Beat the high-score: build a game using libGDX and Kotlin

Playing games is fun but making games is even better, especially with Kotlin and libGDX. Let's build together a breakout game and let's explore the gaming framework libGDX.

This session will show some libGDX's concepts: how to draw and animate elements of our game, how collision system works to destroy our bricks, what Kotlin brings to libGDX. Then we will dive into more advanced topics like shaders, in order to handle pixels from our images. Why are we doing all of this? To break the high score, of course!

Code: https://github.com/dwursteisen/beat-the-high-score
Game: https://play.google.com/store/apps/details?id=com.github.dwursteisen.beat
Video: https://www.youtube.com/watch?v=kDxerDYelLs

(KotlinConf 2018 - 4th October 2018 - Amsterdam)

Transcript

1. Build a game using libGDX and Kotlin
   Build a game using libGDX and Kotlin
   Build a game using libGDX and Kotlin
   Build a game using libGDX and Kotlin
   Beat the High score
   Beat the High score
   Build a game using libGDX and Kotlin
   

   View Slide

2. -Gilles Allain
   In a farm… far, far away…
   

   View Slide

3. -Gilles Allain
   a sneaky fox appears in the darkness of the night.
   

   View Slide

4. View Slide

5. -Gilles Allain
   In a mighty move, he stole all the chickens of the farm...
   

   View Slide

6. View Slide

7. -Gilles Allain
   those chickens were our...friends.
   

   View Slide

8. -Gilles Allain
   the same night, a thunder strikes you!
   

   View Slide

9. View Slide

10. -Gilles Allain
    ...this strike have given you powers to bring back...
    ...our friends!
    

    View Slide

11. David
    Wursteisen
    

    View Slide

12. View Slide

13. View Slide

14. John Carmack
    

    View Slide

15. View Slide

16. View Slide

17. Rota Pong
    

    View Slide

18. Wiz 

    The Wizard
    

    View Slide

19. Beat 

    The High 

    Score
    

    View Slide

20. Game engines
    

    View Slide

21. View Slide

22. ❤
    

    View Slide

23. Pavel Quest
    Destroy Blocks
    Mirage Realms
    

    View Slide

24. Hair Dash - http://cleancutgames.com/
    

    View Slide

25. View Slide

26. View Slide

27. View Slide

28. Core
    iOS
    GWT
    Android
    Desktop
    
    
    

    View Slide

29. dependencies {
    compile "com.badlogicgames.gdx:gdx:$gdxVersion"
    compile "com.badlogicgames.gdx:gdx-box2d:$gdxVersion"
    compile "com.badlogicgames.ashley:ashley:$ashleyVersion"
    compile "org.jetbrains.kotlin:kotlin-stdlib:$kotlinVersion"
    compile "io.github.libktx:ktx-ashley:$ktxVersion"
    compile "io.github.libktx:ktx-graphics:$ktxVersion"
    compile "io.github.libktx:ktx-scene2d:$ktxVersion"
    compile "io.github.libktx:ktx-log:$ktxVersion"
    compile "com.github.dwursteisen.libgdx-addons:aseprite-addons:$libgdx_addons"
    compile "com.github.dwursteisen.libgdx-addons:ashley-addons:$libgdx_addons"
    compile "com.strongjoshua:libgdx-inGameConsole:$console"
    }
    

    View Slide

30. dependencies {
    compile "com.badlogicgames.gdx:gdx:$gdxVersion"
    compile "com.badlogicgames.gdx:gdx-box2d:$gdxVersion"
    compile "com.badlogicgames.ashley:ashley:$ashleyVersion"
    compile "org.jetbrains.kotlin:kotlin-stdlib:$kotlinVersion"
    compile "io.github.libktx:ktx-ashley:$ktxVersion"
    compile "io.github.libktx:ktx-graphics:$ktxVersion"
    compile "io.github.libktx:ktx-scene2d:$ktxVersion"
    compile "io.github.libktx:ktx-log:$ktxVersion"
    compile "com.github.dwursteisen.libgdx-addons:aseprite-addons:$libgdx_addons"
    compile "com.github.dwursteisen.libgdx-addons:ashley-addons:$libgdx_addons"
    compile "com.strongjoshua:libgdx-inGameConsole:$console"
    }
    

    View Slide

31. dependencies {
    compile "com.badlogicgames.gdx:gdx:$gdxVersion"
    compile "com.badlogicgames.gdx:gdx-box2d:$gdxVersion"
    compile "com.badlogicgames.ashley:ashley:$ashleyVersion"
    compile "org.jetbrains.kotlin:kotlin-stdlib:$kotlinVersion"
    compile "io.github.libktx:ktx-ashley:$ktxVersion"
    compile "io.github.libktx:ktx-graphics:$ktxVersion"
    compile "io.github.libktx:ktx-scene2d:$ktxVersion"
    compile "io.github.libktx:ktx-log:$ktxVersion"
    compile "com.github.dwursteisen.libgdx-addons:aseprite-addons:$libgdx_addons"
    compile "com.github.dwursteisen.libgdx-addons:ashley-addons:$libgdx_addons"
    compile "com.strongjoshua:libgdx-inGameConsole:$console"
    }
    

    View Slide

32. dependencies {
    compile "com.badlogicgames.gdx:gdx:$gdxVersion"
    compile "com.badlogicgames.gdx:gdx-box2d:$gdxVersion"
    compile "com.badlogicgames.ashley:ashley:$ashleyVersion"
    compile "org.jetbrains.kotlin:kotlin-stdlib:$kotlinVersion"
    compile "io.github.libktx:ktx-ashley:$ktxVersion"
    compile "io.github.libktx:ktx-graphics:$ktxVersion"
    compile "io.github.libktx:ktx-scene2d:$ktxVersion"
    compile "io.github.libktx:ktx-log:$ktxVersion"
    compile "com.github.dwursteisen.libgdx-addons:aseprite-addons:$libgdx_addons"
    compile "com.github.dwursteisen.libgdx-addons:ashley-addons:$libgdx_addons"
    compile "com.strongjoshua:libgdx-inGameConsole:$console"
    }
    

    View Slide

33. dependencies {
    compile "com.badlogicgames.gdx:gdx:$gdxVersion"
    compile "com.badlogicgames.gdx:gdx-box2d:$gdxVersion"
    compile "com.badlogicgames.ashley:ashley:$ashleyVersion"
    compile "org.jetbrains.kotlin:kotlin-stdlib:$kotlinVersion"
    compile "io.github.libktx:ktx-ashley:$ktxVersion"
    compile "io.github.libktx:ktx-graphics:$ktxVersion"
    compile "io.github.libktx:ktx-scene2d:$ktxVersion"
    compile "io.github.libktx:ktx-log:$ktxVersion"
    compile "com.github.dwursteisen.libgdx-addons:aseprite-addons:$libgdx_addons"
    compile "com.github.dwursteisen.libgdx-addons:ashley-addons:$libgdx_addons"
    compile "com.strongjoshua:libgdx-inGameConsole:$console"
    }
    

    View Slide

34. Let’s make a game!
    

    View Slide

35. public void render(float delta) {

    movePlayer(delta);

    moveEnemies(delta);

    moveWorld(delta);

    

    renderWorld();

    renderEnemies();

    renderPlayer();

    }
    

    View Slide

36. public void render(float delta) {

    movePlayer(delta);

    moveEnemies(delta);

    moveWorld(delta);

    

    renderWorld();

    renderEnemies();

    renderPlayer();

    }
    

    View Slide

37. public void render(float delta) {

    movePlayer(delta);

    moveEnemies(delta);

    moveWorld(delta);

    

    renderWorld();

    renderEnemies();

    renderPlayer();

    }
    

    View Slide

38. public void render(float delta) {

    movePlayer(delta);

    moveEnemies(delta);

    moveWorld(delta);

    

    renderWorld();

    renderEnemies();

    renderPlayer();

    }
    60x

    seconds
    

    View Slide

39. View Slide

40. class MyScreen : ScreenAdapter() {
    lateinit var batch: SpriteBatch
    override fun create() {
    batch = SpriteBatch()
    }
    override fun render() {
    batch.begin()
    batch.draw(image, x, y)
    batch.end()
    }
    }
    

    View Slide

41. class MyScreen : ScreenAdapter() {
    lateinit var batch: SpriteBatch
    override fun create() {
    batch = SpriteBatch()
    }
    override fun render() {
    batch.begin()
    batch.draw(image, x, y)
    batch.end()
    }
    }
    

    View Slide

42. class MyScreen : ScreenAdapter() {
    lateinit var batch: SpriteBatch
    override fun create() {
    batch = SpriteBatch()
    }
    override fun render() {
    batch.begin()
    batch.draw(image, x, y)
    batch.end()
    }
    }
    

    View Slide

43. class MyScreen : ScreenAdapter() {
    lateinit var batch: SpriteBatch
    override fun create() {
    batch = SpriteBatch()
    }
    override fun render() {
    batch.begin()
    batch.draw(image, x, y)
    batch.end()
    }
    }
    

    View Slide

44. class MyScreen : ScreenAdapter() {
    lateinit var batch: ShapeRenderer
    override fun create() {
    batch = ShapeRenderer()
    }
    override fun render() {
    batch.begin(ShapeRenderer.ShapeType.Filled)
    batch.color = Color.CHARTREUSE
    batch.circle(x, y, radius)
    batch.end()
    }
    }
    

    View Slide

45. class MyScreen : ScreenAdapter() {
    lateinit var batch: ShapeRenderer
    override fun create() {
    batch = ShapeRenderer()
    }
    override fun render() {
    batch.begin(ShapeRenderer.ShapeType.Filled)
    batch.color = Color.CHARTREUSE
    batch.circle(x, y, radius)
    batch.end()
    }
    }
    

    View Slide

46. class MyScreen : ScreenAdapter() {
    lateinit var batch: ShapeRenderer
    override fun create() {
    batch = ShapeRenderer()
    }
    override fun render() {
    batch.begin(ShapeRenderer.ShapeType.Filled)
    batch.color = Color.CHARTREUSE
    batch.circle(x, y, radius)
    batch.end()
    }
    }
    

    View Slide

47. class MyScreen : ScreenAdapter() {
    lateinit var batch: ShapeRenderer
    override fun create() {
    batch = ShapeRenderer()
    }
    override fun render() {
    batch.begin(ShapeRenderer.ShapeType.Filled)
    batch.color = Color.CHARTREUSE
    batch.circle(x, y, radius)
    batch.end()
    }
    }
    

    View Slide

48. class MyScreen : ScreenAdapter() {
    lateinit var batch: SpriteBatch
    override fun create() {
    batch = SpriteBatch()
    }
    override fun render() {
    batch.begin()
    batch.draw(image, x, y)
    batch.end()
    }
    }
    

    View Slide

49. class MyScreen : KtxScreen {
    val batch: SpriteBatch = SpriteBatch()
    override fun render() {
    batch.use {
    it.draw(sprite, x, y)
    }
    }
    }
    Inherit
    

    View Slide

50. (0,0)
    x
    y
    

    View Slide

51. class MyScreen : ScreenAdapter() {
    lateinit var batch: ShapeRenderer
    private val position: Vector2 = Vector2(0f, 0f)
    override fun create() {
    batch = ShapeRenderer()
    }
    override fun render(delta: Float) {
    position.add(0f, -0.5f)
    batch.begin(ShapeRenderer.ShapeType.Filled)
    batch.color = Color.CHARTREUSE
    batch.circle(position.x, position.y, radius)
    batch.end()
    }
    }
    

    View Slide

52. class MyScreen : ScreenAdapter() {
    lateinit var batch: ShapeRenderer
    private val position: Vector2 = Vector2(0f, 0f)
    override fun create() {
    batch = ShapeRenderer()
    }
    override fun render(delta: Float) {
    position.add(0f, -0.5f)
    batch.begin(ShapeRenderer.ShapeType.Filled)
    batch.color = Color.CHARTREUSE
    batch.circle(position.x, position.y, radius)
    batch.end()
    }
    }
    

    View Slide

53. class MyScreen : ScreenAdapter() {
    lateinit var batch: ShapeRenderer
    private val position: Vector2 = Vector2(0f, 0f)
    override fun create() {
    batch = ShapeRenderer()
    }
    override fun render(delta: Float) {
    position.add(0f, -0.5f)
    batch.begin(ShapeRenderer.ShapeType.Filled)
    batch.color = Color.CHARTREUSE
    batch.circle(position.x, position.y, radius)
    batch.end()
    }
    }
    

    View Slide

54. class MyScreen : ScreenAdapter() {
    lateinit var batch: ShapeRenderer
    private val position: Vector2 = Vector2(0f, 0f)
    override fun create() {
    batch = ShapeRenderer()
    }
    override fun render(delta: Float) {
    position.add(0f, -0.5f)
    batch.begin(ShapeRenderer.ShapeType.Filled)
    batch.color = Color.CHARTREUSE
    batch.circle(position.x, position.y, radius)
    batch.end()
    }
    }
    

    View Slide

55. class MyScreen : ScreenAdapter() {
    lateinit var batch: ShapeRenderer
    private val position: Vector2 = Vector2(0f, 0f)
    private var time: Float = 0f
    override fun create() {
    batch = ShapeRenderer()
    }
    override fun render(delta: Float) {
    val (x, y) = position
    time += delta
    batch.begin(ShapeRenderer.ShapeType.Filled)
    batch.color = Color.CHARTREUSE
    batch.circle(x + MathUtils.cos(time), y, radius)
    batch.end()
    }
    }
    

    View Slide

56. class MyScreen : ScreenAdapter() {
    lateinit var batch: ShapeRenderer
    private val position: Vector2 = Vector2(0f, 0f)
    private var time: Float = 0f
    override fun create() {
    batch = ShapeRenderer()
    }
    override fun render(delta: Float) {
    val (x, y) = position
    time += delta
    batch.begin(ShapeRenderer.ShapeType.Filled)
    batch.color = Color.CHARTREUSE
    batch.circle(x + MathUtils.cos(time), y, radius)
    batch.end()
    }
    }
    

    View Slide

57. class MyScreen : ScreenAdapter() {
    lateinit var batch: ShapeRenderer
    private val position: Vector2 = Vector2(0f, 0f)
    private var time: Float = 0f
    override fun create() {
    batch = ShapeRenderer()
    }
    override fun render(delta: Float) {
    val (x, y) = position
    time += delta
    batch.begin(ShapeRenderer.ShapeType.Filled)
    batch.color = Color.CHARTREUSE
    batch.circle(x + MathUtils.cos(time), y, radius)
    batch.end()
    }
    }
    

    View Slide

58. class MyScreen : ScreenAdapter() {
    lateinit var batch: ShapeRenderer
    private val position: Vector2 = Vector2(0f, 0f)
    private var time: Float = 0f
    override fun create() {
    batch = ShapeRenderer()
    }
    override fun render(delta: Float) {
    val (x, y) = position
    time += delta
    batch.begin(ShapeRenderer.ShapeType.Filled)
    batch.color = Color.CHARTREUSE
    batch.circle(x + MathUtils.cos(time), y, radius)
    batch.end()
    }
    }
    

    View Slide

59. /**
    * Operator function that allows to deconstruct this vector.
    * @return X component.
    */
    operator fun Vector2.component1(): Float = this.x
    /**
    * Operator function that allows to deconstruct this vector.
    * @return Y component.
    */
    operator fun Vector2.component2(): Float = this.y
    val vector = Vector2(45f, 50f)
    val (x, y) = vector
    

    View Slide

60. /**
    * Operator function that allows to deconstruct this vector.
    * @return X component.
    */
    operator fun Vector2.component1(): Float = this.x
    /**
    * Operator function that allows to deconstruct this vector.
    * @return Y component.
    */
    operator fun Vector2.component2(): Float = this.y
    val (x, y) = Vector2(45f, 50f)
    

    View Slide

61. entity.add(Ball())
    .add(Position(Vector2(-100f, -100f)))
    .add(Size(Vector2(8f, 9f)))
    .add(Rotation(Vector2(4f, 4f)))
    

    View Slide

62. entity.add(Ball())
    .add(Position(Vector2(-100f, -100f)))
    .add(Size(Vector2(8f, 9f)))
    .add(Rotation(Vector2(4f, 4f)))
    

    View Slide

63. entity.add(Ball())
    .add(Position(-100 v2 -100f))
    .add(Size(8 v2 9))
    .add(Rotation(4 v2 4))
    Create a 

    new Vector2
    infix fun Number.v2(other: Number): Vector2 {
    return Vector2(this.toFloat(), other.toFloat())
    }
    

    View Slide

64. Math: back to school
    

    View Slide

65. View Slide

66. Side
    Racket
    Ball
    

    View Slide

67. Racket
    Side
    Side
    Ball
    

    View Slide

68. Racket
    Side
    Side
    Ball dx = dx * -1
    

    View Slide

69. Racket
    Side
    Side
    Ball dx = dx * -1
    

    View Slide

70. Racket
    Side
    Side
    Ball
    Alpha
    dy = dy * -1 * alpha
    dx = dx * alpha
    

    View Slide

71. val alpha = Math.abs(ball.x - raquet.x)
    val direction: Vector2 = Vector2(10f, 20f)
    direction.scl(1f, -1f)
    .scl(alpha)
    .nor()
    .rotate(306f)
    .add(10f, 20f)
    

    View Slide

72. val ball = Rectangle(68f, 64f, 5f, 5f)
    val player = Rectangle(64f, 64f, 100f, 10f)
    // the ball hit the player?
    player.overlaps(ball)
    

    View Slide

73. val ball = Rectangle(68f, 64f, 5f, 5f)
    val player = Rectangle(64f, 64f, 100f, 10f)
    // the ball hit the player?
    player.overlaps(ball)
    

    View Slide

74. val ball = Rectangle(68f, 64f, 5f, 5f)
    val player = Rectangle(64f, 64f, 100f, 10f)
    // the ball hit the player?
    player.overlaps(ball)
    

    View Slide

75. View Slide

76. View Slide

77. View Slide

78. Box2D
    

    View Slide

79. var world = World(Vector2(0, -10), true)
    // ...
    // Do in render method
    world.step(1/60f, 6, 2);
    val bodyDef = BodyDef()
    // Set its world position
    bodyDef.position.set(position.x, position.y)
    bodyDef.type = BodyDef.BodyType.DynamicBody
    bodyDef.angle = 0f
    val body = world.createBody(bodyDef)
    val shape = CircleShape()
    shape.radius = 8f
    // 2. Create a FixtureDef, as usual.
    val fd = FixtureDef()
    fd.density = 1f
    fd.friction = 2f
    fd.shape = shape
    body.createFixture(fd)
    body.userData = Any // attach sprite data
    shape.dispose()
    

    View Slide

80. var world = World(Vector2(0, -10), true)
    // ...
    // Do in render method
    world.step(1/60f, 6, 2);
    val bodyDef = BodyDef()
    // Set its world position
    bodyDef.position.set(position.x, position.y)
    bodyDef.type = BodyDef.BodyType.DynamicBody
    bodyDef.angle = 0f
    val body = world.createBody(bodyDef)
    val shape = CircleShape()
    shape.radius = 8f
    // 2. Create a FixtureDef, as usual.
    val fd = FixtureDef()
    fd.density = 1f
    fd.friction = 2f
    fd.shape = shape
    body.createFixture(fd)
    body.userData = Any // attach sprite data
    shape.dispose()
    Gravity
    

    View Slide

81. var world = World(Vector2(0, -10), true)
    // ...
    // Do in render method
    world.step(1/60f, 6, 2);
    val bodyDef = BodyDef()
    // Set its world position
    bodyDef.position.set(position.x, position.y)
    bodyDef.type = BodyDef.BodyType.DynamicBody
    bodyDef.angle = 0f
    val body = world.createBody(bodyDef)
    val shape = CircleShape()
    shape.radius = 8f
    // 2. Create a FixtureDef, as usual.
    val fd = FixtureDef()
    fd.density = 1f
    fd.friction = 2f
    fd.shape = shape
    body.createFixture(fd)
    body.userData = Any // attach sprite data
    shape.dispose()
    

    View Slide

82. var world = World(Vector2(0, -10), true)
    // ...
    // Do in render method
    world.step(1/60f, 6, 2);
    val bodyDef = BodyDef()
    // Set its world position
    bodyDef.position.set(position.x, position.y)
    bodyDef.type = BodyDef.BodyType.DynamicBody
    bodyDef.angle = 0f
    val body = world.createBody(bodyDef)
    val shape = CircleShape()
    shape.radius = 8f
    // 2. Create a FixtureDef, as usual.
    val fd = FixtureDef()
    fd.density = 1f
    fd.friction = 2f
    fd.shape = shape
    body.createFixture(fd)
    body.userData = Any // attach sprite data
    shape.dispose()
    Configuration of the
    « thing »
    

    View Slide

83. var world = World(Vector2(0, -10), true)
    // ...
    // Do in render method
    world.step(1/60f, 6, 2);
    val bodyDef = BodyDef()
    // Set its world position
    bodyDef.position.set(position.x, position.y)
    bodyDef.type = BodyDef.BodyType.DynamicBody
    bodyDef.angle = 0f
    val body = world.createBody(bodyDef)
    val shape = CircleShape()
    shape.radius = 8f
    // 2. Create a FixtureDef, as usual.
    val fd = FixtureDef()
    fd.density = 1f
    fd.friction = 2f
    fd.shape = shape
    body.createFixture(fd)
    body.userData = Any // attach sprite data
    shape.dispose()
    

    View Slide

84. var world = World(Vector2(0, -10), true)
    // ...
    // Do in render method
    world.step(1/60f, 6, 2);
    val bodyDef = BodyDef()
    // Set its world position
    bodyDef.position.set(position.x, position.y)
    bodyDef.type = BodyDef.BodyType.DynamicBody
    bodyDef.angle = 0f
    val body = world.createBody(bodyDef)
    val shape = CircleShape()
    shape.radius = 8f
    // 2. Create a FixtureDef, as usual.
    val fd = FixtureDef()
    fd.density = 1f
    fd.friction = 2f
    fd.shape = shape
    body.createFixture(fd)
    body.userData = Any // attach sprite data
    shape.dispose()
    

    View Slide

85. var world = World(Vector2(0, -10), true)
    // ...
    // Do in render method
    world.step(1/60f, 6, 2);
    val bodyDef = BodyDef()
    // Set its world position
    bodyDef.position.set(position.x, position.y)
    bodyDef.type = BodyDef.BodyType.DynamicBody
    bodyDef.angle = 0f
    val body = world.createBody(bodyDef)
    val shape = CircleShape()
    shape.radius = 8f
    // 2. Create a FixtureDef, as usual.
    val fd = FixtureDef()
    fd.density = 1f
    fd.friction = 2f
    fd.shape = shape
    body.createFixture(fd)
    body.userData = Any // attach sprite data
    shape.dispose()
    

    View Slide

86. Traversable
    

    View Slide

87. Math: Interpolation
    

    View Slide

88. View Slide

89. View Slide

90. View Slide

91. y = Interpolation.bounceOut.apply(time) * 100f
    Non linear
    Should be a
    percentage (0..1)
    y will go from 0 to 100
    

    View Slide

92. The screen, the viewport 

    and the camera
    

    View Slide

93. Game
    screen
    screen
    screen screen screen
    

    View Slide

94. open class MenuScreen(val game: Game) : ScreenAdapter() {
    override fun render(delta: Float) {
    // clear the screen
    Gdx.gl.glClearColor(0f, 0f, 0f, 1f)
    Gdx.gl.glClear(GL20.GL_COLOR_BUFFER_BIT)
    batch.begin()
    // ...
    batch.end()
    if (goToMenu) {
    game.setScreen(menuScreen)
    }
    }
    }
    

    View Slide

95. open class MenuScreen(val game: Game) : ScreenAdapter() {
    override fun render(delta: Float) {
    // clear the screen
    Gdx.gl.glClearColor(0f, 0f, 0f, 1f)
    Gdx.gl.glClear(GL20.GL_COLOR_BUFFER_BIT)
    batch.begin()
    // ...
    batch.end()
    if (goToMenu) {
    game.setScreen(menuScreen)
    }
    }
    }
    ⚠⚠⚠⚠⚠⚠⚠⚠⚠⚠⚠⚠⚠⚠
    game.setScreen(screen) 

    is not the same that

    game.screen = screen
    ⚠⚠⚠⚠⚠⚠⚠⚠⚠⚠⚠⚠⚠⚠
    

    View Slide

96. View Slide

97. View Slide

98. View Slide

99. class MyScreen : ScreenAdapter() {
    private lateinit var viewport: Viewport
    private lateinit var bath: SpriteBatch
    override fun show() {
    viewport = FitViewport(200f, 200f)
    bath = SpriteBath()
    }
    override fun render(delta: Float) {
    Gdx.gl.glClearColor(91f / 256f, 110f / 256f, 225f / 256f, 1f)
    Gdx.gl.glClear(GL20.GL_COLOR_BUFFER_BIT)
    batch.begin()
    batch.projectionMatrix = viewport.camera.combined
    // render
    batch.end()
    }
    override fun resize(width: Int, height: Int) {
    viewport.update(width, height)
    }
    }
    

    View Slide

100. class MyScreen : ScreenAdapter() {
     private lateinit var viewport: Viewport
     private lateinit var bath: SpriteBatch
     override fun show() {
     viewport = FitViewport(200f, 200f)
     bath = SpriteBath()
     }
     override fun render(delta: Float) {
     Gdx.gl.glClearColor(91f / 256f, 110f / 256f, 225f / 256f, 1f)
     Gdx.gl.glClear(GL20.GL_COLOR_BUFFER_BIT)
     batch.begin()
     batch.projectionMatrix = viewport.camera.combined
     // render
     batch.end()
     }
     override fun resize(width: Int, height: Int) {
     viewport.update(width, height)
     }
     }
     Size of the world you’ll
     display on the screen
     

     View Slide

101. class MyScreen : ScreenAdapter() {
     private lateinit var viewport: Viewport
     private lateinit var bath: SpriteBatch
     override fun show() {
     viewport = FitViewport(200f, 200f)
     bath = SpriteBath()
     }
     override fun render(delta: Float) {
     Gdx.gl.glClearColor(91f / 256f, 110f / 256f, 225f / 256f, 1f)
     Gdx.gl.glClear(GL20.GL_COLOR_BUFFER_BIT)
     batch.begin()
     batch.projectionMatrix = viewport.camera.combined
     // render
     batch.end()
     }
     override fun resize(width: Int, height: Int) {
     viewport.update(width, height)
     }
     }
     

     View Slide

102. View Slide

103. ScreenViewport
     

     View Slide

104. StretchViewport
     

     View Slide

105. FitViewport
     Clear this
     zone
     Clear this
     zone
     

     View Slide

106. FillViewport
     

     View Slide

107. ExtendViewport
     Displaying
     this zone
     

     View Slide

108. View Slide

109. View Slide

110. viewport.camera.position.add(0f, 40f, 0f)
     // Recalculates the projection and
     // view matrix of this camera
     // Use this after you've manipulated any of
     // the attributes of the camera.
     viewport.camera.update()
     viewport.camera.rotate(10f, 0f, 0f, 1f)
     viewport.camera.update()
     

     View Slide

111. viewport.camera.position.add(0f, 40f, 0f)
     // Recalculates the projection and
     // view matrix of this camera
     // Use this after you've manipulated any of
     // the attributes of the camera.
     viewport.camera.update()
     viewport.camera.rotate(10f, 0f, 0f, 1f)
     viewport.camera.update()
     Will move the camera up
     

     View Slide

112. viewport.camera.position.add(0f, 40f, 0f)
     // Recalculates the projection and
     // view matrix of this camera
     // Use this after you've manipulated any of
     // the attributes of the camera.
     viewport.camera.update()
     viewport.camera.rotate(10f, 0f, 0f, 1f)
     viewport.camera.update()
     Rotate the camera on the z Axis
     

     View Slide

113. Around the game
     

     View Slide

114. View Slide

115. View Slide

116. // load texture
     val texture = Texture(Gdx.files.internal("texture.png"))
     val split = TextureRegion.split(texture, 128, 128)
     // select frames
     val frames = Array()
     frames.add(split[0][0])
     frames.add(split[0][1])
     frames.add(split[0][2])
     frames.add(split[0][4])
     // create animation
     val animation = Animation(100f, frames)
     // select frame to draw
     val keyToRender = animation.getKeyFrame(time)
     

     View Slide

117. // load texture
     val texture = Texture(Gdx.files.internal("texture.png"))
     val split = TextureRegion.split(texture, 128, 128)
     // select frames
     val frames = Array()
     frames.add(split[0][0])
     frames.add(split[0][1])
     frames.add(split[0][2])
     frames.add(split[0][4])
     // create animation
     val animation = Animation(100f, frames)
     // select frame to draw
     val keyToRender = animation.getKeyFrame(time)
     

     View Slide

118. // load texture
     val texture = Texture(Gdx.files.internal("texture.png"))
     val split = TextureRegion.split(texture, 128, 128)
     // select frames
     val frames = Array()
     frames.add(split[0][0])
     frames.add(split[0][1])
     frames.add(split[0][2])
     frames.add(split[0][4])
     // create animation
     val animation = Animation(100f, frames)
     // select frame to draw
     val keyToRender = animation.getKeyFrame(time)
     
     

     View Slide

119. // load texture
     val texture = Texture(Gdx.files.internal("texture.png"))
     val split = TextureRegion.split(texture, 128, 128)
     // select frames
     val frames = com.badlogic.gdx.utils.Array()
     frames.add(split[0][0])
     frames.add(split[0][1])
     frames.add(split[0][2])
     frames.add(split[0][4])
     // create animation
     val animation = Animation(100f, frames)
     // select frame to draw
     val keyToRender = animation.getKeyFrame(time)
     import com.badlogic.gdx.utils.Array as GdxArray
     

     View Slide

120. // load texture
     val texture = Texture(Gdx.files.internal("texture.png"))
     val split = TextureRegion.split(texture, 128, 128)
     // select frames
     val frames = GdxArray()
     frames.add(split[0][0])
     frames.add(split[0][1])
     frames.add(split[0][2])
     frames.add(split[0][4])
     // create animation
     val animation = Animation(100f, frames)
     // select frame to draw
     val keyToRender = animation.getKeyFrame(time)
     

     View Slide

121. // load texture
     val texture = Texture(Gdx.files.internal("texture.png"))
     val split = TextureRegion.split(texture, 128, 128)
     // select frames
     val frames = GdxArray()
     frames.add(split[0][0])
     frames.add(split[0][1])
     frames.add(split[0][2])
     frames.add(split[0][4])
     // create animation
     val animation = Animation(100f, frames)
     // select frame to draw
     val keyToRender = animation.getKeyFrame(time)
     Duration per frame
     

     View Slide

122. 100ms 100ms 100ms 100ms
     

     View Slide

123. 800ms 100ms 100ms 100ms
     100ms
     100ms
     100ms
     100ms
     100ms
     100ms
     100ms
     

     View Slide

124. Loading…
     

     View Slide

125. val assetsManager = AssetManager()
     assetsManager.load("player.png", Texture::class.java)
     assetsManager.load("sfx/beat_intro.ogg", Music::class.java)
     assetsManager.load("krungthep2.fnt", BitmapFont::class.java)
     assetsManager.load("sheets/intro", Aseprite::class.java)
     // call it until it's loaded
     val isLoaded = assetsManager.update()
     val texture = assetsManager.get("player.png", Texture::class.java)
     

     View Slide

126. val assetsManager = AssetManager()
     assetsManager.load("player.png", Texture::class.java)
     assetsManager.load("sfx/beat_intro.ogg", Music::class.java)
     assetsManager.load("krungthep2.fnt", BitmapFont::class.java)
     assetsManager.load("sheets/intro", Aseprite::class.java)
     // call it until it's loaded
     val isLoaded = assetsManager.update()
     val texture = assetsManager.get("player.png", Texture::class.java)
     

     View Slide

127. val assetsManager = AssetManager()
     assetsManager.load("player.png", Texture::class.java)
     assetsManager.load("sfx/beat_intro.ogg", Music::class.java)
     assetsManager.load("krungthep2.fnt", BitmapFont::class.java)
     assetsManager.load("sheets/intro", Aseprite::class.java)
     // call it until it's loaded
     val isLoaded = assetsManager.update()
     val texture = assetsManager.get("player.png", Texture::class.java)
     

     View Slide

128. val assetsManager = AssetManager()
     assetsManager.load("player.png", Texture::class.java)
     assetsManager.load("sfx/beat_intro.ogg", Music::class.java)
     assetsManager.load("krungthep2.fnt", BitmapFont::class.java)
     assetsManager.load("sheets/intro", Aseprite::class.java)
     // call it until it's loaded
     val isLoaded = assetsManager.update()
     val texture = assetsManager.get("player.png", Texture::class.java)
     

     View Slide

129. val assetsManager = AssetManager()
     assetsManager.load("player.png", Texture::class.java)
     assetsManager.load("sfx/beat_intro.ogg", Music::class.java)
     assetsManager.load("krungthep2.fnt", BitmapFont::class.java)
     assetsManager.load("sheets/intro", Aseprite::class.java)
     // call it until it's loaded
     val isLoaded = assetsManager.update()
     val texture = assetsManager.get("player.png", Texture::class.java)
     Call it in the render method
     

     View Slide

130. val assetsManager = AssetManager()
     assetsManager.load("player.png", Texture::class.java)
     assetsManager.load("sfx/beat_intro.ogg", Music::class.java)
     assetsManager.load("krungthep2.fnt", BitmapFont::class.java)
     assetsManager.load("sheets/intro", Aseprite::class.java)
     // call it until it's loaded
     val isLoaded = assetsManager.update()
     val texture = assetsManager.get("player.png", Texture::class.java)
     

     View Slide

131. val assetsManager = AssetManager()
     assetsManager.load("player.png", Texture::class.java)
     assetsManager.load("sfx/beat_intro.ogg", Music::class.java)
     assetsManager.load("krungthep2.fnt", BitmapFont::class.java)
     assetsManager.load("sheets/intro", Aseprite::class.java)
     // call it until it's loaded
     val isLoaded = assetsManager.update()
     val texture: Texture = assetsManager["player.png"]
     inline operator fun AssetManager.get(filename: String): T {
     return this.get(filename, T::class.java)
     }
     

     View Slide

132. Scrollpane
     Label
     Button
     Select box
     

     View Slide

133. val scene = verticalGroup {
     setFillParent(true)
     pad(10f)
     label("Hello KotlinConf!")
     horizontalGroup {
     textButton("Click On Me")
     label("<-- here")
     }
     label("Another label...")
     selectBoxOf(GdxArray().apply {
     add("value 1")
     add("value 2")
     add("value 3")
     })
     }
     stage = Stage(FitViewport(screenWidth, screenHeight))
     stage.addActor(scene)
     

     View Slide

134. val scene = verticalGroup {
     setFillParent(true)
     pad(10f)
     label("Hello KotlinConf!")
     horizontalGroup {
     textButton("Click On Me")
     label("<-- here")
     }
     label("Another label...")
     selectBoxOf(GdxArray().apply {
     add("value 1")
     add("value 2")
     add("value 3")
     })
     }
     stage = Stage(FitViewport(screenWidth, screenHeight))
     stage.addActor(scene)
     

     View Slide

135. val scene = verticalGroup {
     setFillParent(true)
     pad(10f)
     label("Hello KotlinConf!")
     horizontalGroup {
     textButton("Click On Me")
     label("<-- here")
     }
     label("Another label...")
     selectBoxOf(GdxArray().apply {
     add("value 1")
     add("value 2")
     add("value 3")
     })
     }
     stage = Stage(FitViewport(screenWidth, screenHeight))
     stage.addActor(scene)
     

     View Slide

136. val scene = verticalGroup {
     setFillParent(true)
     pad(10f)
     label("Hello KotlinConf!")
     horizontalGroup {
     textButton("Click On Me")
     label("<-- here")
     }
     label("Another label...")
     selectBoxOf(GdxArray().apply {
     add("value 1")
     add("value 2")
     add("value 3")
     })
     }
     stage = Stage(FitViewport(screenWidth, screenHeight))
     stage.addActor(scene)
     

     View Slide

137. Entity System
     

     View Slide

138. Position
     Animation
     Player
     State
     

     View Slide

139. val player = Entity()
     player.add(Player()))
     player.add(Position(100 v2 100))
     player.add(Animation("idle"))
     player.add(StateComponent())
     Position
     Animation
     Player
     State
     

     View Slide

140. ComponentMapper player = ComponentMapper.getFor(Player.class);
     ComponentMapper position = ComponentMapper.getFor(Position.class);
     ComponentMapper animation = ComponentMapper.getFor(Animation.class);
     ComponentMapper state = ComponentMapper.getFor(StateComponent.class);
     ...
     player.get(entity).life;
     position.get(entity).xy;
     animation.get(entity).getFrame(time);
     state.get(entity).time;
     Extractor
     Extraction
     

     View Slide

141. inline fun EntitySystem.get(): ComponentMapper = 

     ComponentMapper.getFor(T::class.java)
     inline operator fun Entity.get(mapper: ComponentMapper): T = 

     mapper.get(this)
     

     View Slide

142. val player: ComponentMapper = get()
     val position: ComponentMapper = get()
     val animation: ComponentMapper = get()
     val state: ComponentMapper = get()
     // access to components
     entity[player].life
     entity[position].xy
     entity[animation].frame(time)
     entity[state].time
     

     View Slide

143. val player: ComponentMapper = get()
     val position: ComponentMapper = get()
     val animation: ComponentMapper = get()
     val state: ComponentMapper = get()
     // access to components
     entity[player].life
     entity[position].xy
     entity[animation].frame(time)
     entity[state].time
     Accessing like a map
     

     View Slide

144. Close Open
     

     View Slide

145. fun on(event: Int, block: Transition): OnState {
     var currentTransitions = parent.transitions[state] ?: emptyMap()
     currentTransitions += event to block
     parent.transitions += state to currentTransitions
     return this
     }
     Lambda
     

     View Slide

146. startWith(WAIT)
     onState(WAIT).on(GameEvents.EVENT_COMPUTER_ALLOW_MOVE) { entity, event ->
     if (entity[dragon].currentTurn > 3) {
     entity[dragon].currentTurn = -1
     go(FIRE, entity, event)
     } else {
     go(MOVE, entity, event)
     }
     }
     onState(FIRE).on(GameEvents.EVENT_DRAGON_FIRE_BALL) { entity, event ->
     go(MOVE, entity, event)
     }
     Lambda
     

     View Slide

147. startWith(WAIT)
     onState(WAIT).on(GameEvents.EVENT_COMPUTER_ALLOW_MOVE) { entity, event ->
     if (entity[dragon].currentTurn > 3) {
     entity[dragon].currentTurn = -1
     go(FIRE, entity, event)
     } else {
     go(MOVE, entity, event)
     }
     }
     onState(FIRE).on(GameEvents.EVENT_DRAGON_FIRE_BALL) { entity, event ->
     go(MOVE, entity, event)
     }
     State Event Transition
     

     View Slide

148. Pitfalls
     

     View Slide

149. Garbage Collector
     Garbage Collector
     Garbage Collector
     Garbage Collecto
     arbage C
     Garbage
     STOP THE
     WORLD
     

     View Slide

150. altLayers = map.layers
     .mapIndexed { index, layer -> index to layer }
     .filter { it.second.name.startsWith("alt_") }
     .map { it.first }
     .toIntArray()
     List 1
     List 2
     List 3
     List 4
     mutableList
     

     View Slide

151. val ball = Rectangle(68f, 64f, 5f, 5f)
     val player = Rectangle(64f, 64f, 100f, 10f)
     // the ball hit the player?
     player.overlaps(ball)
     

     View Slide

152. val pool = object : Pool() {
     override fun newObject(): Rectangle = Rectangle()
     }
     // ...
     val ball = pool.obtain().apply {
     set(68f, 64f, 5f, 5f)
     }
     val player = pool.obtain().apply {
     set(64f, 64f, 100f, 10f)
     }
     // the ball hit the player?
     player.overlaps(ball)
     pool.free(ball)
     pool.free(player)
     

     View Slide

153. val pool = object : Pool() {
     override fun newObject(): Rectangle = Rectangle()
     }
     // ...
     val ball = pool.obtain().apply {
     set(68f, 64f, 5f, 5f)
     }
     val player = pool.obtain().apply {
     set(64f, 64f, 100f, 10f)
     }
     // the ball hit the player?
     player.overlaps(ball)
     pool.free(ball)
     pool.free(player)
     

     View Slide

154. val pool = object : Pool() {
     override fun newObject(): Rectangle = Rectangle()
     }
     // ...
     val ball = pool.obtain().apply {
     set(68f, 64f, 5f, 5f)
     }
     val player = pool.obtain().apply {
     set(64f, 64f, 100f, 10f)
     }
     // the ball hit the player?
     player.overlaps(ball)
     pool.free(ball)
     pool.free(player)
     

     View Slide

155. val pool = object : Pool() {
     override fun newObject(): Rectangle = Rectangle()
     }
     // ...
     val ball = pool.obtain().apply {
     set(68f, 64f, 5f, 5f)
     }
     val player = pool.obtain().apply {
     set(64f, 64f, 100f, 10f)
     }
     // the ball hit the player?
     player.overlaps(ball)
     pool.free(ball)
     pool.free(player)
     

     View Slide

156. Integration with other tools
     

     View Slide

157. View Slide

158. View Slide

159. View Slide

160. View Slide

161. View Slide

162. // can be loaded using AssetManager too
     val tmxMap = TmxMapLoader().load(mapName)
     tmxMap.layers["bricks"]?.objects?.forEach { brick ->
     // create game entity
     }
     mapRenderer = OrthogonalTiledMapRenderer(tmxMap)
     // render method
     mapRenderer.setView(viewport.camera as OrthographicCamera)
     mapRenderer.render()
     

     View Slide

163. // can be loaded using AssetManager too
     val tmxMap = TmxMapLoader().load(mapName)
     tmxMap.layers["bricks"]?.objects?.forEach { brick ->
     // create game entity
     }
     mapRenderer = OrthogonalTiledMapRenderer(tmxMap)
     // render method
     mapRenderer.setView(viewport.camera as OrthographicCamera)
     mapRenderer.render()
     

     View Slide

164. // can be loaded using AssetManager too
     val tmxMap = TmxMapLoader().load(mapName)
     tmxMap.layers["bricks"]?.objects?.forEach { brick ->
     // create game entity
     }
     mapRenderer = OrthogonalTiledMapRenderer(tmxMap)
     // render method
     mapRenderer.setView(viewport.camera as OrthographicCamera)
     mapRenderer.render()
     

     View Slide

165. // can be loaded using AssetManager too
     val tmxMap = TmxMapLoader().load(mapName)
     tmxMap.layers["bricks"]?.objects?.forEach { brick ->
     // create game entity
     }
     mapRenderer = OrthogonalTiledMapRenderer(tmxMap)
     // render method
     mapRenderer.setView(viewport.camera as OrthographicCamera)
     mapRenderer.render()
     

     View Slide

166. View Slide

167. hit 4
     sound chicken.wav
     

     View Slide

168. tmxMap.layers["bricks"].objects.forEach { brick ->
     val hit: Any = brick.properties["hit"]
     }
     Error prone
     Error prone
     

     View Slide

169. class BrickProperties(properties: MapProperties) {
     val x: Double by properties
     val y: Double by properties
     val hit: Int by properties
     val sound: String by properties
     }
     tmxMap.layers["bricks"].objects.forEach { brick ->
     val props = BrickProperties(brick.properties)
     val hit = props.hit
     }
     

     View Slide

170. class BrickProperties(properties: MapProperties) {
     val x: Double by properties
     val y: Double by properties
     val hit: Int by properties
     val sound: String by properties
     }
     tmxMap.layers["bricks"].objects.forEach { brick ->
     val props = BrickProperties(brick.properties)
     val hit = props.hit
     }
     

     View Slide

171. class BrickProperties(properties: MapProperties) {
     val x: Double by properties
     val y: Double by properties
     val hit: Int by properties
     val sound: String by properties
     }
     tmxMap.layers["bricks"].objects.forEach { brick ->
     val props = BrickProperties(brick.properties)
     val hit = props.hit
     }
     Delegates
     

     View Slide

172. inline operator fun MapProperties.getValue(thisRef: Any?, property: KProperty<*>): T
     {
     val asStr = this[property.name].toString()
     return when (T::class) {
     Double::class -> asStr.toDouble()
     Int::class -> asStr.toInt()
     Boolean::class -> "true" == asStr
     String::class -> asStr
     else -> this[property.name]
     } as T
     }
     

     View Slide

173. val chicken: Aseprite = assets["sheets/chicken"]
     val idleAnimation: Animation = chicken["idle"]
     

     View Slide

174. Json
     Json
     Json
     

     View Slide

175. open class AsepriteTask : DefaultTask() {
     // ...
     @TaskAction
     fun export() {
     val exec = getExecActionFactory().newExecAction()
     val exts = project.extensions.getByType(AsepritePluginExtentions::class.java)
     val aseprite = exts.exec ?: invalideAsepritePath()
     // ...
     }
     private fun invalideAsepritePath(): Nothing {
     TODO("""Missing aseprite executable path.
     Please configure it using aseprite.exec property (ie: in your ~/.gradle/gradle.properties)
     aseprite.exec=
     or using aseprite extension in your build.gradle
     aseprite {
     exec=
     }
     MacOS specific : point to aseprite located into /Aseprite.app/Contents/MacOS/aseprite""")
     }
     }
     

     View Slide

176. open class AsepriteTask : DefaultTask() {
     // ...
     @TaskAction
     fun export() {
     val exec = getExecActionFactory().newExecAction()
     val exts = project.extensions.getByType(AsepritePluginExtentions::class.java)
     val aseprite = exts.exec ?: invalideAsepritePath()
     // ...
     }
     private fun invalideAsepritePath(): Nothing {
     TODO("""Missing aseprite executable path.
     Please configure it using aseprite.exec property (ie: in your ~/.gradle/gradle.properties)
     aseprite.exec=
     or using aseprite extension in your build.gradle
     aseprite {
     exec=
     }
     MacOS specific : point to aseprite located into /Aseprite.app/Contents/MacOS/aseprite""")
     }
     }
     What happens if null?
     Encountered an error, lol!
     

     View Slide

177. open class AsepriteTask : DefaultTask() {
     // ...
     @TaskAction
     fun export() {
     val exec = getExecActionFactory().newExecAction()
     val exts = project.extensions.getByType(AsepritePluginExtentions::class.java)
     val aseprite = exts.exec ?: invalideAsepritePath()
     // ...
     }
     private fun invalideAsepritePath(): Nothing {
     TODO("""Missing aseprite executable path.
     Please configure it using aseprite.exec property (ie: in your ~/.gradle/gradle.properties)
     aseprite.exec=
     or using aseprite extension in your build.gradle
     aseprite {
     exec=
     }
     MacOS specific : point to aseprite located into /Aseprite.app/Contents/MacOS/aseprite""")
     }
     }
     

     View Slide

178. open class AsepriteTask : DefaultTask() {
     // ...
     @TaskAction
     fun export() {
     val exec = getExecActionFactory().newExecAction()
     val exts = project.extensions.getByType(AsepritePluginExtentions::class.java)
     val aseprite = exts.exec ?: invalideAsepritePath()
     // ...
     }
     private fun invalideAsepritePath(): Nothing {
     TODO("""Missing aseprite executable path.
     Please configure it using aseprite.exec property (ie: in your ~/.gradle/gradle.properties)
     aseprite.exec=
     or using aseprite extension in your build.gradle
     aseprite {
     exec=
     }
     MacOS specific : point to aseprite located into /Aseprite.app/Contents/MacOS/aseprite""")
     }
     }
     

     View Slide

179. Shaders
     

     View Slide

180. void main() {

     vec4 sum = vec4(0);

     

     float step = iResolution.y;

     // y

     for(float i = -area ; i <= area ; i += 1.) {

     // x

     for(float j = -area ; j <= area ; j += 1.) {

     float x = v_texCoords.x + i / iResolution.x;

     float y = v_texCoords.y + j / iResolution.y;

     sum += texture2D(u_texture, vec2(x, y)) * 0.005;

     }

     }

     gl_FragColor = texture2D(u_texture, v_texCoords) + sum;

     }
     OpenGL Shading Language (GLSL)
     

     View Slide

181. View Slide

182. View Slide

183. View Slide

184. View Slide

185. View Slide

186. View Slide

187. View Slide

188. View Slide

189. View Slide

190. if (color_pixel < cutoff) {
     // light dark
     pixel = gl_FragColor = vec4(0.3, 0.2, 0.4., 1.0);
     } else {
     pixel = color_pixel;
     }
     0
     1
     Cut off
     

     View Slide

191. if (color_pixel < cutoff) {
     // light dark
     pixel = gl_FragColor = vec4(0.3, 0.2, 0.4., 1.0);
     } else {
     pixel = color_pixel;
     }
     

     View Slide

192. View Slide

193. View Slide

194. View Slide

195. https://www.shadertoy.com/view/ld3Gz2
     

     View Slide

196. fun makeGames()
     

     View Slide

197. fun makeGames()
     

     View Slide

198. @dwursteisen
     http://bit.ly/2poORfk
     

     View Slide

199. Beat The High Score Game https://github.com/dwursteisen/beat-the-high-score
     libGDX Lib https://libgdx.badlogicgames.com/
     KTX 

     (This is NOT Android KTX)
     Lib https://github.com/libktx/ktx/
     libGDX addons Lib https://github.com/dwursteisen/libgdx-addons/
     kTerminal Lib https://github.com/heatherhaks/kterminal
     Game Services Lib https://github.com/MrStahlfelge/gdx-gamesvcs
     In Game Console

     (A la quake)
     Lib https://github.com/StrongJoshua/libgdx-inGameConsole
     Gif Recorder Lib https://github.com/Anuken/GDXGifRecorder
     Tiled Editor Editor https://www.mapeditor.org
     Aseprite Editor https://www.aseprite.org
     

     View Slide