613 lines
18 KiB
XML
613 lines
18 KiB
XML
<?xml version="1.0" encoding="UTF-8" standalone="no"?>
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<svg viewBox="-200 -150 400 300" version="1.1" xmlns="http://www.w3.org/2000/svg">
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<style>
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#frames {
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position: absolute;
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right: 0px;
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}
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p {
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border: 1px solid black;
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box-size: border-box;
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}
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rect#bg {
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fill: gray;
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}
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.ship rect {
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fill: green;
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}
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.ship circle {
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fill: white;
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}
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#crosshair {
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opacity: 0.5;
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}
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circle.bullet {
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fill: yellow;
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}
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#frames {
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padding: 1px;
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font-size: 4pt;
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font-family: courier;
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}
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#triangles {
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opacity: 0.5;
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}
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#triangles line {
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stroke: limegreen;
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stroke-width: 0.5px;
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}
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#triangles polygon {
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fill-opacity: 0.2;
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stroke-width: 0.5px;
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fill: none;
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stroke: none;
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}
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#triangles polygon.clockwise-orientation {
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fill: white;
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stroke: red;
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}
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#lines line {
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stroke: gold;
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}
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#legs {
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display: none;
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}
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#triangles polygon.obtuse {
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stroke: orangered;
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stroke-dasharray: 5 10;
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}
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#triangles polygon.anti-clockwise {
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stroke: orange;
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stroke-dasharray: 1 5;
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}
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</style>
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<rect id="bg" x="-200" y="-150" width="400" height="300"/>
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<g>
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<g class="hitbox">
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<g class="ship">
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<line id="cannon" x1="0" y1="0" x2="0" y2="8" stroke="black"/>
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<circle id="body" cx="0" cy="0" r="5"/>
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<g id="legs">
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<path d="M 3 2 l 2 2 v 2 m -2 0 h 4" stroke="black" fill="none" />
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<path d="M -3 2 l -2 2 v 2 m -2 0 h 4" stroke="black" fill="none" />
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</g>
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</g>
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</g>
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<!-- <polygon id="wall" points="20,20 40,20 40,40 20,40" /> -->
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<polygon id="wall" points="-10,-30 -10,-40 30,-50 60,-30 80,0 150,0 150,10 60,50 -10,40 -20,20 20,20 20,-20" />
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<g id="triangles"></g>
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<g id="lines"></g>
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<g id="bullets"></g>
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</g>
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<foreignObject x="-200" y="-150" width="100%" height="100%">
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<div id="frames" xmlns="http://www.w3.org/1999/xhtml">
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<span id="time" xmlns="http://www.w3.org/1999/xhtml">0</span> s
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<span id="fps" xmlns="http://www.w3.org/1999/xhtml">0</span> fps
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</div>
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<pre id="debug" xmlns="http://www.w3.org/1999/xhtml"></pre>
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</foreignObject>
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<script type="text/javascript">//<![CDATA[
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const namespaceURIsvg = 'http://www.w3.org/2000/svg';
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const degsRegex = /(-?\d*\.{0,1}\d+)deg/g;
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const regex = /(-?\d*\.{0,1}\d+)px/g;
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const bullets = [];
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const halfPi = Math.PI / 2;
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let previous, zero, frameCount = 0;
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let position = [0, 0]; // meters
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let velocity = [0, 0]; // meters per second
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let acceleration = [0, 0]; // meters per second per second
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// let friction = 7.5;
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let friction = 0;
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let rotate = 0;
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let rotationSpeed = 0.25;
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const maxSpeed = 100;
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let started = false;
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const svg = document.querySelector('svg');
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const fps = document.querySelector("#fps");
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const time = document.querySelector("#time");
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const info = document.querySelector("#debug");
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const ship = document.querySelector(".ship");
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const gun = ship.querySelector('#cannon');
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const shipBody = ship.querySelector("circle");
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const hitbox = document.querySelector(".hitbox");
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const bulletsContainer = document.querySelector("#bullets");
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const wall = document.querySelector('#wall');
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const pt = svg.createSVGPoint();
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const cornerPt = svg.createSVGPoint();
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const points = wall.getAttribute('points').split(' ').map(coords => {
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const [x, y] = coords.split(',');
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return [+x, +y];
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});
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const triangleContainer = document.querySelector('#triangles');
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const lineContainer = document.querySelector('#lines');
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const edgePts = points.map((pt, i) => [pt, points[(i + 1) % points.length]]);
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const drawCollisionLines = false;
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function drawEdges(lpts) {
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let edges = lpts.map(e => e.join(' '));
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edges.forEach(e => {
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const [x, y] = e.split(' ');
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const [x1, y1] = x.split(',');
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const [x2, y2] = y.split(',');
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const el = document.createElementNS(namespaceURIsvg, 'line');
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el.setAttribute('x1', x1);
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el.setAttribute('y1', y1);
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el.setAttribute('x2', x2);
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el.setAttribute('y2', y2);
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lineContainer.appendChild(el)
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});
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}
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drawEdges(edgePts);
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function drawTriangles(container, pts, [positionX, positionY]) {
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pts.forEach(([[x1, y1], [x2, y2]]) => {
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const el = document.createElementNS(namespaceURIsvg, 'polygon');
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const attr = `${x1},${y1} ${x2},${y2} ${positionX},${positionY}`
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el.setAttribute('points', attr);
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container.appendChild(el)
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});
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}
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drawTriangles(triangleContainer, edgePts, position);
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const triangles = triangleContainer.querySelectorAll('polygon');
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// Triangle has a clockwise orientation
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function isClockwise([xa, ya], [xb, yb], [xc, yc]) {
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// https://en.wikipedia.org/wiki/Curve_orientation#Practical_considerations
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// Determinant for a convex polygon
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const det = (+xb - +xa) * (+yc - +ya) - (+xc - +xa) * (+yb - +ya);
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return det < 0;
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}
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function isAcute([xa, ya], [xb, yb], [xc, yc]) {
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const da = distance(xa, ya, xc, yc);
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const db = distance(xb, yb, xc, yc);
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const dc = distance(xa, ya, xb, yb);
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// https://en.wikipedia.org/wiki/Law_of_cosines
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// Solve for angles alpha and beta with inverse cosine (arccosine)
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const alpha = Math.acos((db ** 2 + dc ** 2 - da ** 2) / (2 * db * dc));
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const beta = Math.acos((da ** 2 + dc ** 2 - db ** 2) / (2 * da * dc));
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return alpha < halfPi && beta < halfPi;
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}
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function findEdges(verts, [xc, yc]) {
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return verts.reduce((acc, [a, b]) => {
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const isFound = [isClockwise, isAcute].every(c => c(a, b, [xc, yc]));
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// return isFound ? [...acc, `${xa},${ya} ${xb},${yb}`] : acc;
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return isFound ? [...acc, `${a[0]},${a[1]} ${b[0]},${b[1]}`] : acc;
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}, []);
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}
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const collisionEdges = findEdges(edgePts, position);
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function updateTriangles([positionX, positionY]) {
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const delim = ' ';
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const className = 'clockwise-orientation';
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const visible = [];
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triangles.forEach(t => {
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const attr = t.getAttribute('points').split(delim);
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const [[xa, ya], [xb, yb], [xc, yc]] = attr.map(t => t.split(','));
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// https://en.wikipedia.org/wiki/Curve_orientation#Practical_considerations
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// Determinant for a convex polygon
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const det = (+xb - +xa) * (+yc - +ya) - (+xc - +xa) * (+yb - +ya);
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const pos = `${positionX},${positionY}`;
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const isClockwise = det < 0;
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let isAcute = false;
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if (isClockwise) {
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const [[ax, ay], [bx, by], [shipx, shipy]] =
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t.getAttribute('points').split(' ').map(n => n.split(',').map(n => +n));
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const da = distance(ax, ay, shipx, shipy);
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const db = distance(bx, by, shipx, shipy);
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const dc = distance(ax, ay, bx, by);
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// https://en.wikipedia.org/wiki/Law_of_cosines
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// Solve for angles alpha and beta with inverse cosine (arccosine)
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const alpha = Math.acos((db ** 2 + dc ** 2 - da ** 2) / (2 * db * dc));
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const beta = Math.acos((da ** 2 + dc ** 2 - db ** 2) / (2 * da * dc));
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isAcute = alpha < halfPi && beta < halfPi;
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}
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if (pos !== attr.pop()) {
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attr.push(pos);
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t.setAttribute('points', attr.join(delim));
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}
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if (drawCollisionLines) {
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t.classList[isClockwise && isAcute ? "add" : "remove"](className);
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t.classList[isClockwise && !isAcute ? "add" : "remove"]("obtuse");
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t.classList[!isClockwise ? "add" : "remove"]("anti-clockwise");
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}
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if (isClockwise && isAcute) visible.push(t);
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});
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return visible;
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}
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function wrapPos(positionX, positionY) {
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let x, y;
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if (positionY > 150) y = positionY - 300;
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else if (positionY < -150) y = positionY + 300;
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else y = positionY;
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if (positionX > 200) x = positionX - 400;
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else if (positionX < -200) x = positionX + 400;
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else x = positionX;
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return [x, y];
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}
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function fireBullet(x, y, velocity) {
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const speed = 200; // meters per second
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const degrees = getRotate(gun);
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const radians = degrees * Math.PI / 180; // toFixed(15)?
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const vx = -Math.sin(radians);
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const vy = Math.cos(radians);
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const bulletTimeout = 5000; // miliseconds
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const cannonLength = 8;
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const el = document.createElementNS(namespaceURIsvg, 'circle');
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el.classList.add('bullet');
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el.setAttribute('r', 1);
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el.setAttribute('cx', 0);
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el.setAttribute('cy', 0);
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const bullet = {
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x: x + vx * cannonLength,
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y: y + vy * cannonLength,
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vx: vx * speed + velocity[0],
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vy: vy * speed + velocity[1],
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time: bulletTimeout,
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node: bulletsContainer.appendChild(el)
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}
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bullets.push(bullet);
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}
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function getTranslate(el) {
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let x, y;
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if (el.style.transform.length === 0) {
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x = 0;
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y = 0;
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} else {
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[[, x], [, y] = ["0px", "0"]] = [...el.style.transform.matchAll(regex)];
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}
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return [+x, +y];
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}
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function getRotate(el) {
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let [[, degrees] = ["0deg", "0"]] = [...el.style.transform.matchAll(degsRegex)];
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return +degrees;
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}
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function updateBullets(elapsed) {
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const deleteCount = 1;
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const pt = document.querySelector('svg').createSVGPoint();
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[...bullets].forEach((bullet, index) => {
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bullet.time -= elapsed;
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const x = bullet.x + 0.001 * elapsed * bullet.vx;
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const y = bullet.y + 0.001 * elapsed * bullet.vy;
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pt.x = x;
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pt.y = y;
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if (bullet.time > 0 && !wall.isPointInFill(pt)) {
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[bullet.x, bullet.y] = wrapPos(x, y);
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bullet.node.style.transform = `translate(${bullet.x}px, ${bullet.y}px)`;
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} else {
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bullet.node.remove();
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bullets.splice(index, deleteCount);
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}
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});
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}
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function detectCollision(points, [xc, yc], edges) {
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const cornerCollision = points.some(([x, y]) => {
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cornerPt.x = x - xc;
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cornerPt.y = y - yc;
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return shipBody.isPointInFill(cornerPt);
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});
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const shipRadius = 5;
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const sideCollision = edges.reduce((acc, e) => {
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const [[xa, ya], [xb, yb]] = e.split(' ').map(n => n.split(',').map(n => +n));
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const da = distance(xa, ya, xc, yc);
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const db = distance(xb, yb, xc, yc);
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// TODO: calculate this one ahead of time
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const dc = distance(xa, ya, xb, yb);
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// https://en.wikipedia.org/wiki/Altitude_(triangle)#Altitude_in_terms_of_the_sides
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// Find altitude of side c (the base)
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const s = (1 / 2) * (da + db + dc);
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const hc = (2 / dc) * Math.sqrt(s * (s - da) * (s - db) * (s - dc));
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return [...acc, hc];
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}, []).some(h => h <= shipRadius);
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return cornerCollision || sideCollision;
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}
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function updateShip(elapsed) {
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if (rotate > 0) gun.style.transform = `rotate(${(+degrees + rotationSpeed * elapsed) % 360}deg)`;
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else if (rotate < 0) gun.style.transform = `rotate(${(+degrees - rotationSpeed * elapsed) % 360}deg)`;
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let [velocityX, velocityY] = restart ? [0, 0] : velocity;
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let [accelerationX, accelerationY] = restart ? [0, 0] : acceleration;
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if (velocityX > 0) accelerationX += -friction;
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else if (velocityX < 0) accelerationX += friction;
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if (velocityY > 0) accelerationY += -friction;
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else if (velocityY < 0) accelerationY += friction;
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velocityX = velocityX > 0 && velocityX + accelerationX < 0 ? 0 : velocityX + accelerationX;
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velocityY = velocityY > 0 && velocityY + accelerationY < 0 ? 0 : velocityY + accelerationY;
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velocity = [velocityX, velocityY];
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if (velocity[0] > maxSpeed) velocity[0] = maxSpeed;
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else if (velocity[0] < -maxSpeed) velocity[0] = -maxSpeed
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if (velocity[1] > maxSpeed) velocity[1] = maxSpeed;
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else if (velocity[1] < -maxSpeed) velocity[1] = -maxSpeed
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const changeX = 0.001 * elapsed * velocityX;
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const changeY = 0.001 * elapsed * velocityY;
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let [x, y] = getTranslate(hitbox);
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let position = [positionX, positionY] = restart ? [0, 0] : wrapPos(changeX + x, changeY + y);
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hitbox.style.transform = `translate(${positionX}px, ${positionY}px)`;
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return position;
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}
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function updateEdges(position) {
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const mappedEdges = findEdges(edgePts, position);
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[...lineContainer.children].forEach(l => {
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const x1 = l.getAttribute('x1');
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const y1 = l.getAttribute('y1');
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const x2 = l.getAttribute('x2');
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const y2 = l.getAttribute('y2');
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const edge = `${x1},${y1} ${x2},${y2}`;
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if (mappedEdges.includes(edge))
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if ([
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lineContainer.childElementCount <= collisionEdges.length,
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!collisionEdges.includes(edge)
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].some(c => c))
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l.remove();
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});
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}
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let start;
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let restart = false;
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function firstFrame(timestamp) {
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zero = timestamp;
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zeroForTimer = timestamp;
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previous = timestamp;
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animate(timestamp);
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}
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function distance(x1, y1, x2, y2) {
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return Math.sqrt((x2 - x1) ** 2 + (y2 - y1) ** 2);
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}
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let isReadingKeys = true;
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function animate(timestamp) {
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const elapsed = timestamp - previous;
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const delta = timestamp - zero;
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let degrees = getRotate(gun);
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previous = timestamp;
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time.innerText = ((timestamp - zeroForTimer) * 0.001).toFixed(3);
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if (delta >= 1000) {
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fps.innerText = frameCount;
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// info.innerText = `velocity ${velocity}\n`
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// + 'bullets\nx\ty\tvx\tvy\n'
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// + bullets.map(b => {
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// return `${b.x.toFixed(2)}\t${b.y.toFixed(2)}\t${b.vx.toFixed(2)}\t${b.vy.toFixed(2)}`;
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// }).join("\n");
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zero = timestamp;
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frameCount = 0;
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} else {
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frameCount++;
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}
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position = updateShip(elapsed);
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updateBullets(elapsed);
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updateEdges(position);
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if (restart) {
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restart = false;
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[...lineContainer.children].forEach(c => c.remove());;
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drawEdges(edgePts);
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}
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const collision = detectCollision(points, position, findEdges(edgePts, position));
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wall.setAttribute('fill', collision ? 'red' : 'black');
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if (collision) {
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// restart game
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zeroForTimer = timestamp;
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restart = true;
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started = false;
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isReadingKeys = false;
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}
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// if (+y < 200)
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// if (timestamp < 10000)
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if (lineContainer.childElementCount > 0 && started)
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requestAnimationFrame(t => animate(t));
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}
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let force = 1;
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let spacePressed = false;
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let upPressed = false;
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let downPressed = false;
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let leftPressed = false;
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let rightPressed = false;
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let rotateCWPressed = false;
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let rotateCCWPressed = false;
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document.addEventListener("keydown", function(e) {
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if (!isReadingKeys) return;
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if (!started && !restart) {
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started = true;
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requestAnimationFrame(firstFrame);
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} else if (restart) {
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requestAnimationFrame(firstFrame);
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}
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switch (e.code) {
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case "Space":
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if (!spacePressed) {
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|
spacePressed = true;
|
|
const [x, y] = getTranslate(hitbox);
|
|
fireBullet(x, y, velocity);
|
|
}
|
|
break;
|
|
case "KeyW":
|
|
case "ArrowUp":
|
|
if (!upPressed) {
|
|
upPressed = true;
|
|
acceleration[1] += -force;
|
|
}
|
|
break;
|
|
case "KeyS":
|
|
case "ArrowDown":
|
|
if (!downPressed) {
|
|
downPressed = true;
|
|
acceleration[1] += force;
|
|
}
|
|
break;
|
|
case "KeyA":
|
|
case "ArrowLeft":
|
|
if (!leftPressed) {
|
|
leftPressed = true;
|
|
acceleration[0] += -force;
|
|
}
|
|
break;
|
|
case "KeyD":
|
|
case "ArrowRight":
|
|
if (!rightPressed) {
|
|
rightPressed = true;
|
|
acceleration[0] += force;
|
|
}
|
|
break;
|
|
case "KeyQ":
|
|
case "Comma":
|
|
if (!rotateCCWPressed) {
|
|
rotateCCWPressed = true;
|
|
rotate += -1;
|
|
}
|
|
break;
|
|
case "KeyE":
|
|
case "Period":
|
|
if (!rotateCWPressed) {
|
|
rotateCWPressed = true;
|
|
rotate += 1;
|
|
}
|
|
break;
|
|
}
|
|
});
|
|
|
|
document.addEventListener("keyup", function(e) {
|
|
isReadingKeys = true;
|
|
|
|
switch (e.code) {
|
|
case "Space":
|
|
spacePressed = false;
|
|
break;
|
|
case "KeyW":
|
|
case "ArrowUp":
|
|
if (upPressed) {
|
|
upPressed = false;
|
|
acceleration[1] -= -force;
|
|
}
|
|
break;
|
|
case "KeyS":
|
|
case "ArrowDown":
|
|
if (downPressed) {
|
|
downPressed = false;
|
|
acceleration[1] -= force;
|
|
}
|
|
break;
|
|
case "KeyA":
|
|
case "ArrowLeft":
|
|
if (leftPressed) {
|
|
leftPressed = false;
|
|
acceleration[0] -= -force;
|
|
}
|
|
break;
|
|
case "KeyD":
|
|
case "ArrowRight":
|
|
if (rightPressed) {
|
|
rightPressed = false;
|
|
acceleration[0] -= force;
|
|
}
|
|
break;
|
|
case "KeyQ":
|
|
case "Comma":
|
|
if (rotateCCWPressed) {
|
|
rotateCCWPressed = false;
|
|
rotate -= -1;
|
|
}
|
|
break;
|
|
case "KeyE":
|
|
case "Period":
|
|
if (rotateCWPressed) {
|
|
rotateCWPressed = false;
|
|
rotate -= 1;
|
|
}
|
|
break;
|
|
}
|
|
});
|
|
//]]></script>
|
|
</svg>
|
|
|