Refactor to use better interfaces and event callbacks.

elements/flyeye.go

@@ -0,0 +1,153 @@
+package elements
+
+import (
+	"image"
+	"image/color"
+	"math"
+	"mover/assets"
+	"mover/gamedata"
+
+	"github.com/hajimehoshi/ebiten/v2"
+)
+
+type FlyEye struct {
+	Sprite     *ebiten.Image
+	Maks       *ebiten.Image
+	MaksDest   *ebiten.Image
+	position   gamedata.Coordinates
+	target     gamedata.Coordinates
+	state      gamedata.EnemyState
+	cycle      int
+	dyingcount int
+	hit        bool
+	touched    bool
+	toggle     bool
+}
+
+func NewFlyEye() *FlyEye {
+	f := &FlyEye{
+		Sprite:     ebiten.NewImage(46, 46),
+		Maks:       ebiten.NewImage(48, 48),
+		MaksDest:   ebiten.NewImage(48, 48),
+		cycle:      0,
+		dyingcount: 0,
+		hit:        false,
+		touched:    false,
+		toggle:     false,
+	}
+	f.Maks.Fill(color.White)
+	return f
+}
+
+func (f *FlyEye) Update() error {
+
+	//close loop on target
+	if f.state <= gamedata.EnemyStateHit {
+		dx := f.target.X - f.position.X
+		dy := f.target.Y - f.position.Y
+		if math.Abs(dx) > 3 || math.Abs(dy) > 3 {
+			angle := math.Atan2(dy, dx)
+
+			f.position.X += math.Cos(angle) * 3
+			f.position.Y += math.Sin(angle) * 3
+		}
+	}
+
+	if f.state == gamedata.EnemyStateDying {
+		f.dyingcount++
+	}
+
+	f.cycle++
+
+	return nil
+}
+
+func (f *FlyEye) Draw() {
+	f.Sprite.Clear()
+	f.MaksDest.Clear()
+
+	idx := (f.cycle / 8) % 4
+
+	y0 := 0
+	y1 := 48
+	x0 := 48 * idx
+	x1 := x0 + 48
+
+	switch f.state {
+	case gamedata.EnemyStateDefault:
+		if !f.toggle {
+			f.Sprite.DrawImage(assets.ImageBank[assets.FlyEyeNormal].SubImage(image.Rect(x0, y0, x1, y1)).(*ebiten.Image), nil)
+		} else {
+			f.Sprite.DrawImage(assets.ImageBank[assets.FlyEyeDamaged].SubImage(image.Rect(x0, y0, x1, y1)).(*ebiten.Image), nil)
+		}
+	case gamedata.EnemyStateDying:
+		//after some condition, set to exploding
+		if (f.cycle/5)%2 == 0 {
+
+			f.MaksDest.DrawImage(assets.ImageBank[assets.FlyEyeDamaged].SubImage(image.Rect(x0, y0, x1, y1)).(*ebiten.Image), nil)
+			op := &ebiten.DrawImageOptions{}
+			op.GeoM.Reset()
+			op.Blend = ebiten.BlendSourceAtop
+			f.MaksDest.DrawImage(f.Maks, op)
+			f.Sprite.DrawImage(f.MaksDest, nil)
+
+		} else {
+			f.Sprite.DrawImage(assets.ImageBank[assets.FlyEyeDamaged].SubImage(image.Rect(x0, y0, x1, y1)).(*ebiten.Image), nil)
+		}
+		if f.dyingcount >= 31 {
+			f.cycle = 0
+			f.state = gamedata.EnemyStateExploding
+		}
+	case gamedata.EnemyStateExploding:
+		f.Sprite.DrawImage(assets.ImageBank[assets.FlyEyeDying].SubImage(image.Rect(x0, y0, x1, y1)).(*ebiten.Image), nil)
+		if idx == 3 {
+			f.state = gamedata.EnemyStateDead
+		}
+	}
+}
+
+func (f *FlyEye) GetPosition() gamedata.Coordinates {
+	return f.position
+}
+
+func (f *FlyEye) SetTarget(p gamedata.Coordinates) {
+	f.target = p
+}
+
+func (f *FlyEye) GetSprite() *ebiten.Image {
+	return f.Sprite
+}
+
+func (f *FlyEye) SetHit() {
+	f.hit = true
+	f.state = gamedata.EnemyStateDying
+	f.cycle = 0
+}
+
+func (f *FlyEye) IsTouched() bool {
+	return f.touched
+}
+
+func (f *FlyEye) SetTouched() {
+	f.touched = true
+}
+
+func (f *FlyEye) ClearTouched() {
+	f.touched = false
+}
+
+func (f *FlyEye) SetToggle() {
+	f.toggle = !f.toggle
+}
+
+func (f *FlyEye) IsToggled() bool {
+	return f.toggle
+}
+
+func (f *FlyEye) GetEnemyState() gamedata.EnemyState {
+	return f.state
+}
+
+func (f *FlyEye) SetPosition(p gamedata.Coordinates) {
+	f.position = p
+}