[feature] Add tracker state to gcState

Author: g3force

internal/app/engine/ssl_gc_engine.pb.go

@@ -2,27 +2,62 @@ syntax = "proto2";
 
 option go_package = "github.com/RoboCup-SSL/ssl-game-controller/internal/app/engine";
 
+import "ssl_game_event.proto";
+
 message GcState {
     map<string, GcStateTeam> team_state = 1;
     map<string, GcStateAutoRef> auto_ref_state = 2;
+    map<string, GcStateTracker> tracker_state = 3;
 }
 
 message GcStateTeam {
+    // true: The team is connected
     optional bool connected = 1;
+
+    // true: The team connected via TLS with a verified certificate
     optional bool connection_verified = 2;
 }
 
 message GcStateAutoRef {
+    // true: The autoRef connected via TLS with a verified certificate
     optional bool connection_verified = 1;
 
+    // if current state is prepare_kickoff, prepare_penalty, stop or ball_placement:
+    // true: all conditions are met to continue from the current state
+    // false: at least one condition not met yet
+    // not present: not supported by the autoRef
+    // else:
+    // undefined
     optional bool ready_to_continue = 2;
+
+    // if current state is stop:
+    // true: ball placement not required, can directly continue
+    // false: need to initiate ball placement
+    // if current state is ball placement:
+    // true: ball placement done, all conditions met
+    // false: ball not yet placed successfully
     optional bool ball_placed = 3;
+
+    // UNIX timestamp [μs] when the ball last moved
+    // Used by the GC to determine if there is still progress
     optional uint64 last_progress = 4;
 
+    // map team -> team specific state
     map<string, GcStateAutoRefTeam> team_state = 5;
 }
 
 message GcStateAutoRefTeam {
+    // Number of robots currently on the field
     optional uint32 number_of_robots = 1;
+
+    // When the ball is in play, this flag indicates, if this team may change the keeper in confirmation with the rules
     optional bool may_change_keeper = 2;
 }
+
+message GcStateTracker {
+    // Current ball position [m]
+    optional Location ball_pos = 1;
+
+    // Current ball velocity [m/s]
+    optional Location ball_vel = 2;
+}