From 9c5779adc0a52cb88ccbfa315cf11544f00148bb Mon Sep 17 00:00:00 2001 From: Jaron Kent-Dobias Date: Thu, 24 Jan 2019 14:32:04 -0500 Subject: simplified random graph creation to only use uniform voronoi sites --- lib/src/graph.cpp | 73 +++---------------------------------------------------- 1 file changed, 4 insertions(+), 69 deletions(-) (limited to 'lib/src/graph.cpp') diff --git a/lib/src/graph.cpp b/lib/src/graph.cpp index 7c50ed0..2bd62a5 100644 --- a/lib/src/graph.cpp +++ b/lib/src/graph.cpp @@ -136,7 +136,7 @@ unsigned int get_triangle_signature(unsigned int j1, unsigned int j2, unsigned i } } -graph::graph(double Lx, double Ly, std::mt19937& rng, double relax, double step) { +graph::graph(double Lx, double Ly, std::mt19937& rng) { L = {Lx, Ly}; // randomly choose N to be floor(Lx * Ly / 2) or ceil(Lx * Ly / 2) with @@ -150,8 +150,8 @@ graph::graph(double Lx, double Ly, std::mt19937& rng, double relax, double step) // the coordinates of the lattice, from which a delaunay triangulation // and corresponding voronoi tessellation will be built. Everyone is in the // rectangle (0, 0) (Lx, Ly) - for (unsigned int i = 0; i < nv; i++) { - vertices[i] = {{L.x * d(rng), L.y * d(rng)}}; + for (vertex &v : vertices) { + v = {{Lx * d(rng), Ly * d(rng)}}; } // set up the voronoi objects @@ -160,72 +160,6 @@ graph::graph(double Lx, double Ly, std::mt19937& rng, double relax, double step) jcv_rect bounds = {{-Lx, -Ly}, {2 * Lx, 2 * Ly}}; std::vector points(9 * nv); - double rstep = sqrt(step); - - double max_difference = std::numeric_limits::max(); - while (max_difference > pow(relax, 2) * 2 * N) { - double cur_diff = 0; - // to make the resulting tessellation periodic, we tile eight (!) copies of - // the original points for a total of nine. note that the index of each - // point quotient 9 is equal to the original index (we'll use this to - // translate back) - for (unsigned int i = 0; i < nv; i++) { - const vertex& v = vertices[i]; - - points[9 * i + 0] = {v.r.x - L.x, v.r.y - L.y}; - points[9 * i + 1] = {v.r.x + 0.0, v.r.y - L.y}; - points[9 * i + 2] = {v.r.x + L.x, v.r.y - L.y}; - points[9 * i + 3] = {v.r.x - L.x, v.r.y + 0.0}; - points[9 * i + 4] = {v.r.x + 0.0, v.r.y + 0.0}; - points[9 * i + 5] = {v.r.x + L.x, v.r.y + 0.0}; - points[9 * i + 6] = {v.r.x - L.x, v.r.y + L.y}; - points[9 * i + 7] = {v.r.x + 0.0, v.r.y + L.y}; - points[9 * i + 8] = {v.r.x + L.x, v.r.y + L.y}; - } - - // run voronoi - jcv_diagram_generate(9 * nv, points.data(), &bounds, &diagram); - - // relax the sites by moving the vertices towards their centroids - const jcv_site* sites = jcv_diagram_get_sites(&diagram); - for (int i = 0; i < diagram.numsites; i++) { - const jcv_site* site = &sites[i]; - unsigned int ind = site->index; - if (ind % 9 == 4) { - double Cx = 0.0; - double Cy = 0.0; - double A = 0.0; - - const jcv_graphedge* e = site->edges; - while (e) { - double dA = e->pos[0].x * e->pos[1].y - e->pos[1].x * e->pos[0].y; - - A += dA; - Cx += (e->pos[0].x + e->pos[1].x) * dA; - Cy += (e->pos[0].y + e->pos[1].y) * dA; - - e = e->next; - } - - A /= 2; - Cx /= 6 * A; - Cy /= 6 * A; - - double dx = Cx - vertices[ind / 9].r.x; - double dy = Cy - vertices[ind / 9].r.y; - - double dist = pow(dx, 2) + pow(dy, 2); - if (dist > cur_diff) { - cur_diff = dist; - } - vertices[ind / 9] = {{mod(vertices[ind / 9].r.x + rstep * dx, L.x), mod(vertices[ind / 9].r.y + rstep * dy, L.y)}}; - } - } - max_difference = cur_diff; - jcv_diagram_free(&diagram); - memset(&diagram, 0, sizeof(jcv_diagram)); - } - for (unsigned int i = 0; i < nv; i++) { const vertex& v = vertices[i]; points[9 * i + 0] = {v.r.x - L.x, v.r.y - L.y}; @@ -238,6 +172,7 @@ graph::graph(double Lx, double Ly, std::mt19937& rng, double relax, double step) points[9 * i + 7] = {v.r.x + 0.0, v.r.y + L.y}; points[9 * i + 8] = {v.r.x + L.x, v.r.y + L.y}; } + jcv_diagram_generate(9 * nv, points.data(), &bounds, &diagram); const jcv_site* sites = jcv_diagram_get_sites(&diagram); -- cgit v1.2.3-70-g09d2