Adding upstream version 0.0~git20250520.a1d9079+dfsg.

Signed-off-by: Daniel Baumann <daniel@debian.org>

example/flappy/main.go

@@ -0,0 +1,98 @@
+// Copyright 2015 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+//go:build darwin || linux
+
+// Flappy Gopher is a simple one-button game that uses the
+// mobile framework and the experimental sprite engine.
+package main
+
+import (
+	"math/rand"
+	"time"
+
+	"golang.org/x/mobile/app"
+	"golang.org/x/mobile/event/key"
+	"golang.org/x/mobile/event/lifecycle"
+	"golang.org/x/mobile/event/paint"
+	"golang.org/x/mobile/event/size"
+	"golang.org/x/mobile/event/touch"
+	"golang.org/x/mobile/exp/gl/glutil"
+	"golang.org/x/mobile/exp/sprite"
+	"golang.org/x/mobile/exp/sprite/clock"
+	"golang.org/x/mobile/exp/sprite/glsprite"
+	"golang.org/x/mobile/gl"
+)
+
+func main() {
+	rand.Seed(time.Now().UnixNano())
+
+	app.Main(func(a app.App) {
+		var glctx gl.Context
+		var sz size.Event
+		for e := range a.Events() {
+			switch e := a.Filter(e).(type) {
+			case lifecycle.Event:
+				switch e.Crosses(lifecycle.StageVisible) {
+				case lifecycle.CrossOn:
+					glctx, _ = e.DrawContext.(gl.Context)
+					onStart(glctx)
+					a.Send(paint.Event{})
+				case lifecycle.CrossOff:
+					onStop()
+					glctx = nil
+				}
+			case size.Event:
+				sz = e
+			case paint.Event:
+				if glctx == nil || e.External {
+					continue
+				}
+				onPaint(glctx, sz)
+				a.Publish()
+				a.Send(paint.Event{}) // keep animating
+			case touch.Event:
+				if down := e.Type == touch.TypeBegin; down || e.Type == touch.TypeEnd {
+					game.Press(down)
+				}
+			case key.Event:
+				if e.Code != key.CodeSpacebar {
+					break
+				}
+				if down := e.Direction == key.DirPress; down || e.Direction == key.DirRelease {
+					game.Press(down)
+				}
+			}
+		}
+	})
+}
+
+var (
+	startTime = time.Now()
+	images    *glutil.Images
+	eng       sprite.Engine
+	scene     *sprite.Node
+	game      *Game
+)
+
+func onStart(glctx gl.Context) {
+	images = glutil.NewImages(glctx)
+	eng = glsprite.Engine(images)
+	game = NewGame()
+	scene = game.Scene(eng)
+}
+
+func onStop() {
+	eng.Release()
+	images.Release()
+	game = nil
+}
+
+func onPaint(glctx gl.Context, sz size.Event) {
+	glctx.ClearColor(1, 1, 1, 1)
+	glctx.Clear(gl.COLOR_BUFFER_BIT)
+	now := clock.Time(time.Since(startTime) * 60 / time.Second)
+	game.Update(now)
+	eng.Render(scene, now, sz)
+}