feat(editor): LaserPointer based freedraw (#11507)

Introduces constant width freedraw mode, keeping the original variable mode as default.

---------

Signed-off-by: Mark Tolmacs <mark@lazycat.hu>
Co-authored-by: dwelle <5153846+dwelle@users.noreply.github.com>
This commit is contained in:
Márk Tolmács
2026-06-24 09:16:22 +02:00
committed by GitHub
parent 0642e72cfa
commit cd514d72d6
48 changed files with 1635 additions and 225 deletions
+2
View File
@@ -0,0 +1,2 @@
export * from "./state";
export type { Point } from "./math";
+105
View File
@@ -0,0 +1,105 @@
export type Point = [x: number, y: number, r: number];
export function add([ax, ay, ar]: Point, [bx, by, br]: Point): Point {
return [ax + bx, ay + by, ar + br];
}
export function sub([ax, ay, ar]: Point, [bx, by, br]: Point): Point {
return [ax - bx, ay - by, ar - br];
}
export function smul([x, y, r]: Point, s: number): Point {
return [x * s, y * s, r * s];
}
export function norm([x, y, r]: Point): Point {
return [x / Math.sqrt(x ** 2 + y ** 2), y / Math.sqrt(x ** 2 + y ** 2), r];
}
export function rot([x, y, r]: Point, rad: number): Point {
return [
Math.cos(rad) * x - Math.sin(rad) * y,
Math.sin(rad) * x + Math.cos(rad) * y,
r,
];
}
export function plerp(a: Point, b: Point, t: number): Point {
return add(a, smul(sub(b, a), t));
}
export function lerp(a: number, b: number, t: number): number {
return a + (b - a) * t;
}
export function angle(p: Point, p1: Point, p2: Point) {
return (
Math.atan2(p2[1] - p[1], p2[0] - p[0]) -
Math.atan2(p1[1] - p[1], p1[0] - p[0])
);
}
export function normAngle(a: number) {
return Math.atan2(Math.sin(a), Math.cos(a));
}
export function mag([x, y]: Point) {
return Math.sqrt(x ** 2 + y ** 2);
}
export function dist([ax, ay]: Point, [bx, by]: Point): number {
return Math.sqrt((bx - ax) ** 2 + (by - ay) ** 2);
}
export function getCircleAndPerpendicularLineIntersectionsAtPoint(
point: Point,
direction: Point,
radius: number,
): [Point, Point] {
return [
add(point, smul(norm(rot(direction, Math.PI / 2)), radius)),
add(point, smul(norm(rot(direction, -Math.PI / 2)), radius)),
];
}
export function runLength(ps: Point[]): number {
if (ps.length < 2) {
return 0;
}
let len = 0;
for (let i = 1; i <= ps.length - 1; i++) {
len += dist(ps[i - 1], ps[i]);
}
len += dist(ps[ps.length - 2], ps[ps.length - 1]);
return len;
}
export const clamp = (v: number, min: number, max: number) =>
Math.max(min, Math.min(max, v));
export function distancePointToSegment(p3: Point, p1: Point, p2: Point) {
const sMag = dist(p1, p2);
if (sMag === 0) {
return dist(p3, p1);
}
const u = clamp(
((p3[0] - p1[0]) * (p2[0] - p1[0]) + (p3[1] - p1[1]) * (p2[1] - p1[1])) /
sMag ** 2,
0,
1,
);
const pi: Point = [
p1[0] + u * (p2[0] - p1[0]),
p1[1] + u * (p2[1] - p1[1]),
p3[2],
];
return dist(pi, p3);
}
+42
View File
@@ -0,0 +1,42 @@
import { type Point, distancePointToSegment } from "./math";
export function douglasPeucker(points: Point[], epsilon: number): Point[] {
if (epsilon === 0) {
return points;
}
if (points.length <= 2) {
return points;
}
const first = points[0];
const last = points[points.length - 1];
const [maxDistance, maxIndex] = points.reduce(
([maxDistance, maxIndex], point, index) => {
const distance = distancePointToSegment(point, first, last);
return distance > maxDistance
? [distance, index]
: [maxDistance, maxIndex];
},
[0, -1],
);
if (maxDistance >= epsilon) {
const maxIndexPoint = points[maxIndex];
return [
...douglasPeucker(
[first, ...points.slice(1, maxIndex), maxIndexPoint],
epsilon,
).slice(0, -1),
maxIndexPoint,
...douglasPeucker(
[maxIndexPoint, ...points.slice(maxIndex, -1), last],
epsilon,
).slice(1),
];
}
return [first, last];
}
+377
View File
@@ -0,0 +1,377 @@
import * as m from "./math";
import { douglasPeucker } from "./simplify";
import type { Point } from "./math";
export type SizeMappingDetails = {
pressure: number;
runningLength: number;
currentIndex: number;
totalLength: number;
};
export type LaserPointerOptions = {
size: number;
streamline: number;
simplify: number;
simplifyPhase: "tail" | "output" | "input";
keepHead: boolean;
sizeMapping: (details: SizeMappingDetails) => number;
};
export class LaserPointer {
static defaults: LaserPointerOptions = {
size: 2,
streamline: 0.45,
simplify: 0.1,
simplifyPhase: "output",
keepHead: false,
sizeMapping: () => 1,
};
static constants = {
cornerDetectionMaxAngle: 75,
cornerDetectionVariance: (s: number) => (s > 35 ? 0.5 : 1),
maxTailLength: 50,
};
options: LaserPointerOptions;
constructor(options: Partial<LaserPointerOptions>) {
this.options = Object.assign({}, LaserPointer.defaults, options);
}
originalPoints: Point[] = [];
private stablePoints: Point[] = [];
private tailPoints: Point[] = [];
private isFresh = true;
private get lastPoint(): Point {
return (
this.tailPoints[this.tailPoints.length - 1] ??
this.stablePoints[this.stablePoints.length - 1]
);
}
addPoint(point: Point) {
const lastPoint = this.originalPoints[this.originalPoints.length - 1];
if (lastPoint && lastPoint[0] === point[0] && lastPoint[1] === point[1]) {
return;
}
this.originalPoints.push(point);
if (this.isFresh) {
this.isFresh = false;
this.stablePoints.push(point);
return;
}
if (this.options.streamline > 0) {
point = m.plerp(this.lastPoint, point, 1 - this.options.streamline);
}
this.tailPoints.push(point);
if (m.runLength(this.tailPoints) > LaserPointer.constants.maxTailLength) {
this.stabilizeTail();
}
}
close() {
this.stabilizeTail();
}
stabilizeTail() {
if (this.options.simplify > 0 && this.options.simplifyPhase === "tail") {
throw new Error("Not implemented yet");
} else {
this.stablePoints.push(...this.tailPoints);
this.tailPoints = [];
}
}
private getSize(
sizeOverride: number | undefined,
pressure: number,
index: number,
totalLength: number,
runningLength: number,
) {
return (
(sizeOverride ?? this.options.size) *
this.options.sizeMapping({
pressure,
runningLength,
currentIndex: index,
totalLength,
})
);
}
getStrokeOutline(sizeOverride?: number | undefined): Point[] {
if (this.isFresh) {
return [];
}
let points = [...this.stablePoints, ...this.tailPoints];
if (this.options.simplify > 0 && this.options.simplifyPhase === "input") {
points = douglasPeucker(points, this.options.simplify);
}
const len = points.length;
if (len === 0) {
return [];
}
if (len === 1) {
const c = points[0];
const size = this.getSize(sizeOverride, c[2], 0, len, 0);
if (size < 0.5) {
return [];
}
const ps: Point[] = [];
for (let theta = 0; theta <= Math.PI * 2; theta += Math.PI / 16) {
ps.push(m.add(c, m.smul(m.rot([1, 0, 0] as Point, theta), size)));
}
ps.push(
m.add(
c,
m.smul(
[1, 0, 0] as Point,
this.getSize(sizeOverride, c[2], 0, len, 0),
),
),
);
return ps;
}
if (len === 2) {
const c = points[0];
const n = points[1];
const cSize = this.getSize(sizeOverride, c[2], 0, len, 0);
const nSize = this.getSize(sizeOverride, n[2], 0, len, 0);
if (cSize < 0.5 || nSize < 0.5) {
return [];
}
const ps: Point[] = [];
const pAngle = m.angle(c, [c[0], c[1] - 100, c[2]] as Point, n);
for (
let theta = pAngle;
theta <= Math.PI + pAngle;
theta += Math.PI / 16
) {
ps.push(m.add(c, m.smul(m.rot([1, 0, 0] as Point, theta), cSize)));
}
for (
let theta = Math.PI + pAngle;
theta <= Math.PI * 2 + pAngle;
theta += Math.PI / 16
) {
ps.push(m.add(n, m.smul(m.rot([1, 0, 0] as Point, theta), nSize)));
}
ps.push(ps[0]);
return ps;
}
const forwardPoints: Point[] = [];
const backwardPoints: Point[] = [];
let speed = 0;
let prevSpeed = 0;
let visibleStartIndex = 0;
let runningLength = 0;
for (let i = 1; i < len - 1; i++) {
const p = points[i - 1];
const c = points[i];
const n = points[i + 1];
const pressure = c[2];
const d = m.dist(p, c);
runningLength += d;
speed = prevSpeed + (d - prevSpeed) * 0.2;
const cSize = this.getSize(sizeOverride, pressure, i, len, runningLength);
if (cSize === 0) {
visibleStartIndex = i + 1;
continue;
}
const dirPC = m.norm(m.sub(p, c));
const dirNC = m.norm(m.sub(n, c));
const p1dirPC = m.rot(dirPC, Math.PI / 2);
const p2dirPC = m.rot(dirPC, -Math.PI / 2);
const p1dirNC = m.rot(dirNC, Math.PI / 2);
const p2dirNC = m.rot(dirNC, -Math.PI / 2);
const p1PC = m.add(c, m.smul(p1dirPC, cSize));
const p2PC = m.add(c, m.smul(p2dirPC, cSize));
const p1NC = m.add(c, m.smul(p1dirNC, cSize));
const p2NC = m.add(c, m.smul(p2dirNC, cSize));
const ftdir = m.add(p1dirPC, p2dirNC);
const btdir = m.add(p2dirPC, p1dirNC);
const paPC = m.add(
c,
m.smul(m.mag(ftdir) === 0 ? dirPC : m.norm(ftdir), cSize),
);
const paNC = m.add(
c,
m.smul(m.mag(btdir) === 0 ? dirNC : m.norm(btdir), cSize),
);
const cAngle = m.normAngle(m.angle(c, p, n));
const D_ANGLE =
(LaserPointer.constants.cornerDetectionMaxAngle / 180) *
Math.PI *
LaserPointer.constants.cornerDetectionVariance(speed);
if (Math.abs(cAngle) < D_ANGLE) {
const tAngle = Math.abs(m.normAngle(Math.PI - cAngle)); // turn angle
if (tAngle === 0) {
continue;
}
if (cAngle < 0) {
backwardPoints.push(p2PC, paNC);
for (let theta = 0; theta <= tAngle; theta += tAngle / 4) {
forwardPoints.push(m.add(c, m.rot(m.smul(p1dirPC, cSize), theta)));
}
for (let theta = tAngle; theta >= 0; theta -= tAngle / 4) {
backwardPoints.push(m.add(c, m.rot(m.smul(p1dirPC, cSize), theta)));
}
backwardPoints.push(paNC, p1NC);
} else {
forwardPoints.push(p1PC, paPC);
for (let theta = 0; theta <= tAngle; theta += tAngle / 4) {
backwardPoints.push(
m.add(c, m.rot(m.smul(p1dirPC, -cSize), -theta)),
);
}
for (let theta = tAngle; theta >= 0; theta -= tAngle / 4) {
forwardPoints.push(
m.add(c, m.rot(m.smul(p1dirPC, -cSize), -theta)),
);
}
forwardPoints.push(paPC, p2NC);
}
} else {
forwardPoints.push(paPC);
backwardPoints.push(paNC);
}
prevSpeed = speed;
}
if (visibleStartIndex >= len - 2) {
if (this.options.keepHead) {
const c = points[len - 1];
const ps: Point[] = [];
for (let theta = 0; theta <= Math.PI * 2; theta += Math.PI / 16) {
ps.push(
m.add(
c,
m.smul(m.rot([1, 0, 0] as Point, theta), this.options.size),
),
);
}
ps.push(m.add(c, m.smul([1, 0, 0] as Point, this.options.size)));
return ps;
}
return [];
}
const first = points[visibleStartIndex];
const second = points[visibleStartIndex + 1];
const penultimate = points[len - 2];
const ultimate = points[len - 1];
const dirFS = m.norm(m.sub(second, first));
const dirPU = m.norm(m.sub(penultimate, ultimate));
const ppdirFS = m.rot(dirFS, -Math.PI / 2);
const ppdirPU = m.rot(dirPU, Math.PI / 2);
const startCapSize = this.getSize(sizeOverride, first[2], 0, len, 0);
const startCap: Point[] = [];
const endCapSize = this.options.keepHead
? this.options.size
: this.getSize(sizeOverride, penultimate[2], len - 2, len, runningLength);
const endCap: Point[] = [];
// Lowered threshold to 0.1,
// ensuring virtually all strokes get proper rounded caps for visual consistency.
if (startCapSize > 0.1) {
for (let theta = 0; theta <= Math.PI; theta += Math.PI / 16) {
startCap.unshift(
m.add(first, m.rot(m.smul(ppdirFS, startCapSize), -theta)),
);
}
startCap.unshift(m.add(first, m.smul(ppdirFS, -startCapSize)));
} else {
startCap.push(first);
}
for (let theta = 0; theta <= Math.PI * 3; theta += Math.PI / 16) {
endCap.push(m.add(ultimate, m.rot(m.smul(ppdirPU, -endCapSize), -theta)));
}
const strokeOutline = [
...startCap,
...forwardPoints,
...endCap.reverse(),
...backwardPoints.reverse(),
];
if (startCap.length > 0) {
strokeOutline.push(startCap[0]);
}
if (this.options.simplify > 0 && this.options.simplifyPhase === "output") {
return douglasPeucker(strokeOutline, this.options.simplify);
}
return strokeOutline;
}
}