move menu logic to menu.go

konstructor/menu.go

@@ -1,5 +1,15 @@
 package konstructor
 
+import (
+	"image/color"
+
+	"github.com/hajimehoshi/ebiten"
+	"github.com/hajimehoshi/ebiten/examples/resources/fonts"
+	"github.com/hajimehoshi/ebiten/text"
+	"golang.org/x/image/font"
+	"golang.org/x/image/font/opentype"
+)
+
 type MenuMap map[string]Menu
 
 type MenuLayout struct {
@@ -19,3 +29,41 @@ type Menu struct {
 	MenuLayout      MenuLayout
 	MenuItems       []MenuItem
 }
+
+func (e *Engine) MenuDraw(screen *ebiten.Image) {
+	menu := e.MenuMap[e.KContext.Screen.Value]
+	face := e.menuGetFontFace(menu)
+
+	for i, menu_item := range menu.MenuItems {
+		var c color.Color
+		if menu.CurrentSelected == i {
+			c = color.RGBA{R: 0, G: 255, B: 0, A: 100}
+		} else {
+			c = color.White
+		}
+		text.Draw(screen, menu_item.Label+"\n", face, 8, 24*(i+1), c)
+	}
+}
+
+func (e *Engine) MenuUpdate() {
+	menu := e.MenuMap[e.KContext.Screen.Value]
+	if e.Controller.DownPressed() && menu.CurrentSelected != len(menu.MenuItems)-1 {
+		menu.CurrentSelected++
+	}
+
+	if e.Controller.UpPressed() && menu.CurrentSelected != 0 {
+		menu.CurrentSelected--
+	}
+
+	e.MenuMap[e.KContext.Screen.Value] = menu
+}
+
+func (e *Engine) menuGetFontFace(menu Menu) font.Face {
+	tt, _ := opentype.Parse(fonts.MPlus1pRegular_ttf)
+	face, _ := opentype.NewFace(tt, &opentype.FaceOptions{
+		Size:    menu.MenuLayout.DPI,
+		DPI:     menu.MenuLayout.Size,
+		Hinting: font.HintingVertical,
+	})
+	return face
+}