Function tick

assets/js/block_ninja.js:1511–1850

(width, height, simTime, simSpeed, lag)

function tick(width, height, simTime, simSpeed, lag) {
	PERF_START('frame');
	PERF_START('tick');

	state.game.time += simTime;

	if (slowmoRemaining > 0) {
		slowmoRemaining -= simTime;
		if (slowmoRemaining < 0) {
			slowmoRemaining = 0;
		}
		targetSpeed = pointerIsDown ? 0.075 : 0.3;
	} else {
		const menuPointerDown = isMenuVisible() && pointerIsDown;
		targetSpeed = menuPointerDown ? 0.025 : 1;
	}

	renderSlowmoStatus(slowmoRemaining / slowmoDuration);

	gameSpeed += (targetSpeed - gameSpeed) / 22 * lag;
	gameSpeed = clamp(gameSpeed, 0, 1);

	const centerX = width / 2;
	const centerY = height / 2;

	const simAirDrag = 1 - (airDrag * simSpeed);
	const simAirDragSpark = 1 - (airDragSpark * simSpeed);

	// Pointer Tracking
	// -------------------

	// Compute speed and x/y deltas.
	// There is also a "scaled" variant taking game speed into account. This serves two purposes:
	//  - Lag won't create large spikes in speed/deltas
	//  - In slow mo, speed is increased proportionately to match "reality". Without this boost,
	//    it feels like your actions are dampened in slow mo.
	const forceMultiplier = 1 / (simSpeed * 0.75 + 0.25);
	pointerDelta.x = 0;
	pointerDelta.y = 0;
	pointerDeltaScaled.x = 0;
	pointerDeltaScaled.y = 0;
	const lastPointer = touchPoints[touchPoints.length - 1];

	if (pointerIsDown && lastPointer && !lastPointer.touchBreak) {
		pointerDelta.x = (pointerScene.x - lastPointer.x);
		pointerDelta.y = (pointerScene.y - lastPointer.y);
		pointerDeltaScaled.x = pointerDelta.x * forceMultiplier;
		pointerDeltaScaled.y = pointerDelta.y * forceMultiplier;
	}
	const pointerSpeed = Math.hypot(pointerDelta.x, pointerDelta.y);
	const pointerSpeedScaled = pointerSpeed * forceMultiplier;

	// Track points for later calculations, including drawing trail.
	touchPoints.forEach(p => p.life -= simTime);

	if (pointerIsDown) {
		touchPoints.push({
			x: pointerScene.x,