mirror of
https://github.com/EsotericSoftware/spine-runtimes.git
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271 lines
9.8 KiB
TypeScript
271 lines
9.8 KiB
TypeScript
/******************************************************************************
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* Spine Runtimes License Agreement
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* Last updated April 5, 2025. Replaces all prior versions.
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*
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* Copyright (c) 2013-2025, Esoteric Software LLC
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*
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* Integration of the Spine Runtimes into software or otherwise creating
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* derivative works of the Spine Runtimes is permitted under the terms and
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* conditions of Section 2 of the Spine Editor License Agreement:
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* http://esotericsoftware.com/spine-editor-license
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*
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* Otherwise, it is permitted to integrate the Spine Runtimes into software
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* or otherwise create derivative works of the Spine Runtimes (collectively,
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* "Products"), provided that each user of the Products must obtain their own
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* Spine Editor license and redistribution of the Products in any form must
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* include this license and copyright notice.
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*
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* THE SPINE RUNTIMES ARE PROVIDED BY ESOTERIC SOFTWARE LLC "AS IS" AND ANY
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* EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
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* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
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* DISCLAIMED. IN NO EVENT SHALL ESOTERIC SOFTWARE LLC BE LIABLE FOR ANY
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* DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
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* (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES,
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* BUSINESS INTERRUPTION, OR LOSS OF USE, DATA, OR PROFITS) HOWEVER CAUSED AND
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* ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
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* THE SPINE RUNTIMES, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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*****************************************************************************/
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import { type NumberArrayLike, Pool } from "./Utils.js";
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export class Triangulator {
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private convexPolygons = [] as Array<number>[];
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private convexPolygonsIndices = [] as Array<number>[];
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private indicesArray = [] as number[];
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private isConcaveArray = [] as boolean[];
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private triangles = [] as number[];
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private polygonPool = new Pool<Array<number>>(() => {
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return [] as number[];
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});
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private polygonIndicesPool = new Pool<Array<number>>(() => {
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return [] as number[];
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});
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public triangulate (verticesArray: NumberArrayLike): Array<number> {
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const vertices = verticesArray;
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let vertexCount = verticesArray.length >> 1;
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const indices = this.indicesArray;
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indices.length = 0;
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for (let i = 0; i < vertexCount; i++)
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indices[i] = i;
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const isConcave = this.isConcaveArray;
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isConcave.length = 0;
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for (let i = 0, n = vertexCount; i < n; ++i)
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isConcave[i] = Triangulator.isConcave(i, vertexCount, vertices, indices);
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const triangles = this.triangles;
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triangles.length = 0;
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while (vertexCount > 3) {
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// Find ear tip.
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let previous = vertexCount - 1, i = 0, next = 1;
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while (true) {
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// biome-ignore lint/suspicious/noConfusingLabels: reference runtime
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outer:
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if (!isConcave[i]) {
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const p1 = indices[previous] << 1, p2 = indices[i] << 1, p3 = indices[next] << 1;
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const p1x = vertices[p1], p1y = vertices[p1 + 1];
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const p2x = vertices[p2], p2y = vertices[p2 + 1];
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const p3x = vertices[p3], p3y = vertices[p3 + 1];
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for (let ii = (next + 1) % vertexCount; ii !== previous; ii = (ii + 1) % vertexCount) {
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if (!isConcave[ii]) continue;
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const v = indices[ii] << 1;
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const vx = vertices[v], vy = vertices[v + 1];
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if (Triangulator.positiveArea(p3x, p3y, p1x, p1y, vx, vy)) {
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if (Triangulator.positiveArea(p1x, p1y, p2x, p2y, vx, vy)) {
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if (Triangulator.positiveArea(p2x, p2y, p3x, p3y, vx, vy)) break outer;
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}
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}
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}
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break;
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}
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if (next === 0) {
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do {
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if (!isConcave[i]) break;
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i--;
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} while (i > 0);
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break;
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}
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previous = i;
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i = next;
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next = (next + 1) % vertexCount;
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}
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// Cut ear tip.
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triangles.push(indices[(vertexCount + i - 1) % vertexCount]);
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triangles.push(indices[i]);
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triangles.push(indices[(i + 1) % vertexCount]);
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indices.splice(i, 1);
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isConcave.splice(i, 1);
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vertexCount--;
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const previousIndex = (vertexCount + i - 1) % vertexCount;
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const nextIndex = i === vertexCount ? 0 : i;
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isConcave[previousIndex] = Triangulator.isConcave(previousIndex, vertexCount, vertices, indices);
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isConcave[nextIndex] = Triangulator.isConcave(nextIndex, vertexCount, vertices, indices);
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}
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if (vertexCount === 3) {
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triangles.push(indices[2]);
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triangles.push(indices[0]);
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triangles.push(indices[1]);
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}
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return triangles;
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}
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decompose (verticesArray: Array<number>, triangles: Array<number>): Array<Array<number>> {
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const vertices = verticesArray;
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const convexPolygons = this.convexPolygons;
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this.polygonPool.freeAll(convexPolygons);
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convexPolygons.length = 0;
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const convexPolygonsIndices = this.convexPolygonsIndices;
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this.polygonIndicesPool.freeAll(convexPolygonsIndices);
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convexPolygonsIndices.length = 0;
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let polygonIndices = this.polygonIndicesPool.obtain();
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polygonIndices.length = 0;
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let polygon = this.polygonPool.obtain();
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polygon.length = 0;
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// Merge subsequent triangles if they form a triangle fan.
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let fanBaseIndex = -1, lastWinding = 0;
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for (let i = 0, n = triangles.length; i < n; i += 3) {
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const t1 = triangles[i] << 1, t2 = triangles[i + 1] << 1, t3 = triangles[i + 2] << 1;
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const x1 = vertices[t1], y1 = vertices[t1 + 1];
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const x2 = vertices[t2], y2 = vertices[t2 + 1];
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const x3 = vertices[t3], y3 = vertices[t3 + 1];
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// If the base of the last triangle is the same as this triangle, check if they form a convex polygon (triangle fan).
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let merged = false;
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if (fanBaseIndex === t1) {
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const o = polygon.length - 4;
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const winding1 = Triangulator.winding(polygon[o], polygon[o + 1], polygon[o + 2], polygon[o + 3], x3, y3);
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const winding2 = Triangulator.winding(x3, y3, polygon[0], polygon[1], polygon[2], polygon[3]);
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if (winding1 === lastWinding && winding2 === lastWinding) {
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polygon.push(x3);
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polygon.push(y3);
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polygonIndices.push(t3);
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merged = true;
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}
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}
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// Otherwise make this triangle the new base.
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if (!merged) {
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if (polygon.length > 0) {
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convexPolygons.push(polygon);
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convexPolygonsIndices.push(polygonIndices);
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} else {
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this.polygonPool.free(polygon)
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this.polygonIndicesPool.free(polygonIndices);
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}
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polygon = this.polygonPool.obtain();
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polygon.length = 0;
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polygon.push(x1);
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polygon.push(y1);
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polygon.push(x2);
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polygon.push(y2);
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polygon.push(x3);
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polygon.push(y3);
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polygonIndices = this.polygonIndicesPool.obtain();
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polygonIndices.length = 0;
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polygonIndices.push(t1);
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polygonIndices.push(t2);
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polygonIndices.push(t3);
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lastWinding = Triangulator.winding(x1, y1, x2, y2, x3, y3);
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fanBaseIndex = t1;
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}
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}
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if (polygon.length > 0) {
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convexPolygons.push(polygon);
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convexPolygonsIndices.push(polygonIndices);
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}
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// Go through the list of polygons and try to merge the remaining triangles with the found triangle fans.
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for (let i = 0, n = convexPolygons.length; i < n; i++) {
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polygonIndices = convexPolygonsIndices[i];
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if (polygonIndices.length === 0) continue;
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const firstIndex = polygonIndices[0];
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const lastIndex = polygonIndices[polygonIndices.length - 1];
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polygon = convexPolygons[i];
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const o = polygon.length - 4;
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let prevPrevX = polygon[o], prevPrevY = polygon[o + 1];
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let prevX = polygon[o + 2], prevY = polygon[o + 3];
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const firstX = polygon[0], firstY = polygon[1];
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const secondX = polygon[2], secondY = polygon[3];
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const winding = Triangulator.winding(prevPrevX, prevPrevY, prevX, prevY, firstX, firstY);
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for (let ii = 0; ii < n; ii++) {
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if (ii === i) continue;
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const otherIndices = convexPolygonsIndices[ii];
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if (otherIndices.length !== 3) continue;
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const otherFirstIndex = otherIndices[0];
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const otherSecondIndex = otherIndices[1];
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const otherLastIndex = otherIndices[2];
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const otherPoly = convexPolygons[ii];
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const x3 = otherPoly[otherPoly.length - 2], y3 = otherPoly[otherPoly.length - 1];
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if (otherFirstIndex !== firstIndex || otherSecondIndex !== lastIndex) continue;
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const winding1 = Triangulator.winding(prevPrevX, prevPrevY, prevX, prevY, x3, y3);
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const winding2 = Triangulator.winding(x3, y3, firstX, firstY, secondX, secondY);
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if (winding1 === winding && winding2 === winding) {
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otherPoly.length = 0;
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otherIndices.length = 0;
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polygon.push(x3);
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polygon.push(y3);
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polygonIndices.push(otherLastIndex);
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prevPrevX = prevX;
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prevPrevY = prevY;
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prevX = x3;
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prevY = y3;
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ii = 0;
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}
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}
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}
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// Remove empty polygons that resulted from the merge step above.
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for (let i = convexPolygons.length - 1; i >= 0; i--) {
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polygon = convexPolygons[i];
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if (polygon.length === 0) {
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convexPolygons.splice(i, 1);
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this.polygonPool.free(polygon);
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polygonIndices = convexPolygonsIndices[i]
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convexPolygonsIndices.splice(i, 1)
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this.polygonIndicesPool.free(polygonIndices);
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}
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}
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return convexPolygons;
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}
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private static isConcave (index: number, vertexCount: number, vertices: NumberArrayLike, indices: NumberArrayLike): boolean {
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const previous = indices[(vertexCount + index - 1) % vertexCount] << 1;
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const current = indices[index] << 1;
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const next = indices[(index + 1) % vertexCount] << 1;
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return !Triangulator.positiveArea(vertices[previous], vertices[previous + 1], vertices[current], vertices[current + 1], vertices[next],
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vertices[next + 1]);
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}
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private static positiveArea (p1x: number, p1y: number, p2x: number, p2y: number, p3x: number, p3y: number): boolean {
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return p1x * (p3y - p2y) + p2x * (p1y - p3y) + p3x * (p2y - p1y) >= 0;
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}
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private static winding (p1x: number, p1y: number, p2x: number, p2y: number, p3x: number, p3y: number): number {
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const px = p2x - p1x, py = p2y - p1y;
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return p3x * py - p3y * px + px * p1y - p1x * py >= 0 ? 1 : -1;
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}
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}
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