Step 8: Add a Title Screen

Use the StateMachine to add a title screen before gameplay begins.

What you will learn

The GameState interface (Enter, Update, Draw, Exit)
Creating a StateMachine to manage game states
Switching between a title screen and gameplay
Drawing text with DrawText

The single Game struct from Step 6 has been split into three types. All gameplay fields and asset loading moved into PlayState. A new TitleState draws the start screen. The top-level Game just owns the state machine.

TitleState (new)

type TitleState struct {
	sm    *gosprite64.StateMachine
	blink int
	show  bool
}

func (s *TitleState) Enter() {
	s.show = true
}

func (s *TitleState) Update() {
	s.blink++
	if s.blink%30 == 0 {
		s.show = !s.show
	}
	if gosprite64.IsButtonJustPressed(gosprite64.ButtonA) || gosprite64.IsButtonJustPressed(gosprite64.ButtonStart) {
		s.sm.Switch(&PlayState{sm: s.sm})
	}
}

func (s *TitleState) Draw() {
	gosprite64.ClearScreenWith(gosprite64.DarkBlue)
	gosprite64.DrawText("PLATFORMER", 104, 60, gosprite64.White)
	gosprite64.DrawText("A GoSprite64 Tutorial", 60, 80, gosprite64.LightGray)
	if s.show {
		gosprite64.DrawText("PRESS START", 96, 140, gosprite64.Yellow)
	}
}

func (s *TitleState) Exit() {}

PlayState (moved from Game)

PlayState is the same code as Step 6's Game struct. The only difference is that it now implements GameState instead of the top-level Game interface, and it holds a reference to the state machine (sm). The Enter method replaces Init - asset loading happens there. Update and Draw are unchanged. Exit is empty.

Game (new top-level wrapper)

type Game struct {
	sm *gosprite64.StateMachine
}

func (g *Game) Init() {
	title := &TitleState{}
	g.sm = gosprite64.NewStateMachine(title)
	title.sm = g.sm
	g.sm.Init()
}

func (g *Game) Update() { g.sm.Update() }
func (g *Game) Draw()   { g.sm.Draw() }

How it works

The GameState interface

Every state implements four methods:

Method	When called
`Enter()`	State becomes active
`Update()`	Every frame
`Draw()`	Every frame after Update
`Exit()`	State is replaced

The StateMachine

NewStateMachine(title) creates the machine with an initial state. Init() calls Enter on it. From then on Game just forwards Update and Draw to the machine. Switch calls Exit on the current state, replaces it, and calls Enter on the new one.

The blinking text

A frame counter toggles "PRESS START" visibility every 30 frames (half a second at 60 FPS). DrawText renders a string at a screen pixel position in the given color using the engine's built-in font.

Build and run

go generate ./examples/platformer
GOENV=n64.env go1.24.5-embedded build -o examples/platformer/game.elf ./examples/platformer

The game now starts on a dark blue title screen with "PLATFORMER" and blinking "PRESS START" text. Press A or Start to switch to gameplay. All the movement, animation, and camera following from Step 6 works exactly as before.

GoSprite64 Documentation