feat: Precise hit testing (#9488)

This commit is contained in:
Márk Tolmács
2025-06-07 12:56:32 +02:00
committed by GitHub
parent 56c05b3099
commit ca1a4f25e7
52 changed files with 2223 additions and 2718 deletions

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@ -1,135 +0,0 @@
import {
lineSegment,
pointFrom,
polygonIncludesPoint,
pointOnLineSegment,
pointOnPolygon,
polygonFromPoints,
type GlobalPoint,
type LocalPoint,
type Polygon,
} from "@excalidraw/math";
import type { Curve } from "@excalidraw/math";
import { pointInEllipse, pointOnEllipse } from "./shape";
import type { Polycurve, Polyline, GeometricShape } from "./shape";
// check if the given point is considered on the given shape's border
export const isPointOnShape = <Point extends GlobalPoint | LocalPoint>(
point: Point,
shape: GeometricShape<Point>,
tolerance = 0,
) => {
// get the distance from the given point to the given element
// check if the distance is within the given epsilon range
switch (shape.type) {
case "polygon":
return pointOnPolygon(point, shape.data, tolerance);
case "ellipse":
return pointOnEllipse(point, shape.data, tolerance);
case "line":
return pointOnLineSegment(point, shape.data, tolerance);
case "polyline":
return pointOnPolyline(point, shape.data, tolerance);
case "curve":
return pointOnCurve(point, shape.data, tolerance);
case "polycurve":
return pointOnPolycurve(point, shape.data, tolerance);
default:
throw Error(`shape ${shape} is not implemented`);
}
};
// check if the given point is considered inside the element's border
export const isPointInShape = <Point extends GlobalPoint | LocalPoint>(
point: Point,
shape: GeometricShape<Point>,
) => {
switch (shape.type) {
case "polygon":
return polygonIncludesPoint(point, shape.data);
case "line":
return false;
case "curve":
return false;
case "ellipse":
return pointInEllipse(point, shape.data);
case "polyline": {
const polygon = polygonFromPoints(shape.data.flat());
return polygonIncludesPoint(point, polygon);
}
case "polycurve": {
return false;
}
default:
throw Error(`shape ${shape} is not implemented`);
}
};
// check if the given element is in the given bounds
export const isPointInBounds = <Point extends GlobalPoint | LocalPoint>(
point: Point,
bounds: Polygon<Point>,
) => {
return polygonIncludesPoint(point, bounds);
};
const pointOnPolycurve = <Point extends LocalPoint | GlobalPoint>(
point: Point,
polycurve: Polycurve<Point>,
tolerance: number,
) => {
return polycurve.some((curve) => pointOnCurve(point, curve, tolerance));
};
const cubicBezierEquation = <Point extends LocalPoint | GlobalPoint>(
curve: Curve<Point>,
) => {
const [p0, p1, p2, p3] = curve;
// B(t) = p0 * (1-t)^3 + 3p1 * t * (1-t)^2 + 3p2 * t^2 * (1-t) + p3 * t^3
return (t: number, idx: number) =>
Math.pow(1 - t, 3) * p3[idx] +
3 * t * Math.pow(1 - t, 2) * p2[idx] +
3 * Math.pow(t, 2) * (1 - t) * p1[idx] +
p0[idx] * Math.pow(t, 3);
};
const polyLineFromCurve = <Point extends LocalPoint | GlobalPoint>(
curve: Curve<Point>,
segments = 10,
): Polyline<Point> => {
const equation = cubicBezierEquation(curve);
let startingPoint = [equation(0, 0), equation(0, 1)] as Point;
const lineSegments: Polyline<Point> = [];
let t = 0;
const increment = 1 / segments;
for (let i = 0; i < segments; i++) {
t += increment;
if (t <= 1) {
const nextPoint: Point = pointFrom(equation(t, 0), equation(t, 1));
lineSegments.push(lineSegment(startingPoint, nextPoint));
startingPoint = nextPoint;
}
}
return lineSegments;
};
export const pointOnCurve = <Point extends LocalPoint | GlobalPoint>(
point: Point,
curve: Curve<Point>,
threshold: number,
) => {
return pointOnPolyline(point, polyLineFromCurve(curve), threshold);
};
export const pointOnPolyline = <Point extends LocalPoint | GlobalPoint>(
point: Point,
polyline: Polyline<Point>,
threshold = 10e-5,
) => {
return polyline.some((line) => pointOnLineSegment(point, line, threshold));
};

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@ -24,7 +24,7 @@ exports[`exportToSvg > with default arguments 1`] = `
"currentItemFontSize": 20,
"currentItemOpacity": 100,
"currentItemRoughness": 1,
"currentItemRoundness": "round",
"currentItemRoundness": "sharp",
"currentItemStartArrowhead": null,
"currentItemStrokeColor": "#1e1e1e",
"currentItemStrokeStyle": "solid",

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@ -1,90 +0,0 @@
import {
curve,
degreesToRadians,
lineSegment,
lineSegmentRotate,
pointFrom,
pointRotateDegs,
} from "@excalidraw/math";
import type { Curve, Degrees, GlobalPoint } from "@excalidraw/math";
import { pointOnCurve, pointOnPolyline } from "../src/collision";
import type { Polyline } from "../src/shape";
describe("point and curve", () => {
const c: Curve<GlobalPoint> = curve(
pointFrom(1.4, 1.65),
pointFrom(1.9, 7.9),
pointFrom(5.9, 1.65),
pointFrom(6.44, 4.84),
);
it("point on curve", () => {
expect(pointOnCurve(c[0], c, 10e-5)).toBe(true);
expect(pointOnCurve(c[3], c, 10e-5)).toBe(true);
expect(pointOnCurve(pointFrom(2, 4), c, 0.1)).toBe(true);
expect(pointOnCurve(pointFrom(4, 4.4), c, 0.1)).toBe(true);
expect(pointOnCurve(pointFrom(5.6, 3.85), c, 0.1)).toBe(true);
expect(pointOnCurve(pointFrom(5.6, 4), c, 0.1)).toBe(false);
expect(pointOnCurve(c[1], c, 0.1)).toBe(false);
expect(pointOnCurve(c[2], c, 0.1)).toBe(false);
});
});
describe("point and polylines", () => {
const polyline: Polyline<GlobalPoint> = [
lineSegment(pointFrom(1, 0), pointFrom(1, 2)),
lineSegment(pointFrom(1, 2), pointFrom(2, 2)),
lineSegment(pointFrom(2, 2), pointFrom(2, 1)),
lineSegment(pointFrom(2, 1), pointFrom(3, 1)),
];
it("point on the line", () => {
expect(pointOnPolyline(pointFrom(1, 0), polyline)).toBe(true);
expect(pointOnPolyline(pointFrom(1, 2), polyline)).toBe(true);
expect(pointOnPolyline(pointFrom(2, 2), polyline)).toBe(true);
expect(pointOnPolyline(pointFrom(2, 1), polyline)).toBe(true);
expect(pointOnPolyline(pointFrom(3, 1), polyline)).toBe(true);
expect(pointOnPolyline(pointFrom(1, 1), polyline)).toBe(true);
expect(pointOnPolyline(pointFrom(2, 1.5), polyline)).toBe(true);
expect(pointOnPolyline(pointFrom(2.5, 1), polyline)).toBe(true);
expect(pointOnPolyline(pointFrom(0, 1), polyline)).toBe(false);
expect(pointOnPolyline(pointFrom(2.1, 1.5), polyline)).toBe(false);
});
it("point on the line with rotation", () => {
const truePoints = [
pointFrom(1, 0),
pointFrom(1, 2),
pointFrom(2, 2),
pointFrom(2, 1),
pointFrom(3, 1),
];
truePoints.forEach((p) => {
const rotation = (Math.random() * 360) as Degrees;
const rotatedPoint = pointRotateDegs(p, pointFrom(0, 0), rotation);
const rotatedPolyline = polyline.map((line) =>
lineSegmentRotate(line, degreesToRadians(rotation), pointFrom(0, 0)),
);
expect(pointOnPolyline(rotatedPoint, rotatedPolyline)).toBe(true);
});
const falsePoints = [pointFrom(0, 1), pointFrom(2.1, 1.5)];
falsePoints.forEach((p) => {
const rotation = (Math.random() * 360) as Degrees;
const rotatedPoint = pointRotateDegs(p, pointFrom(0, 0), rotation);
const rotatedPolyline = polyline.map((line) =>
lineSegmentRotate(line, degreesToRadians(rotation), pointFrom(0, 0)),
);
expect(pointOnPolyline(rotatedPoint, rotatedPolyline)).toBe(false);
});
});
});