game.go

package main

import (
	"korok.io/korok/game"
	"korok.io/korok/gui"
	"korok.io/korok/gfx"
	"korok.io/korok/asset"
	"korok.io/korok/engi"
	"korok.io/korok"
	"korok.io/korok/math/f32"
	"korok.io/korok/hid/input"
	"korok.io/korok/anim/ween"
	"korok.io/korok/math/ease"
	"korok.io/korok/audio"
)


type StateEnum int

const (
	Ready StateEnum = iota
	Running
	Over
)

type BirdStateEnum int

const (
	Flying BirdStateEnum = iota
	Dead
)


const (
	Gravity = 600
	TapImpulse = 280
	ScrollVelocity = 100

	RotTrigger = 200
	MaxAngle = 3.14/6
	MinAngle = -3.14/2
	AngleVelocity = 3.14 * 4
)

type GameScene struct {
	state StateEnum

	ready struct{
		gfx.Tex2D
		gui.Rect
	}
		tap struct{
		gfx.Tex2D
		gui.Rect
	}
	gameover struct{
		gfx.Tex2D
		gui.Rect
	}
	score struct{
		gfx.Tex2D
		gui.Rect
	}
	restart struct{
		gfx.Tex2D
		gui.Rect
	}

	bg engi.Entity

	bird struct{
		state BirdStateEnum
		engi.Entity
		f32.Vec2
		vy float32
		w, h float32
		rotate float32
	}

	ground struct{
		engi.Entity
		f32.Vec2
		vx float32
	}

	sound struct{
		rise uint16
		drop uint16
		collision uint16
		point uint16
		swooshing uint16
	}

	PipeSystem
	alphaTween ween.ColorTween
	bounceTween ween.F32Tween
}

func (sn *GameScene) borrow(bird, bg, ground engi.Entity) {
	sn.bird.Entity, sn.bg, sn.ground.Entity = bird, bg, ground
}

func (sn *GameScene) Load() {
	asset.Audio.Load("sound/rise.ogg", false)
	asset.Audio.Load("sound/drop.ogg", false)
	asset.Audio.Load("sound/point.ogg", false)
	asset.Audio.Load("sound/collision.ogg", false)
	asset.Audio.Load("sound/swooshing.ogg", false)
}

func (sn *GameScene) OnEnter(g *game.Game) {
	at, _ := asset.Texture.Atlas("images/bird.png")

	// ready and tap image
	sn.ready.Tex2D, _ = at.GetByName("getready.png")
	sn.ready.Rect = gui.Rect{
		X: (320-233)/2,
		Y: 70,
		W: 233,
		H: 70,
	}
	sn.tap.Tex2D, _ = at.GetByName("tap.png")
	sn.tap.Rect = gui.Rect{
		X: (320-143)/2,
		Y: 200,
		W: 143, // 286
		H: 123, // 246
	}

	sn.gameover.Tex2D, _ = at.GetByName("gameover.png")
	sn.gameover.Rect = gui.Rect{
		X: (320-233)/2,
		Y: 70,
		W: 233,
		H: 70,
	}
	sn.score.Tex2D, _ = at.GetByName("result_board.png")
	sn.score.Rect = gui.Rect{
		X: (320 - 240)/2,
		Y: 200,
		W: 240,
		H: 120,
	}
	sn.restart.Tex2D, _ = at.GetByName("start.png")
	sn.restart.Rect = gui.Rect{
		X: (320 - 120)/2,
		Y: 360,
		W: 120,
		H: 60,
	}

	// sound
	sn.sound.rise, _ = asset.Audio.Get("sound/rise.ogg")
	sn.sound.drop, _ = asset.Audio.Get("sound/drop.ogg")
	sn.sound.point, _ = asset.Audio.Get("sound/point.ogg")
	sn.sound.collision, _ = asset.Audio.Get("sound/collision.ogg")
	sn.sound.swooshing, _ = asset.Audio.Get("sound/swooshing.ogg")



	korok.Transform.Comp(sn.bird.Entity).SetPosition(f32.Vec2{80, 240})
	sn.bird.Vec2 = f32.Vec2{80, 240}

	sn.ground.Vec2 = f32.Vec2{0, 100}
	sn.ground.vx = ScrollVelocity

	// setup pipes (129, 801)
	top, _ := at.GetByName("top_pipe.png")
	bottom, _ := at.GetByName("bottom_pipe.png")

	ps := &sn.PipeSystem
	ps.initialize(top, bottom, 6)
	ps.setDelay(0) // 3 seconds
	ps.setRate(2.5)  // generate pipe every 2 seconds
	ps.setGap(100)
	ps.setLimit(300, 150)
	ps.StartScroll()

	sn.alphaTween.Range(gfx.White, gfx.Transparent).Animate(g.TweenEngine.NewAnimator())
	sn.alphaTween.Animator().SetFunction(ease.InOutSine).SetDuration(.5).Forward()

	sn.bounceTween.Range(240, 0).Animate(g.TweenEngine.NewAnimator())
	sn.bounceTween.Animator().SetFunction(ease.OutBounce).SetDuration(1)
}

func (sn *GameScene) Update(dt float32) {
	if sn.alphaTween.Value().A > 0 {
		z := gui.SetZOrder(gui.DefaultZOrder+1)
		gui.ColorRect(gui.Rect{0,0, 320, 480}, sn.alphaTween.Value(), 0)
		gui.SetZOrder(z)
	}

	if st := sn.state; st == Ready {
		sn.showReady(dt); return
	} else if st == Over {
		sn.showOver(dt)
		return
	}

	if input.PointerButton(0).JustPressed() {
		sn.bird.vy = TapImpulse
		// play effect
		audio.PlayEffect(sn.sound.rise, 1)
	}
	sn.bird.vy -= Gravity * dt
	sn.bird.Vec2[1] += sn.bird.vy * dt

	// rotate
	if sn.bird.vy > -RotTrigger && sn.bird.rotate < MaxAngle {
		sn.bird.rotate +=  AngleVelocity * dt
	} else if sn.bird.vy < -RotTrigger && sn.bird.rotate > MinAngle {
		sn.bird.rotate += -AngleVelocity * dt
	}

	// update bird position
	b := korok.Transform.Comp(sn.bird.Entity)
	b.SetPosition(sn.bird.Vec2)
	b.SetRotation(sn.bird.rotate)

	// scroll background
	// windows.width = 320, ground.width = 420, so if we move by 100(420-320),
	// then reset position, it looks like the ground scroll seamless.
	x := sn.ground.Vec2[0]
	if x < -100 {
		x = x + 90 // magic number (bridge start and end of the image)
	}
	x -= sn.ground.vx * dt
	sn.ground.Vec2[0] = x

	// update ground shift
	g := korok.Transform.Comp(sn.ground.Entity)
	g.SetPosition(sn.ground.Vec2)

	// update pipes
	sn.PipeSystem.Update(dt)
	// detect collision with pipes
	ps := &sn.PipeSystem
	if c, _ := ps.CheckCollision(sn.bird.Vec2, f32.Vec2{sn.bird.w, sn.bird.h}); c {
		if sn.bird.state != Dead {
			ps.StopScroll()
			sn.bird.state = Dead

			// stop bird animation
			audio.PlayEffect(sn.sound.collision, 1)
			korok.Flipbook.Comp(sn.bird.Entity).Stop()
		}
	}


	// detect collision with ground and sky
	if y := sn.bird.Vec2[1]; y > 480 {
		sn.bird.Vec2[1] = 480
	} else if y < 100 {
		y = 100; sn.state = Over

		if sn.bird.state != Dead {
			sn.bird.state = Dead
			audio.PlayEffect(sn.sound.collision, 1)
			korok.Flipbook.Comp(sn.bird.Entity).Stop()
		}

		audio.PlayEffect(sn.sound.drop, 2)
		sn.bounceTween.Animator().Forward() // 如何
	}
}

func (sn *GameScene) showReady(dt float32) {
	// show ready
	gui.Image(1, sn.ready.Rect, sn.ready.Tex2D, nil)

	// show tap hint
	gui.Image(2, sn.tap.Rect, sn.tap.Tex2D, nil)

	// check any click
	if input.PointerButton(0).JustPressed() {
		sn.state = Running
	}
}

func (sn *GameScene) showOver(dt float32) {
	//
	sn.score.Rect.Y = sn.bounceTween.Value() + 160
	sn.restart.Rect.Y = sn.bounceTween.Value() + 320


	// show game over
	gui.Image(1, sn.gameover.Rect, sn.gameover.Tex2D, nil)

	// show score
	gui.Image(2, sn.score.Rect, sn.score.Tex2D, nil)

	// show restart button
	e := gui.ImageButton(3, sn.restart.Rect, sn.restart.Tex2D, sn.restart.Tex2D, nil)
	if e.JustPressed() {
		sn.alphaTween.Range(gfx.Transparent, gfx.White)
		sn.alphaTween.Animator().SetFunction(ease.InOutSine).SetDuration(.5).OnComplete(func (r bool) {
			sn.reStart()
		}).Forward()
	}
}

func (sn *GameScene) reStart() {
	sn.state = Ready

	// bird
	sn.bird.state = Flying
	sn.bird.Vec2 = f32.Vec2{80, 240}
	sn.bird.vy = 0
	sn.bird.rotate = 0
	korok.Transform.Comp(sn.bird.Entity).SetRotation(0)
	korok.Flipbook.Comp(sn.bird.Entity).Play("flying")
	// pipes
	sn.PipeSystem.Reset()
	sn.PipeSystem.StartScroll()

	// reverse
	sn.alphaTween.Animator().OnComplete(nil).Reverse()
}


func (sn *GameScene) OnExit() {
}