[WIP] skycraft server

skycraft/chunk.ts

@@ -135,9 +135,11 @@ function faceTexture(type: number, dir: direction) {
     }
 }
 
-function* makeChunkFaces(chunk) {
+function* makeChunkFaces(chunk, getChunk) {
     const cs = CHUNKSIZE;
 
+    console.log(`make chunk faces for ${chunk.seed} at ${chunk.position}`);
+
     function faceCenter(pos: linalg.Vec3, dir: direction) {
         switch (dir) {
             case '-x': return [pos[0] - 0.5, pos[1], pos[2]];
@@ -304,10 +306,19 @@ function getBodyChunks(seed: number) {
     return chunks;
 }
 
-export function getBodyGeometry(seed: number) {
+export function getBodyGeometry(chunks) {
-    const faces = getBodyChunks(seed)
+    function lookup(seed: number, chunkX: number, chunkY: number, chunkZ: number) {
+        for (const chunk of chunks) {
+            const [cx, cy, cz] = chunk.layout;
+            if (chunkX == cx && chunkY == cy && chunkZ == cz) {
+                return chunk;
+            }
+        }
+    }
+
+    const faces = chunks
         .filter(chunk => !chunk.underground)
-        .map(chunk => [...makeChunkFaces(chunk)]);
+        .map(chunk => [...makeChunkFaces(chunk, memoize(lookup))]);
 
     return faces.reduce((a, b) => a.concat(b));
 }

skycraft/client.ts

@@ -0,0 +1,15 @@
+const backend = 'http://localhost:8080/api/';
+
+/** Get all chunks for the given body */
+export async function getBody(seed: number) {
+    const resp = await fetch(backend + `body/${seed}`);
+
+    return await resp.json();
+}
+
+/** Get a complete solar system */
+export async function getSystem(seed: number) {
+    const resp = await fetch(backend + `system/${seed}`);
+
+    return await resp.json();
+}

skycraft/draw.ts

@@ -172,9 +172,9 @@ void main() {
   
   lowp float f = sqrt(x * x + y * y);
   
-  if (f > 1.00) {
+  if (f > 1.01) {
     discard;
-  } else if (f < 0.98) {
+  } else if (f < 0.99) {
     discard;
   }
   gl_FragColor = vec4(1, .5, 0, 0.5);
@@ -304,11 +304,20 @@ export function draw(context) {
 
     gl.clear(gl.COLOR_BUFFER_BIT | gl.DEPTH_BUFFER_BIT);
 
-    const viewMatrix = se3.inverse([
+    let camtf;
-        player.tf,  // player position & orientation
+    if (camera.overhead) {
-        camera.tf,  // camera orientation relative to player
+        camtf = [
-        se3.translation(0, 1, 4),  // step back from the player
+            se3.translation(0, 500, 0),
-    ].reduce(se3.product));
+            se3.rotx(-Math.PI / 2),
+        ].reduce(se3.product);
+    } else {
+        camtf = [
+            player.tf,  // player position & orientation
+            camera.tf,  // camera orientation relative to player
+            se3.translation(0, 1, 4),  // step back from the player
+        ].reduce(se3.product)
+    }
+    const viewMatrix = se3.inverse(camtf);
     let lastGlContext;
 
     for (const {position, orientation, geometry, glContext, glowColor} of objects) {

skycraft/index.ts

@@ -1,5 +1,6 @@
 import { makeFace } from '../geometry';
 
+import * as client from './client';
 import * as linalg from './linalg';
 import { loadObjModel } from './obj';
 import * as se3 from '../se3';
@@ -17,7 +18,24 @@ function closeToPlanet(context) {
     return linalg.norm(relativePos) < 20;
 }
 
-function getSolarSystem(seed: number) {
+async function getSolarSystem(seed: number) {
+    async function getGeometry(body) {
+        const chunks = await client.getBody(body.seed);
+        console.log(chunks);
+        body.geometry = getBodyGeometry(chunks);
+        console.log(body);
+        for (const child of body.children) {
+            await getGeometry(child);
+        }
+    }
+
+    const system = await client.getSystem(seed);
+    await getGeometry(system);
+
+    return system;
+}
+
+function _getSolarSystem(seed: number) {
     /// XXX: only returns 1 body for now
 
     return {
@@ -161,6 +179,10 @@ function initUiListeners(canvas: HTMLCanvasElement, context) {
                             context.landing = True;
                         }
                         return false;
+
+                    case 'KeyO':
+                        context.camera.overhead ^= 1;
+                        return false;
                     case 'Space':
                         if (!context.flying) {
                             if (context.jumpAmount > 0) {
@@ -313,6 +335,7 @@ function updateGeometry(context, timeout_ms = 10) {
 }
 
 function tick(time: number, context) {
+    time = new Date().getTime();
     handleInput(context);
     const simTime = time * 0.001 + context.timeOffset;
     updatePhysics(simTime, context);
@@ -390,7 +413,7 @@ async function main() {
         isOnGround: false,
         gravity: -17,
         jumpForce: 6.5,
-        universe: getSolarSystem(0),
+        universe: await getSolarSystem(0),
         timeOffset: 0,
     };
 

skycraft/orbit.html

@@ -0,0 +1,495 @@
+<!DOCTYPE html>
+<html>
+<head>
+<title>Kepler orbit simulation</title>
+<style>
+#canvas {
+    border: 1px solid black;
+    margin-right: 10px;
+    width: 500px;
+    height: 500px;
+}
+#info {
+    width: 300px;
+    border: 1px solid black;
+    padding: 6px;
+}
+</style>
+</head>
+<body>
+<table cellspacing="0" cellpadding="0">
+    <tbody>
+        <tr>
+            <td>
+                <canvas id="canvas"></canvas>
+            </td>
+            <td>
+                Kepler orbit simulation<br><br>
+                <div id="info"></div>
+                <br><br>
+                - Press the space bar to start/stop the simulation<br>
+                - Drag the green circle/arrowhead to change the position/velocity<br>
+                - Scroll to zoom in/out<br>
+                - Press the arrow keys to adjust the velocity
+            </td>
+        </tr>
+    </tbody>
+</table>
+
+<script>
+function Point(x, y) {
+    this.x = x;
+    this.y = y;
+}
+
+function State(e, p, u, thp, th0, ccw, E, t) {
+    this.e = e; // eccentricity
+    this.p = p; // semi-latus rectum
+    this.u = u; // G(m_1 + m_2)
+    this.thp = thp; // initial true anomaly
+    this.th0 = th0; //
+    this.ccw = ccw; // counter-clockwise orbit
+    this.t = t; // time since periapsis
+    this.E = E; // eccentric anomaly (redundant with t)
+
+    // redundant info (for performance)
+    this.r = new Point(0, 0); // position
+    this.v = new Point(0, 0); // velocity
+    this.T = 0; // period
+}
+
+function norm(v) { return Math.sqrt(v.x * v.x + v.y * v.y); }
+
+function add(v, w) { return new Point(v.x + w.x, v.y + w.y); }
+function minus(v, w) { return new Point(v.x - w.x, v.y - w.y); }
+function mult(v, c) { return new Point(v.x * c, v.y * c); }
+
+function dot(v, w) { return v.x * w.x + v.y * w.y; }
+function vccw(v, w) { return v.x * w.y - v.y * w.x; }
+
+function pow2(x) { return x*x; }
+function cosh(x) { return (Math.exp(x) + Math.exp(-x)) / 2; }
+function sinh(x) { return (Math.exp(x) - Math.exp(-x)) / 2; }
+function tanh(x) { return (Math.exp(x) - Math.exp(-x)) / (Math.exp(x) + Math.exp(-x)); }
+function atanh(x) { return 0.5 * Math.log((1 + x) / (1 - x)); }
+
+var G = 6.67384e-11; // gravitational constant
+var m1 = 5.97219e24; // mass of the center object
+var m2 = 7.3477e22; // mass of the orbiting object
+var u = G * (m1 + m2);
+var st; // the state variable
+
+(function(){
+    // initial states
+    var a = 384748000;
+    var e=0.0549006, p=a*(1-e*e), thp=0, th0=0, ccw=true;
+    var t=0;
+    var E=0;
+    st = new State(e, p, u, thp, th0, ccw, E, t);
+})();
+
+
+var canvas = document.getElementById("canvas");
+var ctx = canvas.getContext("2d");
+
+var dpr = window.devicePixelRatio || 1;
+canvas.width = 500 * dpr;
+canvas.height = 500 * dpr;
+ctx.scale(dpr, dpr);
+
+var vscale = 50000;
+var drawScale = 1/2000000;
+
+function toTheta(E, e) {
+    // eccentric anomaly -> true anomaly
+    if (e < 1)
+        return 2 * Math.atan( Math.sqrt((1+e) / (1-e))  * Math.tan(E/2) );
+    if (e > 1)
+        return 2 * Math.atan( Math.sqrt((1+e) / (e-1))  * tanh(E/2) );
+    return 2 * Math.atan(E);
+}
+
+function toE(theta, e) {
+    // true anomaly -> eccentric anomaly
+    if (e < 1)
+        return Math.atan2( Math.sqrt(1-e*e) * Math.sin(theta) , e + Math.cos(theta));
+    if (e > 1)
+        return atanh( Math.sqrt(e*e-1) * Math.sin(theta) / ( e +Math.cos(theta)));
+    return Math.tan(theta / 2);
+}
+
+function findT(E, e, u, p, ccw) {
+    // eccentric anomaly -> time since periapsis
+    if (!ccw)
+        E = -E;
+    var a = p / (1 - e*e);
+    if (e < 1)
+        return a * Math.sqrt(a / u) * (E - e * Math.sin(E));
+    if (e > 1)
+        return -a * Math.sqrt(-a / u) * (e * sinh(E) - E);
+    return Math.sqrt(p * p * p / (u * 8)) * (E + E*E*E/3);
+}
+
+function findE(t, e, u, p, E0, ccw) {
+    // time since periapsis -> eccentric anomaly
+    var E = E0;
+    var a = p / (1 - e*e);
+    if (e < 1)
+        M = Math.sqrt(u / (a*a*a)) * t;
+    else if (e > 1)
+        M = Math.sqrt(u / (-a*a*a)) * t;
+    else
+        M = Math.sqrt((u * 8) / (p * p * p)) * t;
+
+    if (!ccw)
+        M = -M;
+
+    // Newton's method
+    var E2;
+    for (var i = 1; i < 20; ++i) {
+        if (e < 1)
+            E2 = E - (E - e * Math.sin(E) - M) / (1 - e * Math.cos(E));
+        else if (e > 1)
+            E2 = E - (-E + e * sinh(E) - M) / (e * cosh(E) - 1);
+        else
+            E2 = E - (E + E*E*E/3 - M) / (1 + E*E);
+        if (Math.abs(E - E2) < 1e-10)
+            break;
+        E = E2;
+    }
+    return E;
+}
+
+function calculateState(r, v, u) {
+    // Find the state variables from initial position and velocity
+
+    var ccw = vccw(r, v);
+
+    // TODO: radial trajectory - this is a non-trivial special case.
+    if (ccw == 0) {
+        v.x += 0.1; // cheat
+        ccw = vccw(r, v);
+    }
+
+    var rs = norm(r);
+    //r1 = new Point(r.x / rs, r.y / rs);
+    //vr = dot(v, r1);
+    //vtt = new Point(v.x - r1.x * vr, v.y - r1.y * vr);
+    //r1 = new Point(r.x / rs, r.y / rs);
+    var vr = dot(v, r) / rs;
+    var k = dot(v, r) / dot(r, r);
+    var vrr = new Point(r.x * k, r.y * k);
+    var vtt = new Point(v.x - vrr.x, v.y - vrr.y);
+
+    var vt = norm(vtt);
+
+    var p = dot(r, r) * dot(vtt, vtt) / u;
+    var v0 = u / Math.sqrt(dot(r, r) * dot(vtt, vtt));
+    var v0inv = Math.sqrt(dot(r, r) * dot(vtt, vtt)) / u;
+    //v0 = u / Math.sqrt();
+    var e = Math.sqrt( pow2(vt*v0inv - 1) + pow2(vr*v0inv) );
+    //v02 = u / p;
+    //e = Math.sqrt( dot(vtt,vtt) - 2*vt*v0 + v02 + (dot(v, r) * dot(v, r) / dot(r, r)  )) / v0;
+
+    //e2 = Math.sqrt(dot(vtt,vtt) - 2*vt*v0 + v02 + (dot(v, r) * dot(v, r) / dot(r, r) ));
+    //cos = (vt/v0-1) / e;
+    //sin = (vr / v0) / e;
+
+    //cos = (vt - v0) / e2;
+    //sin = vr / e2;
+
+    var thp = Math.atan2(vr, vt - v0);
+    if (ccw < 0)
+        thp = -thp;
+
+    var th0 = Math.atan2(r.y, r.x);
+
+    return new State(e, p, u, thp, th0, ccw >= 0, st.E, st.t);
+}
+
+function findRV(st) {
+    // Find the position and velocity of the current state
+    var e = st.e;
+    var p = st.p;
+    var u = st.u;
+    var thp = st.thp;
+    var th0 = st.th0;
+    var E = st.E;
+    var ccw = st.ccw;
+
+    var theta = toTheta(E, e);
+    var rv = p / (1+e*Math.cos(theta));
+    var r = new Point(rv*Math.cos((th0 - thp) + theta), rv*Math.sin((th0 - thp) + theta));
+
+    var v0 = Math.sqrt(u / p);
+    var vt = (e * Math.cos(theta) + 1) * v0;
+    var vr = e * Math.sin(theta) * v0;
+    var rs = norm(r);
+    var r1 = new Point(r.x / rs, r.y / rs);
+    var t1 = new Point(-r1.y, r1.x);
+    if (!ccw) {
+        vt = -vt;
+        vr = -vr;
+    }
+
+    var v = new Point(vr*r1.x + vt*t1.x, vr*r1.y + vt*t1.y);
+
+    // cache
+    st.r = r;
+    st.v = v;
+
+    return {r:r, v:v};
+}
+
+function recalculate(_st, dx, dy) {
+    // Adjust the velocity by (dx, dy)
+    var d = findRV(_st);
+    var r = d.r;
+    var v = d.v;
+    v = new Point(v.x + dx, v.y + dy);
+
+    st = calculateState(r, v, _st.u);
+    st.E = toE(st.thp, st.e);
+    st.t = findT(st.E, st.e, st.u, st.p, st.ccw);
+}
+
+
+function redraw(st) {
+    var e = st.e;
+    var p = st.p;
+    var u = st.u;
+    var thp = st.thp;
+    var th0 = st.th0;
+
+    ctx.clearRect(0, 0, 500, 500);
+
+    ctx.save();
+    ctx.translate(250, 250);
+
+    // center
+    ctx.fillStyle="#FF0000";
+    ctx.beginPath();
+    ctx.arc(0, 0, 6, 0, 2*Math.PI);
+    ctx.fill();
+
+    // trace
+    ctx.strokeStyle ="#FF0000";
+    if (e == 0) { // circle
+        ctx.beginPath();
+        ctx.arc(0, 0, p*drawScale, 0, 2*Math.PI);
+        ctx.stroke();
+    } /*else if (e < 1) { // ellipse
+        ctx.save();
+        var a = p / (1 - e*e);
+        ctx.rotate( th0 - thp );
+        ctx.translate(-e * a, 0);
+        ctx.scale(1, Math.sqrt(1 - e*e));
+        ctx.beginPath();
+        ctx.arc(0, 0, a, 0, 2*Math.PI);
+        ctx.stroke();
+        ctx.restore();
+    } */ else {
+        var th;
+        var rv;
+        ctx.beginPath();
+        for (th=-Math.PI; th < Math.PI; th+=0.01) {
+            rv = p / (1+e*Math.cos(th));
+            if (rv <= 0)
+                continue;
+            ctx.lineTo( rv*Math.cos(th + (th0 - thp))*drawScale, rv*Math.sin(th + (th0 - thp))*drawScale );
+        }
+        ctx.stroke();
+    }
+
+
+    var d = findRV(st);
+    var r = d.r;
+    var v = d.v;
+
+    // the orbiting object
+    ctx.fillStyle ="#008000";
+    ctx.beginPath();
+    ctx.arc(r.x * drawScale, r.y * drawScale, 5, 0, 2*Math.PI);
+    ctx.fill();
+
+    // the velocity line
+    ctx.strokeStyle ="#0000FF";
+    ctx.beginPath();
+    ctx.moveTo(r.x * drawScale, r.y * drawScale);
+    ctx.lineTo((r.x + v.x * vscale) * drawScale, (r.y + v.y * vscale) * drawScale);
+    ctx.stroke();
+
+    // arrowhead
+    ctx.save();
+    ctx.translate((r.x + v.x * vscale) * drawScale, (r.y + v.y * vscale) * drawScale);
+    ctx.rotate(-Math.atan2(v.x, v.y));
+    ctx.strokeStyle ="#0000FF";
+    ctx.beginPath();
+    ctx.moveTo(-8, -10);
+    ctx.lineTo(0, 0);
+    ctx.lineTo(8, -10);
+    ctx.stroke();
+    ctx.restore();
+
+    ctx.restore();
+
+    updateInfo();
+}
+
+
+
+
+var moving = false;
+var timer;
+
+redraw(st);
+
+
+var state = 0;
+var r0, v0;
+var saveMoving;
+
+canvas.onmousemove = function(event) {
+    var x = event.offsetX == undefined ? event.layerX : event.offsetX;
+    var y = event.offsetY == undefined ? event.layerY : event.offsetY;
+    var p = mult(new Point(x - 250, y - 250), 1/drawScale);
+    var d = findRV(st);
+    var r = d.r;
+    var v = d.v;
+
+    if (state <= 2) {
+        if (norm(minus(p, r)) < 14 / drawScale) {
+            canvas.style.cursor = 'pointer';
+            state = 1;
+        } else if (norm( minus( add(r, mult(v, vscale)) , p ) ) < 14 / drawScale) {
+            canvas.style.cursor = 'pointer';
+            state = 2;
+        } else {
+            canvas.style.cursor = 'default';
+            state = 0;
+        }
+        return;
+    }
+
+
+    if (state == 3) {
+        if (p.x == 0 && p.y == 0)
+            p.x = 0.1;
+        r = p;
+        v = v0;
+    } else if (state == 4) {
+        r = r0;
+        v = mult(minus(p, r), 1/vscale);
+    }
+
+    st = calculateState(r, v, st.u);
+    var thp = st.thp;
+    var th0 = st.th0;
+
+    st.E = toE(thp, st.e);   // why only THP ?
+    st.t = findT(st.E, st.e, st.u, st.p, st.ccw);
+    redraw(st);
+}
+
+canvas.onmousedown = function(event) {
+    var d = findRV(st);
+    r0 = d.r;
+    v0 = d.v;
+    if (state == 1 || state == 2) {
+        state += 2;
+        saveMoving = moving;
+        stopMoving();
+    }
+
+    canvas.onmousemove(event);
+    event.preventDefault();
+}
+
+var mousewheel = function (e) {
+    var delta = e.wheelDelta ? e.wheelDelta : e.detail;
+    console.log(delta);
+    drawScale = drawScale + delta / 10000000000;
+    drawScale = Math.max(drawScale, 0.000000001);
+    redraw(st);
+    e.preventDefault();
+};
+
+canvas.addEventListener(canvas.hasOwnProperty("onmousewheel") ?
+  "mousewheel" : "DOMMouseScroll", mousewheel);
+
+document.onmouseup = function(event) {
+    state = 0;
+    if (saveMoving)
+        startMoving();
+    canvas.style.cursor = 'default';
+}
+
+function updateInfo() {
+    function curveType(e) {
+        if (e == 0) return "circle";
+        if (e < 1) return "ellipse";
+        if (e == 1) return "parabola";
+        return "hyperbola";
+    }
+
+    var a = st.p / (1 - st.e*st.e);
+    var T = 2 * Math.PI * a * Math.sqrt(a / st.u);
+
+    var div = document.getElementById("info");
+    s = "";
+    s += "curve = " + curveType(st.e) + "<br>";
+    s += "eccentricity = " + st.e.toFixed(2) + "<br>";
+    s += "altitude = " + Math.round(norm(st.r)/1000) + " km<br>";
+    s += "periapsis = " + Math.round((1-st.e)*a/1000) + " km<br>";
+    // is the apoapsis for parabola/hyperbola really infinity?
+    s += "apoapsis = " + ((st.e < 1) ? (Math.round((1+st.e)*a/1000) + " km") : "&infin;") + "<br>";
+    s += "velocity = " + Math.round(norm(st.v)/1000 * 10)/10 + " km/s<br>";
+    s += "eccentric anomaly = " + Math.round((((st.E / Math.PI) % 2) + 2) % 2 * 10) / 10 + "&pi;<br>";
+    s += "period = " + ((st.e < 1) ? (Math.round(T / (24*60*60) * 10) / 10 + " days") : "&infin;") + "<br>";
+    div.innerHTML = s;
+}
+
+function animate() {
+    st.t += 24*60*60*0.1;
+    st.E = findE(st.t, st.e, st.u, st.p, st.E, st.ccw);
+    redraw(st);
+}
+
+function stopMoving() {
+    clearInterval(timer);
+    moving = false;
+}
+
+function startMoving() {
+    if (moving)
+        return;
+    timer = setInterval(animate, 30);
+    moving = true;
+}
+
+document.onkeydown = function(event) {
+    var dx=0, dy=0;
+    if (event.keyCode == 38) { // up
+        dy = -1;
+    } else if (event.keyCode == 40) { // down
+        dy = 1;
+    } else if (event.keyCode == 37) { // left
+        dx = -1;
+    } else if (event.keyCode == 39) { // right
+        dx = 1;
+    } else if (event.keyCode == 32) {
+        if (moving) {
+            stopMoving();
+        } else {
+            startMoving();
+        }
+    }
+    if (dx != 0 || dy != 0) {
+        recalculate(st, dx * 10, dy * 10);
+        redraw(st);
+    }
+}
+
+</script>
+</body>
+</html>

skycraft/orbit.ts

@@ -4,10 +4,10 @@ import {Vec3} from './linalg';
 
 interface Orbit {
     excentricity: number,
-    semimajorAxis: number,
+    semimajor_axis: number,
     inclination: number,
-    ascendingNodeLongitude: number,
+    ascending_node_longitude: number,
-    periapsisArgument: number,
+    periapsis_argument: number,
     t0: number,
 
     lastE: number | undefined,
@@ -63,7 +63,7 @@ export function findSoi(rootBody: Body, position: number[]) : Body {
         }
 
         for (const child of body.children) {
-            const soi = child.orbit.semimajorAxis * Math.pow(child.mass / body.mass, 2/5);
+            const soi = child.orbit.semimajor_axis * Math.pow(child.mass / body.mass, 2/5);
             const pos = position;
             const bod = child.position;
             const dr = [pos[0] - bod[0], pos[1] - bod[1], pos[2] - bod[2]];
@@ -128,10 +128,14 @@ export function computeOrbit(player: any, body: Body, time: number) {
         E = 2 * Math.atanh(Math.sqrt((e-1)/(e+1)) * Math.tan(nu/2));
         const n = Math.sqrt(-mu / (a**3));
         t0 = time - (e*Math.sinh(E) - E) / n;
+
+        t0 %= 2 * Math.PI / n;
     } else {
         E = 2 * Math.atan(Math.sqrt((1-e)/(1+e)) * Math.tan(nu/2));
         const n = Math.sqrt(mu / (a**3));
         t0 = time - (1/n)*(E - e*Math.sin(E));
+
+        t0 %= 2 * Math.PI / n;
     }
 
     // column-major... see se3.js
@@ -144,10 +148,10 @@ export function computeOrbit(player: any, body: Body, time: number) {
 
     const orbit = {
         excentricity: e,
-        semimajorAxis: a,
+        semimajor_axis: a,
         inclination: i,
-        ascendingNodeLongitude: Om,
+        ascending_node_longitude: Om,
-        periapsisArgument: w,
+        periapsis_argument: w,
         t0,
         tf,
         lastE: E,
@@ -167,17 +171,17 @@ export function computeOrbit(player: any, body: Body, time: number) {
 export function getCartesianState(orbit: Orbit, mu: number, time: number) {
     const {
         excentricity: e,
-        semimajorAxis: a,
+        semimajor_axis: a,
         inclination: i,
-        ascendingNodeLongitude: Om,
+        ascending_node_longitude: Om,
-        periapsisArgument: w,
+        periapsis_argument: w,
         t0,
     } = orbit;
     let n = Math.sqrt(mu/(a**3));
     if (a < 0) {
         n = Math.sqrt(mu/-(a**3));  // mean motion
     }
-    const M = n * (time - t0);  // mean anomaly
+    const M = (n * (time - t0)) % (2 * Math.PI);  // mean anomaly
 
     // Newton's method
     var E2 = 0;
@@ -253,10 +257,10 @@ export function makeOrbitObject(gl: WebGLRenderingContext, glContext: any, orbit
     const buffer = gl.createBuffer();
     gl.bindBuffer(gl.ARRAY_BUFFER, buffer);
 
-    const a = orbit.semimajorAxis;
+    const a = orbit.semimajor_axis;
     const b = a * Math.sqrt(1 - orbit.excentricity**2);
 
-    const x = - orbit.semimajorAxis * orbit.excentricity;
+    const x = - orbit.semimajor_axis * orbit.excentricity;
 
     gl.bufferData(gl.ARRAY_BUFFER, new Float32Array([
         x-a, -b, 0, -1, -1,

skycraft/server/.cargo/config.toml

@@ -0,0 +1,2 @@
+[build]
+rustflags = ["-C", "link-arg=-fuse-ld=lld"]

skycraft/server/.gitignore

@@ -0,0 +1 @@
+/target

skycraft/server/Cargo.toml

@@ -0,0 +1,12 @@
+[package]
+name = "skycraft-server"
+version = "0.1.0"
+edition = "2021"
+
+# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+
+[dependencies]
+tide = "0.14.0"
+async-std = { version = "1.6.0", features = ["attributes"] }
+serde = { version = "1.0", features = ["derive"] }
+serde_json = "1.0"

skycraft/server/src/main.rs

@@ -0,0 +1,262 @@
+use tide::Request;
+use tide::Response;
+use tide::prelude::*;
+//use serde_json::json;
+use std::f64::consts::PI;
+
+#[derive(Default, Serialize)]
+struct SystemBody {
+    name: String,
+    mass: f32,
+    seed: u32,
+    spin: [f32; 3],
+//    geometry: ,
+    glow_color: [f32; 3],
+    orbit: KeplerOrbit,
+    children: Vec<SystemBody>,
+}
+
+#[derive(Default, Serialize)]
+struct KeplerOrbit {
+    excentricity: f32,
+    semimajor_axis: f32,
+    inclination: f32,
+    ascending_node_longitude: f32,
+    periapsis_argument: f32,
+    t0: f32,
+}
+
+const CHUNKSIZE: usize = 32;
+
+#[derive(Serialize)]
+struct Chunk {
+    position: [f32; 3],
+    layout: [i32; 3],
+    #[serde(serialize_with = "<[_]>::serialize")]
+    blocks: [u32; CHUNKSIZE.pow(3)],
+    seed: u32,
+    underground: bool,
+}
+
+impl PartialEq for Chunk {
+    fn eq(&self, other: &Chunk) -> bool {
+        self.seed == other.seed && self.position == other.position
+    }
+}
+
+#[async_std::main]
+async fn main() -> tide::Result<()> {
+    let mut app = tide::new();
+    app.at("/api/system/:seed").get(get_system);
+    app.at("/api/body/:seed").get(get_body);
+    app.listen("127.0.0.1:8080").await?;
+    Ok(())
+}
+
+fn get_sun_chunk(seed: u32, pos: [i32; 3]) -> Chunk {
+    let cs = CHUNKSIZE as i32;
+    Chunk {
+        position: pos.map(|x| ((x * cs - cs / 2) as f32)),
+        layout: pos,
+        blocks: [8; CHUNKSIZE.pow(3)],
+        seed: seed,
+        underground: false,
+    }
+}
+
+fn get_dirt_chunk(seed: u32, pos: [i32; 3]) -> Chunk {
+    let cs = CHUNKSIZE as i32;
+    Chunk {
+        position: pos.map(|x| ((x * cs - cs / 2) as f32)),
+        layout: pos,
+        blocks: [2; CHUNKSIZE.pow(3)],
+        seed: seed,
+        underground: false,
+    }
+}
+
+fn get_chunk(seed: u32, pos: [i32; 3]) -> Option<Chunk>{
+    match seed {
+        0 => match pos {
+            [0, 0, 0] => Some(get_sun_chunk(seed, pos)),
+            _ => None,
+        },
+        _ => match pos {
+            [0, 0, 0] => Some(get_dirt_chunk(seed, pos)),
+            _ => None,
+        },
+    }
+}
+
+fn get_body_chunks(seed: u32) -> Vec<Chunk> {
+    let mut chunks = vec![];
+    let mut tocheck = vec![[0, 0, 0]];
+
+    while tocheck.len() > 0 {
+        let pos = tocheck.pop().unwrap();
+        let thischunk = get_chunk(seed, pos);
+        if thischunk.is_none() || chunks.contains(thischunk.as_ref().unwrap()) {
+            continue;
+        }
+        chunks.push(thischunk.unwrap());
+        println!("Adding chunk for seed {seed} at position {:?}", pos);
+        
+        let [ci, cj, ck] = pos;
+        tocheck.push([ci - 1, cj, ck]);
+        tocheck.push([ci + 1, cj, ck]);
+        tocheck.push([ci, cj - 1, ck]);
+        tocheck.push([ci, cj + 1, ck]);
+        tocheck.push([ci, cj, ck - 1]);
+        tocheck.push([ci, cj, ck + 1]);
+    }
+
+    chunks
+}
+
+async fn get_body(req: Request<()>) -> tide::Result {
+    let seed: u32 = req.param("seed")?.parse()?;
+    let chunks = get_body_chunks(seed);
+    let response = Response::builder(200)
+        .body(serde_json::to_string(&chunks)?)
+        .content_type("application/json")
+        .header("access-control-allow-origin", "*")
+        .build();
+    Ok(response)
+}
+
+// TODO
+// ----
+// [ ] serve chunks
+// [ ] universe simulation?
+// [ ] websocket with client updates
+
+async fn get_system(_req: Request<()>) -> tide::Result {
+//    let seed: i32 = req.param("seed")?.parse()?;
+    let response = Response::builder(200)
+        .content_type("application/json")
+        .header("access-control-allow-origin", "*")
+        .body(serde_json::to_string(&SystemBody
+        {
+            name: "Tat".to_string(),
+            seed: 0,
+
+            mass: 1000.0,
+            spin: [0.0, 0.0, 0.2],
+
+    //        geometry: getBodyGeometry(0),
+            glow_color: [0.5, 0.5, 0.46],
+
+            children: Vec::from([
+                SystemBody {
+                    name: "Quicksilver".to_string(),
+                    seed: 1336,
+
+                    mass: 0.1,
+                    spin: [0.0, 0.0, 0.05],
+
+    //                geometry: makeCube([0, 4]),
+
+                    orbit: KeplerOrbit {
+                        excentricity: 0.0,
+                        semimajor_axis: 200.0,
+                        inclination: 0.8,
+                        ascending_node_longitude: 0.0,
+                        periapsis_argument: 0.0,
+                        t0: 0.0,
+                    },
+
+                    ..Default::default()
+                },
+                SystemBody {
+                    name: "Satourne".to_string(),
+                    seed: 1338,
+
+                    mass: 0.1,
+                    spin: [0.0, 0.5, 0.0],
+
+    //                geometry: makeCube([0, 5]),
+
+                    orbit: KeplerOrbit {
+                        excentricity: 0.0,
+                        semimajor_axis: 900.0,
+                        inclination: 0.0,
+                        ascending_node_longitude: 0.0,
+                        periapsis_argument: 0.0,
+                        t0: 0.0,
+                    },
+
+                    children: Vec::from([
+                        SystemBody {
+                            name: "Kyoujin".to_string(),
+                            seed: 13381,
+
+                            mass: 0.01,
+                            spin: [0.0, 0.0, 0.05],
+
+    //                        geometry: makeCube([0, 6]),
+
+                            orbit: KeplerOrbit {
+                                excentricity: 0.0,
+                                semimajor_axis: 20.0,
+                                inclination: (PI / 2.0) as f32,
+                                ascending_node_longitude: 0.0,
+                                periapsis_argument: 0.0,
+                                t0: 0.0,
+                            },
+
+                            ..Default::default()
+                        },
+                    ]),
+
+                    ..Default::default()
+                },
+                SystemBody {
+                    name: "Tataooine".to_string(),
+                    seed: 1337,
+
+                    mass: 50.0,
+                    spin: [0.0, 0.0, 0.05],
+
+    //                geometry: getBodyGeometry(1337),
+
+                    orbit: KeplerOrbit {
+                        excentricity: 0.3,
+                        semimajor_axis: 500.0,
+                        inclination: 0.0,
+                        ascending_node_longitude: 0.0,
+                        periapsis_argument: 0.0,
+                        t0: 0.0,
+                    },
+
+                    children: Vec::from([
+                        SystemBody {
+                            name: "Mun".to_string(),
+                            seed: 13371,
+
+                            mass: 0.01,
+                            spin: [0.0, 0.0, 0.05],
+
+    //                        geometry: makeCube([0, 7]),
+
+                            orbit: KeplerOrbit {
+                                excentricity: 0.0,
+                                semimajor_axis: 50.0,
+                                inclination: (PI / 2.0) as f32,
+                                ascending_node_longitude: 0.0,
+                                periapsis_argument: 0.0,
+                                t0: 0.0,
+                            },
+
+                            ..Default::default()
+                        },
+                    ]),
+
+                    ..Default::default()
+                },
+            ]),
+
+            ..Default::default()
+        })?)
+        .build();
+    Ok(response)
+}