skycraft: smoother ship controls

skycraft/chunk.ts

@@ -138,7 +138,7 @@ function faceTexture(type: number, dir: direction) {
 function* makeChunkFaces(chunk) {
     const cs = CHUNKSIZE;
 
-    function faceCenter(pos: linalg.vec3, dir: direction) {
+    function faceCenter(pos: linalg.Vec3, dir: direction) {
         switch (dir) {
             case '-x': return [pos[0] - 0.5, pos[1], pos[2]];
             case '+x': return [pos[0] + 0.5, pos[1], pos[2]];

skycraft/draw.ts

@@ -259,7 +259,7 @@ function getObjects(context, body, parentPosition = undefined) {
     } else {
         const shipOrientation = [
             se3.rotationOnly(player.tf),
-            se3.rotationOnly(context.camera.tf),
+            //se3.rotationOnly(context.camera.tf),
             se3.rotxyz(-Math.PI / 2, Math.PI / 2, Math.PI / 2),
         ].reduce(se3.product);
         const shipPos = player.position;
@@ -280,7 +280,7 @@ function getObjects(context, body, parentPosition = undefined) {
     return objects;
 }
 
-function sunDirection(position: linalg.vec3) {
+function sunDirection(position: linalg.Vec3) {
     return linalg.scale(position, 1/linalg.norm(position));
 }
 

skycraft/index.ts

@@ -6,6 +6,7 @@ import * as se3 from '../se3';
 import { computeOrbit, findSoi, getCartesianState, updateBodyPhysics } from './orbit';
 import { getBodyGeometry } from './chunk';
 import { draw, getOrbitDrawContext, initWorldGl } from './draw';
+import * as quat from './quat';
 
 const kEpoch = 0;
 
@@ -175,12 +176,13 @@ function initUiListeners(canvas: HTMLCanvasElement, context) {
             }
         };
         const moveListener = e => {
-            context.camera.orientation[0] -= e.movementY / 500;
-            context.camera.orientation[1] -= e.movementX / 500;
-            context.camera.tf = se3.product(
-                se3.roty(context.camera.orientation[1]),
-                se3.rotx(context.camera.orientation[0]),
-            );
+//            context.camera.orientation[0] -= e.movementY / 500;
+//            context.camera.orientation[1] -= e.movementX / 500;
+            context.camera.tf =[
+                context.camera.tf,
+                se3.roty(-e.movementX / 500),
+                se3.rotx(-e.movementY / 500),
+            ].reduce(se3.product);
         };
         const changeListener = () => {
             if (document.pointerLockElement === canvas) {
@@ -224,11 +226,8 @@ function handleInput(context) {
         if (context.flying) {
             context.player.tf = [
                 context.player.tf,
-                context.camera.tf,
                 se3.translation(...dir),
             ].reduce(se3.product);
-            context.camera.tf = se3.identity();
-            context.camera.orientation = [0, 0, 0];
         } else {
             const vel = context.player.velocity;
             const dv = linalg.scale(se3.apply(tf, dir), 1/dir[3]);
@@ -258,6 +257,17 @@ function handleInput(context) {
     });
 }
 
+function slerp(current: linalg.Mat4, target: linalg.Mat4, maxVelocity: number) : linalg.Mat4 {
+    const q0 = quat.mat2Quat(current);
+    const q1 = quat.mat2Quat(target);
+
+    const dq = quat.diff(q1, q0);
+    const maxt = maxVelocity / quat.norm(dq);
+
+    const q = quat.normalize(quat.add(q0, quat.scale(dq, Math.min(1, maxt))));
+    return quat.quat2Mat(q);
+}
+
 function updatePhysics(time: number, context) {
     const {player} = context;
     const dt = time - (context.lastTime || 0);
@@ -267,6 +277,10 @@ function updatePhysics(time: number, context) {
 
     updateBodyPhysics(time, context.universe);
 
+    const dr = slerp(se3.identity(), context.camera.tf, 0.007);
+    player.tf = se3.product(player.tf, dr);
+    context.camera.tf = se3.product(context.camera.tf, se3.inverse(dr));
+
     if (!context.flying) {
         if (context.orbit === undefined) {
             const newPos = linalg.add(player.position, linalg.scale(player.velocity, dt));
@@ -293,7 +307,6 @@ function updatePhysics(time: number, context) {
             }
         }
     }
-
 }
 
 function updateGeometry(context, timeout_ms = 10) {
@@ -304,8 +317,6 @@ function tick(time: number, context) {
     const simTime = time * 0.001 + context.timeOffset;
     updatePhysics(simTime, context);
 
-    const campos = context.player.position;
-
     // world generation / geometry update
     {
         // frame time is typically 16.7ms, so this may lag a bit

skycraft/linalg.ts

@@ -1,6 +1,7 @@
-export type vec3 = [number, number, number];
+export type Vec3 = [number, number, number];
+export type Mat4 = number[];
 
-export function cross(a: vec3, b: vec3) : vec3 {
+export function cross(a: Vec3, b: Vec3) : Vec3 {
     return [
         a[1] * b[2] - a[2] * b[1],
         a[2] * b[0] - a[0] * b[2],
@@ -8,7 +9,7 @@ export function cross(a: vec3, b: vec3) : vec3 {
     ];
 }
 
-export function diff(a: vec3, b: vec3) : vec3 {
+export function diff(a: Vec3, b: Vec3) : Vec3 {
     return [
         a[0] - b[0],
         a[1] - b[1],
@@ -16,7 +17,7 @@ export function diff(a: vec3, b: vec3) : vec3 {
     ];
 }
 
-export function add(a: vec3, b: vec3) : vec3 {
+export function add(a: Vec3, b: Vec3) : Vec3 {
     return [
         a[0] + b[0],
         a[1] + b[1],
@@ -24,14 +25,14 @@ export function add(a: vec3, b: vec3) : vec3 {
     ];
 }
 
-export function norm(a: vec3) : number {
+export function norm(a: Vec3) : number {
     return Math.sqrt(a[0] ** 2 + a[1] ** 2 + a[2] ** 2);
 }
 
-export function dot(a: vec3, b: vec3) : number {
+export function dot(a: Vec3, b: Vec3) : number {
     return a[0] * b[0] + a[1] * b[1] + a[2] * b[2];
 }
-export function scale(a: vec3, s: number) : vec3 {
+export function scale(a: Vec3, s: number) : Vec3 {
     return [
         a[0] * s,
         a[1] * s,

skycraft/orbit.ts

@@ -1,9 +1,6 @@
 import * as se3 from '../se3';
 import * as linalg from './linalg';
-import {vec3} from './linalg';
-
-type mat4 = number[];
-type vec4 = [number, number, number, number];
+import {Vec3} from './linalg';
 
 interface Orbit {
     excentricity: number,
@@ -18,13 +15,13 @@ interface Orbit {
 }
 
 interface Body {
-    position: vec3,
-    velocity: vec3,
-    orientation: vec4,
+    position: Vec3,
+    velocity: Vec3,
+    orientation: Vec3,
     children: Body[],
     mass: number,
     orbit: Orbit,
-    spin: vec3,
+    spin: Vec3,
     name: string,
 }
 

skycraft/quat.ts

@@ -0,0 +1,124 @@
+import {Mat4} from './linalg';
+import * as se3 from '../se3';
+
+export interface Quat {
+    x: number,
+    y: number,
+    z: number,
+    w: number,
+}
+
+export function mat2Quat(m: Mat4) : Quat {
+    const q : Quat = {};
+
+    if (m[0 * 4 + 0] + m[1 * 4 + 1] + m[2 * 4 + 2] > 0.0) {
+        const t = + m[0 * 4 + 0] + m[1 * 4 + 1] + m[2 * 4 + 2] + 1.0;
+        const s = 0.5 / Math.sqrt(t);
+        q.w = s * t;
+        q.z = (m[1 * 4 + 0] - m[0 * 4 + 1]) * s;
+        q.y = (m[0 * 4 + 2] - m[2 * 4 + 0]) * s;
+        q.x = (m[2 * 4 + 1] - m[1 * 4 + 2]) * s;
+    } else if (m[0 * 4 + 0] > m[1 * 4 + 1] && m[0 * 4 + 0] > m[2 * 4 + 2]) {
+        const t = + m[0 * 4 + 0] - m[1 * 4 + 1] - m[2 * 4 + 2] + 1.0;
+        const s = 0.5 / Math.sqrt(t);
+        q.x = s * t;
+        q.y = (m[1 * 4 + 0] + m[0 * 4 + 1]) * s;
+        q.z = (m[0 * 4 + 2] + m[2 * 4 + 0]) * s;
+        q.w = (m[2 * 4 + 1] - m[1 * 4 + 2]) * s;
+    } else if (m[1 * 4 + 1] > m[2 * 4 + 2]) {
+        const t = - m[0 * 4 + 0] + m[1 * 4 + 1] - m[2 * 4 + 2] + 1.0;
+        const s = 0.5 / Math.sqrt(t);
+        q.y = s * t;
+        q.x = (m[1 * 4 + 0] + m[0 * 4 + 1]) * s;
+        q.w = (m[0 * 4 + 2] - m[2 * 4 + 0]) * s;
+        q.z = (m[2 * 4 + 1] + m[1 * 4 + 2]) * s;
+    } else {
+        const t = - m[0 * 4 + 0] - m[1 * 4 + 1] + m[2 * 4 + 2] + 1.0;
+        const s = 0.5 / Math.sqrt(t);
+        q.z = s * t;
+        q.w = (m[1 * 4 + 0] - m[0 * 4 + 1]) * s;
+        q.x = (m[0 * 4 + 2] + m[2 * 4 + 0]) * s;
+        q.y = (m[2 * 4 + 1] + m[1 * 4 + 2]) * s;
+    }
+
+    return q;
+}
+
+export function quat2Mat(q: Quat): Mat4 {
+    const m: Mat4 = se3.identity();
+
+    const x2 = q.x + q.x;
+    const y2 = q.y + q.y;
+    const z2 = q.z + q.z;
+    {
+        const xx2 = q.x * x2;
+        const yy2 = q.y * y2;
+        const zz2 = q.z * z2;
+        m[0 * 4 + 0] = 1.0 - yy2 - zz2;
+        m[1 * 4 + 1] = 1.0 - xx2 - zz2;
+        m[2 * 4 + 2] = 1.0 - xx2 - yy2;
+    }
+    {
+        const yz2 = q.y * z2;
+        const wx2 = q.w * x2;
+        m[1 * 4 + 2] = yz2 - wx2;
+        m[2 * 4 + 1] = yz2 + wx2;
+    }
+    {
+        const xy2 = q.x * y2;
+        const wz2 = q.w * z2;
+        m[0 * 4 + 1] = xy2 - wz2;
+        m[1 * 4 + 0] = xy2 + wz2;
+    }
+    {
+        const xz2 = q.x * z2;
+        const wy2 = q.w * y2;
+        m[2 * 4 + 0] = xz2 - wy2;
+        m[0 * 4 + 2] = xz2 + wy2;
+    }
+
+    return m;
+}
+
+export function normalize(q: Quat) : Quat {
+    const n = norm(q);
+    if (n < 1e-10) {
+        return {x: 0, y: 0, z: 0, w: 1};
+    }
+    return {
+        x: q.x / n,
+        y: q.y / n,
+        z: q.z / n,
+        w: q.w / n,
+    };
+}
+
+export function diff(q0: Quat, q1: Quat) {
+    return {
+        x: q0.x - q1.x,
+        y: q0.y - q1.y,
+        z: q0.z - q1.z,
+        w: q0.w - q1.w,
+    };
+}
+export function norm(q: Quat) {
+    return Math.sqrt(q.x**2 + q.y**2 + q.z**2 + q.w**2);
+}
+
+export function add(q0: Quat, q1: Quat) {
+    return {
+        x: q0.x + q1.x,
+        y: q0.y + q1.y,
+        z: q0.z + q1.z,
+        w: q0.w + q1.w,
+    };
+}
+
+export function scale(q: Quat, a: number): Quat {
+    return {
+        x: a * q.x,
+        y: a * q.y,
+        z: a * q.z,
+        w: a * q.w,
+    };
+}