mirror of
https://github.com/EsotericSoftware/spine-runtimes.git
synced 2025-12-21 09:46:02 +08:00
344 lines
14 KiB
C++
344 lines
14 KiB
C++
/******************************************************************************
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* Spine Runtimes Software License v2.5
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*
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* Copyright (c) 2013-2016, Esoteric Software
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* All rights reserved.
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*
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* You are granted a perpetual, non-exclusive, non-sublicensable, and
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* non-transferable license to use, install, execute, and perform the Spine
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* Runtimes software and derivative works solely for personal or internal
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* use. Without the written permission of Esoteric Software (see Section 2 of
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* the Spine Software License Agreement), you may not (a) modify, translate,
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* adapt, or develop new applications using the Spine Runtimes or otherwise
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* create derivative works or improvements of the Spine Runtimes or (b) remove,
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* delete, alter, or obscure any trademarks or any copyright, trademark, patent,
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* or other intellectual property or proprietary rights notices on or in the
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* Software, including any copy thereof. Redistributions in binary or source
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* form must include this license and terms.
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*
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* THIS SOFTWARE IS PROVIDED BY ESOTERIC SOFTWARE "AS IS" AND ANY EXPRESS OR
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* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
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* MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO
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* EVENT SHALL ESOTERIC SOFTWARE BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
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* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
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* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES, BUSINESS INTERRUPTION, OR LOSS OF
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* USE, DATA, OR PROFITS) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER
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* IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
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* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
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* POSSIBILITY OF SUCH DAMAGE.
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*****************************************************************************/
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#ifndef Spine_Triangulator_h
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#define Spine_Triangulator_h
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#include <spine/Vector.h>
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#include <spine/Pool.h>
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namespace Spine
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{
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class Triangulator
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{
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public:
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public Vector<int> triangulate(Vector<float>& verticesArray)
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{
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var vertices = verticesArray.Items;
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int vertexCount = verticesArray.Count >> 1;
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var indicesArray = _indicesArray;
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indicesArray.Clear();
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int[] indices = indicesArray.Resize(vertexCount).Items;
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for (int i = 0; i < vertexCount; i++)
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{
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indices[i] = i;
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}
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var isConcaveArray = _isConcaveArray;
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bool[] isConcave = isConcaveArray.Resize(vertexCount).Items;
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for (int i = 0, n = vertexCount; i < n; ++i)
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{
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isConcave[i] = isConcave(i, vertexCount, vertices, indices);
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}
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var triangles = _triangles;
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triangles.Clear();
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triangles.EnsureCapacity(Math.Max(0, vertexCount - 2) << 2);
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while (vertexCount > 3)
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{
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// Find ear tip.
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int previous = vertexCount - 1, i = 0, next = 1;
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// outer:
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while (true)
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{
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if (!isConcave[i])
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{
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int p1 = indices[previous] << 1, p2 = indices[i] << 1, p3 = indices[next] << 1;
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float p1x = vertices[p1], p1y = vertices[p1 + 1];
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float p2x = vertices[p2], p2y = vertices[p2 + 1];
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float p3x = vertices[p3], p3y = vertices[p3 + 1];
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for (int ii = (next + 1) % vertexCount; ii != previous; ii = (ii + 1) % vertexCount)
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{
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if (!isConcave[ii]) continue;
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int v = indices[ii] << 1;
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float vx = vertices[v], vy = vertices[v + 1];
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if (positiveArea(p3x, p3y, p1x, p1y, vx, vy))
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{
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if (positiveArea(p1x, p1y, p2x, p2y, vx, vy))
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{
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if (positiveArea(p2x, p2y, p3x, p3y, vx, vy))
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{
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goto break_outer; // break outer;
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}
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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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break_outer:
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if (next == 0)
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{
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do
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{
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if (!isConcave[i])
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{
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break;
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}
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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.Add(indices[(vertexCount + i - 1) % vertexCount]);
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triangles.Add(indices[i]);
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triangles.Add(indices[(i + 1) % vertexCount]);
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indicesArray.RemoveAt(i);
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isConcaveArray.RemoveAt(i);
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vertexCount--;
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int previousIndex = (vertexCount + i - 1) % vertexCount;
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int nextIndex = i == vertexCount ? 0 : i;
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isConcave[previousIndex] = isConcave(previousIndex, vertexCount, vertices, indices);
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isConcave[nextIndex] = isConcave(nextIndex, vertexCount, vertices, indices);
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}
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if (vertexCount == 3)
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{
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triangles.Add(indices[2]);
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triangles.Add(indices[0]);
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triangles.Add(indices[1]);
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}
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return triangles;
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}
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public Vector<Vector<float>> decompose(Vector<float>& verticesArray, Vector<int>& triangles)
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{
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var vertices = verticesArray.Items;
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var convexPolygons = _convexPolygons;
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for (int i = 0, n = convexPolygons.Count; i < n; i++)
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{
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polygonPool.Free(convexPolygons.Items[i]);
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}
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convexPolygons.Clear();
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var convexPolygonsIndices = _convexPolygonsIndices;
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for (int i = 0, n = convexPolygonsIndices.Count; i < n; i++)
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{
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polygonIndicesPool.Free(convexPolygonsIndices.Items[i]);
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}
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convexPolygonsIndices.Clear();
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var polygonIndices = polygonIndicesPool.Obtain();
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polygonIndices.Clear();
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var polygon = polygonPool.Obtain();
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polygon.Clear();
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// Merge subsequent triangles if they form a triangle fan.
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int fanBaseIndex = -1, lastwinding = 0;
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int[] trianglesItems = triangles.Items;
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for (int i = 0, n = triangles.Count; i < n; i += 3)
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{
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int t1 = trianglesItems[i] << 1, t2 = trianglesItems[i + 1] << 1, t3 = trianglesItems[i + 2] << 1;
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float x1 = vertices[t1], y1 = vertices[t1 + 1];
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float x2 = vertices[t2], y2 = vertices[t2 + 1];
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float 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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var merged = false;
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if (fanBaseIndex == t1)
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{
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int o = polygon.Count - 4;
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float[] p = polygon.Items;
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int winding1 = winding(p[o], p[o + 1], p[o + 2], p[o + 3], x3, y3);
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int winding2 = winding(x3, y3, p[0], p[1], p[2], p[3]);
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if (winding1 == lastwinding && winding2 == lastwinding)
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{
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polygon.Add(x3);
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polygon.Add(y3);
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polygonIndices.Add(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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{
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if (polygon.Count > 0)
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{
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convexPolygons.Add(polygon);
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convexPolygonsIndices.Add(polygonIndices);
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}
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else
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{
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polygonPool.Free(polygon);
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polygonIndicesPool.Free(polygonIndices);
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}
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polygon = polygonPool.Obtain();
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polygon.Clear();
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polygon.Add(x1);
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polygon.Add(y1);
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polygon.Add(x2);
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polygon.Add(y2);
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polygon.Add(x3);
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polygon.Add(y3);
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polygonIndices = polygonIndicesPool.Obtain();
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polygonIndices.Clear();
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polygonIndices.Add(t1);
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polygonIndices.Add(t2);
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polygonIndices.Add(t3);
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lastwinding = 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.Count > 0)
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{
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convexPolygons.Add(polygon);
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convexPolygonsIndices.Add(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 (int i = 0, n = convexPolygons.Count; i < n; ++i)
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{
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polygonIndices = convexPolygonsIndices.Items[i];
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if (polygonIndices.Count == 0) continue;
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int firstIndex = polygonIndices.Items[0];
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int lastIndex = polygonIndices.Items[polygonIndices.Count - 1];
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polygon = convexPolygons.Items[i];
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int o = polygon.Count - 4;
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float[] p = polygon.Items;
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float prevPrevX = p[o], prevPrevY = p[o + 1];
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float prevX = p[o + 2], prevY = p[o + 3];
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float firstX = p[0], firstY = p[1];
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float secondX = p[2], secondY = p[3];
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int winding = winding(prevPrevX, prevPrevY, prevX, prevY, firstX, firstY);
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for (int ii = 0; ii < n; ii++)
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{
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if (ii == i)
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{
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continue;
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}
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var otherIndices = convexPolygonsIndices.Items[ii];
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if (otherIndices.Count != 3)
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{
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continue;
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}
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int otherFirstIndex = otherIndices.Items[0];
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int otherSecondIndex = otherIndices.Items[1];
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int otherLastIndex = otherIndices.Items[2];
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var otherPoly = convexPolygons.Items[ii];
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float x3 = otherPoly.Items[otherPoly.Count - 2], y3 = otherPoly.Items[otherPoly.Count - 1];
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if (otherFirstIndex != firstIndex || otherSecondIndex != lastIndex)
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{
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continue;
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}
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int winding1 = winding(prevPrevX, prevPrevY, prevX, prevY, x3, y3);
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int winding2 = winding(x3, y3, firstX, firstY, secondX, secondY);
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if (winding1 == winding && winding2 == winding)
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{
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otherPoly.Clear();
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otherIndices.Clear();
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polygon.Add(x3);
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polygon.Add(y3);
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polygonIndices.Add(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 (int i = convexPolygons.Count - 1; i >= 0; --i)
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{
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polygon = convexPolygons.Items[i];
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if (polygon.Count == 0)
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{
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convexPolygons.RemoveAt(i);
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polygonPool.Free(polygon);
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polygonIndices = convexPolygonsIndices.Items[i];
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convexPolygonsIndices.RemoveAt(i);
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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:
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Vector<Vector<float>> _convexPolygons;
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Vector<Vector<int>> _convexPolygonsIndices;
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Vector<int> _indicesArray;
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Vector<bool> _isConcaveArray;
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Vector<int> _triangles;
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Pool<Vector<float>> _polygonPool;
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Pool<Vector<int>> _polygonIndicesPool;
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static bool isConcave(int index, int vertexCount, Vector<float> vertices, Vector<int> indices)
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{
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int previous = indices[(vertexCount + index - 1) % vertexCount] << 1;
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int current = indices[index] << 1;
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int next = indices[(index + 1) % vertexCount] << 1;
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return !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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static bool positiveArea(float p1x, float p1y, float p2x, float p2y, float p3x, float p3y)
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{
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return p1x * (p3y - p2y) + p2x * (p1y - p3y) + p3x * (p2y - p1y) >= 0;
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}
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static int winding(float p1x, float p1y, float p2x, float p2y, float p3x, float p3y)
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{
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float 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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}
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#endif /* Spine_Triangulator_h */
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