refactor(geom): add interfaces, split out common.ts into /func folder

packages/geom/package.json

@@ -13,7 +13,7 @@
     "license": "Apache-2.0",
     "scripts": {
         "build": "yarn run clean && tsc --declaration",
-        "clean": "rm -rf *.js *.d.ts .nyc_output build coverage doc",
+        "clean": "rm -rf *.js *.d.ts .nyc_output build coverage doc func",
         "cover": "yarn test && nyc report --reporter=lcov",
         "doc": "node_modules/.bin/typedoc --mode modules --out doc src",
         "pub": "yarn run build && yarn publish --access public",

packages/geom/src/api.ts

@@ -0,0 +1,61 @@
+import { ICopy } from "@thi.ng/api/api";
+import { IDistance, IMix } from "@thi.ng/vectors/api";
+
+export type SampleableVector<T> = ICopy<T> & IDistance<T> & IMix<T>;
+
+export interface IArea {
+    /**
+     * Computes and returns area. For types where orientation is taken
+     * into account, setting `signed` to false will always return the
+     * absolute area (default is `true`).
+     *
+     * @param unsigned
+     */
+    area(signed?: boolean): number;
+}
+
+export interface IArcLength {
+    /**
+     * Returns arc length, or for closed shapes, circumference.
+     */
+    arcLength(): number;
+}
+
+export interface IBounds<T> {
+    bounds(): T;
+    /**
+     * Dimension along x-axis.
+     */
+    width(): number;
+    /**
+     * Dimension along y-axis.
+     */
+    height(): number;
+    /**
+     * Dimension along z-axis.
+     */
+    depth(): number;
+}
+
+export interface ICentroid<T> {
+    /**
+     * Computes & returns centroid. If `c` is given it MUST be a zero
+     * vector and will be used to store result.
+     *
+     * @param c
+     */
+    centroid(c?: T): T;
+}
+
+export interface IEdges<T> {
+    edges(): Iterable<T>;
+}
+
+export interface IToPolygon2 {
+    // FIXME return type should be interface
+    toPolygon2(opts?: any): any;
+}
+
+export interface IVertices<T> {
+    vertices(opts?: any): Iterable<T>;
+}

packages/geom/src/circle2.ts

@@ -1,11 +1,28 @@
-import { IObjectOf } from "@thi.ng/api/api";
+import { IObjectOf, IToHiccup } from "@thi.ng/api/api";
+import { IToPolygon2, IVertices, IBounds, ICentroid, IArcLength } from "@thi.ng/geom/src/api";
 import { normRange } from "@thi.ng/transducers/iter/norm-range";
 import { Vec } from "@thi.ng/vectors/api";
 import { mix1, PI, TAU } from "@thi.ng/vectors/math";
 import { setS2, toCartesian2, Vec2 } from "@thi.ng/vectors/vec2";
+import { circumCenter } from "./func/circumcenter";
 import { Polygon2 } from "./poly2";
 
-export class Circle2 {
+export class Circle2 implements
+    IArcLength,
+    IBounds<Vec2[]>,
+    ICentroid<Vec2>,
+    IToHiccup,
+    IToPolygon2,
+    IVertices<Vec2> {
+
+    static from3Points(a: Readonly<Vec2>, b: Readonly<Vec2>, c: Readonly<Vec2>) {
+        const o = circumCenter(a, b, c);
+        if (o) {
+            return new Circle2(o, a.dist(o));
+        }
+    }
+
+    static DEFAULT_RES = 20;
 
     pos: Vec2;
     r: number;
@@ -42,15 +59,15 @@ export class Circle2 {
         return dest;
     }
 
-    vertices(res = 20) {
+    vertices(res = Circle2.DEFAULT_RES) {
         return Vec2.mapBuffer(this.verticesRaw(0, TAU, res, false), res);
     }
 
     area() {
         return PI * this.r * this.r;
     }
 
-    circumference() {
+    arcLength() {
         return TAU * this.r;
     }
 
@@ -61,7 +78,23 @@ export class Circle2 {
         ];
     }
 
-    toPolygon(res = 20) {
+    width() {
+        return this.r * 2;
+    }
+
+    height() {
+        return this.width();
+    }
+
+    depth() {
+        return 0;
+    }
+
+    centroid(c?: Vec2) {
+        return c ? c.set(this.pos) : this.pos;
+    }
+
+    toPolygon2(res = Circle2.DEFAULT_RES) {
         return new Polygon2(this.vertices(res));
     }
 

packages/geom/src/container2.ts

@@ -2,10 +2,13 @@ import { IObjectOf } from "@thi.ng/api/api";
 import { illegalArgs } from "@thi.ng/errors/illegal-arguments";
 import { Mat23 } from "@thi.ng/vectors/mat23";
 import { Vec2, vec2 } from "@thi.ng/vectors/vec2";
-import { IBounds } from "./api";
+import { IBounds, ICentroid, IVertices } from "./api";
+import { bounds } from "./func/bounds";
 
 export class PointContainer2 implements
-    IBounds<Vec2[]> {
+    IBounds<Vec2[]>,
+    ICentroid<Vec2>,
+    IVertices<Vec2> {
 
     points: Vec2[];
     attribs: IObjectOf<any>;
@@ -24,15 +27,7 @@ export class PointContainer2 implements
     }
 
     bounds() {
-        const pts = this.points;
-        const min = Vec2.MAX.copy();
-        const max = Vec2.MIN.copy();
-        for (let i = pts.length; --i >= 0;) {
-            const p = pts[i];
-            min.min(p);
-            max.max(p);
-        }
-        return [min, max];
+        return bounds(this.points, Vec2.MAX.copy(), Vec2.MIN.copy());
     }
 
     width() {

packages/geom/src/container3.ts

@@ -2,10 +2,13 @@ import { IObjectOf } from "@thi.ng/api/api";
 import { illegalArgs } from "@thi.ng/errors/illegal-arguments";
 import { Mat44 } from "@thi.ng/vectors/mat44";
 import { Vec3, vec3 } from "@thi.ng/vectors/vec3";
-import { IBounds } from "./api";
+import { IBounds, ICentroid, IVertices } from "./api";
+import { bounds } from "./func/bounds";
 
 export class PointContainer3 implements
-    IBounds<Vec3[]> {
+    IBounds<Vec3[]>,
+    ICentroid<Vec3>,
+    IVertices<Vec3> {
 
     points: Vec3[];
     attribs: IObjectOf<any>;
@@ -24,15 +27,7 @@ export class PointContainer3 implements
     }
 
     bounds() {
-        const pts = this.points;
-        const min = Vec3.MAX.copy();
-        const max = Vec3.MIN.copy();
-        for (let i = pts.length; --i >= 0;) {
-            const p = pts[i];
-            min.min(p);
-            max.max(p);
-        }
-        return [min, max];
+        return bounds(this.points, Vec3.MAX.copy(), Vec3.MIN.copy());
     }
 
     width() {

packages/geom/src/func/arc-length.ts

@@ -0,0 +1,14 @@
+import { IDistance } from "@thi.ng/vectors/api";
+
+export const arcLength = <T extends IDistance<T>>(pts: Readonly<T>[], closed = false) => {
+    const num = pts.length;
+    if (num < 2) return 0;
+    let i = pts[0];
+    let j = pts[1];
+    let res = 0;
+    for (let k = 1; k < num; k++ , i = j, j = pts[k]) {
+        res += i.dist(j);
+    }
+    closed && (res += i.dist(pts[0]));
+    return res;
+};

packages/geom/src/func/bounds.ts

@@ -0,0 +1,10 @@
+import { IMinMax } from "@thi.ng/vectors/api";
+
+export const bounds = <T extends IMinMax<T>>(pts: T[], vmin: T, vmax: T) => {
+    for (let i = pts.length; --i >= 0;) {
+        const p = pts[i];
+        vmin.min(p);
+        vmax.max(p);
+    }
+    return [vmin, vmax];
+};

packages/geom/src/func/circumcenter.ts

@@ -0,0 +1,41 @@
+import { Vec2 } from "@thi.ng/vectors/vec2";
+
+export const circumCenter = (a: Readonly<Vec2>, b: Readonly<Vec2>, c: Readonly<Vec2>) => {
+    let m1, m2, mx1, mx2, my1, my2, xc, yc;
+    const deltaAB = Math.abs(a.y - b.y),
+        deltaBC = Math.abs(b.y - c.y);
+
+    if (deltaAB < 1e-6 && deltaBC < 1e-6) {
+        return null;
+    }
+    const ax = a.x, ay = a.y,
+        bx = b.x, by = b.y,
+        cx = c.x, cy = c.y;
+    if (deltaAB < 1e-6) {
+        m2 = - (cx - bx) / (cy - by);
+        mx2 = (bx + cx) / 2;
+        my2 = (by + cy) / 2;
+        xc = (bx + ax) / 2;
+        yc = m2 * (xc - mx2) + my2;
+    } else if (deltaBC < 1e-6) {
+        m1 = - (bx - ax) / (by - ay);
+        mx1 = (ax + bx) / 2;
+        my1 = (ay + by) / 2;
+        xc = (cx + bx) / 2;
+        yc = m1 * (xc - mx1) + my1;
+    } else {
+        m1 = - (bx - ax) / (by - ay);
+        m2 = - (cx - bx) / (cy - by);
+        mx1 = (ax + bx) / 2;
+        my1 = (ay + by) / 2;
+        mx2 = (bx + cx) / 2;
+        my2 = (by + cy) / 2;
+        xc = (m1 * mx1 - m2 * mx2 + my2 - my1) / (m1 - m2);
+        if (deltaAB > deltaBC) {
+            yc = m1 * (xc - mx1) + my1;
+        } else {
+            yc = m2 * (xc - mx2) + my2;
+        }
+    }
+    return new Vec2(xc, yc);
+}

packages/geom/src/func/edges.ts

@@ -0,0 +1,6 @@
+import { wrap } from "@thi.ng/transducers/iter/wrap";
+import { partition } from "@thi.ng/transducers/xform/partition";
+
+export const edges = <T>(vertices: T[], closed = false) => {
+    return partition(2, 1, closed ? wrap(vertices, 1, false, true) : vertices);
+};

packages/geom/src/common.ts → packages/geom/src/func/sample-uniform.ts

@@ -1,21 +1,5 @@
 import { peek } from "@thi.ng/transducers/func/peek";
-import { wrap } from "@thi.ng/transducers/iter/wrap";
-import { partition } from "@thi.ng/transducers/xform/partition";
-import { IDistance } from "@thi.ng/vectors/api";
-import { SampleableVector } from "./api";
-
-export const arcLength = <T extends IDistance<T>>(pts: Readonly<T>[], closed = false) => {
-    const num = pts.length;
-    if (num < 2) return 0;
-    let i = pts[0];
-    let j = pts[1];
-    let res = 0;
-    for (let k = 1; k < num; k++ , i = j, j = pts[k]) {
-        res += i.dist(j);
-    }
-    closed && (res += i.dist(pts[0]));
-    return res;
-}
+import { SampleableVector } from "../api";
 
 /**
  * Re-samples given polyline at given uniform distance. Returns array of
@@ -39,8 +23,3 @@ export const sampleUniform = <T extends SampleableVector<T>>(pts: T[], step: num
     res.push(peek(pts));
     return res;
 };
-
-
-export function edges<T>(vertices: T[], closed = false) {
-    return partition(2, 1, closed ? wrap(vertices, 1, false, true) : vertices);
-}

packages/geom/src/poly2.ts

@@ -1,12 +1,15 @@
-import { IObjectOf } from "@thi.ng/api/api";
+import { IObjectOf, IToHiccup } from "@thi.ng/api/api";
 import { Vec2 } from "@thi.ng/vectors/vec2";
-import { IArcLength, IArea } from "./api";
-import { arcLength, edges } from "./common";
+import { IArcLength, IArea, IEdges } from "./api";
 import { PointContainer2 } from "./container2";
+import { arcLength } from "./func/arc-length";
+import { edges } from "./func/edges";
 
 export class Polygon2 extends PointContainer2 implements
     IArcLength,
-    IArea {
+    IArea,
+    IEdges<Vec2[]>,
+    IToHiccup {
 
     constructor(points: Vec2[], attribs?: IObjectOf<any>) {
         super(points, attribs);

packages/geom/src/polyline2.ts

@@ -1,9 +1,16 @@
-import { IObjectOf } from "@thi.ng/api/api";
+import { IObjectOf, IToHiccup } from "@thi.ng/api/api";
 import { Vec2 } from "@thi.ng/vectors/vec2";
-import { arcLength, edges, sampleUniform } from "./common";
+import { IArcLength, IArea, IEdges } from "./api";
 import { PointContainer2 } from "./container2";
-
-export class Polyline2 extends PointContainer2 {
+import { arcLength } from "./func/arc-length";
+import { edges } from "./func/edges";
+import { sampleUniform } from "./func/sample-uniform";
+
+export class Polyline2 extends PointContainer2 implements
+    IArcLength,
+    IArea,
+    IEdges<Vec2[]>,
+    IToHiccup {
 
     constructor(points: Vec2[], attribs?: IObjectOf<any>) {
         super(points, attribs);