added manager, scene, and first examples

examples/splashmenu/menu.go

@@ -0,0 +1,68 @@
+package splashmenu
+
+import (
+	"image/color"
+	"log"
+
+	"github.com/hajimehoshi/ebiten/v2"
+	"github.com/hajimehoshi/ebiten/v2/examples/resources/fonts"
+	"github.com/hajimehoshi/ebiten/v2/inpututil"
+	"github.com/hajimehoshi/ebiten/v2/text"
+	"golang.org/x/image/font"
+	"golang.org/x/image/font/opentype"
+)
+
+var (
+	menuFont font.Face
+)
+
+func init() {
+	tt, err := opentype.Parse(fonts.PressStart2P_ttf)
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	const dpi = 72
+	menuFont, err = opentype.NewFace(tt, &opentype.FaceOptions{
+		Size:    12,
+		DPI:     dpi,
+		Hinting: font.HintingVertical,
+	})
+	if err != nil {
+		log.Fatal(err)
+	}
+}
+
+type Menu struct {
+	bgcolor   color.RGBA
+	completed bool
+}
+
+func NewMenu() Menu {
+	return Menu{
+		bgcolor:   color.RGBA{0x33, 0x33, 0x99, 0xFF},
+		completed: false,
+	}
+}
+
+func (m *Menu) Draw(screen *ebiten.Image) {
+	screen.Fill(m.bgcolor)
+	text.Draw(screen, "menu", menuFont, 40, 40, color.White)
+}
+
+func (m *Menu) Update() error {
+
+	var keysPressed []ebiten.Key
+	keysPressed = inpututil.AppendPressedKeys(keysPressed[:0])
+	for _, k := range keysPressed {
+		if k == ebiten.KeyEnter {
+			m.completed = true
+		}
+	}
+
+	return nil
+}
+
+func (m *Menu) Completed() bool {
+	return m.completed
+}

examples/splashmenu/splash.go

@@ -0,0 +1,69 @@
+package splashmenu
+
+import (
+	"image/color"
+	"log"
+
+	"github.com/hajimehoshi/ebiten/v2"
+	"github.com/hajimehoshi/ebiten/v2/examples/resources/fonts"
+	"github.com/hajimehoshi/ebiten/v2/text"
+	"golang.org/x/image/font"
+	"golang.org/x/image/font/opentype"
+)
+
+var (
+	splashFont font.Face
+)
+
+func init() {
+	tt, err := opentype.Parse(fonts.PressStart2P_ttf)
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	const dpi = 72
+	splashFont, err = opentype.NewFace(tt, &opentype.FaceOptions{
+		Size:    12,
+		DPI:     dpi,
+		Hinting: font.HintingVertical,
+	})
+	if err != nil {
+		log.Fatal(err)
+	}
+}
+
+type Splash struct {
+	bgcolor   color.RGBA
+	completed bool
+	increment int
+}
+
+func NewSplash() Splash {
+	return Splash{
+		bgcolor:   color.RGBA{0xFF, 0xFF, 0xFF, 0xFF},
+		completed: false,
+	}
+}
+
+func (s *Splash) Draw(screen *ebiten.Image) {
+	screen.Fill(s.bgcolor)
+	text.Draw(screen, "splash", splashFont, 40, 40, color.White)
+}
+
+func (s *Splash) Update() error {
+	s.increment++
+
+	s.bgcolor.R = (s.bgcolor.R - 2) % 0xFF
+	s.bgcolor.G = (s.bgcolor.G - 2) % 0xFF
+	s.bgcolor.B = (s.bgcolor.B - 2) % 0xFF
+
+	if s.bgcolor.R == 0x00 {
+		s.completed = true
+	}
+
+	return nil
+}
+
+func (s *Splash) Completed() bool {
+	return s.completed
+}

go.mod

@@ -1,3 +1,19 @@
 module groovy
 
 go 1.21.0
+
+require (
+	github.com/hajimehoshi/ebiten/v2 v2.5.6
+	golang.org/x/image v0.6.0
+)
+
+require (
+	github.com/ebitengine/purego v0.4.0 // indirect
+	github.com/go-gl/glfw/v3.3/glfw v0.0.0-20221017161538-93cebf72946b // indirect
+	github.com/jezek/xgb v1.1.0 // indirect
+	golang.org/x/exp v0.0.0-20190731235908-ec7cb31e5a56 // indirect
+	golang.org/x/mobile v0.0.0-20230301163155-e0f57694e12c // indirect
+	golang.org/x/sync v0.1.0 // indirect
+	golang.org/x/sys v0.7.0 // indirect
+	golang.org/x/text v0.8.0 // indirect
+)

groovy/manager.go

@@ -0,0 +1,94 @@
+package groovy
+
+import (
+	"os"
+
+	"github.com/hajimehoshi/ebiten/v2"
+)
+
+const (
+	defaultWidth  = 1024
+	defaultHeight = 768
+)
+
+type Area struct {
+	Width  int
+	Height int
+}
+
+type GameInfo struct {
+	Name      string
+	Version   string
+	Dimension Area
+}
+
+type Manager struct {
+	Info           GameInfo
+	currentScene   Scene
+	currentSceneId int
+	scenes         []Scene
+}
+
+func NewManager() Manager {
+	return Manager{
+		Info: GameInfo{
+			Name:    "groovy",
+			Version: "1.0",
+			Dimension: Area{
+				Width:  defaultWidth,
+				Height: defaultHeight},
+		},
+		currentSceneId: 0,
+	}
+}
+
+func (m *Manager) Update() error {
+	if m.currentScene == nil {
+		return nil
+	}
+
+	m.CheckTransitions()
+	m.CheckExit()
+
+	//call the current scene's update method
+	return m.currentScene.Update()
+
+}
+
+// check for exit condition
+func (m *Manager) CheckExit() {
+	if m.currentSceneId >= len(m.scenes) {
+		os.Exit(0)
+	}
+}
+
+// check for scene completion and if reached, set up next scene (if available)
+func (m *Manager) CheckTransitions() {
+	if m.currentScene.Completed() {
+		m.currentSceneId++
+		if m.currentSceneId < len(m.scenes) {
+			m.currentScene = m.scenes[m.currentSceneId]
+		}
+	}
+}
+
+func (m *Manager) Draw(screen *ebiten.Image) {
+	if m.currentScene != nil {
+		m.currentScene.Draw(screen)
+	}
+}
+
+func (m *Manager) Layout(outsideWidth, outsideHeight int) (screenWidth, screenHeight int) {
+	return m.Info.Dimension.Width, m.Info.Dimension.Height
+}
+
+func (m *Manager) AddScene(s Scene) {
+	m.scenes = append(m.scenes, s)
+}
+
+func (m *Manager) SetCurrentScene(sceneId int) {
+	if sceneId >= 0 && sceneId < len(m.scenes) {
+		m.currentSceneId = sceneId
+		m.currentScene = m.scenes[m.currentSceneId]
+	}
+}

groovy/scene.go

@@ -0,0 +1,9 @@
+package groovy
+
+import "github.com/hajimehoshi/ebiten/v2"
+
+type Scene interface {
+	Update() error
+	Draw(screen *ebiten.Image)
+	Completed() bool
+}

main.go

@@ -1,5 +1,38 @@
 package main
 
+import (
+	"fmt"
+	"groovy/examples/splashmenu"
+	"groovy/groovy"
+	"log"
+
+	"github.com/hajimehoshi/ebiten/v2"
+)
+
 func main() {
+	manager := groovy.NewManager()
+
+	loadScenes(&manager)
+
+	ebiten.SetWindowSize(manager.Info.Dimension.Width, manager.Info.Dimension.Height)
+	ebiten.SetWindowTitle(manager.Info.Name)
+
+	fmt.Println(manager.Info.Name + ": v" + manager.Info.Version)
+
+	if err := ebiten.RunGame(&manager); err != nil {
+		log.Fatal(err)
+	}
 
 }
+
+// Example loading of two scenes
+func loadScenes(m *groovy.Manager) {
+	sceneSplash := splashmenu.NewSplash()
+	m.AddScene(&sceneSplash)
+
+	sceneMenu := splashmenu.NewMenu()
+	m.AddScene(&sceneMenu)
+
+	//sets current scene to the splash menu
+	m.SetCurrentScene(0)
+}