementCoordinator{gcEngine: e}