Using a temp free online sprite for now to test sprites

internal/game/game.go

@@ -13,18 +13,57 @@ import (
 	"github.com/atridad/BigFeelings/internal/ui/menu"
 )
 
+// ============================================================
+// CONFIGURATION
+// Tweak these values to change game settings
+// ============================================================
+
 const (
 	ScreenWidth  = 960
 	ScreenHeight = 540
-
-	TargetTPS   = 60
-	WindowTitle = "Big Feelings"
+	TargetTPS    = 60
+	WindowTitle  = "Big Feelings"
 )
 
 var (
 	backgroundColor = color.NRGBA{R: 0, G: 0, B: 0, A: 255}
 )
 
+// Hero configuration
+const (
+	heroStartX       = ScreenWidth / 2
+	heroStartY       = ScreenHeight / 2
+	heroRadius       = 28.0
+	heroSpeed        = 180.0
+	heroMaxStamina   = 100.0
+	heroStaminaDrain = 50.0
+	heroStaminaRegen = 30.0
+)
+
+var (
+	heroColor = color.NRGBA{R: 210, G: 220, B: 255, A: 255}
+)
+
+// HUD configuration
+const (
+	hudX = ScreenWidth - 220
+	hudY = 20
+)
+
+// Stamina bar colors
+var (
+	staminaNormalColor = color.NRGBA{R: 0, G: 255, B: 180, A: 255}
+	staminaLowColor    = color.NRGBA{R: 255, G: 60, B: 60, A: 255}
+)
+
+const (
+	staminaLowThreshold = 0.2
+)
+
+// ============================================================
+// TYPES
+// ============================================================
+
 type gameState int
 
 const (
@@ -40,63 +79,10 @@ type controls struct {
 	Sprint bool
 }
 
-func readControls() controls {
-	return controls{
-		Left:   ebiten.IsKeyPressed(ebiten.KeyArrowLeft) || ebiten.IsKeyPressed(ebiten.KeyA),
-		Right:  ebiten.IsKeyPressed(ebiten.KeyArrowRight) || ebiten.IsKeyPressed(ebiten.KeyD),
-		Up:     ebiten.IsKeyPressed(ebiten.KeyArrowUp) || ebiten.IsKeyPressed(ebiten.KeyW),
-		Down:   ebiten.IsKeyPressed(ebiten.KeyArrowDown) || ebiten.IsKeyPressed(ebiten.KeyS),
-		Sprint: ebiten.IsKeyPressed(ebiten.KeyShift),
-	}
-}
-
 type Game struct {
 	state *state
 }
 
-func New() *Game {
-	return &Game{state: newState()}
-}
-
-func (g *Game) Update() error {
-	// Handle escape key to toggle pause
-	if inpututil.IsKeyJustPressed(ebiten.KeyEscape) {
-		if g.state.gameState == statePlaying {
-			g.state.gameState = statePaused
-			g.state.pauseMenu.Reset()
-		} else if g.state.gameState == statePaused {
-			g.state.gameState = statePlaying
-			// Reset lastTick to prevent delta time accumulation while paused
-			g.state.lastTick = time.Now()
-		}
-	}
-
-	if g.state.gameState == statePlaying {
-		g.state.update(readControls())
-	} else if g.state.gameState == statePaused {
-		if selectedOption := g.state.pauseMenu.Update(); selectedOption != nil {
-			switch *selectedOption {
-			case menu.OptionResume:
-				g.state.gameState = statePlaying
-				// Reset lastTick to prevent delta time accumulation while paused
-				g.state.lastTick = time.Now()
-			case menu.OptionQuit:
-				return ebiten.Termination
-			}
-		}
-	}
-
-	return nil
-}
-
-func (g *Game) Draw(screen *ebiten.Image) {
-	g.state.draw(screen)
-}
-
-func (g *Game) Layout(outsideWidth, outsideHeight int) (int, int) {
-	return ScreenWidth, ScreenHeight
-}
-
 type state struct {
 	hero      *hero.Hero
 	hud       hud.Overlay
@@ -106,22 +92,30 @@ type state struct {
 	gameState gameState
 }
 
+// ============================================================
+// INITIALIZATION
+// ============================================================
+
+func New() *Game {
+	return &Game{state: newState()}
+}
+
 func newState() *state {
 	now := time.Now()
 	return &state{
 		hero: hero.New(hero.Config{
-			StartX:       ScreenWidth / 2,
-			StartY:       ScreenHeight / 2,
-			Radius:       28,
-			Speed:        180,
-			Color:        color.NRGBA{R: 210, G: 220, B: 255, A: 255},
-			MaxStamina:   100,
-			StaminaDrain: 50,
-			StaminaRegen: 30,
+			StartX:       heroStartX,
+			StartY:       heroStartY,
+			Radius:       heroRadius,
+			Speed:        heroSpeed,
+			Color:        heroColor,
+			MaxStamina:   heroMaxStamina,
+			StaminaDrain: heroStaminaDrain,
+			StaminaRegen: heroStaminaRegen,
 		}),
 		hud: hud.Overlay{
-			X:     ScreenWidth - 220,
-			Y:     20,
+			X:     hudX,
+			Y:     hudY,
 			Color: color.White,
 		},
 		bounds: hero.Bounds{
@@ -134,6 +128,52 @@ func newState() *state {
 	}
 }
 
+// ============================================================
+// INPUT
+// ============================================================
+
+func readControls() controls {
+	return controls{
+		Left:   ebiten.IsKeyPressed(ebiten.KeyArrowLeft) || ebiten.IsKeyPressed(ebiten.KeyA),
+		Right:  ebiten.IsKeyPressed(ebiten.KeyArrowRight) || ebiten.IsKeyPressed(ebiten.KeyD),
+		Up:     ebiten.IsKeyPressed(ebiten.KeyArrowUp) || ebiten.IsKeyPressed(ebiten.KeyW),
+		Down:   ebiten.IsKeyPressed(ebiten.KeyArrowDown) || ebiten.IsKeyPressed(ebiten.KeyS),
+		Sprint: ebiten.IsKeyPressed(ebiten.KeyShift),
+	}
+}
+
+// ============================================================
+// UPDATE
+// ============================================================
+
+func (g *Game) Update() error {
+	if inpututil.IsKeyJustPressed(ebiten.KeyEscape) {
+		if g.state.gameState == statePlaying {
+			g.state.gameState = statePaused
+			g.state.pauseMenu.Reset()
+		} else if g.state.gameState == statePaused {
+			g.state.gameState = statePlaying
+			g.state.lastTick = time.Now()
+		}
+	}
+
+	if g.state.gameState == statePlaying {
+		g.state.update(readControls())
+	} else if g.state.gameState == statePaused {
+		if selectedOption := g.state.pauseMenu.Update(); selectedOption != nil {
+			switch *selectedOption {
+			case menu.OptionResume:
+				g.state.gameState = statePlaying
+				g.state.lastTick = time.Now()
+			case menu.OptionQuit:
+				return ebiten.Termination
+			}
+		}
+	}
+
+	return nil
+}
+
 func (s *state) update(input controls) {
 	now := time.Now()
 	dt := now.Sub(s.lastTick).Seconds()
@@ -148,14 +188,21 @@ func (s *state) update(input controls) {
 	}, dt, s.bounds)
 }
 
+// ============================================================
+// RENDERING
+// ============================================================
+
+func (g *Game) Draw(screen *ebiten.Image) {
+	g.state.draw(screen)
+}
+
 func (s *state) draw(screen *ebiten.Image) {
 	screen.Fill(backgroundColor)
 	s.hero.Draw(screen)
 
-	// Create stamina meter from hero's stamina
-	staminaColor := color.NRGBA{R: 0, G: 255, B: 180, A: 255}
-	if s.hero.Stamina < s.hero.MaxStamina*0.2 {
-		staminaColor = color.NRGBA{R: 255, G: 60, B: 60, A: 255}
+	staminaColor := staminaNormalColor
+	if s.hero.Stamina < s.hero.MaxStamina*staminaLowThreshold {
+		staminaColor = staminaLowColor
 	}
 
 	staminaMeter := status.Meter{
@@ -166,8 +213,11 @@ func (s *state) draw(screen *ebiten.Image) {
 	}
 	s.hud.Draw(screen, []status.Meter{staminaMeter})
 
-	// Draw pause menu if paused
 	if s.gameState == statePaused {
 		s.pauseMenu.Draw(screen, ScreenWidth, ScreenHeight)
 	}
 }
+
+func (g *Game) Layout(outsideWidth, outsideHeight int) (int, int) {
+	return ScreenWidth, ScreenHeight
+}

internal/hero/hero.go

@@ -5,10 +5,37 @@ import (
 	"math"
 
 	"github.com/hajimehoshi/ebiten/v2"
-	"github.com/hajimehoshi/ebiten/v2/vector"
 )
 
-// Direction flags from the controls.
+// ============================================================
+// CONFIGURATION
+// Tweak these values to change gameplay behavior
+// ============================================================
+
+const (
+	// Default values if not specified in config
+	defaultRadius       = 24.0
+	defaultSpeed        = 180.0
+	defaultMaxStamina   = 100.0
+	defaultStaminaDrain = 50.0 // Per second when sprinting
+	defaultStaminaRegen = 30.0 // Per second when not sprinting
+
+	// Sprint mechanics
+	sprintSpeedMultiplier   = 2.0
+	sprintRecoveryThreshold = 0.2 // 20% stamina needed to sprint again
+
+	// Animation
+	normalAnimSpeed = 0.15 // Seconds per frame when walking
+	sprintAnimSpeed = 0.08 // Seconds per frame when sprinting
+
+	// Visual state thresholds
+	exhaustedThreshold = 0.2 // Show exhausted state below 20% stamina
+)
+
+// ============================================================
+// TYPES
+// ============================================================
+
 type Input struct {
 	Left   bool
 	Right  bool
@@ -17,13 +44,11 @@ type Input struct {
 	Sprint bool
 }
 
-// Playfield limits for movement.
 type Bounds struct {
 	Width  float64
 	Height float64
 }
 
-// Visual states for the hero.
 type VisualState int
 
 const (
@@ -32,23 +57,42 @@ const (
 	StateExhausted
 )
 
-// Player avatar data.
+type Direction int
+
+const (
+	DirDown Direction = iota
+	DirUp
+	DirLeft
+	DirRight
+)
+
 type Hero struct {
-	X             float64
-	Y             float64
-	Radius        float64
-	Speed         float64
-	Color         color.NRGBA
-	Stamina       float64
-	MaxStamina    float64
-	StaminaDrain  float64
-	StaminaRegen  float64
+	// Position and size
+	X      float64
+	Y      float64
+	Radius float64
+
+	// Movement
+	Speed float64
+
+	// Appearance
+	Color color.NRGBA
+
+	// Stamina system
+	Stamina      float64
+	MaxStamina   float64
+	StaminaDrain float64
+	StaminaRegen float64
+
+	// Internal state
 	canSprint     bool
 	wasSprintHeld bool
 	isSprinting   bool
+	direction     Direction
+	animFrame     int
+	animTimer     float64
 }
 
-// Spawn settings for the avatar.
 type Config struct {
 	StartX       float64
 	StartY       float64
@@ -60,25 +104,28 @@ type Config struct {
 	StaminaRegen float64
 }
 
-// Builds an avatar from the config with fallbacks.
+// ============================================================
+// INITIALIZATION
+// ============================================================
+
 func New(cfg Config) *Hero {
 	if cfg.Radius <= 0 {
-		cfg.Radius = 24
+		cfg.Radius = defaultRadius
 	}
 	if cfg.Speed <= 0 {
-		cfg.Speed = 180
+		cfg.Speed = defaultSpeed
 	}
 	if cfg.Color.A == 0 {
 		cfg.Color = color.NRGBA{R: 210, G: 220, B: 255, A: 255}
 	}
 	if cfg.MaxStamina <= 0 {
-		cfg.MaxStamina = 100
+		cfg.MaxStamina = defaultMaxStamina
 	}
 	if cfg.StaminaDrain <= 0 {
-		cfg.StaminaDrain = 50
+		cfg.StaminaDrain = defaultStaminaDrain
 	}
 	if cfg.StaminaRegen <= 0 {
-		cfg.StaminaRegen = 30
+		cfg.StaminaRegen = defaultStaminaRegen
 	}
 
 	return &Hero{
@@ -93,24 +140,40 @@ func New(cfg Config) *Hero {
 		StaminaRegen:  cfg.StaminaRegen,
 		canSprint:     true,
 		wasSprintHeld: false,
+		direction:     DirDown,
+		animFrame:     0,
+		animTimer:     0,
 	}
 }
 
-// Applies movement input and clamps to the playfield.
+// ============================================================
+// UPDATE
+// ============================================================
+
 func (h *Hero) Update(input Input, dt float64, bounds Bounds) {
+	h.updateMovement(input, dt, bounds)
+	h.updateStamina(input, dt)
+	h.updateAnimation(input, dt)
+}
+
+func (h *Hero) updateMovement(input Input, dt float64, bounds Bounds) {
 	dx, dy := 0.0, 0.0
 
 	if input.Left {
 		dx -= 1
+		h.direction = DirLeft
 	}
 	if input.Right {
 		dx += 1
+		h.direction = DirRight
 	}
 	if input.Up {
 		dy -= 1
+		h.direction = DirUp
 	}
 	if input.Down {
 		dy += 1
+		h.direction = DirDown
 	}
 
 	isMoving := dx != 0 || dy != 0
@@ -122,28 +185,9 @@ func (h *Hero) Update(input Input, dt float64, bounds Bounds) {
 	}
 
 	speed := h.Speed
-
-	if !input.Sprint {
-		h.wasSprintHeld = false
-		if h.Stamina >= h.MaxStamina*0.2 {
-			h.canSprint = true
-		}
-	}
-
 	h.isSprinting = input.Sprint && h.canSprint && h.Stamina > 0 && isMoving
 	if h.isSprinting {
-		speed *= 2.0
-		h.wasSprintHeld = true
-		h.Stamina -= h.StaminaDrain * dt
-		if h.Stamina <= 0 {
-			h.Stamina = 0
-			h.canSprint = false
-		}
-	} else {
-		h.Stamina += h.StaminaRegen * dt
-		if h.Stamina > h.MaxStamina {
-			h.Stamina = h.MaxStamina
-		}
+		speed *= sprintSpeedMultiplier
 	}
 
 	h.X += dx * speed * dt
@@ -156,9 +200,54 @@ func (h *Hero) Update(input Input, dt float64, bounds Bounds) {
 	h.Y = clamp(h.Y, h.Radius, maxY)
 }
 
-// Returns the current visual state based on hero state.
+func (h *Hero) updateStamina(input Input, dt float64) {
+	if !input.Sprint {
+		h.wasSprintHeld = false
+		if h.Stamina >= h.MaxStamina*sprintRecoveryThreshold {
+			h.canSprint = true
+		}
+	}
+
+	if h.isSprinting {
+		h.wasSprintHeld = true
+		h.Stamina -= h.StaminaDrain * dt
+		if h.Stamina <= 0 {
+			h.Stamina = 0
+			h.canSprint = false
+		}
+	} else {
+		h.Stamina += h.StaminaRegen * dt
+		if h.Stamina > h.MaxStamina {
+			h.Stamina = h.MaxStamina
+		}
+	}
+}
+
+func (h *Hero) updateAnimation(input Input, dt float64) {
+	isMoving := input.Left || input.Right || input.Up || input.Down
+
+	if isMoving {
+		animSpeed := normalAnimSpeed
+		if h.isSprinting {
+			animSpeed = sprintAnimSpeed
+		}
+		h.animTimer += dt
+		if h.animTimer >= animSpeed {
+			h.animTimer = 0
+			h.animFrame = 1 - h.animFrame
+		}
+	} else {
+		h.animFrame = 0
+		h.animTimer = 0
+	}
+}
+
+// ============================================================
+// STATE
+// ============================================================
+
 func (h *Hero) getVisualState() VisualState {
-	if h.Stamina < h.MaxStamina*0.2 {
+	if h.Stamina < h.MaxStamina*exhaustedThreshold {
 		return StateExhausted
 	}
 
@@ -169,175 +258,70 @@ func (h *Hero) getVisualState() VisualState {
 	return StateIdle
 }
 
-// Renders the avatar.
+// ============================================================
+// RENDERING
+// ============================================================
+
 func (h *Hero) Draw(screen *ebiten.Image) {
-	state := h.getVisualState()
+	sprite := h.getCurrentSprite()
 
-	vector.FillCircle(
-		screen,
-		float32(h.X),
-		float32(h.Y),
-		float32(h.Radius),
-		h.Color,
-		false,
-	)
+	if sprite != nil {
+		op := &ebiten.DrawImageOptions{}
+		bounds := sprite.Bounds()
+		w, height := float64(bounds.Dx()), float64(bounds.Dy())
+		op.GeoM.Translate(-w/2, -height/2)
+		op.GeoM.Translate(h.X, h.Y)
 
-	eyeOffsetX := h.Radius * 0.3
-	eyeOffsetY := h.Radius * 0.25
+		state := h.getVisualState()
+		switch state {
+		case StateExhausted:
+			op.ColorScale.ScaleWithColor(color.RGBA{R: 255, G: 100, B: 100, A: 255})
+		case StateSprinting:
+			// No color change
+		case StateIdle:
+			// No color change
+		}
 
-	switch state {
-	case StateExhausted:
-		drawExhaustedFace(screen, h.X, h.Y, h.Radius, eyeOffsetX, eyeOffsetY)
-	case StateSprinting:
-		drawSprintingFace(screen, h.X, h.Y, h.Radius, eyeOffsetX, eyeOffsetY)
-	case StateIdle:
-		drawIdleFace(screen, h.X, h.Y, h.Radius, eyeOffsetX, eyeOffsetY)
+		screen.DrawImage(sprite, op)
 	}
 }
 
-func drawIdleFace(screen *ebiten.Image, x, y, radius, eyeOffsetX, eyeOffsetY float64) {
-	eyeRadius := radius * 0.15
+func (h *Hero) getCurrentSprite() *ebiten.Image {
+	var sprite *ebiten.Image
 
-	vector.FillCircle(
-		screen,
-		float32(x-eyeOffsetX),
-		float32(y-eyeOffsetY),
-		float32(eyeRadius),
-		color.NRGBA{R: 0, G: 0, B: 0, A: 255},
-		false,
-	)
-
-	vector.FillCircle(
-		screen,
-		float32(x+eyeOffsetX),
-		float32(y-eyeOffsetY),
-		float32(eyeRadius),
-		color.NRGBA{R: 0, G: 0, B: 0, A: 255},
-		false,
-	)
-
-	smileRadius := radius * 0.5
-	smileY := y + radius*0.15
-	for angle := 0.3; angle <= 2.84; angle += 0.15 {
-		smileX := x + smileRadius*math.Cos(angle)
-		smileYPos := smileY + smileRadius*0.3*math.Sin(angle)
-		vector.FillCircle(
-			screen,
-			float32(smileX),
-			float32(smileYPos),
-			float32(radius*0.08),
-			color.NRGBA{R: 0, G: 0, B: 0, A: 255},
-			false,
-		)
-	}
-}
-
-func drawSprintingFace(screen *ebiten.Image, x, y, radius, eyeOffsetX, eyeOffsetY float64) {
-	eyeWidth := radius * 0.2
-	eyeHeight := radius * 0.12
-
-	for ex := -eyeWidth; ex <= eyeWidth; ex += radius * 0.08 {
-		for ey := -eyeHeight; ey <= eyeHeight; ey += radius * 0.08 {
-			if ex*ex/(eyeWidth*eyeWidth)+ey*ey/(eyeHeight*eyeHeight) <= 1 {
-				vector.FillCircle(
-					screen,
-					float32(x-eyeOffsetX+ex),
-					float32(y-eyeOffsetY+ey),
-					float32(radius*0.05),
-					color.NRGBA{R: 0, G: 0, B: 0, A: 255},
-					false,
-				)
-			}
+	switch h.direction {
+	case DirUp:
+		if h.animFrame == 0 {
+			sprite = spriteBack1
+		} else {
+			sprite = spriteBack2
+		}
+	case DirDown:
+		if h.animFrame == 0 {
+			sprite = spriteFront1
+		} else {
+			sprite = spriteFront2
+		}
+	case DirLeft:
+		if h.animFrame == 0 {
+			sprite = spriteLeft1
+		} else {
+			sprite = spriteLeft2
+		}
+	case DirRight:
+		if h.animFrame == 0 {
+			sprite = spriteRight1
+		} else {
+			sprite = spriteRight2
 		}
 	}
 
-	for ex := -eyeWidth; ex <= eyeWidth; ex += radius * 0.08 {
-		for ey := -eyeHeight; ey <= eyeHeight; ey += radius * 0.08 {
-			if ex*ex/(eyeWidth*eyeWidth)+ey*ey/(eyeHeight*eyeHeight) <= 1 {
-				vector.FillCircle(
-					screen,
-					float32(x+eyeOffsetX+ex),
-					float32(y-eyeOffsetY+ey),
-					float32(radius*0.05),
-					color.NRGBA{R: 0, G: 0, B: 0, A: 255},
-					false,
-				)
-			}
-		}
-	}
-
-	mouthY := y + radius*0.3
-	mouthWidth := radius * 0.5
-	for mx := -mouthWidth; mx <= mouthWidth; mx += radius * 0.08 {
-		vector.FillCircle(
-			screen,
-			float32(x+mx),
-			float32(mouthY),
-			float32(radius*0.06),
-			color.NRGBA{R: 0, G: 0, B: 0, A: 255},
-			false,
-		)
-	}
+	return sprite
 }
 
-func drawExhaustedFace(screen *ebiten.Image, x, y, radius, eyeOffsetX, eyeOffsetY float64) {
-	eyeSize := radius * 0.15
-
-	for i := -eyeSize; i <= eyeSize; i += radius * 0.08 {
-		vector.FillCircle(
-			screen,
-			float32(x-eyeOffsetX+i),
-			float32(y-eyeOffsetY+i),
-			float32(radius*0.05),
-			color.NRGBA{R: 0, G: 0, B: 0, A: 255},
-			false,
-		)
-		vector.FillCircle(
-			screen,
-			float32(x-eyeOffsetX+i),
-			float32(y-eyeOffsetY-i),
-			float32(radius*0.05),
-			color.NRGBA{R: 0, G: 0, B: 0, A: 255},
-			false,
-		)
-	}
-
-	for i := -eyeSize; i <= eyeSize; i += radius * 0.08 {
-		vector.FillCircle(
-			screen,
-			float32(x+eyeOffsetX+i),
-			float32(y-eyeOffsetY+i),
-			float32(radius*0.05),
-			color.NRGBA{R: 0, G: 0, B: 0, A: 255},
-			false,
-		)
-		vector.FillCircle(
-			screen,
-			float32(x+eyeOffsetX+i),
-			float32(y-eyeOffsetY-i),
-			float32(radius*0.05),
-			color.NRGBA{R: 0, G: 0, B: 0, A: 255},
-			false,
-		)
-	}
-
-	mouthY := y + radius*0.35
-	mouthWidth := radius * 0.2
-	mouthHeight := radius * 0.25
-
-	for angle := 0.0; angle < 2*math.Pi; angle += 0.3 {
-		mx := x + mouthWidth*math.Cos(angle)
-		my := mouthY + mouthHeight*math.Sin(angle)
-		vector.FillCircle(
-			screen,
-			float32(mx),
-			float32(my),
-			float32(radius*0.06),
-			color.NRGBA{R: 0, G: 0, B: 0, A: 255},
-			false,
-		)
-	}
-}
+// ============================================================
+// UTILITIES
+// ============================================================
 
 func clamp(value, min, max float64) float64 {
 	if value < min {

internal/hero/sprites.go

@@ -0,0 +1,65 @@
+package hero
+
+import (
+	"image"
+	"image/color"
+	_ "image/gif"
+	"os"
+
+	"github.com/hajimehoshi/ebiten/v2"
+)
+
+var (
+	spriteBack1  *ebiten.Image
+	spriteBack2  *ebiten.Image
+	spriteFront1 *ebiten.Image
+	spriteFront2 *ebiten.Image
+	spriteLeft1  *ebiten.Image
+	spriteLeft2  *ebiten.Image
+	spriteRight1 *ebiten.Image
+	spriteRight2 *ebiten.Image
+)
+
+func init() {
+	spriteBack1 = loadSprite("assets/hero/avt1_bk1.gif")
+	spriteBack2 = loadSprite("assets/hero/avt1_bk2.gif")
+	spriteFront1 = loadSprite("assets/hero/avt1_fr1.gif")
+	spriteFront2 = loadSprite("assets/hero/avt1_fr2.gif")
+	spriteLeft1 = loadSprite("assets/hero/avt1_lf1.gif")
+	spriteLeft2 = loadSprite("assets/hero/avt1_lf2.gif")
+	spriteRight1 = loadSprite("assets/hero/avt1_rt1.gif")
+	spriteRight2 = loadSprite("assets/hero/avt1_rt2.gif")
+}
+
+func loadSprite(path string) *ebiten.Image {
+	file, err := os.Open(path)
+	if err != nil {
+		panic(err)
+	}
+	defer file.Close()
+
+	img, _, err := image.Decode(file)
+	if err != nil {
+		panic(err)
+	}
+
+	bounds := img.Bounds()
+	rgba := image.NewRGBA(bounds)
+	for y := bounds.Min.Y; y < bounds.Max.Y; y++ {
+		for x := bounds.Min.X; x < bounds.Max.X; x++ {
+			r, g, b, a := img.At(x, y).RGBA()
+			if r > 0xf000 && g > 0xf000 && b > 0xf000 {
+				rgba.Set(x, y, color.RGBA{0, 0, 0, 0})
+			} else {
+				rgba.Set(x, y, color.RGBA{
+					R: uint8(r >> 8),
+					G: uint8(g >> 8),
+					B: uint8(b >> 8),
+					A: uint8(a >> 8),
+				})
+			}
+		}
+	}
+
+	return ebiten.NewImageFromImage(rgba)
+}