Initial commit.

elements/slider.go

@@ -0,0 +1,87 @@
+package elements
+
+import (
+	"ducky/gamedata"
+	"image/color"
+	"math"
+
+	"github.com/hajimehoshi/ebiten/v2"
+	"golang.org/x/exp/rand"
+)
+
+const (
+	sliderWidth  = 640 / 5
+	sliderHeight = 480
+	easeValue    = 16
+)
+
+type Slider struct {
+	Sprite         *ebiten.Image
+	position       gamedata.Coordinates
+	targetposition gamedata.Coordinates
+	cycle          int
+	callback       func()
+	called         bool
+	color          color.Color
+}
+
+func NewSlider() *Slider {
+	slider := &Slider{
+		Sprite: ebiten.NewImage(sliderWidth, sliderHeight),
+		called: false,
+		color: color.RGBA{
+			R: uint8(rand.Intn(256)) & 0xff,
+			G: uint8(rand.Intn(256)) & 0xff,
+			B: uint8(rand.Intn(256)) & 0xff,
+			A: 0xff,
+		},
+	}
+	return slider
+}
+
+func (s *Slider) Update() {
+
+	dx := s.targetposition.X - s.position.X
+	dy := s.targetposition.Y - s.position.Y
+
+	deltapos := math.Sqrt(dx*dx + dy*dy)
+
+	if deltapos > 0.5 {
+		s.position.X = s.position.X + dx/easeValue
+		s.position.Y = s.position.Y + dy/easeValue
+	} else {
+		if s.callback != nil && !s.called {
+			s.callback()
+			s.called = true
+		}
+	}
+
+	s.cycle++
+}
+
+func (s *Slider) Draw() {
+	s.Sprite.Clear()
+	s.Sprite.Fill(s.color)
+}
+
+func (s *Slider) GetPosition() gamedata.Coordinates {
+	return s.position
+}
+
+func (s *Slider) SetPosition(pos gamedata.Coordinates) {
+	s.position = pos
+}
+
+func (s *Slider) SetTargetPosition(pos gamedata.Coordinates) {
+	s.targetposition = pos
+}
+
+func (s *Slider) SetCallback(f func()) {
+	if f != nil {
+		s.callback = f
+	}
+}
+
+func (s *Slider) Reset() {
+	s.called = false
+}