From 33bfa28983025c2387388e0e5f7d7bdd0ceb0f8a Mon Sep 17 00:00:00 2001 From: Francois Fleuret Date: Sat, 1 Apr 2017 23:09:31 +0200 Subject: [PATCH] Fixed a major bug in the border forces, and changed the dissipation model to max-speed one. --- polygon.cc | 23 ++++++++++++++--------- 1 file changed, 14 insertions(+), 9 deletions(-) diff --git a/polygon.cc b/polygon.cc index ba629c5..353486e 100644 --- a/polygon.cc +++ b/polygon.cc @@ -31,7 +31,7 @@ using namespace std; static const scalar_t dl = 20.0; static const scalar_t repulsion_constant = 0.2; -static const scalar_t dissipation = 0.5; +static const scalar_t speed_max = 1e2; Polygon::Polygon(scalar_t mass, scalar_t red, scalar_t green, scalar_t blue, @@ -306,17 +306,18 @@ void Polygon::initialize(int nb_polygons) { } bool Polygon::update(scalar_t dt) { + scalar_t speed = sqrt(_dcenter_x * _dcenter_x + _dcenter_y * _dcenter_y); + scalar_t speed_target = speed_max - exp(-speed / speed_max) * speed_max; + + _dcenter_x = speed_target * _dcenter_x / speed; + _dcenter_y = speed_target * _dcenter_y / speed; + if(!_nailed) { _center_x += _dcenter_x * dt; _center_y += _dcenter_y * dt; _theta += _dtheta * dt; } - scalar_t d = exp(log(dissipation) * dt); - _dcenter_x *= d; - _dcenter_y *= d; - _dtheta *= d; - scalar_t vx = cos(_theta), vy = sin(_theta); for(int n = 0; n < _nb_vertices; n++) { @@ -366,11 +367,15 @@ void Polygon::apply_border_forces(scalar_t dt, scalar_t x = _x[v] * (1 - s) + _x[vp] * s; scalar_t y = _y[v] * (1 - s) + _y[vp] * s; scalar_t vx = 0, vy = 0; - if(x < xmin) vx = xmin - x; + if(x < xmin) vx = x - xmin; else if(x > xmax) vx = x - xmax; - if(y < ymin) vy = ymin - y; + if(y < ymin) vy = y - ymin; else if(y > ymax) vy = y - ymax; - apply_force(dt, x, y, - dl * vx * repulsion_constant, - dl * vy * repulsion_constant); + if(vx != 0 || vy != 0) { + // cerr << "apply_border_forces vx = " << vx << " vy = " << vy << endl; + apply_force(dt, x, y, + - dl * vx * repulsion_constant, - dl * vy * repulsion_constant); + } } } } -- 2.39.5