feat: new body() events, land and headbutted, mirrors of `headb…

[lajbel]

• Closes feat: event when an object is stomped on or headbutted (reflected forms of onGround and onHeadbutt) #300

[pkg-pr-new]

commit: 0e831c1

pnpm add https://pkg.pr.new/kaplayjs/kaplay@301

Open in Stackblitz •

[dragoncoder047]

would've done this change myself but I'm working on the rest of the game :)

[dragoncoder047]

also, maybe a separate issue/pr, but can an event when the object that triggered the "land" event (and itself got a "ground" event) moves away, can the object get an "unLand" event? I am calling it "unstomp" but you get the idea. Not sure exactly what the un-headbutted event should be called.

[lajbel]

when an object is out of a platform, it calls onCollideEnd, the same with the headbutt

[dragoncoder047]

when an object is out of a platform, it calls onCollideEnd, the same with the headbutt

Ok, this works, but I noticed that if the player clips the corner of the button as you're jumping up on to the button, it triggers the "onCollideEnd" too, but it wouldn't be a valid "unstomped" event. How would I check if it's a valid "unstomp"?

[lajbel]

can you give me a playground link?

[dragoncoder047]

can you give me a playground link?

The kaplayground doesn't have the latest version with onLand() yet, but this should work (when it does):

kaplay();
loadSprite("bean", "/sprites/bean.png");
loadSprite("spike", "/sprites/spike.png");
loadSprite("grass", "/sprites/grass.png");

const SPEED = 480;

setGravity(2400);

const level = addLevel([
    "@  ^   ",
    "=======",
], {
    tileWidth: 64,
    tileHeight: 64,
    pos: vec2(100, 200),
    tiles: {
        "@": () => [sprite("bean"), area(), body(), anchor("bot"), "player"],
        "=": () => [sprite("grass"), area(), body({ isStatic: true }), anchor("bot")],
        "^": () => [sprite("spike"), area(), body({ isStatic: true }), anchor("bot"), "danger"],
    },
});

const player = level.get("player")[0];
const spikes = level.get("danger")[0];

onKeyPress("space", () => {
    if (player.isGrounded()) {
        player.jump();
    }
});

onKeyDown("left", () => {
    player.move(-SPEED, 0);
});

onKeyDown("right", () => {
    player.move(SPEED, 0);
});

spikes.onCollideEnd(() => {
    debug.log("unstomped");
});

spikes.onLand(() => {
    debug.log("stomped");
});

Also, in this example the "unstomped" log occurs when you bonk the spikes from the side, and then move away (as well as the corner clipping I described above: hold arrow key to go against the spikes, while still holding the key, press space). So there needs to be more filtering on whether it's a valid "unstomp".