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refactor(geom): add tessellate() multi-fn, move/rename tessellators
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| Original file line number | Diff line number | Diff line change |
|---|---|---|
| @@ -0,0 +1,179 @@ | ||
| import { isFunction } from "@thi.ng/checks"; | ||
| import { | ||
| comp, | ||
| last, | ||
| map, | ||
| mapcat, | ||
| partition, | ||
| push, | ||
| range, | ||
| reducer, | ||
| repeat, | ||
| scan, | ||
| transduce, | ||
| tuples, | ||
| wrap | ||
| } from "@thi.ng/transducers"; | ||
| import { | ||
| mixN, | ||
| ReadonlyVec, | ||
| signedArea2, | ||
| Vec | ||
| } from "@thi.ng/vectors3"; | ||
| import { Tessellator } from "../api"; | ||
| import { centroidRaw } from "../internal/centroid"; | ||
| import { pointInTriangle2 } from "../internal/triangle-point-inside"; | ||
| import { polyArea } from "../internal/poly-area"; | ||
|
|
||
| const snip = ( | ||
| points: ReadonlyVec[], | ||
| u: number, | ||
| v: number, | ||
| w: number, | ||
| n: number, | ||
| ids: number[] | ||
| ) => { | ||
| const a = points[ids[u]]; | ||
| const b = points[ids[v]]; | ||
| const c = points[ids[w]]; | ||
| if (signedArea2(a, b, c) > 0) { | ||
| for (let i = 0; i < n; i++) { | ||
| if (i !== u && i !== v && i !== w) { | ||
| if (pointInTriangle2(points[ids[i]], a, b, c)) { | ||
| return; | ||
| } | ||
| } | ||
| } | ||
| return [a, b, c]; | ||
| } | ||
| }; | ||
|
|
||
| export const tesselEarCut = | ||
| (points: ReadonlyVec[]) => { | ||
| const tris: Vec[][] = []; | ||
| let n = points.length; | ||
| const ids = [ | ||
| ...(polyArea(points) > 0 ? | ||
| range(n) : | ||
| range(n - 1, -1, -1)) | ||
| ]; | ||
| let count = 2 * n - 1; | ||
| let v = n - 1, u, w, t; | ||
| while (count > 0 && n > 2) { | ||
| u = n <= v ? 0 : v; | ||
| v = u + 1; | ||
| v = n <= v ? 0 : v; | ||
| w = v + 1; | ||
| w = n <= w ? 0 : w; | ||
| t = snip(points, u, v, w, n, ids); | ||
| if (t !== undefined) { | ||
| tris.push(t); | ||
| ids.splice(v, 1); | ||
| n--; | ||
| count = 2 * n; | ||
| } else { | ||
| count--; | ||
| } | ||
| } | ||
| return tris; | ||
| }; | ||
|
|
||
| export const tesselTriFan = | ||
| (points: ReadonlyVec[]) => { | ||
| const c = centroidRaw(points); | ||
| return transduce( | ||
| comp( | ||
| partition<Vec>(2, 1), | ||
| map(([a, b]) => [a, b, c]) | ||
| ), | ||
| push(), | ||
| wrap(points, 1, false, true) | ||
| ); | ||
| }; | ||
|
|
||
| export const tesselQuadFan = | ||
| (points: ReadonlyVec[]) => { | ||
| const p = centroidRaw(points); | ||
| return transduce( | ||
| comp( | ||
| partition<Vec>(3, 1), | ||
| map(([a, b, c]) => [mixN([], a, b, 0.5), b, mixN([], b, c, 0.5), p]) | ||
| ), | ||
| push(), | ||
| wrap(points, 1, true, true) | ||
| ); | ||
| }; | ||
|
|
||
| export const tesselEdgeSplit = | ||
| (points: ReadonlyVec[]) => { | ||
| const c = centroidRaw(points); | ||
| return transduce( | ||
| comp( | ||
| partition<Vec>(2, 1), | ||
| mapcat(([a, b]) => { | ||
| const m = mixN([], a, b, 0.5); | ||
| return [[a, m, c], [m, b, c]]; | ||
| })), | ||
| push(), | ||
| wrap(points, 1, false, true) | ||
| ); | ||
| }; | ||
|
|
||
| export const tesselRimTris = | ||
| (points: ReadonlyVec[]) => { | ||
| const edgeCentroids = transduce( | ||
| comp( | ||
| partition<Vec>(2, 1), | ||
| map((e) => mixN([], e[0], e[1], 0.5)) | ||
| ), | ||
| push(), | ||
| wrap(points, 1, false, true) | ||
| ); | ||
| return transduce( | ||
| comp( | ||
| partition<Vec[]>(2, 1), | ||
| map((t) => [t[0][0], t[1][1], t[1][0]]) | ||
| ), | ||
| push(), | ||
| [edgeCentroids], | ||
| wrap([...tuples(edgeCentroids, points)], 1, true, false) | ||
| ); | ||
| }; | ||
|
|
||
| export const tesselInset = | ||
| (inset = 0.5, keepInterior = false) => | ||
| (points: ReadonlyVec[]) => { | ||
| const c = centroidRaw(points); | ||
| const inner = points.map((p) => mixN([], p, c, inset)); | ||
| return transduce( | ||
| comp( | ||
| partition<Vec[]>(2, 1), | ||
| map(([[a, b], [c, d]]) => [a, b, d, c]) | ||
| ), | ||
| push(), | ||
| keepInterior ? [inner] : [], | ||
| wrap([...tuples(points, inner)], 1, false, true) | ||
| ); | ||
| }; | ||
|
|
||
| export function tessellatePoints(points: ReadonlyVec[], tessFn: Tessellator, iter?: number): Vec[][]; | ||
| export function tessellatePoints(points: ReadonlyVec[], tessFns: Iterable<Tessellator>): Vec[][]; | ||
| export function tessellatePoints(...args): Vec[][] { | ||
| return transduce( | ||
| scan( | ||
| reducer( | ||
| () => [args[0]], | ||
| (acc: Vec[][], fn: Tessellator) => | ||
| transduce( | ||
| mapcat(fn), | ||
| push(), | ||
| acc | ||
| ) | ||
| ) | ||
| ), | ||
| last(), | ||
| isFunction(args[1]) ? | ||
| repeat(args[1], args[2] || 1) : | ||
| args[1] | ||
| ); | ||
| } |
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| Original file line number | Diff line number | Diff line change |
|---|---|---|
| @@ -1,179 +1,10 @@ | ||
| import { isFunction } from "@thi.ng/checks"; | ||
| import { | ||
| comp, | ||
| last, | ||
| map, | ||
| mapcat, | ||
| partition, | ||
| push, | ||
| range, | ||
| reducer, | ||
| repeat, | ||
| scan, | ||
| transduce, | ||
| tuples, | ||
| wrap | ||
| } from "@thi.ng/transducers"; | ||
| import { | ||
| mixN, | ||
| ReadonlyVec, | ||
| signedArea2, | ||
| Vec | ||
| } from "@thi.ng/vectors3"; | ||
| import { Tessellator } from "../api"; | ||
| import { centroidRaw } from "../internal/centroid"; | ||
| import { pointInTriangle2 } from "../internal/triangle-point-inside"; | ||
| import { polyArea } from "../internal/poly-area"; | ||
| import { DEFAULT, defmulti } from "@thi.ng/defmulti"; | ||
| import { Vec } from "@thi.ng/vectors3"; | ||
| import { IShape, Tessellator } from "../api"; | ||
| import { dispatch } from "../internal/dispatch"; | ||
| import { tessellatePoints } from "../internal/tessellate"; | ||
| import { vertices } from "./vertices"; | ||
|
|
||
| const snip = ( | ||
| points: ReadonlyVec[], | ||
| u: number, | ||
| v: number, | ||
| w: number, | ||
| n: number, | ||
| ids: number[] | ||
| ) => { | ||
| const a = points[ids[u]]; | ||
| const b = points[ids[v]]; | ||
| const c = points[ids[w]]; | ||
| if (signedArea2(a, b, c) > 0) { | ||
| for (let i = 0; i < n; i++) { | ||
| if (i !== u && i !== v && i !== w) { | ||
| if (pointInTriangle2(points[ids[i]], a, b, c)) { | ||
| return; | ||
| } | ||
| } | ||
| } | ||
| return [a, b, c]; | ||
| } | ||
| }; | ||
| export const tessellate = defmulti<IShape, Tessellator[], Vec[][]>(dispatch); | ||
|
|
||
| export const earCut = | ||
| (points: ReadonlyVec[]) => { | ||
| const tris: Vec[][] = []; | ||
| let n = points.length; | ||
| const ids = [ | ||
| ...(polyArea(points) > 0 ? | ||
| range(n) : | ||
| range(n - 1, -1, -1)) | ||
| ]; | ||
| let count = 2 * n - 1; | ||
| let v = n - 1, u, w, t; | ||
| while (count > 0 && n > 2) { | ||
| u = n <= v ? 0 : v; | ||
| v = u + 1; | ||
| v = n <= v ? 0 : v; | ||
| w = v + 1; | ||
| w = n <= w ? 0 : w; | ||
| t = snip(points, u, v, w, n, ids); | ||
| if (t !== undefined) { | ||
| tris.push(t); | ||
| ids.splice(v, 1); | ||
| n--; | ||
| count = 2 * n; | ||
| } else { | ||
| count--; | ||
| } | ||
| } | ||
| return tris; | ||
| }; | ||
|
|
||
| export const triFan = | ||
| (points: ReadonlyVec[]) => { | ||
| const c = centroidRaw(points); | ||
| return transduce( | ||
| comp( | ||
| partition<Vec>(2, 1), | ||
| map(([a, b]) => [a, b, c]) | ||
| ), | ||
| push(), | ||
| wrap(points, 1, false, true) | ||
| ); | ||
| }; | ||
|
|
||
| export const quadFan = | ||
| (points: ReadonlyVec[]) => { | ||
| const p = centroidRaw(points); | ||
| return transduce( | ||
| comp( | ||
| partition<Vec>(3, 1), | ||
| map(([a, b, c]) => [mixN([], a, b, 0.5), b, mixN([], b, c, 0.5), p]) | ||
| ), | ||
| push(), | ||
| wrap(points, 1, true, true) | ||
| ); | ||
| }; | ||
|
|
||
| export const edgeSplit = | ||
| (points: ReadonlyVec[]) => { | ||
| const c = centroidRaw(points); | ||
| return transduce( | ||
| comp( | ||
| partition<Vec>(2, 1), | ||
| mapcat(([a, b]) => { | ||
| const m = mixN([], a, b, 0.5); | ||
| return [[a, m, c], [m, b, c]]; | ||
| })), | ||
| push(), | ||
| wrap(points, 1, false, true) | ||
| ); | ||
| }; | ||
|
|
||
| export const rimTris = | ||
| (points: ReadonlyVec[]) => { | ||
| const edgeCentroids = transduce( | ||
| comp( | ||
| partition<Vec>(2, 1), | ||
| map((e) => mixN([], e[0], e[1], 0.5)) | ||
| ), | ||
| push(), | ||
| wrap(points, 1, false, true) | ||
| ); | ||
| return transduce( | ||
| comp( | ||
| partition<Vec[]>(2, 1), | ||
| map((t) => [t[0][0], t[1][1], t[1][0]]) | ||
| ), | ||
| push(), | ||
| [edgeCentroids], | ||
| wrap([...tuples(edgeCentroids, points)], 1, true, false) | ||
| ); | ||
| }; | ||
|
|
||
| export const inset = | ||
| (inset = 0.5, keepInterior = false) => | ||
| (points: ReadonlyVec[]) => { | ||
| const c = centroidRaw(points); | ||
| const inner = points.map((p) => mixN([], p, c, inset)); | ||
| return transduce( | ||
| comp( | ||
| partition<Vec[]>(2, 1), | ||
| map(([[a, b], [c, d]]) => [a, b, d, c]) | ||
| ), | ||
| push(), | ||
| keepInterior ? [inner] : [], | ||
| wrap([...tuples(points, inner)], 1, false, true) | ||
| ); | ||
| }; | ||
|
|
||
| export function tessellatePoints(points: ReadonlyVec[], tessFn: Tessellator, iter?: number): Vec[][]; | ||
| export function tessellatePoints(points: ReadonlyVec[], tessFns: Iterable<Tessellator>): Vec[][]; | ||
| export function tessellatePoints(...args): Vec[][] { | ||
| return transduce( | ||
| scan( | ||
| reducer( | ||
| () => [args[0]], | ||
| (acc: Vec[][], fn: Tessellator) => | ||
| transduce( | ||
| mapcat(fn), | ||
| push(), | ||
| acc | ||
| ) | ||
| ) | ||
| ), | ||
| last(), | ||
| isFunction(args[1]) ? | ||
| repeat(args[1], args[2] || 1) : | ||
| args[1] | ||
| ); | ||
| } | ||
| tessellate.add(DEFAULT, ($, fns) => tessellatePoints(vertices($), fns)); |