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#include <2geom/d2.h>
#include <2geom/sbasis.h>
#include <2geom/sbasis-geometric.h>
#include <2geom/svg-path-parser.h>
#include <2geom/sbasis-math.h>
#include <toys/path-cairo.h>
#include <toys/toy-framework-2.h>
//Random walkers toy, written by mgsloan, initially for a school video proj.
using namespace Geom;
static void dot_plot(cairo_t *cr, Piecewise<D2<SBasis> > const &M, double min, double max, double space=10){
for( double t = min; t < max; t += space) {
Point pos = M(t), perp = M.valueAndDerivatives(t, 2)[1].cw() * 3;
draw_line_seg(cr, pos + perp, pos - perp);
}
cairo_stroke(cr);
}
D2<SBasis> random_d2() {
D2<SBasis> ret(SBasis(6, Linear()),
SBasis(6, Linear()));
ret[0][0] = Linear(uniform()*720, uniform()*720);
ret[1][0] = Linear(uniform()*480, uniform()*480);
int mul = 1;
for(int i = 1; i < 6; i++) {
ret[0][i] = Linear(uniform()*2000*mul - 1000, uniform()*2000*mul - 1000);
ret[1][i] = Linear(uniform()*2000*mul - 1000, uniform()*2000*mul - 1000);
mul*=2;
}
return ret;
}
class Worm {
Piecewise<D2<SBasis> > path;
int spawn_time, last_time;
double red, green, blue, length;
public:
void tele(int t) {
Piecewise<D2<SBasis> > new_path(portion(path, 0, t - last_time));
new_path.push(random_d2(), path.domain().max()+1);
path = arc_length_parametrization(new_path);
}
void add_section(const D2<SBasis> x) {
Piecewise<D2<SBasis> > new_path(path);
D2<SBasis> seg(x);
seg[0][0][0] = path.segs.back()[0][0][1];
seg[1][0][0] = path.segs.back()[1][0][1];
new_path.push(seg, path.domain().max()+1);
path = arc_length_parametrization(new_path);
}
Worm (int t, double r, double g, double b, double l) : spawn_time(t), last_time(t), red(r), green(g), blue(b), length(l) {
path = Piecewise<D2<SBasis> >(random_d2());
add_section(random_d2());
}
void draw(cairo_t *cr, int t) {
if(t - last_time > path.domain().max()) add_section(random_d2());
if(t - last_time - length > path.cuts[1]) {
Piecewise<D2<SBasis> > new_path;
new_path.push_cut(0);
for(unsigned i = 1; i < path.size(); i++) {
new_path.push(path[i], path.cuts[i+1] - path.cuts[1]);
}
last_time = t - length;
path = new_path;
}
cairo_set_source_rgb(cr, red, green, blue);
Piecewise<D2<SBasis> > port = portion(path, std::max(t - last_time - length, 0.), t - last_time);
cairo_pw_d2_sb(cr, port);
cairo_stroke(cr);
double d = 4;
cairo_set_dash(cr, &d, 1, 0);
for(unsigned i = 1; i < path.size(); i++) {
if(path[i].at0() != path[i-1].at1()) {
draw_line_seg(cr, path[i].at0(), path[i-1].at1());
}
}
cairo_stroke(cr);
cairo_set_dash(cr, &d, 0, 0);
cairo_set_source_rgb(cr, 0., 0., 1.);
dot_plot(cr, path, std::max(t - last_time - length, 0.), t - last_time);
}
void reverse_direction(int t) {
path = portion(path, 0, t - last_time);
D2<SBasis> seg = random_d2(), last = path[path.size()-1];
for(unsigned c = 0; c < 2; c++)
for(unsigned d = 1; d < seg[c].size() && d < last[c].size(); d++)
seg[c][d][0] = -last[c][d][1];
add_section(seg);
}
};
class Intro: public Toy {
int t;
vector<Worm> worms;
void draw(cairo_t *cr, std::ostringstream *notify, int width, int height, bool save, std::ostringstream *timer_stream) override {
t++;
if(t < 40 && t % 2 == 0) {
worms.emplace_back(t, uniform(), uniform(), uniform(), uniform() * 200 + 50);
}
for(auto & worm : worms) {
worm.draw(cr, t);
if(uniform() > .999) worm.tele(t);
}
Toy::draw(cr, notify, width, height, save,timer_stream);
redraw();
}
int should_draw_bounds() override { return 0; }
public:
Intro () {
t = 0;
}
};
int main(int argc, char **argv) {
init(argc, argv, new Intro(), 720, 480);
return 0;
}
/*
Local Variables:
mode:c++
c-file-style:"stroustrup"
c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
indent-tabs-mode:nil
fill-column:99
End:
*/
// vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=4:softtabstop=4:fileencoding=utf-8:textwidth=99 :
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