Initial commit

server.js

@@ -0,0 +1,184 @@
+const app = require('express')();
+const http = require('http').Server(app);
+const io = require('socket.io')(http);
+const convert = require('color-convert');
+
+app.get('/', function (req, res) {
+  res.sendFile(__dirname + '/client.html');
+});
+
+function randomColor() {
+  return '#' + convert.hsl.hex([randInt(0, 256), randInt(50, 200), 256]);
+}
+
+function randInt(min, max) {
+  return Math.floor(min + Math.random() * (max - min));
+}
+
+function intersects(a1, a2, b1, b2) {
+  let det, gamma, lambda;
+  det = (a2.x - a1.x) * (b2.y - b1.y) - (b2.x - b1.x) * (a2.y - a1.y);
+  if (det === 0) {
+    return false;
+  } else {
+    lambda = ((b2.y - b1.y) * (b2.x - a1.x) + (b1.x - b2.x) * (b2.y - a1.y)) / det;
+    gamma = ((a1.y - a2.y) * (b2.x - a1.x) + (a2.x - a1.x) * (b2.y - a1.y)) / det;
+    return (0 < lambda && lambda < 1) && (0 < gamma && gamma < 1);
+  }
+}
+
+function dist(a1,a2){
+  return Math.sqrt(Math.pow(a1.x-a2.x,2)+Math.pow(a1.y-a2.y,2));
+}
+
+function clone(a){
+  return {x:parseFloat(a.x),y:parseFloat(a.y)};
+}
+
+const HSIZE = 300;
+const MAXX = 1600;
+const MAXY = 900;
+const SPD = 5;
+const MAX_ANGLE_SPEED = Math.PI / 32;
+
+const players = {};
+const history = {};
+
+let upc = 0;
+let ic = 0;
+
+setInterval(function () {
+  //main loop
+  Object.keys(players).forEach(function (name) {
+    const p = players[name];
+    if (p.alive) {
+      const lastpos = clone(p.pos);
+      p.pos.x += SPD * Math.cos(p.angle);
+      p.pos.y += SPD * Math.sin(p.angle);
+      p.angle += p.angleSpd;
+      let exempt = false;
+      if (p.pos.x > MAXX){
+        p.pos.x = 0;
+        exempt = true;
+      }
+      if (p.pos.x < 0){
+        p.pos.x = MAXX;
+        exempt = true;
+      }
+      if (p.pos.y > MAXY){
+        p.pos.y = 0;
+        exempt = true;
+      }
+      if (p.pos.y < 0){
+        p.pos.y = MAXY;
+        exempt = true;
+      }
+
+      if(p.starting <= 0){
+        const h = history[name];
+        h.i0 = (h.i0 + 1) % HSIZE;
+        h.list[h.i0] = clone(p.pos);
+      }
+
+      if(!exempt && p.starting <= 0){
+        const ds = dist(lastpos,p.pos);
+        if(ds <= SPD*0.9)
+          process.stdout.write(`\r${name} moved too slowly : ${ds} [${lastpos.x},${lastpos.y}]->[${p.pos.x},${p.pos.y}]\n`);
+        if(ds >= SPD*1.1)
+          process.stdout.write(`\r${name} moved too quickly : ${ds} [${lastpos.x},${lastpos.y}]->[${p.pos.x},${p.pos.y}]\n`);
+
+        Object.keys(history).forEach(function (name2) {
+          if (p.alive && name !== name2) {
+            const h2 = history[name2];
+            let lastpoint = h2.list[h2.i0];
+            if(!lastpoint)
+              return;
+            for (let di = 1; di < HSIZE; di++) {
+              const point = h2.list[(h2.i0 - di + HSIZE) % HSIZE];
+              if (point !== undefined) {
+                if(Math.abs(lastpoint.x - point.x) < 1600 * .9 && Math.abs(lastpoint.y - point.y) < 900 * .9){
+                  ic++;
+                  if (intersects(lastpos, p.pos, lastpoint, point)) {
+                    process.stdout.write(`\r${name} collided with ${name2}\n`);
+                    p.alive = false;
+                    break;
+                  }
+                }
+                lastpoint = point;
+              } else {
+                break;
+              }
+            }
+          }
+        });
+      }
+
+      if(p.starting > 0)
+        p.starting -= 20;
+
+    }
+  });
+  io.emit('players', players);
+  upc++;
+}, 20);
+
+setInterval(function () {
+  process.stdout.write(`\rtick ${20 * upc * 20 / 1000}/20 ms (${ic} intersect/s)`);
+  upc = 0;
+  ic = 0;
+}, 1000);
+
+io.on('connection', function (socket) {
+  socket.name = '#' + ('0000' + randInt(0, 10000)).slice(-4);
+  process.stdout.write(`\r${socket.name} connected\n`);
+  players[socket.name] = {
+    pos: {
+      x: randInt(100, MAXX - 100),
+      y: randInt(100, MAXY - 100)
+    },
+    angle: Math.random() * Math.PI,
+    angleSpd: 0,
+    color: randomColor(),
+    name: socket.name,
+    alive: true,
+    starting: 2000
+  };
+  history[socket.name] = {
+    i0: -1,
+    list: new Array(HSIZE)
+  };
+  socket.emit('info', {
+    self:players[socket.name],
+    players:players,
+    history:history,
+    hsize:HSIZE
+  });
+
+  socket.on('disconnect', function () {
+    delete players[socket.name];
+    delete history[socket.name];
+    process.stdout.write(`\r${socket.name} disconnected\n`);
+    io.emit('players', players);
+  });
+  socket.on('update', function (newp) {
+    const p = players[newp.name];
+    if (!p) {
+      socket.disconnect();
+      return;
+    }
+    if (!p.alive)
+      return;
+    if (newp.color === 'new')
+      players[newp.name].color = randomColor();
+    if (newp.angleSpd > 0)
+      players[newp.name].angleSpd = MAX_ANGLE_SPEED;
+    else if (newp.angleSpd < 0)
+      players[newp.name].angleSpd = -MAX_ANGLE_SPEED;
+    else
+      players[newp.name].angleSpd = 0;
+  });
+});
+
+http.listen(3001, function () {
+  console.log('listening on *:3001\n');
+});