mirror of
https://github.com/Heretek-AI/GDevelop.git
synced 2026-07-23 10:35:35 -04:00
Florian Rival
a8559bfbbc
* Update all CMakeLists of extensions to use clang-format * Run clang-format on all Extensions * Update GDCore CMakeLists.txt to add clang-format * Run clang-format on GDCore files * Update GDJS and GDCpp CMakeLists.txt to add clang-format * Run clang-format on GDCpp and GDJS files
148 lines
3.4 KiB
C++
148 lines
3.4 KiB
C++
#include <assert.h>
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#include <stdio.h>
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#include <stdlib.h>
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#include <string.h>
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#include "triangulate.h"
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static const float EPSILON = 0.0000000001f;
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float Triangulate::Area(const Vector2fVector &contour) {
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int n = contour.size();
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float A = 0.0f;
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for (int p = n - 1, q = 0; q < n; p = q++) {
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A += contour[p].x * contour[q].y - contour[q].x * contour[p].y;
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}
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return A * 0.5f;
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}
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/*
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InsideTriangle decides if a point P is Inside of the triangle
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defined by A, B, C.
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*/
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bool Triangulate::InsideTriangle(float Ax,
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float Ay,
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float Bx,
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float By,
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float Cx,
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float Cy,
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float Px,
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float Py)
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{
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float ax, ay, bx, by, cx, cy, apx, apy, bpx, bpy, cpx, cpy;
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float cCROSSap, bCROSScp, aCROSSbp;
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ax = Cx - Bx;
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ay = Cy - By;
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bx = Ax - Cx;
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by = Ay - Cy;
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cx = Bx - Ax;
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cy = By - Ay;
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apx = Px - Ax;
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apy = Py - Ay;
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bpx = Px - Bx;
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bpy = Py - By;
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cpx = Px - Cx;
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cpy = Py - Cy;
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aCROSSbp = ax * bpy - ay * bpx;
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cCROSSap = cx * apy - cy * apx;
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bCROSScp = bx * cpy - by * cpx;
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return ((aCROSSbp >= 0.0f) && (bCROSScp >= 0.0f) && (cCROSSap >= 0.0f));
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};
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bool Triangulate::Snip(
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const Vector2fVector &contour, int u, int v, int w, int n, int *V) {
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int p;
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float Ax, Ay, Bx, By, Cx, Cy, Px, Py;
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Ax = contour[V[u]].x;
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Ay = contour[V[u]].y;
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Bx = contour[V[v]].x;
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By = contour[V[v]].y;
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Cx = contour[V[w]].x;
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Cy = contour[V[w]].y;
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if (EPSILON > (((Bx - Ax) * (Cy - Ay)) - ((By - Ay) * (Cx - Ax))))
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return false;
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for (p = 0; p < n; p++) {
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if ((p == u) || (p == v) || (p == w)) continue;
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Px = contour[V[p]].x;
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Py = contour[V[p]].y;
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if (InsideTriangle(Ax, Ay, Bx, By, Cx, Cy, Px, Py)) return false;
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}
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return true;
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}
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bool Triangulate::Process(const Vector2fVector &contour,
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Vector2fVector &result) {
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/* allocate and initialize list of Vertices in polygon */
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int n = contour.size();
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if (n < 3) return false;
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int *V = new int[n];
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/* we want a counter-clockwise polygon in V */
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if (0.0f < Area(contour))
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for (int v = 0; v < n; v++) V[v] = v;
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else
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for (int v = 0; v < n; v++) V[v] = (n - 1) - v;
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int nv = n;
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/* remove nv-2 Vertices, creating 1 triangle every time */
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int count = 2 * nv; /* error detection */
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for (int m = 0, v = nv - 1; nv > 2;) {
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/* if we loop, it is probably a non-simple polygon */
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if (0 >= (count--)) {
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//** Triangulate: ERROR - probable bad polygon!
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return false;
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}
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/* three consecutive vertices in current polygon, <u,v,w> */
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int u = v;
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if (nv <= u) u = 0; /* previous */
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v = u + 1;
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if (nv <= v) v = 0; /* new v */
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int w = v + 1;
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if (nv <= w) w = 0; /* next */
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if (Snip(contour, u, v, w, nv, V)) {
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int a, b, c, s, t;
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/* true names of the vertices */
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a = V[u];
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b = V[v];
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c = V[w];
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/* output Triangle */
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result.push_back(contour[a]);
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result.push_back(contour[b]);
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result.push_back(contour[c]);
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m++;
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/* remove v from remaining polygon */
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for (s = v, t = v + 1; t < nv; s++, t++) V[s] = V[t];
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nv--;
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/* resest error detection counter */
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count = 2 * nv;
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}
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}
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delete V;
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return true;
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}
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