<!DOCTYPE html>
<html>
<head>
<title>Title</title>
<link rel="icon" type="image/png" href="LOGO" />
<style>
body {
/* https://coolors.co/f06449-ede6e3-7d82b8-36382e-613f75 */
--background-color: #ede6e3;
--wall-color: #36382e;
--joystick-color: #210124;
--joystick-head-color: #f06449;
--ball-color: #f06449;
--end-color: #7d82b8;
--text-color: #210124;
font-family: "Segoe UI", Tahoma, Geneva, Verdana, sans-serif;
background-color: var(--background-color);
}
html,
body {
height: 100%;
margin: 0;
}
#center {
display: flex;
align-items: center;
justify-content: center;
height: 100%;
}
#game {
display: grid;
grid-template-columns: auto 150px;
grid-template-rows: 1fr auto 1fr;
gap: 30px;
perspective: 600px;
}
#maze {
position: relative;
grid-row: 1 / -1;
grid-column: 1;
width: 350px;
height: 315px;
display: flex;
justify-content: center;
align-items: center;
}
#end {
width: 65px;
height: 65px;
border: 5px dashed var(--end-color);
border-radius: 50%;
}
#joystick {
position: relative;
background-color: var(--joystick-color);
border-radius: 50%;
width: 50px;
height: 50px;
display: flex;
align-items: center;
justify-content: center;
margin: 10px 50px;
grid-row: 2;
}
#joystick-head {
position: relative;
background-color: var(--joystick-head-color);
border-radius: 50%;
width: 20px;
height: 20px;
cursor: grab;
animation-name: glow;
animation-duration: 0.6s;
animation-iteration-count: infinite;
animation-direction: alternate;
animation-timing-function: ease-in-out;
animation-delay: 4s;
}
@keyframes glow {
0% {
transform: scale(1);
}
100% {
transform: scale(1.2);
}
}
.joystick-arrow:nth-of-type(1) {
position: absolute;
bottom: 55px;
width: 0;
height: 0;
border-left: 10px solid transparent;
border-right: 10px solid transparent;
border-bottom: 10px solid var(--joystick-color);
}
.joystick-arrow:nth-of-type(2) {
position: absolute;
top: 55px;
width: 0;
height: 0;
border-left: 10px solid transparent;
border-right: 10px solid transparent;
border-top: 10px solid var(--joystick-color);
}
.joystick-arrow:nth-of-type(3) {
position: absolute;
left: 55px;
width: 0;
height: 0;
border-top: 10px solid transparent;
border-bottom: 10px solid transparent;
border-left: 10px solid var(--joystick-color);
}
.joystick-arrow:nth-of-type(4) {
position: absolute;
right: 55px;
width: 0;
height: 0;
border-top: 10px solid transparent;
border-bottom: 10px solid transparent;
border-right: 10px solid var(--joystick-color);
}
#note {
grid-row: 3;
grid-column: 2;
text-align: center;
font-size: 0.8em;
color: var(--text-color);
transition: opacity 2s;
}
a:visited {
color: inherit;
}
.ball {
position: absolute;
margin-top: -5px;
margin-left: -5px;
border-radius: 50%;
background-color: var(--ball-color);
width: 10px;
height: 10px;
}
.wall {
position: absolute;
background-color: var(--wall-color);
transform-origin: top center;
margin-left: -5px;
}
.wall::before,
.wall::after {
display: block;
content: "";
width: 10px;
height: 10px;
background-color: inherit;
border-radius: 50%;
position: absolute;
}
.wall::before {
top: -5px;
}
.wall::after {
bottom: -5px;
}
.black-hole {
position: absolute;
margin-top: -9px;
margin-left: -9px;
border-radius: 50%;
background-color: black;
width: 18px;
height: 18px;
}
}
</style>
</head>
<body>
<div id="center">
<div id="game">
<div id="maze">
<div id="end"></div>
</div>
<div id="joystick">
<div class="joystick-arrow"></div>
<div class="joystick-arrow"></div>
<div class="joystick-arrow"></div>
<div class="joystick-arrow"></div>
<div id="joystick-head"></div>
</div>
<div id="note">
Click the joystick to start!
<p>Move every ball to the center. Ready for hard mode? Press H</p>
</div>
</div>
</div>
</body>
<script>
Math.minmax = (value, limit) => {
return Math.max(Math.min(value, limit), -limit);
};
const distance2D = (p1, p2) => {
return Math.sqrt((p2.x - p1.x) ** 2 + (p2.y - p1.y) ** 2);
};
// Angle between the two points
const getAngle = (p1, p2) => {
let angle = Math.atan((p2.y - p1.y) / (p2.x - p1.x));
if (p2.x - p1.x < 0) angle += Math.PI;
return angle;
};
// The closest a ball and a wall cap can be
const closestItCanBe = (cap, ball) => {
let angle = getAngle(cap, ball);
const deltaX = Math.cos(angle) * (wallW / 2 + ballSize / 2);
const deltaY = Math.sin(angle) * (wallW / 2 + ballSize / 2);
return { x: cap.x + deltaX, y: cap.y + deltaY };
};
// Roll the ball around the wall cap
const rollAroundCap = (cap, ball) => {
// The direction the ball can't move any further because the wall holds it back
let impactAngle = getAngle(ball, cap);
// The direction the ball wants to move based on it's velocity
let heading = getAngle(
{ x: 0, y: 0 },
{ x: ball.velocityX, y: ball.velocityY }
);
// The angle between the impact direction and the ball's desired direction
// The smaller this angle is, the bigger the impact
// The closer it is to 90 degrees the smoother it gets (at 90 there would be no collision)
let impactHeadingAngle = impactAngle - heading;
// Velocity distance if not hit would have occurred
const velocityMagnitude = distance2D(
{ x: 0, y: 0 },
{ x: ball.velocityX, y: ball.velocityY }
);
// Velocity component diagonal to the impact
const velocityMagnitudeDiagonalToTheImpact =
Math.sin(impactHeadingAngle) * velocityMagnitude;
// How far should the ball be from the wall cap
const closestDistance = wallW / 2 + ballSize / 2;
const rotationAngle = Math.atan(
velocityMagnitudeDiagonalToTheImpact / closestDistance
);
const deltaFromCap = {
x: Math.cos(impactAngle + Math.PI - rotationAngle) * closestDistance,
y: Math.sin(impactAngle + Math.PI - rotationAngle) * closestDistance
};
const x = ball.x;
const y = ball.y;
const velocityX = ball.x - (cap.x + deltaFromCap.x);
const velocityY = ball.y - (cap.y + deltaFromCap.y);
const nextX = x + velocityX;
const nextY = y + velocityY;
return { x, y, velocityX, velocityY, nextX, nextY };
};
// Decreases the absolute value of a number but keeps it's sign, doesn't go below abs 0
const slow = (number, difference) => {
if (Math.abs(number) <= difference) return 0;
if (number > difference) return number - difference;
return number + difference;
};
const mazeElement = document.getElementById("maze");
const joystickHeadElement = document.getElementById("joystick-head");
const noteElement = document.getElementById("note"); // Note element for instructions and game won, game failed texts
let hardMode = false;
let previousTimestamp;
let gameInProgress;
let mouseStartX;
let mouseStartY;
let accelerationX;
let accelerationY;
let frictionX;
let frictionY;
const pathW = 25; // Path width
const wallW = 10; // Wall width
const ballSize = 10; // Width and height of the ball
const holeSize = 18;
const debugMode = false;
let balls = [];
let ballElements = [];
let holeElements = [];
resetGame();
// Draw balls for the first time
balls.forEach(({ x, y }) => {
const ball = document.createElement("div");
ball.setAttribute("class", "ball");
ball.style.cssText = `left: ${x}px; top: ${y}px; `;
mazeElement.appendChild(ball);
ballElements.push(ball);
});
// Wall metadata
const walls = [
// Border
{ column: 0, row: 0, horizontal: true, length: 10 },
{ column: 0, row: 0, horizontal: false, length: 9 },
{ column: 0, row: 9, horizontal: true, length: 10 },
{ column: 10, row: 0, horizontal: false, length: 9 },
// Horizontal lines starting in 1st column
{ column: 0, row: 6, horizontal: true, length: 1 },
{ column: 0, row: 8, horizontal: true, length: 1 },
// Horizontal lines starting in 2nd column
{ column: 1, row: 1, horizontal: true, length: 2 },
{ column: 1, row: 7, horizontal: true, length: 1 },
// Horizontal lines starting in 3rd column
{ column: 2, row: 2, horizontal: true, length: 2 },
{ column: 2, row: 4, horizontal: true, length: 1 },
{ column: 2, row: 5, horizontal: true, length: 1 },
{ column: 2, row: 6, horizontal: true, length: 1 },
// Horizontal lines starting in 4th column
{ column: 3, row: 3, horizontal: true, length: 1 },
{ column: 3, row: 8, horizontal: true, length: 3 },
// Horizontal lines starting in 5th column
{ column: 4, row: 6, horizontal: true, length: 1 },
// Horizontal lines starting in 6th column
{ column: 5, row: 2, horizontal: true, length: 2 },
{ column: 5, row: 7, horizontal: true, length: 1 },
// Horizontal lines starting in 7th column
{ column: 6, row: 1, horizontal: true, length: 1 },
{ column: 6, row: 6, horizontal: true, length: 2 },
// Horizontal lines starting in 8th column
{ column: 7, row: 3, horizontal: true, length: 2 },
{ column: 7, row: 7, horizontal: true, length: 2 },
// Horizontal lines starting in 9th column
{ column: 8, row: 1, horizontal: true, length: 1 },
{ column: 8, row: 2, horizontal: true, length: 1 },
{ column: 8, row: 3, horizontal: true, length: 1 },
{ column: 8, row: 4, horizontal: true, length: 2 },
{ column: 8, row: 8, horizontal: true, length: 2 },
// Vertical lines after the 1st column
{ column: 1, row: 1, horizontal: false, length: 2 },
{ column: 1, row: 4, horizontal: false, length: 2 },
// Vertical lines after the 2nd column
{ column: 2, row: 2, horizontal: false, length: 2 },
{ column: 2, row: 5, horizontal: false, length: 1 },
{ column: 2, row: 7, horizontal: false, length: 2 },
// Vertical lines after the 3rd column
{ column: 3, row: 0, horizontal: false, length: 1 },
{ column: 3, row: 4, horizontal: false, length: 1 },
{ column: 3, row: 6, horizontal: false, length: 2 },
// Vertical lines after the 4th column
{ column: 4, row: 1, horizontal: false, length: 2 },
{ column: 4, row: 6, horizontal: false, length: 1 },
// Vertical lines after the 5th column
{ column: 5, row: 0, horizontal: false, length: 2 },
{ column: 5, row: 6, horizontal: false, length: 1 },
{ column: 5, row: 8, horizontal: false, length: 1 },
// Vertical lines after the 6th column
{ column: 6, row: 4, horizontal: false, length: 1 },
{ column: 6, row: 6, horizontal: false, length: 1 },
// Vertical lines after the 7th column
{ column: 7, row: 1, horizontal: false, length: 4 },
{ column: 7, row: 7, horizontal: false, length: 2 },
// Vertical lines after the 8th column
{ column: 8, row: 2, horizontal: false, length: 1 },
{ column: 8, row: 4, horizontal: false, length: 2 },
// Vertical lines after the 9th column
{ column: 9, row: 1, horizontal: false, length: 1 },
{ column: 9, row: 5, horizontal: false, length: 2 }
].map((wall) => ({
x: wall.column * (pathW + wallW),
y: wall.row * (pathW + wallW),
horizontal: wall.horizontal,
length: wall.length * (pathW + wallW)
}));
// Draw walls
walls.forEach(({ x, y, horizontal, length }) => {
const wall = document.createElement("div");
wall.setAttribute("class", "wall");
wall.style.cssText = `
left: ${x}px;
top: ${y}px;
width: ${wallW}px;
height: ${length}px;
transform: rotate(${horizontal ? -90 : 0}deg);
`;
mazeElement.appendChild(wall);
});
const holes = [
{ column: 0, row: 5 },
{ column: 2, row: 0 },
{ column: 2, row: 4 },
{ column: 4, row: 6 },
{ column: 6, row: 2 },
{ column: 6, row: 8 },
{ column: 8, row: 1 },
{ column: 8, row: 2 }
].map((hole) => ({
x: hole.column * (wallW + pathW) + (wallW / 2 + pathW / 2),
y: hole.row * (wallW + pathW) + (wallW / 2 + pathW / 2)
}));
joystickHeadElement.addEventListener("mousedown", function (event) {
if (!gameInProgress) {
mouseStartX = event.clientX;
mouseStartY = event.clientY;
gameInProgress = true;
window.requestAnimationFrame(main);
noteElement.style.opacity = 0;
joystickHeadElement.style.cssText = `
animation: none;
cursor: grabbing;
`;
}
});
window.addEventListener("mousemove", function (event) {
if (gameInProgress) {
const mouseDeltaX = -Math.minmax(mouseStartX - event.clientX, 15);
const mouseDeltaY = -Math.minmax(mouseStartY - event.clientY, 15);
joystickHeadElement.style.cssText = `
left: ${mouseDeltaX}px;
top: ${mouseDeltaY}px;
animation: none;
cursor: grabbing;
`;
const rotationY = mouseDeltaX * 0.8; // Max rotation = 12
const rotationX = mouseDeltaY * 0.8;
mazeElement.style.cssText = `
transform: rotateY(${rotationY}deg) rotateX(${-rotationX}deg)
`;
const gravity = 2;
const friction = 0.01; // Coefficients of friction
accelerationX = gravity * Math.sin((rotationY / 180) * Math.PI);
accelerationY = gravity * Math.sin((rotationX / 180) * Math.PI);
frictionX = gravity * Math.cos((rotationY / 180) * Math.PI) * friction;
frictionY = gravity * Math.cos((rotationX / 180) * Math.PI) * friction;
}
});
window.addEventListener("keydown", function (event) {
// If not an arrow key or space or H was pressed then return
if (![" ", "H", "h", "E", "e"].includes(event.key)) return;
// If an arrow key was pressed then first prevent default
event.preventDefault();
// If space was pressed restart the game
if (event.key == " ") {
resetGame();
return;
}
// Set Hard mode
if (event.key == "H" || event.key == "h") {
hardMode = true;
resetGame();
return;
}
// Set Easy mode
if (event.key == "E" || event.key == "e") {
hardMode = false;
resetGame();
return;
}
});
function resetGame() {
previousTimestamp = undefined;
gameInProgress = false;
mouseStartX = undefined;
mouseStartY = undefined;
accelerationX = undefined;
accelerationY = undefined;
frictionX = undefined;
frictionY = undefined;
mazeElement.style.cssText = `
transform: rotateY(0deg) rotateX(0deg)
`;
joystickHeadElement.style.cssText = `
left: 0;
top: 0;
animation: glow;
cursor: grab;
`;
if (hardMode) {
noteElement.innerHTML = `Click the joystick to start!
<p>Hard mode, Avoid black holes. Back to easy mode? Press E</p>`;
} else {
noteElement.innerHTML = `Click the joystick to start!
<p>Move every ball to the center. Ready for hard mode? Press H</p>`;
}
noteElement.style.opacity = 1;
balls = [
{ column: 0, row: 0 },
{ column: 9, row: 0 },
{ column: 0, row: 8 },
{ column: 9, row: 8 }
].map((ball) => ({
x: ball.column * (wallW + pathW) + (wallW / 2 + pathW / 2),
y: ball.row * (wallW + pathW) + (wallW / 2 + pathW / 2),
velocityX: 0,
velocityY: 0
}));
if (ballElements.length) {
balls.forEach(({ x, y }, index) => {
ballElements[index].style.cssText = `left: ${x}px; top: ${y}px; `;
});
}
// Remove previous hole elements
holeElements.forEach((holeElement) => {
mazeElement.removeChild(holeElement);
});
holeElements = [];
// Reset hole elements if hard mode
if (hardMode) {
holes.forEach(({ x, y }) => {
const ball = document.createElement("div");
ball.setAttribute("class", "black-hole");
ball.style.cssText = `left: ${x}px; top: ${y}px; `;
mazeElement.appendChild(ball);
holeElements.push(ball);
});
}
}
function main(timestamp) {
// It is possible to reset the game mid-game. This case the look should stop
if (!gameInProgress) return;
if (previousTimestamp === undefined) {
previousTimestamp = timestamp;
window.requestAnimationFrame(main);
return;
}
const maxVelocity = 1.5;
// Time passed since last cycle divided by 16
// This function gets called every 16 ms on average so dividing by 16 will result in 1
const timeElapsed = (timestamp - previousTimestamp) / 16;
try {
// If mouse didn't move yet don't do anything
if (accelerationX != undefined && accelerationY != undefined) {
const velocityChangeX = accelerationX * timeElapsed;
const velocityChangeY = accelerationY * timeElapsed;
const frictionDeltaX = frictionX * timeElapsed;
const frictionDeltaY = frictionY * timeElapsed;
balls.forEach((ball) => {
if (velocityChangeX == 0) {
// No rotation, the plane is flat
// On flat surface friction can only slow down, but not reverse movement
ball.velocityX = slow(ball.velocityX, frictionDeltaX);
} else {
ball.velocityX = ball.velocityX + velocityChangeX;
ball.velocityX = Math.max(Math.min(ball.velocityX, 1.5), -1.5);
ball.velocityX =
ball.velocityX - Math.sign(velocityChangeX) * frictionDeltaX;
ball.velocityX = Math.minmax(ball.velocityX, maxVelocity);
}
if (velocityChangeY == 0) {
// No rotation, the plane is flat
// On flat surface friction can only slow down, but not reverse movement
ball.velocityY = slow(ball.velocityY, frictionDeltaY);
} else {
ball.velocityY = ball.velocityY + velocityChangeY;
ball.velocityY =
ball.velocityY - Math.sign(velocityChangeY) * frictionDeltaY;
ball.velocityY = Math.minmax(ball.velocityY, maxVelocity);
}
// Preliminary next ball position, only becomes true if no hit occurs
// Used only for hit testing, does not mean that the ball will reach this position
ball.nextX = ball.x + ball.velocityX;
ball.nextY = ball.y + ball.velocityY;
if (debugMode) console.log("tick", ball);
walls.forEach((wall, wi) => {
if (wall.horizontal) {
// Horizontal wall
if (
ball.nextY + ballSize / 2 >= wall.y - wallW / 2 &&
ball.nextY - ballSize / 2 <= wall.y + wallW / 2
) {
// Ball got within the strip of the wall
// (not necessarily hit it, could be before or after)
const wallStart = {
x: wall.x,
y: wall.y
};
const wallEnd = {
x: wall.x + wall.length,
y: wall.y
};
if (
ball.nextX + ballSize / 2 >= wallStart.x - wallW / 2 &&
ball.nextX < wallStart.x
) {
// Ball might hit the left cap of a horizontal wall
const distance = distance2D(wallStart, {
x: ball.nextX,
y: ball.nextY
});
if (distance < ballSize / 2 + wallW / 2) {
if (debugMode && wi > 4)
console.warn("too close h head", distance, ball);
// Ball hits the left cap of a horizontal wall
const closest = closestItCanBe(wallStart, {
x: ball.nextX,
y: ball.nextY
});
const rolled = rollAroundCap(wallStart, {
x: closest.x,
y: closest.y,
velocityX: ball.velocityX,
velocityY: ball.velocityY
});
Object.assign(ball, rolled);
}
}
if (
ball.nextX - ballSize / 2 <= wallEnd.x + wallW / 2 &&
ball.nextX > wallEnd.x
) {
// Ball might hit the right cap of a horizontal wall
const distance = distance2D(wallEnd, {
x: ball.nextX,
y: ball.nextY
});
if (distance < ballSize / 2 + wallW / 2) {
if (debugMode && wi > 4)
console.warn("too close h tail", distance, ball);
// Ball hits the right cap of a horizontal wall
const closest = closestItCanBe(wallEnd, {
x: ball.nextX,
y: ball.nextY
});
const rolled = rollAroundCap(wallEnd, {
x: closest.x,
y: closest.y,
velocityX: ball.velocityX,
velocityY: ball.velocityY
});
Object.assign(ball, rolled);
}
}
if (ball.nextX >= wallStart.x && ball.nextX <= wallEnd.x) {
// The ball got inside the main body of the wall
if (ball.nextY < wall.y) {
// Hit horizontal wall from top
ball.nextY = wall.y - wallW / 2 - ballSize / 2;
} else {
// Hit horizontal wall from bottom
ball.nextY = wall.y + wallW / 2 + ballSize / 2;
}
ball.y = ball.nextY;
ball.velocityY = -ball.velocityY / 3;
if (debugMode && wi > 4)
console.error("crossing h line, HIT", ball);
}
}
} else {
// Vertical wall
if (
ball.nextX + ballSize / 2 >= wall.x - wallW / 2 &&
ball.nextX - ballSize / 2 <= wall.x + wallW / 2
) {
// Ball got within the strip of the wall
// (not necessarily hit it, could be before or after)
const wallStart = {
x: wall.x,
y: wall.y
};
const wallEnd = {
x: wall.x,
y: wall.y + wall.length
};
if (
ball.nextY + ballSize / 2 >= wallStart.y - wallW / 2 &&
ball.nextY < wallStart.y
) {
// Ball might hit the top cap of a horizontal wall
const distance = distance2D(wallStart, {
x: ball.nextX,
y: ball.nextY
});
if (distance < ballSize / 2 + wallW / 2) {
if (debugMode && wi > 4)
console.warn("too close v head", distance, ball);
// Ball hits the left cap of a horizontal wall
const closest = closestItCanBe(wallStart, {
x: ball.nextX,
y: ball.nextY
});
const rolled = rollAroundCap(wallStart, {
x: closest.x,
y: closest.y,
velocityX: ball.velocityX,
velocityY: ball.velocityY
});
Object.assign(ball, rolled);
}
}
if (
ball.nextY - ballSize / 2 <= wallEnd.y + wallW / 2 &&
ball.nextY > wallEnd.y
) {
// Ball might hit the bottom cap of a horizontal wall
const distance = distance2D(wallEnd, {
x: ball.nextX,
y: ball.nextY
});
if (distance < ballSize / 2 + wallW / 2) {
if (debugMode && wi > 4)
console.warn("too close v tail", distance, ball);
// Ball hits the right cap of a horizontal wall
const closest = closestItCanBe(wallEnd, {
x: ball.nextX,
y: ball.nextY
});
const rolled = rollAroundCap(wallEnd, {
x: closest.x,
y: closest.y,
velocityX: ball.velocityX,
velocityY: ball.velocityY
});
Object.assign(ball, rolled);
}
}
if (ball.nextY >= wallStart.y && ball.nextY <= wallEnd.y) {
// The ball got inside the main body of the wall
if (ball.nextX < wall.x) {
// Hit vertical wall from left
ball.nextX = wall.x - wallW / 2 - ballSize / 2;
} else {
// Hit vertical wall from right
ball.nextX = wall.x + wallW / 2 + ballSize / 2;
}
ball.x = ball.nextX;
ball.velocityX = -ball.velocityX / 3;
if (debugMode && wi > 4)
console.error("crossing v line, HIT", ball);
}
}
}
});
// Detect is a ball fell into a hole
if (hardMode) {
holes.forEach((hole, hi) => {
const distance = distance2D(hole, {
x: ball.nextX,
y: ball.nextY
});
if (distance <= holeSize / 2) {
// The ball fell into a hole
holeElements[hi].style.backgroundColor = "red";
throw Error("The ball fell into a hole");
}
});
}
// Adjust ball metadata
ball.x = ball.x + ball.velocityX;
ball.y = ball.y + ball.velocityY;
});
// Move balls to their new position on the UI
balls.forEach(({ x, y }, index) => {
ballElements[index].style.cssText = `left: ${x}px; top: ${y}px; `;
});
}
// Win detection
if (
balls.every(
(ball) => distance2D(ball, { x: 350 / 2, y: 315 / 2 }) < 65 / 2
)
) {
noteElement.innerHTML = `Congrats, you did it!
${!hardMode ? "<p>Press H for hard mode</p>" : ""}
<p>
Follow me
<a href="https://twitter.com/HunorBorbely" , target="_blank"
>@HunorBorbely</a
>
</p>`;
noteElement.style.opacity = 1;
gameInProgress = false;
} else {
previousTimestamp = timestamp;
window.requestAnimationFrame(main);
}
} catch (error) {
if (error.message == "The ball fell into a hole") {
noteElement.innerHTML = `A ball fell into a black hole! Press space to reset the game.
<p>
Back to easy? Press E
</p>`;
noteElement.style.opacity = 1;
gameInProgress = false;
} else throw error;
}
}
</script>
</html>