shaku
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A simple and effective JavaScript game development framework that knows its place!
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<head>
<meta charset="UTF-8">
<title>Shaku</title>
<meta name="description" content="Shaku - a simple and easy-to-use javascript library for videogame programming.">
<meta name="author" content="Ronen Ness">
<link href="css/style.css" rel="stylesheet" type="text/css" media="all">
</head>
<body>
<div class="noselect">
<button class="view-code-btn" onclick="showSampleCode();">View Code</button>
<h1 class="demo-title">Shaku: Basic Collision</h1>
<p>This demo demonstrate basic collision detection with Shaku.collision manager.<br />
Move the shape with your mouse to test collision, press <b>1-4</b> to replace the shape, and <b>+ / -</b> to set size. </p>
<p id="stats-show"></p>
<p id="show-data" style="color: red;"></p>
<!-- include shaku -->
<script src="js/demos.js"></script>
<script src="js/shaku.js"></script>
<!-- demo code -->
<script>
async function runGame()
{
// make shaku only listen to gfx canvas
Shaku.input.setTargetElement(() => Shaku.gfx.canvas);
// init shaku
await Shaku.init();
// add shaku's canvas to document and set resolution to 800x600
document.body.appendChild(Shaku.gfx.canvas);
Shaku.gfx.setResolution(1000, 800, true);
// element to show data
let showDataParagraph = document.getElementById("show-data");
// create collision world
let world = Shaku.collision.createWorld(128);
// shape to use for test
let userShapeType = 0;
let sizeFactor = 1;
// create some test shapes
for (let i = 0; i < 7; ++i)
{
let size = Shaku.gfx.getCanvasSize();
let point = new Shaku.collision.PointShape(new Shaku.utils.Vector2(Math.random() * size.x, Math.random() * size.y));
world.addShape(point);
let rect = new Shaku.collision.RectangleShape(new Shaku.utils.Rectangle(Math.random() * size.x, Math.random() * size.y, 50 + Math.random() * 150, 50 + Math.random() * 150));
world.addShape(rect);
let circle = new Shaku.collision.CircleShape(new Shaku.utils.Circle(new Shaku.utils.Vector2(Math.random() * size.x, Math.random() * size.y), 25 + Math.random() * 150));
world.addShape(circle);
let lineCenter = new Shaku.utils.Vector2(Math.random() * size.x, Math.random() * size.y);
let lines = new Shaku.collision.LinesShape([
new Shaku.utils.Line(lineCenter, lineCenter.add(Math.random() * 200 - 100, Math.random() * 200 - 100)),
new Shaku.utils.Line(lineCenter, lineCenter.add(Math.random() * 200 - 100, Math.random() * 200 - 100))]);
world.addShape(lines);
}
// do a single main loop step
function step()
{
// reset stats
world.resetStats();
// start new frame and clear screen
Shaku.startFrame();
Shaku.gfx.clear(Shaku.utils.Color.aliceblue);
// debug draw world
world.debugDraw(null, null, 0.75);
// create current collision shape to test
let mouse = Shaku.input.mousePosition;
var shapeToTest;
switch (userShapeType)
{
case 0:
shapeToTest = new Shaku.collision.RectangleShape(new Shaku.utils.Rectangle(mouse.x - 60 * sizeFactor, mouse.y - 60 * sizeFactor, 120 * sizeFactor, 120 * sizeFactor));
showDataParagraph.innerHTML = "'RectangleShape' collides with: ";
break;
case 1:
shapeToTest = new Shaku.collision.CircleShape(new Shaku.utils.Circle(mouse, 100 * sizeFactor));
showDataParagraph.innerHTML = "'CircleShape' collides with: ";
break;
case 2:
shapeToTest = new Shaku.collision.PointShape(mouse);
showDataParagraph.innerHTML = "'PointShape' collides with: ";
break;
case 3:
let second = mouse.add(65*sizeFactor, 65*sizeFactor);
shapeToTest = new Shaku.collision.LinesShape([
new Shaku.utils.Line(mouse, second),
new Shaku.utils.Line(second, second.add(65*sizeFactor, -75*sizeFactor))
]);
showDataParagraph.innerHTML = "'LinesShape' collides with: ";
break;
}
// reset all shapes colors
world.iterateShapes((shape) => {
shape.setDebugColor(null);
});
// draw shape the user drags
shapeToTest.setDebugColor(Shaku.utils.Color.green);
shapeToTest.debugDraw(1, world.getOrCreateDebugDrawBatch());
// test collision with many
let collisions = world.testCollisionMany(shapeToTest);
// get shapes we collided with + paint them red
let collisionsTypes = collisions.map((r) => {
r.second.setDebugColor(Shaku.utils.Color.red);
return r.second.constructor.name;
});
showDataParagraph.innerHTML += collisionsTypes.join(',');
// start debug draw for extra stuff
world.getOrCreateDebugDrawBatch().begin();
// test collision single sorted
showDataParagraph.innerHTML += "<br />Nearest collided shape: ";
let collisionSingle = world.testCollision(shapeToTest, true);
if (collisionSingle) {
showDataParagraph.innerHTML += collisionSingle.second.constructor.name;
world.getOrCreateDebugDrawBatch().drawLine(shapeToTest.getCenter(), collisionSingle.second.getCenter(), Shaku.utils.Color.red, 4);
showDataParagraph.style.color = 'red';
}
else {
showDataParagraph.style.color = 'black';
}
// control the shape the user drags
if (Shaku.input.down('1')) { userShapeType = 0; }
if (Shaku.input.down('2')) { userShapeType = 1; }
if (Shaku.input.down('3')) { userShapeType = 2; }
if (Shaku.input.down('4')) { userShapeType = 3; }
if (Shaku.input.pressed('plus')) {sizeFactor += 0.25; }
if (Shaku.input.pressed('minus') && sizeFactor > 0.5) {sizeFactor -= 0.25; }
// show stats
document.getElementById("stats-show").innerHTML = JSON.stringify(world.stats);
// finish open renderings
world.getOrCreateDebugDrawBatch().end();
// end frame and request next frame
Shaku.endFrame();
Shaku.requestAnimationFrame(step);
}
// start main loop
step();
}
runGame();
</script>
</div>
<!-- code example part -->
<div id="sample-code-modal" class="modal">
<div class="modal__overlay jsOverlay"></div>
<div class="modal__container">
<p class="noselect">The following shows a minimal code example for collision detection.</i>
</p>
<pre><code class="language-js">// create collision world
let world = Shaku.collision.createWorld(128);
// add a point to world
let point = new Shaku.collision.PointShape(new Shaku.utils.Vector2(125, 65));
world.addShape(point);
// add a rectngle to world
let rect = new Shaku.collision.RectangleShape(new Shaku.utils.Rectangle(45, 75, 100, 50));
world.addShape(rect);
// add a circle to world
let circle = new Shaku.collision.CircleShape(new Shaku.utils.Circle(new Shaku.utils.Vector2(300, 315), 150));
world.addShape(circle);
// add a line to world
let lines = new Shaku.collision.LinesShape(new Shaku.utils.Line(new Shaku.utils.Vector2(100, 100), new Shaku.utils.Vector2(150, 150)));
world.addShape(lines);
// create a circle at mouse position with radius of 100. we'll use it to check collisions
let shapeToTest = new Shaku.collision.CircleShape(new Shaku.utils.Circle(Shaku.input.mousePosition, 100));
// test a single result, sorted by distance
let collisionSingle = world.testCollision(shapeToTest, true);
if (collisionSingle) {
console.log(collisionSingle.first, collisionSingle.second);
}
// test many results, not sorted
let collisions = world.testCollisionMany(shapeToTest, false);
for (let i = 0; i < collisions.length; ++i) {
console.log(collisions[i].first, collisions[i].second);
}</code></pre>
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