Refactor to use better interfaces and event callbacks.

gamedata/enemystates.go

@@ -0,0 +1,12 @@
+package gamedata
+
+type EnemyState int
+
+const (
+	EnemyStateDefault = iota
+	EnemyStateHit
+	EnemyStateDying
+	EnemyStateExploding
+	EnemyStateDead
+	EnemyStateMax
+)

gamedata/gameevents.go

@@ -0,0 +1,11 @@
+package gamedata
+
+type GameEvent int
+
+const (
+	GameEventPlayerDeath = iota
+	GameEventCharge
+	GameEventNewShot
+	GameEventTargetHit
+	GameEventExplosion
+)

gamedata/gameinputs.go

@@ -0,0 +1,12 @@
+package gamedata
+
+type GameInputs struct {
+	XAxis     float64
+	YAxis     float64
+	ShotAngle float64
+	Shot      bool
+	Start     bool
+	Charge    bool
+	Quit      bool
+	Reset     bool
+}