feat: refactor gameplay logic from main.go to a state machine handler.

game/state/handlers/gameplay.go

@@ -0,0 +1,130 @@
+package handlers
+
+import (
+	"fmt"
+	"image/color"
+
+	"tetris/assets"
+	"tetris/engine/audio"
+	"tetris/engine/core"
+	"tetris/engine/render"
+	"tetris/game"
+	"tetris/game/draw"
+	"tetris/game/state"
+
+	rl "github.com/gen2brain/raylib-go/raylib"
+)
+
+type GamePlay struct {
+	shape      game.Shape
+	shape_pos  core.Vec2i8
+	score      game.Score
+	dropTimer  core.IntervalTimer
+	moveTimer  core.IntervalTimer
+	grid       game.Grid
+	nextShape  game.Shape
+	shapeQueue *game.ShapeQueue
+	r          draw.Renderer
+}
+
+func NewGamePlay() *GamePlay {
+	return &GamePlay{
+		dropTimer: core.NewIntervalTimer(0.3),
+		moveTimer: core.NewIntervalTimer(0.1),
+		r: draw.Renderer{
+			Theme: &draw.Theme{
+				FrameBG:        color.RGBA{R: 30, G: 30, B: 46, A: 255},
+				FrameBorder:    color.RGBA{R: 242, G: 205, B: 205, A: 255},
+				TextHeader:     color.RGBA{R: 242, G: 205, B: 205, A: 255},
+				Text:           color.RGBA{R: 205, G: 214, B: 244, A: 255},
+				GridBackground: color.RGBA{R: 17, G: 17, B: 27, A: 255},
+			},
+		},
+	}
+}
+
+func (gp *GamePlay) Enter() {
+	gp.shapeQueue = game.NewShapeQueue()
+	gp.nextShape = gp.shapeQueue.Next()
+	gp.SpawnShape()
+}
+
+func (GamePlay) Exit() {
+}
+
+func (gp *GamePlay) SpawnShape() {
+	gp.shape = gp.nextShape
+	gp.nextShape = gp.shapeQueue.Next()
+	gp.shape_pos = core.Vec2i8{X: 4, Y: 0}
+}
+
+func (gp *GamePlay) LockShape() {
+	audio.Play(assets.SFX_SHAPE_LOCKED)
+
+	for _, block := range gp.shape.Coordinates() {
+		block = gp.shape_pos.Add(block)
+		// Check bounds
+		if block.X < 0 || block.X > int8(gp.grid.Width()) || block.Y < 0 || block.Y > int8(gp.grid.Height()) {
+			continue
+		}
+		gp.grid.Set(byte(block.X), byte(block.Y), gp.shape.GetBlock())
+	}
+}
+
+func (gp *GamePlay) Update(fsm state.Transitioner, delta float32) {
+	if rl.IsKeyPressed(rl.KeyDown) {
+		gp.dropTimer.SetInterval(0.05)
+	} else if rl.IsKeyReleased(rl.KeyDown) {
+		gp.dropTimer.SetInterval(0.3)
+	}
+
+	if rl.IsKeyPressed(rl.KeyUp) {
+		rotated := gp.shape.RotateCW()
+		if !game.CheckShapeCollision(gp.shape_pos, &rotated, &gp.grid) {
+			gp.shape = rotated
+		}
+	}
+
+	if gp.moveTimer.UpdateReset(delta) && (rl.IsKeyDown(rl.KeyLeft) || rl.IsKeyDown(rl.KeyRight)) {
+		new_pos := gp.shape_pos
+		if rl.IsKeyDown(rl.KeyLeft) {
+			new_pos.X -= 1
+		} else {
+			new_pos.X += 1
+		}
+		if !game.CheckShapeCollision(new_pos, &gp.shape, &gp.grid) {
+			gp.shape_pos.X = new_pos.X
+		}
+	}
+
+	if gp.dropTimer.UpdateReset(delta) {
+		new_pos := gp.shape_pos
+		new_pos.Y += 1
+
+		// Update position if it does not collide
+		if game.CheckShapeCollision(new_pos, &gp.shape, &gp.grid) {
+			gp.LockShape()
+			num_rows := gp.grid.ClearFullRows()
+			if num_rows > 0 {
+				audio.Play(assets.SFX_ROW_CLEARED)
+				gp.score.Lines(num_rows)
+			}
+			gp.SpawnShape()
+		} else {
+			gp.shape_pos = new_pos
+		}
+	}
+}
+
+func (gp GamePlay) Render() {
+	render.Begin(gp.r.Theme.GridBackground)
+	gp.r.DrawGrid(rl.NewVector2(25, 25), gp.grid)
+	draw.DrawShape(rl.NewVector2(25, 25), gp.shape_pos, gp.shape)
+	gp.r.DrawFrame(rl.RectangleInt32{X: 400, Y: 25, Width: 250, Height: 100})
+	gp.r.DrawHeaderText(410, 30, "Score")
+	gp.r.DrawText(410, 65, fmt.Sprintf("%.7d", gp.score))
+	gp.r.DrawFrame(rl.RectangleInt32{X: 400, Y: 150, Width: 250, Height: 200})
+	gp.r.DrawHeaderText(410, 155, "Next")
+	draw.DrawShape(rl.NewVector2(450, 150), core.NewVec2[int8](1, 3), gp.nextShape)
+	render.End()
+}

main.go

@@ -1,120 +1,17 @@
 package main
 
 import (
-	"fmt"
-	"image/color"
-
 	"tetris/assets"
 	"tetris/engine/audio"
-	"tetris/engine/core"
 	"tetris/engine/graphics"
 	"tetris/engine/render"
-	"tetris/game"
+	"tetris/game/state/handlers"
-	"tetris/game/draw"
+	"tetris/game/state/machine"
 
 	rl "github.com/gen2brain/raylib-go/raylib"
 )
 
-var (
-	shape      game.Shape
-	shape_pos  core.Vec2i8
-	score      game.Score
-	dropTimer  = core.NewIntervalTimer(0.3)
-	moveTimer  = core.NewIntervalTimer(0.1)
-	grid       = game.Grid{}
-	nextShape  = game.NewShape(game.SHAPE_O)
-	shapeQueue = game.NewShapeQueue()
-
-	r = draw.Renderer{
-		Theme: &draw.Theme{
-			FrameBG:        color.RGBA{R: 30, G: 30, B: 46, A: 255},
-			FrameBorder:    color.RGBA{R: 242, G: 205, B: 205, A: 255},
-			TextHeader:     color.RGBA{R: 242, G: 205, B: 205, A: 255},
-			Text:           color.RGBA{R: 205, G: 214, B: 244, A: 255},
-			GridBackground: color.RGBA{R: 17, G: 17, B: 27, A: 255},
-		},
-	}
-)
-
-func SpawnShape() {
-	shape = nextShape
-	nextShape = shapeQueue.Next()
-	shape_pos = core.Vec2i8{X: 4, Y: 0}
-}
-
-func LockShape() {
-	audio.Play(assets.SFX_SHAPE_LOCKED)
-
-	for _, block := range shape.Coordinates() {
-		block = shape_pos.Add(block)
-		// Check bounds
-		if block.X < 0 || block.X > int8(grid.Width()) || block.Y < 0 || block.Y > int8(grid.Height()) {
-			continue
-		}
-		grid.Set(byte(block.X), byte(block.Y), shape.GetBlock())
-	}
-}
-
-func Update(delta float32) {
-	if rl.IsKeyPressed(rl.KeyDown) {
-		dropTimer.SetInterval(0.05)
-	} else if rl.IsKeyReleased(rl.KeyDown) {
-		dropTimer.SetInterval(0.3)
-	}
-
-	if rl.IsKeyPressed(rl.KeyUp) {
-		rotated := shape.RotateCW()
-		if !game.CheckShapeCollision(shape_pos, &rotated, &grid) {
-			shape = rotated
-		}
-	}
-
-	if moveTimer.UpdateReset(delta) && (rl.IsKeyDown(rl.KeyLeft) || rl.IsKeyDown(rl.KeyRight)) {
-		new_pos := shape_pos
-		if rl.IsKeyDown(rl.KeyLeft) {
-			new_pos.X -= 1
-		} else {
-			new_pos.X += 1
-		}
-		if !game.CheckShapeCollision(new_pos, &shape, &grid) {
-			shape_pos.X = new_pos.X
-		}
-	}
-
-	if dropTimer.UpdateReset(delta) {
-		new_pos := shape_pos
-		new_pos.Y += 1
-
-		// Update position if it does not collide
-		if game.CheckShapeCollision(new_pos, &shape, &grid) {
-			LockShape()
-			num_rows := grid.ClearFullRows()
-			if num_rows > 0 {
-				audio.Play(assets.SFX_ROW_CLEARED)
-				score.Lines(num_rows)
-			}
-			SpawnShape()
-		} else {
-			shape_pos = new_pos
-		}
-	}
-}
-
-func Render() {
-	render.Begin(r.Theme.GridBackground)
-	r.DrawGrid(rl.NewVector2(25, 25), grid)
-	draw.DrawShape(rl.NewVector2(25, 25), shape_pos, shape)
-	r.DrawFrame(rl.RectangleInt32{X: 400, Y: 25, Width: 250, Height: 100})
-	r.DrawHeaderText(410, 30, "Score")
-	r.DrawText(410, 65, fmt.Sprintf("%.7d", score))
-	r.DrawFrame(rl.RectangleInt32{X: 400, Y: 150, Width: 250, Height: 200})
-	r.DrawHeaderText(410, 155, "Next")
-	draw.DrawShape(rl.NewVector2(450, 150), core.NewVec2[int8](1, 3), nextShape)
-	render.End()
-}
-
 func main() {
-	// Set random blocks to test
 	render.Init(render.Config{
 		Title:        "Tetris",
 		WindowWidth:  685,
@@ -136,13 +33,15 @@ func main() {
 	render.SetTexture(texture)
 	render.SetFont(&assets.Font)
 
-	nextShape = shapeQueue.Next()
+	// Setup state machine.
-
+	fsm := machine.New()
-	SpawnShape()
+	fsm.Register("gameplay", handlers.NewGamePlay())
+	fsm.Start("gameplay")
 
+	// Enter game loop
 	for !rl.WindowShouldClose() {
 		audio.Update()
-		Update(rl.GetFrameTime())
+		fsm.Update(rl.GetFrameTime())
-		Render()
+		fsm.Render()
 	}
 }