More refactor

excalidraw-app/components/DebugCanvas.tsx

@@ -13,15 +13,15 @@ import {
 } from "../../packages/excalidraw/components/icons";
 import { STORAGE_KEYS } from "../app_constants";
 import {
-  isLineSegment,
+  isSegment,
   type GlobalPoint,
-  type LineSegment,
+  type Segment,
 } from "../../packages/math";
 
 const renderLine = (
   context: CanvasRenderingContext2D,
   zoom: number,
-  segment: LineSegment<GlobalPoint>,
+  segment: Segment<GlobalPoint>,
   color: string,
 ) => {
   context.save();
@@ -52,11 +52,11 @@ const render = (
 ) => {
   frame.forEach((el: DebugElement) => {
     switch (true) {
-      case isLineSegment(el.data):
+      case isSegment(el.data):
         renderLine(
           context,
           appState.zoom.value,
-          el.data as LineSegment<GlobalPoint>,
+          el.data as Segment<GlobalPoint>,
           el.color,
         );
         break;

packages/excalidraw/element/binding.ts

@@ -65,7 +65,7 @@ import {
 } from "./heading";
 import type { LocalPoint, Radians } from "../../math";
 import {
-  lineSegment,
+  segment,
   point,
   pointRotateRads,
   type GlobalPoint,
@@ -1615,7 +1615,7 @@ const intersectElementWithLine = (
   elementsMap: ElementsMap,
 ): GlobalPoint[] | undefined => {
   if (isRectangularElement(element)) {
-    return segmentIntersectRectangleElement(element, lineSegment(a, b), gap);
+    return segmentIntersectRectangleElement(element, segment(a, b), gap);
   }
 
   const relateToCenter = relativizationToElementCenter(element, elementsMap);

packages/excalidraw/element/resizeTest.ts

@@ -21,10 +21,10 @@ import type { Bounds } from "./bounds";
 import { getElementAbsoluteCoords } from "./bounds";
 import { SIDE_RESIZING_THRESHOLD } from "../constants";
 import { isLinearElement } from "./typeChecks";
-import type { GlobalPoint, LineSegment, LocalPoint } from "../../math";
+import type { GlobalPoint, Segment, LocalPoint } from "../../math";
 import {
   point,
-  pointOnLineSegment,
+  segmentIncludesPoint,
   pointRotateRads,
   type Radians,
 } from "../../math";
@@ -101,9 +101,9 @@ export const resizeTest = <Point extends GlobalPoint | LocalPoint>(
       for (const [dir, side] of Object.entries(sides)) {
         // test to see if x, y are on the line segment
         if (
-          pointOnLineSegment(
+          segmentIncludesPoint(
             point<Point>(x, y),
-            side as LineSegment<Point>,
+            side as Segment<Point>,
             SPACING,
           )
         ) {
@@ -187,9 +187,9 @@ export const getTransformHandleTypeFromCoords = (
     for (const [dir, side] of Object.entries(sides)) {
       // test to see if x, y are on the line segment
       if (
-        pointOnLineSegment(
+        segmentIncludesPoint(
           scenePointer,
-          side as LineSegment<GlobalPoint>,
+          side as Segment<GlobalPoint>,
           SPACING,
         )
       ) {

packages/excalidraw/frame.ts

@@ -33,10 +33,10 @@ import {
   isLinearElement,
 } from "./element/typeChecks";
 import type { ReadonlySetLike } from "./utility-types";
-import type { GlobalPoint, LineSegment } from "../math";
+import type { GlobalPoint, Segment } from "../math";
 import {
   isPointWithinBounds,
-  lineSegment,
+  segment,
   point,
   pointRotateRads,
   segmentsIntersectAt,
@@ -82,7 +82,7 @@ export const bindElementsToFramesAfterDuplication = (
 const getElementLineSegments = (
   element: ExcalidrawElement,
   elementsMap: ElementsMap,
-): LineSegment<GlobalPoint>[] => {
+): Segment<GlobalPoint>[] => {
   const [x1, y1, x2, y2, cx, cy] = getElementAbsoluteCoords(
     element,
     elementsMap,
@@ -91,13 +91,13 @@ const getElementLineSegments = (
   const center: GlobalPoint = point(cx, cy);
 
   if (isLinearElement(element) || isFreeDrawElement(element)) {
-    const segments: LineSegment<GlobalPoint>[] = [];
+    const segments: Segment<GlobalPoint>[] = [];
 
     let i = 0;
 
     while (i < element.points.length - 1) {
       segments.push(
-        lineSegment(
+        segment(
           pointRotateRads(
             point(
               element.points[i][0] + element.x,
@@ -137,35 +137,35 @@ const getElementLineSegments = (
 
   if (element.type === "diamond") {
     return [
-      lineSegment(n, w),
+      segment(n, w),
-      lineSegment(n, e),
+      segment(n, e),
-      lineSegment(s, w),
+      segment(s, w),
-      lineSegment(s, e),
+      segment(s, e),
     ];
   }
 
   if (element.type === "ellipse") {
     return [
-      lineSegment(n, w),
+      segment(n, w),
-      lineSegment(n, e),
+      segment(n, e),
-      lineSegment(s, w),
+      segment(s, w),
-      lineSegment(s, e),
+      segment(s, e),
-      lineSegment(n, w),
+      segment(n, w),
-      lineSegment(n, e),
+      segment(n, e),
-      lineSegment(s, w),
+      segment(s, w),
-      lineSegment(s, e),
+      segment(s, e),
     ];
   }
 
   return [
-    lineSegment(nw, ne),
+    segment(nw, ne),
-    lineSegment(sw, se),
+    segment(sw, se),
-    lineSegment(nw, sw),
+    segment(nw, sw),
-    lineSegment(ne, se),
+    segment(ne, se),
-    lineSegment(nw, e),
+    segment(nw, e),
-    lineSegment(sw, e),
+    segment(sw, e),
-    lineSegment(ne, w),
+    segment(ne, w),
-    lineSegment(se, w),
+    segment(se, w),
   ];
 };
 

packages/excalidraw/tests/flip.test.tsx

@@ -1,4 +1,3 @@
-import React from "react";
 import ReactDOM from "react-dom";
 import {
   fireEvent,
@@ -27,8 +26,8 @@ import { KEYS } from "../keys";
 import { getBoundTextElementPosition } from "../element/textElement";
 import { createPasteEvent } from "../clipboard";
 import { arrayToMap, cloneJSON } from "../utils";
-import type { LocalPoint } from "../../math";
+import type { LocalPoint, Radians } from "../../math";
-import { point, type Radians } from "../../math";
+import { point, radians } from "../../math";
 
 const { h } = window;
 const mouse = new Pointer("mouse");
@@ -132,7 +131,7 @@ const createLinearElementWithCurveInsideMinMaxPoints = (
     y: -2412.5069664197654,
     width: 1750.4888916015625,
     height: 410.51605224609375,
-    angle: 0 as Radians,
+    angle: radians(0),
     strokeColor: "#000000",
     backgroundColor: "#fa5252",
     fillStyle: "hachure",

packages/excalidraw/visualdebug.ts

@@ -1,5 +1,5 @@
-import type { LineSegment } from "../math";
+import type { Segment } from "../math";
-import { isLineSegment, lineSegment, point, type GlobalPoint } from "../math";
+import { isSegment, segment, point, type GlobalPoint } from "../math";
 import type { Bounds } from "./element/bounds";
 import { isBounds } from "./element/typeChecks";
 
@@ -15,20 +15,20 @@ declare global {
 
 export type DebugElement = {
   color: string;
-  data: LineSegment<GlobalPoint>;
+  data: Segment<GlobalPoint>;
   permanent: boolean;
 };
 
 export const debugDrawLine = (
-  segment: LineSegment<GlobalPoint> | LineSegment<GlobalPoint>[],
+  segment: Segment<GlobalPoint> | Segment<GlobalPoint>[],
   opts?: {
     color?: string;
     permanent?: boolean;
   },
 ) => {
   const segments = (
-    isLineSegment(segment) ? [segment] : segment
+    isSegment(segment) ? [segment] : segment
-  ) as LineSegment<GlobalPoint>[];
+  ) as Segment<GlobalPoint>[];
 
   segments.forEach((data) =>
     addToCurrentFrame({
@@ -51,7 +51,7 @@ export const debugDrawPoint = (
   const yOffset = opts?.fuzzy ? Math.random() * 3 : 0;
 
   debugDrawLine(
-    lineSegment(
+    segment(
       point<GlobalPoint>(p[0] + xOffset - 10, p[1] + yOffset - 10),
       point<GlobalPoint>(p[0] + xOffset + 10, p[1] + yOffset + 10),
     ),
@@ -61,7 +61,7 @@ export const debugDrawPoint = (
     },
   );
   debugDrawLine(
-    lineSegment(
+    segment(
       point<GlobalPoint>(p[0] + xOffset - 10, p[1] + yOffset + 10),
       point<GlobalPoint>(p[0] + xOffset + 10, p[1] + yOffset - 10),
     ),
@@ -82,19 +82,19 @@ export const debugDrawBounds = (
   (isBounds(box) ? [box] : box).forEach((bbox) =>
     debugDrawLine(
       [
-        lineSegment(
+        segment(
           point<GlobalPoint>(bbox[0], bbox[1]),
           point<GlobalPoint>(bbox[2], bbox[1]),
         ),
-        lineSegment(
+        segment(
           point<GlobalPoint>(bbox[2], bbox[1]),
           point<GlobalPoint>(bbox[2], bbox[3]),
         ),
-        lineSegment(
+        segment(
           point<GlobalPoint>(bbox[2], bbox[3]),
           point<GlobalPoint>(bbox[0], bbox[3]),
         ),
-        lineSegment(
+        segment(
           point<GlobalPoint>(bbox[0], bbox[3]),
           point<GlobalPoint>(bbox[0], bbox[1]),
         ),

packages/math/arc.test.ts

@@ -1,11 +1,11 @@
 import { radians } from "./angle";
-import { arc, isPointOnSymmetricArc } from "./arc";
+import { arc, arcIncludesPoint } from "./arc";
 import { point } from "./point";
 
 describe("point on arc", () => {
   it("should detect point on simple arc", () => {
     expect(
-      isPointOnSymmetricArc(
+      arcIncludesPoint(
         arc(point(0, 0), 1, radians(-Math.PI / 4), radians(Math.PI / 4)),
         point(0.92291667, 0.385),
       ),
@@ -13,7 +13,7 @@ describe("point on arc", () => {
   });
   it("should not detect point outside of a simple arc", () => {
     expect(
-      isPointOnSymmetricArc(
+      arcIncludesPoint(
         arc(point(0, 0), 1, radians(-Math.PI / 4), radians(Math.PI / 4)),
         point(-0.92291667, 0.385),
       ),
@@ -21,7 +21,7 @@ describe("point on arc", () => {
   });
   it("should not detect point with good angle but incorrect radius", () => {
     expect(
-      isPointOnSymmetricArc(
+      arcIncludesPoint(
         arc(point(0, 0), 1, radians(-Math.PI / 4), radians(Math.PI / 4)),
         point(-0.5, 0.5),
       ),

packages/math/arc.ts

@@ -1,7 +1,7 @@
 import { cartesian2Polar, radians } from "./angle";
-import { ellipse, interceptPointsOfLineAndEllipse } from "./ellipse";
+import { ellipse, ellipseSegmentInterceptPoints } from "./ellipse";
 import { point } from "./point";
-import type { GenericPoint, LineSegment, Radians, SymmetricArc } from "./types";
+import type { GenericPoint, Segment, Radians, Arc } from "./types";
 import { PRECISION } from "./utils";
 
 /**
@@ -20,15 +20,15 @@ export function arc<Point extends GenericPoint>(
   startAngle: Radians,
   endAngle: Radians,
 ) {
-  return { center, radius, startAngle, endAngle } as SymmetricArc<Point>;
+  return { center, radius, startAngle, endAngle } as Arc<Point>;
 }
 
 /**
  * Determines if a cartesian point lies on a symmetric arc, i.e. an arc which
  * is part of a circle contour centered on 0, 0.
  */
-export function isPointOnSymmetricArc<P extends GenericPoint>(
+export function arcIncludesPoint<P extends GenericPoint>(
-  { center, radius: arcRadius, startAngle, endAngle }: SymmetricArc<P>,
+  { center, radius: arcRadius, startAngle, endAngle }: Arc<P>,
   p: P,
 ): boolean {
   const [radius, angle] = cartesian2Polar(
@@ -47,10 +47,10 @@ export function isPointOnSymmetricArc<P extends GenericPoint>(
  * point and end point and a symmetric arc.
  */
 export function interceptOfSymmetricArcAndSegment<Point extends GenericPoint>(
-  a: Readonly<SymmetricArc<Point>>,
+  a: Readonly<Arc<Point>>,
-  l: Readonly<LineSegment<Point>>,
+  l: Readonly<Segment<Point>>,
 ): Point[] {
-  return interceptPointsOfLineAndEllipse(
+  return ellipseSegmentInterceptPoints(
     ellipse(a.center, radians(0), a.radius, a.radius),
     l,
   ).filter((candidate) => {

packages/math/ellipse.test.ts

@@ -1,12 +1,12 @@
 import { radians } from "./angle";
 import {
   ellipse,
-  interceptPointsOfLineAndEllipse,
+  ellipseSegmentInterceptPoints,
-  pointInEllipse,
+  ellipseIncludesPoint,
-  pointOnEllipse,
+  ellipseTouchesPoint,
 } from "./ellipse";
 import { point } from "./point";
-import { lineSegment } from "./segment";
+import { segment } from "./segment";
 import type { Ellipse, GlobalPoint } from "./types";
 
 describe("point and ellipse", () => {
@@ -14,41 +14,44 @@ describe("point and ellipse", () => {
 
   it("point on ellipse", () => {
     [point(0, 1), point(0, -1), point(2, 0), point(-2, 0)].forEach((p) => {
-      expect(pointOnEllipse(p, target)).toBe(true);
+      expect(ellipseTouchesPoint(p, target)).toBe(true);
     });
-    expect(pointOnEllipse(point(-1.4, 0.7), target, 0.1)).toBe(true);
+    expect(ellipseTouchesPoint(point(-1.4, 0.7), target, 0.1)).toBe(true);
-    expect(pointOnEllipse(point(-1.4, 0.71), target, 0.01)).toBe(true);
+    expect(ellipseTouchesPoint(point(-1.4, 0.71), target, 0.01)).toBe(true);
 
-    expect(pointOnEllipse(point(1.4, 0.7), target, 0.1)).toBe(true);
+    expect(ellipseTouchesPoint(point(1.4, 0.7), target, 0.1)).toBe(true);
-    expect(pointOnEllipse(point(1.4, 0.71), target, 0.01)).toBe(true);
+    expect(ellipseTouchesPoint(point(1.4, 0.71), target, 0.01)).toBe(true);
 
-    expect(pointOnEllipse(point(1, -0.86), target, 0.1)).toBe(true);
+    expect(ellipseTouchesPoint(point(1, -0.86), target, 0.1)).toBe(true);
-    expect(pointOnEllipse(point(1, -0.86), target, 0.01)).toBe(true);
+    expect(ellipseTouchesPoint(point(1, -0.86), target, 0.01)).toBe(true);
 
-    expect(pointOnEllipse(point(-1, -0.86), target, 0.1)).toBe(true);
+    expect(ellipseTouchesPoint(point(-1, -0.86), target, 0.1)).toBe(true);
-    expect(pointOnEllipse(point(-1, -0.86), target, 0.01)).toBe(true);
+    expect(ellipseTouchesPoint(point(-1, -0.86), target, 0.01)).toBe(true);
 
-    expect(pointOnEllipse(point(-1, 0.8), target)).toBe(false);
+    expect(ellipseTouchesPoint(point(-1, 0.8), target)).toBe(false);
-    expect(pointOnEllipse(point(1, -0.8), target)).toBe(false);
+    expect(ellipseTouchesPoint(point(1, -0.8), target)).toBe(false);
   });
 
   it("point in ellipse", () => {
     [point(0, 1), point(0, -1), point(2, 0), point(-2, 0)].forEach((p) => {
-      expect(pointInEllipse(p, target)).toBe(true);
+      expect(ellipseIncludesPoint(p, target)).toBe(true);
     });
 
-    expect(pointInEllipse(point(-1, 0.8), target)).toBe(true);
+    expect(ellipseIncludesPoint(point(-1, 0.8), target)).toBe(true);
-    expect(pointInEllipse(point(1, -0.8), target)).toBe(true);
+    expect(ellipseIncludesPoint(point(1, -0.8), target)).toBe(true);
 
-    expect(pointInEllipse(point(-1, 1), target)).toBe(false);
+    // Point on outline
-    expect(pointInEllipse(point(-1.4, 0.8), target)).toBe(false);
+    expect(ellipseIncludesPoint(point(2, 0), target)).toBe(true);
+
+    expect(ellipseIncludesPoint(point(-1, 1), target)).toBe(false);
+    expect(ellipseIncludesPoint(point(-1.4, 0.8), target)).toBe(false);
   });
 });
 
 describe("line and ellipse", () => {
   it("detects outside segment", () => {
-    const l = lineSegment<GlobalPoint>(point(-100, 0), point(-10, 0));
+    const l = segment<GlobalPoint>(point(-100, 0), point(-10, 0));
     const e = ellipse(point(0, 0), radians(0), 2, 2);
-    expect(interceptPointsOfLineAndEllipse(e, l).length).toBe(0);
+    expect(ellipseSegmentInterceptPoints(e, l).length).toBe(0);
   });
 });

packages/math/ellipse.ts

@@ -6,7 +6,7 @@ import {
   pointFromVector,
   pointRotateRads,
 } from "./point";
-import type { Ellipse, GenericPoint, LineSegment, Radians } from "./types";
+import type { Ellipse, GenericPoint, Segment, Radians } from "./types";
 import { PRECISION } from "./utils";
 import {
   vector,
@@ -16,6 +16,15 @@ import {
   vectorScale,
 } from "./vector";
 
+/**
+ * Construct an Ellipse object from the parameters
+ *
+ * @param center The center of the ellipse
+ * @param angle The slanting of the ellipse in radians
+ * @param halfWidth Half of the width of a non-slanted version of the ellipse
+ * @param halfHeight Half of the height of a non-slanted version of the ellipse
+ * @returns The constructed Ellipse object
+ */
 export function ellipse<Point extends GenericPoint>(
   center: Point,
   angle: Radians,
@@ -30,7 +39,14 @@ export function ellipse<Point extends GenericPoint>(
   } as Ellipse<Point>;
 }
 
-export const pointInEllipse = <Point extends GenericPoint>(
+/**
+ * Determines if a point is inside or on the ellipse outline
+ *
+ * @param p The point to test
+ * @param ellipse The ellipse to compare against
+ * @returns TRUE if the point is inside or on the outline of the ellipse
+ */
+export const ellipseIncludesPoint = <Point extends GenericPoint>(
   p: Point,
   ellipse: Ellipse<Point>,
 ) => {
@@ -52,7 +68,16 @@ export const pointInEllipse = <Point extends GenericPoint>(
   );
 };
 
-export const pointOnEllipse = <Point extends GenericPoint>(
+/**
+ * Tests whether a point lies on the outline of the ellipse within a given
+ * tolerance
+ *
+ * @param point The point to test
+ * @param ellipse The ellipse to compare against
+ * @param threshold The distance to consider a point close enough to be "on" the outline
+ * @returns TRUE if the point is on the ellise outline
+ */
+export const ellipseTouchesPoint = <Point extends GenericPoint>(
   point: Point,
   ellipse: Ellipse<Point>,
   threshold = PRECISION,
@@ -60,7 +85,7 @@ export const pointOnEllipse = <Point extends GenericPoint>(
   return distanceToEllipse(point, ellipse) <= threshold;
 };
 
-export const ellipseAxes = <Point extends GenericPoint>(
+export const ellipseFocusToCenter = <Point extends GenericPoint>(
   ellipse: Ellipse<Point>,
 ) => {
   const widthGreaterThanHeight = ellipse.halfWidth > ellipse.halfHeight;
@@ -72,17 +97,6 @@ export const ellipseAxes = <Point extends GenericPoint>(
     ? ellipse.halfHeight * 2
     : ellipse.halfWidth * 2;
 
-  return {
-    majorAxis,
-    minorAxis,
-  };
-};
-
-export const ellipseFocusToCenter = <Point extends GenericPoint>(
-  ellipse: Ellipse<Point>,
-) => {
-  const { majorAxis, minorAxis } = ellipseAxes(ellipse);
-
   return Math.sqrt(majorAxis ** 2 - minorAxis ** 2);
 };
 
@@ -90,7 +104,14 @@ export const ellipseExtremes = <Point extends GenericPoint>(
   ellipse: Ellipse<Point>,
 ) => {
   const { center, angle } = ellipse;
-  const { majorAxis, minorAxis } = ellipseAxes(ellipse);
+  const widthGreaterThanHeight = ellipse.halfWidth > ellipse.halfHeight;
+
+  const majorAxis = widthGreaterThanHeight
+    ? ellipse.halfWidth * 2
+    : ellipse.halfHeight * 2;
+  const minorAxis = widthGreaterThanHeight
+    ? ellipse.halfHeight * 2
+    : ellipse.halfWidth * 2;
 
   const cos = Math.cos(angle);
   const sin = Math.sin(angle);
@@ -175,9 +196,9 @@ const distanceToEllipse = <Point extends GenericPoint>(
  * Calculate a maximum of two intercept points for a line going throug an
  * ellipse.
  */
-export function interceptPointsOfLineAndEllipse<Point extends GenericPoint>(
+export function ellipseSegmentInterceptPoints<Point extends GenericPoint>(
   e: Readonly<Ellipse<Point>>,
-  l: Readonly<LineSegment<Point>>,
+  l: Readonly<Segment<Point>>,
 ): Point[] {
   const rx = e.halfWidth;
   const ry = e.halfHeight;

packages/math/polygon.ts

@@ -1,5 +1,5 @@
 import { pointsEqual } from "./point";
-import { lineSegment, pointOnLineSegment } from "./segment";
+import { segment, segmentIncludesPoint } from "./segment";
 import type { GenericPoint, Polygon } from "./types";
 import { PRECISION } from "./utils";
 
@@ -44,7 +44,7 @@ export const pointOnPolygon = <Point extends GenericPoint>(
   let on = false;
 
   for (let i = 0, l = poly.length - 1; i < l; i++) {
-    if (pointOnLineSegment(p, lineSegment(poly[i], poly[i + 1]), threshold)) {
+    if (segmentIncludesPoint(p, segment(poly[i], poly[i + 1]), threshold)) {
       on = true;
       break;
     }

packages/math/segment.test.ts

@@ -1,15 +1,15 @@
 import { point } from "./point";
-import { lineSegment, segmentsIntersectAt } from "./segment";
+import { segment, segmentsIntersectAt } from "./segment";
-import type { GlobalPoint, LineSegment } from "./types";
+import type { GlobalPoint, Segment } from "./types";
 
 describe("segment intersects segment", () => {
-  const lineA: LineSegment<GlobalPoint> = lineSegment(point(1, 4), point(3, 4));
+  const lineA: Segment<GlobalPoint> = segment(point(1, 4), point(3, 4));
-  const lineB: LineSegment<GlobalPoint> = lineSegment(point(2, 1), point(2, 7));
+  const lineB: Segment<GlobalPoint> = segment(point(2, 1), point(2, 7));
-  const lineC: LineSegment<GlobalPoint> = lineSegment(point(1, 8), point(3, 8));
+  const lineC: Segment<GlobalPoint> = segment(point(1, 8), point(3, 8));
-  const lineD: LineSegment<GlobalPoint> = lineSegment(point(1, 8), point(3, 8));
+  const lineD: Segment<GlobalPoint> = segment(point(1, 8), point(3, 8));
-  const lineE: LineSegment<GlobalPoint> = lineSegment(point(1, 9), point(3, 9));
+  const lineE: Segment<GlobalPoint> = segment(point(1, 9), point(3, 9));
-  const lineF: LineSegment<GlobalPoint> = lineSegment(point(1, 2), point(3, 4));
+  const lineF: Segment<GlobalPoint> = segment(point(1, 2), point(3, 4));
-  const lineG: LineSegment<GlobalPoint> = lineSegment(point(0, 1), point(2, 3));
+  const lineG: Segment<GlobalPoint> = segment(point(0, 1), point(2, 3));
 
   it("intersection", () => {
     expect(segmentsIntersectAt(lineA, lineB)).toEqual([2, 4]);

packages/math/segment.ts

@@ -4,7 +4,7 @@ import {
   pointFromVector,
   pointRotateRads,
 } from "./point";
-import type { GenericPoint, LineSegment, Radians } from "./types";
+import type { GenericPoint, Segment, Radians } from "./types";
 import { PRECISION } from "./utils";
 import {
   vectorAdd,
@@ -20,18 +20,15 @@ import {
  * @param points The two points delimiting the line segment on each end
  * @returns The line segment delineated by the points
  */
-export function lineSegment<P extends GenericPoint>(
+export function segment<P extends GenericPoint>(a: P, b: P): Segment<P> {
-  a: P,
+  return [a, b] as Segment<P>;
-  b: P,
-): LineSegment<P> {
-  return [a, b] as LineSegment<P>;
 }
 
-export function lineSegmentFromPointArray<P extends GenericPoint>(
+export function segmentFromPointArray<P extends GenericPoint>(
   pointArray: P[],
-): LineSegment<P> | undefined {
+): Segment<P> | undefined {
   return pointArray.length === 2
-    ? lineSegment<P>(pointArray[0], pointArray[1])
+    ? segment<P>(pointArray[0], pointArray[1])
     : undefined;
 }
 
@@ -40,9 +37,9 @@ export function lineSegmentFromPointArray<P extends GenericPoint>(
  * @param segment
  * @returns
  */
-export const isLineSegment = <Point extends GenericPoint>(
+export const isSegment = <Point extends GenericPoint>(
   segment: unknown,
-): segment is LineSegment<Point> =>
+): segment is Segment<Point> =>
   Array.isArray(segment) &&
   segment.length === 2 &&
   isPoint(segment[0]) &&
@@ -57,12 +54,12 @@ export const isLineSegment = <Point extends GenericPoint>(
  * @param origin
  * @returns
  */
-export const lineSegmentRotate = <Point extends GenericPoint>(
+export const segmentRotate = <Point extends GenericPoint>(
-  l: LineSegment<Point>,
+  l: Segment<Point>,
   angle: Radians,
   origin?: Point,
-): LineSegment<Point> => {
+): Segment<Point> => {
-  return lineSegment(
+  return segment(
     pointRotateRads(l[0], origin || pointCenter(l[0], l[1]), angle),
     pointRotateRads(l[1], origin || pointCenter(l[0], l[1]), angle),
   );
@@ -73,8 +70,8 @@ export const lineSegmentRotate = <Point extends GenericPoint>(
  * intersect at.
  */
 export const segmentsIntersectAt = <Point extends GenericPoint>(
-  a: Readonly<LineSegment<Point>>,
+  a: Readonly<Segment<Point>>,
-  b: Readonly<LineSegment<Point>>,
+  b: Readonly<Segment<Point>>,
 ): Point | null => {
   const a0 = vectorFromPoint(a[0]);
   const a1 = vectorFromPoint(a[1]);
@@ -105,12 +102,12 @@ export const segmentsIntersectAt = <Point extends GenericPoint>(
   return null;
 };
 
-export const pointOnLineSegment = <Point extends GenericPoint>(
+export const segmentIncludesPoint = <Point extends GenericPoint>(
   point: Point,
-  line: LineSegment<Point>,
+  line: Segment<Point>,
   threshold = PRECISION,
 ) => {
-  const distance = distanceToLineSegment(point, line);
+  const distance = segmentDistanceToPoint(point, line);
 
   if (distance === 0) {
     return true;
@@ -119,9 +116,9 @@ export const pointOnLineSegment = <Point extends GenericPoint>(
   return distance < threshold;
 };
 
-export const distanceToLineSegment = <Point extends GenericPoint>(
+export const segmentDistanceToPoint = <Point extends GenericPoint>(
   point: Point,
-  line: LineSegment<Point>,
+  line: Segment<Point>,
 ) => {
   const [x, y] = point;
   const [[x1, y1], [x2, y2]] = line;

packages/math/types.ts

@@ -67,8 +67,8 @@ export type Line<P extends GenericPoint> = [p: P, q: P] & {
  * line that is bounded by two distinct end points, and
  * contains every point on the line that is between its endpoints.
  */
-export type LineSegment<P extends GenericPoint> = [a: P, b: P] & {
+export type Segment<P extends GenericPoint> = [a: P, b: P] & {
-  _brand: "excalimath_linesegment";
+  _brand: "excalimath_segment";
 };
 
 /**
@@ -81,23 +81,14 @@ export type Vector = [u: number, v: number] & {
 /**
  * A triangle represented by 3 points
  */
-export type Triangle<P extends GlobalPoint | LocalPoint | ViewportPoint> = [
+export type Triangle<P extends GenericPoint> = [a: P, b: P, c: P] & {
-  a: P,
-  b: P,
-  c: P,
-] & {
   _brand: "excalimath__triangle";
 };
 
 /**
  * A rectangular shape represented by 4 points at its corners
  */
-export type Rectangle<P extends GlobalPoint | LocalPoint | ViewportPoint> = [
+export type Rectangle<P extends GenericPoint> = [a: P, b: P, c: P, d: P] & {
-  a: P,
-  b: P,
-  c: P,
-  d: P,
-] & {
   _brand: "excalimath__rectangle";
 };
 
@@ -105,28 +96,24 @@ export type Rectangle<P extends GlobalPoint | LocalPoint | ViewportPoint> = [
  * A polygon is a closed shape by connecting the given points
  * rectangles and diamonds are modelled by polygons
  */
-export type Polygon<Point extends GlobalPoint | LocalPoint | ViewportPoint> =
+export type Polygon<Point extends GenericPoint> = Point[] & {
-  Point[] & {
   _brand: "excalimath_polygon";
 };
 
 /**
  * Cubic bezier curve with four control points
  */
-export type Curve<Point extends GlobalPoint | LocalPoint | ViewportPoint> = [
+export type Curve<Point extends GenericPoint> = [Point, Point, Point, Point] & {
-  Point,
-  Point,
-  Point,
-  Point,
-] & {
   _brand: "excalimath_curve";
 };
 
 /**
+ * Represents a symmetric arc, a segment of a circular path
+ *
  * Angles are in radians and centered on 0, 0. Zero radians on a 1 radius circle
  * corresponds to (1, 0) cartesian coordinates (point), i.e. to the "right"
  */
-export type SymmetricArc<Point extends GenericPoint> = {
+export type Arc<Point extends GenericPoint> = {
   center: Point;
   radius: number;
   startAngle: Radians;

packages/utils/collision.test.ts

@@ -2,8 +2,8 @@ import type { Curve, Degrees, GlobalPoint } from "../math";
 import {
   curve,
   degreesToRadians,
-  lineSegment,
+  segment,
-  lineSegmentRotate,
+  segmentRotate,
   point,
   pointRotateDegs,
 } from "../math";
@@ -34,10 +34,10 @@ describe("point and curve", () => {
 
 describe("point and polylines", () => {
   const polyline: Polyline<GlobalPoint> = [
-    lineSegment(point(1, 0), point(1, 2)),
+    segment(point(1, 0), point(1, 2)),
-    lineSegment(point(1, 2), point(2, 2)),
+    segment(point(1, 2), point(2, 2)),
-    lineSegment(point(2, 2), point(2, 1)),
+    segment(point(2, 2), point(2, 1)),
-    lineSegment(point(2, 1), point(3, 1)),
+    segment(point(2, 1), point(3, 1)),
   ];
 
   it("point on the line", () => {
@@ -68,7 +68,7 @@ describe("point and polylines", () => {
       const rotation = (Math.random() * 360) as Degrees;
       const rotatedPoint = pointRotateDegs(p, point(0, 0), rotation);
       const rotatedPolyline = polyline.map((line) =>
-        lineSegmentRotate(line, degreesToRadians(rotation), point(0, 0)),
+        segmentRotate(line, degreesToRadians(rotation), point(0, 0)),
       );
       expect(pointOnPolyline(rotatedPoint, rotatedPolyline)).toBe(true);
     });
@@ -79,7 +79,7 @@ describe("point and polylines", () => {
       const rotation = (Math.random() * 360) as Degrees;
       const rotatedPoint = pointRotateDegs(p, point(0, 0), rotation);
       const rotatedPolyline = polyline.map((line) =>
-        lineSegmentRotate(line, degreesToRadians(rotation), point(0, 0)),
+        segmentRotate(line, degreesToRadians(rotation), point(0, 0)),
       );
       expect(pointOnPolyline(rotatedPoint, rotatedPolyline)).toBe(false);
     });

packages/utils/collision.ts

@@ -2,14 +2,14 @@ import type { Polycurve, Polyline } from "./geometry/shape";
 import { type GeometricShape } from "./geometry/shape";
 import type { Curve, GenericPoint } from "../math";
 import {
-  lineSegment,
+  segment,
   point,
   polygonIncludesPoint,
-  pointOnLineSegment,
+  segmentIncludesPoint,
   pointOnPolygon,
   polygonFromPoints,
-  pointOnEllipse,
+  ellipseTouchesPoint,
-  pointInEllipse,
+  ellipseIncludesPoint,
 } from "../math";
 
 // check if the given point is considered on the given shape's border
@@ -22,9 +22,9 @@ export const isPointOnShape = <Point extends GenericPoint>(
     case "polygon":
       return pointOnPolygon(point, shape.data, tolerance);
     case "ellipse":
-      return pointOnEllipse(point, shape.data, tolerance);
+      return ellipseTouchesPoint(point, shape.data, tolerance);
     case "line":
-      return pointOnLineSegment(point, shape.data, tolerance);
+      return segmentIncludesPoint(point, shape.data, tolerance);
     case "polyline":
       return pointOnPolyline(point, shape.data, tolerance);
     case "curve":
@@ -49,7 +49,7 @@ export const isPointInShape = <Point extends GenericPoint>(
     case "curve":
       return false;
     case "ellipse":
-      return pointInEllipse(p, shape.data);
+      return ellipseIncludesPoint(p, shape.data);
     case "polyline": {
       const polygon = polygonFromPoints(shape.data.flat());
       return polygonIncludesPoint(p, polygon);
@@ -96,7 +96,7 @@ const polyLineFromCurve = <Point extends GenericPoint>(
     t += increment;
     if (t <= 1) {
       const nextPoint: Point = point(equation(t, 0), equation(t, 1));
-      lineSegments.push(lineSegment(startingPoint, nextPoint));
+      lineSegments.push(segment(startingPoint, nextPoint));
       startingPoint = nextPoint;
     }
   }
@@ -117,5 +117,5 @@ export const pointOnPolyline = <Point extends GenericPoint>(
   polyline: Polyline<Point>,
   threshold = 10e-5,
 ) => {
-  return polyline.some((line) => pointOnLineSegment(point, line, threshold));
+  return polyline.some((line) => segmentIncludesPoint(point, line, threshold));
 };

packages/utils/geometry/geometry.test.ts

@@ -1,20 +1,20 @@
-import type { GlobalPoint, LineSegment, Polygon } from "../../math";
+import type { GlobalPoint, Segment, Polygon } from "../../math";
 import {
   point,
-  lineSegment,
+  segment,
   polygon,
-  pointOnLineSegment,
+  segmentIncludesPoint,
   pointOnPolygon,
   polygonIncludesPoint,
 } from "../../math";
 
 describe("point and line", () => {
-  const s: LineSegment<GlobalPoint> = lineSegment(point(1, 0), point(1, 2));
+  const s: Segment<GlobalPoint> = segment(point(1, 0), point(1, 2));
 
   it("point on the line", () => {
-    expect(pointOnLineSegment(point(0, 1), s)).toBe(false);
+    expect(segmentIncludesPoint(point(0, 1), s)).toBe(false);
-    expect(pointOnLineSegment(point(1, 1), s, 0)).toBe(true);
+    expect(segmentIncludesPoint(point(1, 1), s, 0)).toBe(true);
-    expect(pointOnLineSegment(point(2, 1), s)).toBe(false);
+    expect(segmentIncludesPoint(point(2, 1), s)).toBe(false);
   });
 });
 

packages/utils/geometry/shape.ts

@@ -16,7 +16,7 @@ import type {
   Curve,
   Ellipse,
   GenericPoint,
-  LineSegment,
+  Segment,
   Polygon,
   Radians,
   ViewportPoint,
@@ -24,7 +24,7 @@ import type {
 import {
   curve,
   ellipse,
-  lineSegment,
+  segment,
   point,
   pointFromArray,
   pointFromVector,
@@ -63,7 +63,7 @@ import { invariant } from "../../excalidraw/utils";
 // this corresponds to a straight line element in the editor but it could also
 // be used to model other elements
 export type Polyline<Point extends GlobalPoint | LocalPoint | ViewportPoint> =
-  LineSegment<Point>[];
+  Segment<Point>[];
 
 // a polycurve is a curve consisting of ther curves, this corresponds to a complex
 // curve on the canvas
@@ -73,7 +73,7 @@ export type Polycurve<Point extends GlobalPoint | LocalPoint | ViewportPoint> =
 export type GeometricShape<Point extends GenericPoint> =
   | {
       type: "line";
-      data: LineSegment<Point>;
+      data: Segment<Point>;
     }
   | {
       type: "polygon";
@@ -242,11 +242,11 @@ const polylineFromPoints = <
   points: Point[],
 ): Polyline<Point> => {
   let previousPoint: Point = points[0];
-  const polyline: LineSegment<Point>[] = [];
+  const polyline: Segment<Point>[] = [];
 
   for (let i = 1; i < points.length; i++) {
     const nextPoint = points[i];
-    polyline.push(lineSegment<Point>(previousPoint, nextPoint));
+    polyline.push(segment<Point>(previousPoint, nextPoint));
     previousPoint = nextPoint;
   }
 
@@ -356,7 +356,7 @@ export const segmentIntersectRectangleElement = <
   Point extends LocalPoint | GlobalPoint,
 >(
   element: ExcalidrawBindableElement,
-  segment: LineSegment<Point>,
+  s: Segment<Point>,
   gap: number = 0,
 ): Point[] => {
   const bounds = [
@@ -371,23 +371,23 @@ export const segmentIntersectRectangleElement = <
   );
 
   return [
-    lineSegment(
+    segment(
       pointRotateRads(point(bounds[0], bounds[1]), center, element.angle),
       pointRotateRads(point(bounds[2], bounds[1]), center, element.angle),
     ),
-    lineSegment(
+    segment(
       pointRotateRads(point(bounds[2], bounds[1]), center, element.angle),
       pointRotateRads(point(bounds[2], bounds[3]), center, element.angle),
     ),
-    lineSegment(
+    segment(
       pointRotateRads(point(bounds[2], bounds[3]), center, element.angle),
       pointRotateRads(point(bounds[0], bounds[3]), center, element.angle),
     ),
-    lineSegment(
+    segment(
       pointRotateRads(point(bounds[0], bounds[3]), center, element.angle),
       pointRotateRads(point(bounds[0], bounds[1]), center, element.angle),
     ),
   ]
-    .map((s) => segmentsIntersectAt(segment, s))
+    .map((l) => segmentsIntersectAt(s, l))
     .filter((i): i is Point => !!i);
 };