mikael-lovqvists-claude-agent
9600a2bc2a
Interactive WebGL Goldberg polyhedron viewer and painter with PBR shading, adjustable environment lighting, paint tools (pen, brush, circle, fill, line, pick), undo/redo, colour palettes, and mesh relaxation. Added to the standalone experiments index. Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
46 lines
1.4 KiB
JavaScript
46 lines
1.4 KiB
JavaScript
import { quat_from_axis_angle, quat_mul } from './math.mjs';
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export class Spin_State {
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constructor() {
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this.active = false;
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this.axis = [0, 1, 0];
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this.target = [0, 1, 0];
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this.speed = 0.00035; // radians per millisecond
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this.last_t = null;
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}
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_random_unit() {
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let x, y, z, r;
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do {
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x = Math.random()*2-1; y = Math.random()*2-1; z = Math.random()*2-1;
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r = Math.sqrt(x*x+y*y+z*z);
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} while (r < 0.001 || r > 1);
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return [x/r, y/r, z/r];
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}
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_new_target() { this.target = this._random_unit(); }
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// Advance spin by dt ms. Returns updated rot_quat (unchanged if not active).
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tick(dt, rot_quat) {
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if (!this.active) { return rot_quat; }
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if (this.last_t === null) { this._new_target(); return rot_quat; }
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const drift = Math.min(1, dt * 0.0003);
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const [ax,ay,az] = this.axis;
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const [tx,ty,tz] = this.target;
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let mx = ax + (tx-ax)*drift, my = ay + (ty-ay)*drift, mz = az + (tz-az)*drift;
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const mr = Math.sqrt(mx*mx+my*my+mz*mz);
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this.axis = [mx/mr, my/mr, mz/mr];
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const dot = this.axis[0]*this.target[0] + this.axis[1]*this.target[1] + this.axis[2]*this.target[2];
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if (dot > 0.999) { this._new_target(); }
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const angle = this.speed * dt;
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const [rx,ry,rz] = this.axis;
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return quat_mul(quat_from_axis_angle(rx, ry, rz, angle), rot_quat);
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}
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start() { this.active = true; this.last_t = null; }
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stop() { this.active = false; this.last_t = null; }
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}
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