Kaboom

Kaboom is a JavaScript library that helps you make games fast and fun!

Start playing around with it in the Kaboom Playground

Examples

// initialize context
kaboom()

// define gravity
setGravity(2400)

// load a sprite called "bean"
loadSprite("bean", "sprites/bean.png")

// compose the player game object from multiple components and add it to the game
const bean = add([
    sprite("bean"),
    pos(80, 40),
    area(),
    body(),
])

// press space to jump
onKeyPress("space", () => {
    // this method is provided by the "body" component above
    bean.jump()
})

Kaboom uses a powerful component system to compose game objects and behaviors.

// add a game obj to the scene from a list of component
const player = add([
    // it renders as a sprite
    sprite("bean"),
    // it has a position
    pos(100, 200),
    // it has a collider
    area(),
    // it is a physical body which will respond to physics
    body(),
    // it has 8 of health
    health(8),
    // or give it tags for easier group behaviors
    "player",
    "friendly",
    // plain objects fields are directly assigned to the game obj
    {
        dir: vec2(-1, 0),
        dead: false,
        speed: 240,
    },
])

Blocky imperative syntax for describing behaviors

// .onCollide() comes from "area" component
player.onCollide("enemy", () => {
    // .hurt() comes from "health" component
    player.hurt(1)
})

// check fall death
player.onUpdate(() => {
    if (player.pos.y >= height()) {
        destroy(player)
        gameOver()
    }
})

// if 'player' onCollide with any object with tag "enemy", run the callback
player.onCollide("enemy", () => {
    player.hp -= 1
})

// all objects with tag "enemy" will move towards 'player' every frame
onUpdate("enemy", (e) => {
    e.move(player.pos.sub(e.pos).unit().scale(e.speed))
})

// move up 100 pixels per second every frame when "w" key is held down
onKeyDown("w", () => {
    player.move(0, 100)
})

Usage

Start a Project With create-kaboom

The fastest way to start a Kaboom game is with create-kaboom

$ npm init kaboom mygame

This will create a directory called mygame for you, containing all the files we need

$ cd mygame
$ npm run dev

Then open http://localhost:5173 and edit src/game.js

Install as NPM Package

$ npm install kaboom

import kaboom from "kaboom"

kaboom()

add([
    text("oh hi"),
    pos(80, 40),
])

also works with CommonJS

const kaboom = require("kaboom")

Note that you'll need to use a bundler like esbuild or webpack to use Kaboom with NPM

Browser CDN

This exports a global kaboom function

<script src="https://unpkg.com/kaboom@3000.0.1/dist/kaboom.js"></script>
<script>
kaboom()
</script>

or use with es modules

<script type="module">
import kaboom from "https://unpkg.com/kaboom@3000.0.1/dist/kaboom.mjs"
kaboom()
</script>

works all CDNs that supports NPM packages, e.g. jsdelivr, skypack

Documentation

• v3000: https://kaboomjs.com/
• v2000: https://2000.kaboomjs.com/
• v0.5.0: https://legacy.kaboomjs.com/

Dev

1. npm install to install dev packages
2. npm run dev to start dev server
3. go to http://localhost:8000/ and pick an example
4. edit examples in examples/ to test

Check out CONTRIBUTION.md for full info.

Community

• Discord Server
• GitHub Discussions
• Twitter

Games

Collection of games made with Kaboom, selected by Kaboom, here.

• on Itch.io
• on Replit
• on Newgrounds

Misc

• Thanks to LaJBel for help building the Kaboom community
• Thanks to abrudz for the amazing APL386 font
• Thanks to Polyducks for the amazing kitchen sink font font
• Thanks to 0x72 for the amazing Dungeon Tileset
• Thanks to Kenney for the amazing 1-Bit Platformer Pack
• Thanks to mulfok for the amazing mulfok32 color palette
• Find bitmap fonts: Oldschool PC Font
• Featured on Console 50
• Thanks to Umayr for kindly offering the "kaboom" npm package name
• Please buy fireworks on kaboom.com
• How to do a KABOOM on a Trampoline

v3000.1.17

• exposed vel property on BodyComp

v3000.1.16

• fixed error not being logged
• fixed error screen scaling error in letterbox mode

v3000.1.15

• fixed loadRoot() not working sometimes
• fixed audio being resumed when the tab is switched on but debug.paused is true

v3000.1.12

• fixed color() and rgb() not working

v3000.1.11

• added option kaboom({ focus: false }) to disable focus on start
• fixed rand() typing for numbers
• fixed mouse position in fullscreen
• added Color#toHSL()

v3000.1.10

• fixed test code accidentally getting shipped (where a screenshot will be downloaded every time you press space)

v3000.1.9

• added fill option to rect(), circle() and sprite()
• fixed view getting cut off in letterbox mode

v3000.1.8

• fixed scale option acting weird when width and height are defined (by @hirnsalat)

v3000.1.7

• fixed debug.paused not pausing audio
• added mask() component
• added support for colored font outline

  loadFont("apl386", "/examples/fonts/apl386.ttf", {
    outline: {
        width: 8,
        color: rgb(0, 0, 255),
    },
  })

• fixed wave() not starting at 0 when time is 0
• kaboom now only displays error screen for kaboom's own error, instead of catching all errors in current window
• added KaboomError class for errors related to current kaboom instance
• setting obj.text with text() component now immediately updates width and height property `js const obj = add([ text("oh hi"), pos(100, 200), ])

// before obj.text = "bye" console.log(obj.width) // still the width of "oh hi" until next render

// before obj.text = "bye" console.log(obj.width) // will be updated to the width of "bye"

### v3000.1.6
- fixed `loadSound` typing to accept `ArrayBuffer`

### v3000.1.5
- added `Event#clear()` method
- fixed `add()` without argument

### v3000.1.4
- added `audio.stop()` method
```js
const music = play("music")
music.stop()

v3000.1.3

• fixed onCollideUpdate() still runs when object is paused
• allow add() and make() without arguments
• added debug.numObjects()
• added width and height properties to SpriteData

  // get sprite size
  getSprite("bean").then((spr) => {
    console.log(spr.width, spr.height)
  })

v3000.1.2

• fixed audio not pausing when tab hidden and backgroundAudio not set
• fixed debug.timeScale not working
• fixed debug.paused not able to resume
• fixed quad option not working in sprite() component
• added onHide() and onShow() for tab visibility event

v3000.1.1

• fixed some indirect fixed related issues

v3000.1

• added game object level input handling

// add a scene game object
const scene = add([])

const bean = scene.add([
    sprite("bean"),
    pos(100, 200),
    area(),
    body(),
])

scene.onKeyPress("space", () => {
  bean.jump()
})

scene.onMousePress(() => {
  bean.jump()
})

// setting scene.paused will pause all the input events
scene.paused = true

// destroying scene will cancel all its input events
scene.destroy()

const ui = add([])

ui.add(makeButton())

// these will only work if ui game object is active
ui.onMousePress(() => {
  // ...
})

// before you'll have to manually clean up events on obj.onDestroy()
const scene = add([])
const evs = []
scene.onDestroy(() => {
  evs.forEach((ev) => ev.cancel())
})
evs.push(k.onKeyPress("space", () => {
  doSomeSceneSpecificStuff()
}))

• added make() to create game object without adding to the scene `js const obj = make([ sprite("bean"), pos(120, 60), ])

add(obj)

- fixed children not inheriting `fixed()` from parent
```js
// before
const ui = add([
  fixed(),
])

ui.add([
  rect(),
  // have to also give all children game objects fixed()
  fixed(),
])

// now
const ui = add([
  fixed(),
])

// you don't have to add fixed() to children
ui.add([
  rect(100, 100),
])

• fixed AreaComp#onClick() event not getting cleaned up when game object is destroyed
• fixed typo isTouchScreen() -> isTouchscreen()
• fixed inspect mode doesn't show the properties box of indirect children game objects
• fixed some problem causing kaboom to not work with vite
• fixed "destroy" event not run on children game objects
• calling shake() when another shake is happening adds to the shake instead of reset it?
• fixed incorrect touch position when canvas is not at top left of page

v3000

Game Objects

• added scene graph, game objects are now stored in a tree-like structure and can have children with obj.add() `js const bean = add([ sprite("bean"), pos(160, 120), ])

const sword = bean.add([ sprite("sword"), // transforms will be relative to parent bean object pos(20, 20), rotate(20), ])

const hat = bean.add([ sprite("hat"), // transforms will be relative to parent bean object pos(0, -10), ])

// children will be moved alongside the parent bean.moveBy(100, 200)

// children will be destroyed alongside the parent bean.destroy()

- added `recursive` and `liveUpdate` options to `get()`
```js
const enemies = get("enemy", {
    // get from all children and descendants, instead of only direct children
    recursive: true,
    // live update the returned list to listen to onAdd and onDestroy events
    liveUpdate: true,
})

console.log(enemies.length) // 3

add([
    sprite("bigbird"),
    "enemy",
])

console.log(enemies.length) // 4

• changed object update order from reversed to not reversed
• (BREAK) removed GameObj#every() and GameObj#revery() in favor of obj.get("*").forEach()
• (BREAK) renamed GameObj#_id to GameObj#id
• addLevel() now returns a GameObj which has all individual grid objects as its children game objects, with LevelComp containing its previous methods
• added onAdd() and onDestroy() events to listen to added / destroyed game objects

Components

• added support for getter and setters in component properties

Area

• added collision support for rotate shapes and polygons
• added option collisionIgnore to area() component, which accepts a list of tags to ignore when checking collision

  const bean = add([
    sprite("bean"),
    pos(100, 80),
    area({
        collisionIgnore: [ "cloud", "particle" ],
    }),
  ])

• added Area#getCollisions to get a list of all current collisions happening

  for (const col of player.getCollisions()) {
    const c = col.target
    if (c.is("chest")) {
        c.open()
    }
  }

• added Area#onCollideUpdate() and onCollideUpdate() to register an event that runs every frame when 2 object is colising
• added Area#onCollideEnd() and onCollideEnd() to register an event that runs once when 2 objects stopped colliding
• added Area#onHover() and onHover() to register an event that runs once when an object(s) is hovered
• added Area#onHoverEnd() and onHoverEnd() to register an event that runs once when an object(s) stopped being hovered
• (BREAK) renamed onHover() to onHoverUpdate() (it registers an event that runs every frame when an object is hovered)
• (BREAK) renamed pushOut() to resolveCollision()

Body

• added Body#onFall() which fires when object starts falling
• added Body#onPhysicsResolve() and Body#onBeforePhysicsResolve() to register events relating to collision resolution

  // make semi-solid platforms that doesn't block player when player is jumping over it
  player.onBeforePhysicsResolve((collision) => {
    if (collision.target.is(["platform", "soft"]) && player.isJumping()) {
        collision.preventResolution()
    }
  })

• (BREAK) removed solid() in favor of body({ isStatic: true })
• added option body({ mass: 3 }) to define how hard a non-static body is to be pushed by another non-static body
• added option body({ stickToPlatform: false }) to turn off object moving with platform
• (BREAK) removed Body#doubleJump() in favor of doubleJump() component
• (BREAK) renamed Body#weight to Body#gravityScale
• (BREAK) renamed Body#onFall() to Body#onFallOff() which triggers when object fall off a platform
• (BREAK) defining setGravity() is now required for enabling gravity, body() by default will only prevent objects from going through each other

Others

• (BREAK) renamed origin() to anchor(), so it won't mess up typescript in global mode
• (BREAK) anchor (previously origin) no longer controls text alignment, use text({ align: "left" }) option instead
• added doubleJump() component to enable double jump (or any number of jumps)
• (BREAK) renamed outview() to offscreen(), and uses a much faster check (but less accurate) for if object is offscreen
  • removed offset option in favor of a simpler distance option
  • renamed onExitView() and onEnterView() to onExitScreen() and onEnterScreen()
• (BREAK) removed cleanup() component in favor of offscreen({ destroy: true })
• added OpacityComp#fadeOut()
• added fadeIn() component
• stay() now accepts a list of scenes to stay for, like stay(["gameover", "menu"])
• (BREAK) changed SpriteComp#flipX and SpriteComp#flipY to properties instead of functions
• (BEARK) sprite.onAnimStart() and sprite.onAnimEnd() now triggers on any animation `js // before obj.onAnimEnd("walk", () => { // do something })

// v3000 obj.onAnimEnd((anim) => { if (anim === "walk") { // do something } })

- (**BREAK**) `ScaleComp#scale` will always be a `Vec2` not `number`
- `shader()` comp `uniform` parameter now supports a callback that returns the uniform every frame
```js
const player = add([
    sprite("bean"),
    // will calculate and send u_time every frame
    shader("flashy", () => ({
        "u_time": time(),
    })),
])

Assets

• added loadProgress() that returns a 0.0 - 1.0 that indicates current asset loading progress
• added option loadingScreen to kaboom() where you can turn off the default loading screen
• added onLoadUpdate() to register a custom loading screen (see "loader" example)

  // custom loading screen
  onLoadUpdate((progress) => {
    drawCircle({
        pos: center(),
        radius: 32,
        end: map(progress, 0, 1, 0, 360),
    })
  })

• added support for multiple sprite sources as frames in loadSprite()

  loadSprite("player", [
    "sprites/player_idle.png",
    "sprites/player_run.png",
    "sprites/player_jump.png",
  ])

• (BREAK) added loadShaderURL(), loadShader() now only load shader code not files

Text

• added loadFont() to load .ttf, .otf, .woff2 or any font supported by browser FontFace `js // Load a custom font from a .ttf file loadFont("FlowerSketches", "/examples/fonts/FlowerSketches.ttf")

// Load a custom font with options loadFont("apl386", "/examples/fonts/apl386.ttf", { outline: 4, filter: "linear" })

- (**BREAK**) renamed previous `loadFont()` to `loadBitmapFont()`
- (**BREAK**) removed built-in `apl386`, `apl386o`, `sink`, `sinko` (still available under `examples/fonts`)
- changed default font size to `36`
- (**BREAK**) changed to bbcode syntax for styled text
```js
// before
"[oh hi].green here's some [styled].wavy text"
// v3000
"[green]oh hi[/green] here's some [wavy]styled[/wavy] text"

Graphics

• fixed visual artifacts on text rendering
• added colors option to drawPolygon() that controls the color of each corner
• added gradient option to drawRect() that specifies the start and end color
• added drawMasked() and drawSubtracted()
• added pushRotateX(), pushRotateY() and pushRotateZ()
• added pixelDensity option to kaboom()
• (BREAK) changed position vertex format from vec3 to vec2 (which is passed in as the first argument of custom frag and vert shader functions)
• added usePostEffect() to add post process shader `js loadShader("invert", null, vec4 frag(vec2 pos, vec2 uv, vec4 color, sampler2D tex) { vec4 c = def_frag(); return vec4(1.0 - c.r, 1.0 - c.g, 1.0 - c.b, c.a); })

usePostEffect("invert")

- shader error logs now yields the correct line number
- added `slice9` option to `loadSprite()` to enable [9 slice scaling](https://en.wikipedia.org/wiki/9-slice_scaling)
```js
loadSprite("grass", "/sprites/grass.png", {
    slice9: {
        left: 8,
        right: 8,
        top: 8,
        bottom: 8,
    },
})

const g = add([
    sprite("grass"),
])

onMouseMove(() => {
    const mpos = mousePos()
    // updating width / height will scale the image but not the sliced frame
    g.width = mpos.x
    g.height = mpos.y
})

Audio

• added option kaboom({ backgroundAudio: false }) to not pause audio when tab not active
• changed speed, detune, volume, loop in AudioPlay from functions to properties
• added onEnd() event for const pb = play("sound") `js // before const music = play("song") music.speed(2) music.volume(0.5) music.loop(true)

// v3000 const music = play("song") music.speed = 2 music.volume = 0.5 music.loop = true

## Input

- added `onScroll(action: (delta: Vec2) => void)` to listen mouse wheel scroll
- fixed touches not treated as mouse
- (**BREAK**) changed `onTouchStart()`, `onTouchMove()` and `onTouchEnd()` callback signature to `(pos: Vec2, touch: Touch) => void` (exposes the native `Touch` object)
- added `onGamepadButtonPress()`, `onGamepadButtonDown()`, `onGamepadButtonRelease()`
- added `isGamepadButtonPressed()`, `isGamepadButtonDown()`, `isGamepadButtonReleased()`
- added `onGamepadStick()` to handle gamepad axes info for left and right sticks
- added `getConnectedGamepads()`
- added `onGamepadConnect()` and `onGamepadDisconnect()`
- added `gamepads` option to `kaboom()` to define custom gamepads


## Level

- (**BREAK**) changed `addLevel()` options API
  - renamed `width` and `height` to `tileWidth` and `tileHeight`
  - renamed `any` to `wildcardTile`
  - now all tile symbols are defined in the `tiles` object

```js
// before
addLevel([
    "@  ^ $$",
    "=======",
], {
    width: 32,
    height: 32,
    "=": () => [
        sprite("grass"),
        area(),
        body({ isStatic: true }),
    ],
    "$": () => [
        sprite("coin"),
        area(),
        "coin",
    ],
    any: (symbol) => {
        if (symbol === "@") {
            return [ /* ... */ ]
        }
    },
})

// v3000
addLevel([
    "@  ^ $$",
    "=======",
], {
    tileWidth: 32,
    tileHeight: 32,
    tiles: {
        "=": () => [
            sprite("grass"),
            area(),
            body({ isStatic: true }),
        ],
        "$": () => [
            sprite("coin"),
            area(),
            "coin",
        ],
    },
    wildcardTile: (symbol) => {
        if (symbol === "@") {
            return [ /* ... */ ]
        }
    },
})

Misc

• sprites are now automatically packed, improving performance
• (BREAK) renamed gravity() into getGravity() and setGravity()
• (BREAK) removed all deprecated functions in v2000.2
• (BREAK) raised esbuild target to esnext
• added setBackground() and getBackground() in addition to background option in kaboom()
• moved type defs for global functions to import "kaboom/global"

// if use global functions
import "kaboom"
import "kaboom/global" // required to load global types

kaboom()

// will have definition
add()

// if don't use global function
import "kaboom"

kaboom({ global: false })

// type error, won't pollute global namespace if not manually import "kaboom/global"
add()

• added tween() for tweening, and a set of built-in easing functions in easings

onMousePress(() => {
    tween(bean.pos.x, mousePos().x, 1, (val) => bean.pos.x = val, easings.easeOutBounce)
    tween(bean.pos.y, mousePos().y, 1, (val) => bean.pos.y = val, easings.easeOutBounce)
})

• (BREAK) changed all event handlers to return a EventController object instead of a function to cancel event

// before
const cancel = onUpdate(() => { /* ... */ })
cancel()

// v3000
const ev = onUpdate(() => { /* ... */ })
ev.paused = true
ev.cancel()

• timers can now be paused

const timer = wait(4, () => { /* ... */ })
timer.paused = true
timer.resume()

const timer = loop(1, () => { /* ... */ })
timer.paused = true
timer.resume()

• kaboom() now automatically focuses the canvas
• added quit() to end everything
• added download(), downloadText(), downloadJSON(), downloadBlob()
• added Recording#stop() to stop the recording and returns the video data as mp4 Blob
• added debug.numFrames() to get the total number of frames elapsed
• added onError() to handle error or even custom error screen
• added onResize() to register an event that runs when canvas resizes
• added setCursorLocked() and isCursorLocked()
• (BREAK) renamed cursor() to setCursor()
• (BREAK) renamed fullscreen() to setFullscreen()
• (BREAK) renamed isTouch() to isTouchscreen()
• (BREAK) removed layers() in favor of parent game objects (see "layers" example)
• (BREAK) removed load() event for components, use onLoad() in add() event
• (BREAK) removed debug.objCount() in favor of getAll().length
• added debug.numFrames() to get the current frame count

v2000.2.6

• fixed text always being wrapped if updated
• fixed text comp properties letterSpacing, charSpacing, transform, styles not being exposed

v2000.2.5

• fixed updating font property on gameobj not updating the text font

v2000.2.4

• fixed focus() not properly exported
• deprecated focus() in favor of canvas.focus() due to name collision

v2000.2.3

• fixed kaboom.d.ts completely messed up

v2000.2.2

• fixed doc for TextCompOpt#styles and DrawTextOpt#styles

v2000.2.1

• fixed updates not running at all when kaboom({ debug: false })

v2000.2 "Fancy Text Mode"

• added formatText() and drawFormattedText()
• added charSpacing and lineSpacing in TextCompOpt and DrawTextOpt
• added optional transitions argument in state() to define allowed transitions
• added StateComp#onStateTransition to register event for specific transitions
• added syntax to style a piece of text "this is a [styled].wavy text" and style option in TextCompOpt and DrawTextOpt to define the styles with CharTransformFunc
• deprecated dir() in favor of Vec2.fromAngle()
• fixed onTouchEnd() fired on touchmove
• added outview() component to control behavior when object leaves visible area
• deprecated cleanup(delay?: number) in favor of cleanup(opt?: CleanupOpt)
• deprecated mouseWorldPos() in favor of toWorld(mousePos())
• deprecated rng() in favor of new RNG()
• added classes Vec2, Color, Mat4, Timer, Quad, RNG, Line, Rect, Circle
• added deprecation warning
• fixed letterbox view mode
• allow non-stretch letterbox
• fixed mouse position malfunction in fullscreen, stretch and letterbox mode

v2000.1.8

• fixed Color#eq() not giving correct result

v2000.1.7

• fixed not having export if installed from github repo with npm
• fixed event canceller returned by raw onUpdate() and onDraw() crashing

v2000.1.6

• fixed debug widget scale

v2000.1.5

• fixed enterState() not passing args to onStateEnter() callback

v2000.1.4

• fixed state() to not require registering onStateUpdate() before using any state

v2000.1.2

• fixed onKeyRelease() wrongfully check for key press instead of release

v2000.1.1

• fixed StateComp#enterState() not accepting any state

v2000.1 "Record Mode"

• added hsl2rgb() for converting HSL color to kaboom RGB
• added record() to start a screen recording
• added F5 to screenshot and F6 to toggle record mode in debug mode
• added DrawTextOpt#transform() and TextCompOpt#transform() for defining style and transformation for each character
• added state() component for finite state machine
• added support for multiple tags in get() and every()
• added UI indicator for debug.paused and debug.timeScale
• changed inspect mode UI style
• added color constants WHITE, BLACK, BLUE, GREEN, RED, MAGENTA, CYAN, YELLOW
• added new API style (on prefix for all event handler function, is prefix for all boolean state getters)
  • onLoad()
  • onUpdate()
  • onDraw()
  • onKeyPress()
  • onKeyPressRepeat()
  • onKeyDown()
  • onKeyRelease()
  • onMousePress()
  • onMouseDown()
  • onMouseRelease()
  • onMoueMove()
  • onTouchStart()
  • onTouchMove()
  • onTouchEnd()
  • onCollide()
  • onClick()
  • onHover()
  • isFocused()
  • isKeyDown()
  • isKeyPressed()
  • isKeyPressedRepeat()
  • isKeyDown()
  • isMouseDown()
  • isMousePressed()
  • isMouseReleased()
  • isMouseMoved()
  • isMouseMoved()
  • GameObj#onUpdate()
  • GameObj#onDraw()
  • AreaComp#onCollide()
  • AreaComp#onHover()
  • AreaComp#onClick()
  • BodyComp#onGround()
  • BodyComp#onFall()
  • BodyComp#onHeadbutt()
  • BodyComp#onDoubleJump()
  • BodyComp#isGrounded()
  • BodyComp#isFalling()
  • SpriteComp#onAnimEnd()
  • SpriteComp#onAnimStart()
  • HealthComp#onDeath()
  • HealthComp#onHurt()
  • HealthComp#onHeal()
  • AudioPlay#isStopped()
  • AudioPlay#isPaused()

v2000 "Burp Mode"

• version jumped to v2000.0.0 (still semver, just big)
• added burp() for easy burping
• added decent typescript / autocomplete support and jsdocs
• introducing new character "bean"
• added loadBean() to load "bean" as a default sprite
• changed default font to APL386, as "apl386o" (default outlined version) and "apl386"
• included font kitchen sink as "sinko" (outlined version) and "sink" (standard version with extended characters for text-mode games)
• added font field in KaboomOpt to set the default font
• added loadSpriteAtlas(src, entries) to load sprite atlas
• inspect mode now displays every comp's state
• BREAK added continuous collision resolution which checks collision in move() if 2 objects are both "solid" (objects now won't pass through other solid object at high speed or low framerate)

// before
add([
    sprite("player"),
    area(),
]);

add([
    sprite("rock"),
    solid(),
]);

keyDown("left", () => {
    player.move(-120, 0);
});

player.action(() => {
    player.resolve(); // or pushOutAll() in beta versions
});

// after
const player = add([
    sprite("player"),
    area(),
    solid(),
]);

// both should be solid
add([
    sprite("rock"),
    area(),
    solid(),
]);

keyDown("left", () => {
    // this will handle collision resolution for you, if the other obj is also "solid"
    player.move(-120, 0);
});

• added comp opacity() to set opacity
• added comp health() to manage health related logic
• added comp move() to manage projectile-like behavior
• added comp cleanup() to auto destroy obj when it leaves screen
• added comp outline() to draw a lil outline
• added comp timer() to attach timers to a game obj
• added comp fixed() to make a game obj unaffected by camera
• added comp stay() to make a game obj stay after scene switch
• added comp lifespan() to destroy game obj after certain amount of time
• added comp z() to define draw order for objs on the same layer
• added weight to BodyComp and BodyCompOpt to control the gravity multiplier
• added djump() to BodyComp for double jump
• added dir() to calculate directional vector from angle
• added constants LEFT, RIGHT, UP, DOWN for unit directional vector
• added fullscreen() to enable real fullscreen mode
• BREAK separated color and opacity, removed rgba() in favor of rgb, use component opacity() to define opacity
• BREAK changed color from 0-1 range to 0-255, angles from radians to degrees

// before
add([
    rotate(Math.PI / 2),
    color(0, 0.5, 1.0, 0.5),
]);

// after
add([
    rotate(90),
    color(0, 127, 255),
    opacity(0.5)
]);

• global and debug flag now are enabled by default, need to turn off manually if you don't want
• added input events touchStart(id, pos), touchMove(id, pos), touchEnd(id, pos), mouseMove(pos)
• added mouseDeltaPos()
• added touchToMouse to control if touch events should be translated to mouse events
• added mousePos() now gets the screen mouse pos, use mouseWorldPos() to get the mouse position affected by camera
• added anim field in SpriteCompOpt to play an anim on start
• beter type support for components
• scene() and start() (also removed in favor of go()) are optional now, if you don't need multiple scenes yet you can just go directly

  kaboom();
  // no mandatory scene() to start kabooming
  add(...);
  keyPress(...);

• BREAK area() is now explicit and not automatically added by sprite(), rect(), and text(), removed each noArea or area config field
• BREAK area() now takes an AreaCompOpt, where you can define the area size, scale, and hover cursor

add([
    sprite("bean"),
    area(), // empty area will derive from sprite size
    area({ scale: 0.5, }), // 0.5x the sprite size
    area({ offset: vec2(0, 12), width: 4, height: 12, }), // more control over the collider region
]);

• BREAK renamed isCollided() to isColliding(), isHovered() to isHovering()
• BREAK removed overlaps() and isOverlapped() and replaced with isColliding() and collides() only checks doesn't return true when 2 objects are just touching each other, use isTouching() to check if they're not colliding but just touching each other
• added isTouching() to check if 2 objects are collided or just touching other
• audio is now paused when you leave the tab
• audio is now paused on debug.paused = true
• added local storage helper getData(key, default?) and setData(key, data)
• added loadShader(id, vert, frag, isUrl)
• added shader() comp for attaching custom shader to an obj
• different layers do not prevent collisions now
• BREAK changed last argument of loadFont() to FontLoadOpt
• all event handlers like keyPress(), mouseClick(), action(), collides() now returns a function to cancel that listener
• added require on component definitions, making it possible to declare dependencies for components, e.g.

  function alwaysRight() {
    return {
        // the id of this component
        id: "alwaysRight",
        // list of component ids that this requires
        require: [ "pos", ],
        update() {
            // so you can use `move()` from pos() component with no worry
            this.move(100, 0);
        },
    };
  }

• BREAK overlapping component fields are not allowed, e.g. you can't have a custom comp that has a collides field if it already have a area component, since it already has that
• BREAK changed text(txt, size, conf) to text(txt, conf) with size as a field
• added obj.c(id) for getting a specific comp's state (by default all comps' states are mounted to the obj by Object.defineProperty)

  // both works
  obj.play("anim");
  obj.c("sprite").play("anim");

• pedit, aseprite plugins are now included by default
• added addKaboom() for quick kaboom explosion
• load*() now accepts null as name and not load into assets manager, instead just return the resource data handle
• BREAK renamed event headbump to headbutt
• BREAK renamed event grounded to ground
• added width, height, and tiled attrib to SpriteCompOpt, for better control over sprite size and tiled sprite support
• BREAK renamed resolve() to pushOutAll() on area comp
• added pushOut() for pushing a single object out from another with area comp
• fixed "add" event getting called twice for tagged objs
• added moveTo(dest: Vec2, speed?: number) to pos() comp
• added keyPress() (and all other key events) with no arg to check for any key
• BREAK renamed camShake() to shake()
• added flipX and flipY on sprite() comp configuration, and flipX() flipY() methods
• BREAK remove flipX() and flipY() on scale() comp
• BREAK removed start() in favor of go()
• BREAK removed changeSprite() in favor of use(sprite("newsprite"))
• tags and components are converged, tags are just empty components now
• added unuse() to remove a component or tag
• BREAK removed rmTag() in favor of unuse()
• BREAK removed camIgnore() in favor of fixed()
• BREAK renamed makeRng() to rng()
• sprite animation now supports defining properties like loop and speed in load step and play step

loadSprite("hero", "hero.png", {
    sliceX: 9,
    anims: {
        idle: { from: 0, to: 3, speed: 3, loop: true },
        run: { from: 4, to: 7, speed: 10, loop: true },
        hit: 8,
    },
});

• BREAK changed .play(anim, ifLoop) under sprite() to accept a dict of properties .play(anim, { loop: true, speed: 60, pingpong: true })
• BREAK now every symbol definition in addLevel() should be a function returning the component list, to ensure there's no weird shared states

addLevel([
    "*    *",
    "*    *",
    "======",
], {
    "*": () => [
        sprite("wall"),
        area(),
        solid(),
    ],
    "=": () => [
        sprite("floor"),
        area(),
        solid(),
    ],
})

• BREAK renamed clearColor to background
• added collision detection functions testLineLine(), testRectRect(), testRectLine() etc.
• added drawing functions drawSprite(), drawRect(), drawCircle(), drawPolygon(), drawEllipse(), drawLine(), drawLines()
• added transformation functions pushTransform(), popTransform(), pushTranslate(), pushRotate(), pushScale()
• BREAK removed areaWidth() and areaHeight() since they won't make sense if the area shape is not rectangle, use worldArea() if you need area data

  const area = player.worldArea();
  if (area.shape === "rect") {
    const width = area.p2.x - area.p1.x;
    const height = area.p2.y - area.p1.y;
  }

v0.5.1

• added plugins npm package support e.g. import asepritePlugin from "kaboom/plugins/aseprite"

v0.5 "Sticky Type"

• platforms are now sticky
• moved to TypeScript
• improved graphics performance
• improved inspect drawing performance
• added on-screen log that catches all kinds of errors
• added cursor()
• added curPlatform() by body()
• added falling() by body()
• added changeSprite() by sprite()
• added duration() and time() for the handle returned by play()
• added optional seek field to the audio play conf play([conf])
• added LoopHandle returned by loop() that has a stop()
• added a default background (can be dismissed by setting clearColor)
• fixed sound.pause() to work on firefox
• fixed collisions not treating explicit default layer the same as implicit default layer
• fixed unable to play another anim in onAnimEnd()
• fixed scene switches happen in the middle of a frame
• fixed scale(0) not working
• fixed mosuePos() not returning the camera affected pos with no layers
• BREAK changed dbg() to plain debug object
• BREAK moved fps(), objCount(), stepFrame(), log(), error() under debug
• BREAK removed debug.logTime
• BREAK changed component debugInfo() hook to inspect()
• BREAK removed timer() component
• BREAK renamed removeTag() to rmTag()
• BREAK changed SpriteAnim from [ from, to ] to { from: number, to: number }
• BREAK removed onAnimPlay() and onAnimEnd() in favor of generic event on("animEnd", (anim: string) => {})
• BREAK removed obj.addTag() in favor of obj.use()
• BREAK merged debug.hoverInfo and debug.showArea into debug.inspect
• BREAK removed sound.resume() in favor of sound.play()

v0.4.1

• fixed on("destroy") handler getting called twice
• fixed sprite play() not playing

v0.4 "Multiboom"

• BREAK removed init() and kaboom.global(), in favor of kaboom(), also allows multiple kaboom games on one page

  // replaces init(), and added a 'global' flag for previous kaboom.global()
  kaboom({
    global: true,
    width: 480,
    height: 480,
  });

  or not global

  const k = kaboom();
  k.scene();
  k.start();
  k.vec2();

• BREAK changed clearColor on kaboom(conf) to accept a 4 number array instead of rgba()
• added a plugin system, see the multiboom example and src/plugins
• BREAK removed support for .kbmsprite, supports newer version of .pedit through pedit plugin
• BREAK loadAseprite() and made it an external plugin under plugins/aseprite.js
• added sceneData() for custom scene data kv store
• fixed mouseClick doesn't work on mobile
• disabled context menu on canvas
• prevented default behavior for 'tab' and function keys
• added numFrames() by sprite()
• added screenshot() that returns of a png base64 data url for a screenshot

v0.3 "King Dedede...Bug!"

• BREAK removed pause() and paused() in favor to kaboom.debug.paused
• BREAK removed velY, curPlatform and maxVel fields by body()
• BREAK changed curAnim by sprite() to method curAnim()
• fixed dt() surge on page visibility change (#20)
• pause audio when page is not visible
• added built in debug control with init({ debug: true, })
  • `: toggle showLog (default on with debug: true)
  • f1: toggle showArea
  • f2: toggle hoverInfo
  • f8: toggle paused
  • f7: decrease timeScale
  • f9: increase timeScale
  • f10: stepFrame()
• added on screen logging with log() and error()
• fixed loadRoot() sometimes doesn't work in async tasks

v0.2 "Hear the Tremble"

• BREAK removed aseSpriteSheet conf field from loadSprite(name, src, conf)
• added pause(), resume(), stop(), loop(), unloop(), volume(), detune(), speed() methods to the handle returned by play()
• added camShake() for built in camera shake
• added loadAseprite(name, imgSrc, jsonSrc)
• added area component generation for text()
• added noArea to conf field of sprite(), rect() and text(), allowing to disable auto area component generation
• added a quad field to sprite comp creation config sprite(id, { quad: quad(0, 0, 0.5, 0.5) })
• fixed resolve() not working if the obj also has solid, so it does not check for itself (#8)
• mousePos() accepts a layer argument, which returns the mouse position affected by camera transform if that layer is not camIgnore()-ed
• fixed camera position getting calculated before completing every object's update (#14)
• fixed some cases on("grounded", f) called multiple times when moving on a smooth platform
• added revery() to iterate objects in reverse order
• added readd() to re-add an object to the scene without triggering events
• added level.spawn()

v0.1 "Oh Hi Mark"

• BREAK changed default origin point to "topleft", so if you want object origin point to be at center you'll need to manual origin("center")
• BREAK integrated kit/physics and kit/level to main lib
• BREAK makes collides() only run on first collision, not run every frame during the same collision
• BREAK camPos() by default focuses to center, so camPos(player.pos) puts player in the center of the screen
• BREAK renamed kaboom.import() to kaboom.global()
• added an arg field to start(scene, ...) to forward args to start scene
• added camScale(), camRot() and camIgnore()
• added obj.overlaps() by area(), and overlaps()
• added 3 ext fonts under ext/fonts