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#include <2geom/d2.h>
#include <2geom/sbasis.h>
#include <2geom/sbasis-2d.h>
#include <2geom/sbasis-geometric.h>
#include <2geom/sbasis-math.h>
#include <2geom/bezier-to-sbasis.h>
#include <2geom/sbasis-to-bezier.h>
#include <2geom/path-intersection.h>
#include <toys/path-cairo.h>
#include <toys/toy-framework-2.h>
#include <sstream>
using std::vector;
using namespace Geom;
using namespace std;
// TODO:
// use path2
// replace Ray stuff with path2 line segments.
//-----------------------------------------------
static void
plot_offset(cairo_t* cr, D2<SBasis> const &M,
Coord offset = 10,
unsigned NbPts = 10){
D2<SBasis> dM = derivative(M);
for (unsigned i = 0;i < NbPts;i++){
double t = i*1./NbPts;
Point V = dM(t);
V = offset*rot90(unit_vector(V));
draw_handle(cr, M(t)+V);
}
}
static void plot(cairo_t* cr, Piecewise<SBasis> const &f,double vscale=1){
D2<Piecewise<SBasis> > plot;
plot[1]=-f*vscale;
plot[1]+=450;
plot[0].cuts.push_back(f.cuts.front());
plot[0].cuts.push_back(f.cuts.back());
plot[0].segs.emplace_back(Linear(150,450));
for (unsigned i=1; i<f.size(); i++){
double t=f.cuts[i],ft=f.segs[i].at0();
cairo_move_to(cr, Point(150+t*300, 450));
cairo_line_to(cr, Point(150+t*300, 450-ft*vscale));
}
cairo_d2_pw_sb(cr, plot);
}
class OffsetTester: public Toy {
PointSetHandle psh;
void draw(cairo_t *cr, std::ostringstream *notify, int width, int height, bool save, std::ostringstream *timer_stream) override {
D2<SBasis> B = psh.asBezier();
*notify << "Curve offset:" << endl;
*notify << " -blue: pointwise plotted offset," << endl;
*notify << " -red: rot90(unitVector(derivative(.)))+rays at cut" << endl;
*notify << " -gray: cos(atan2),sin(atan2)" << endl;
cairo_set_line_width (cr, 1);
cairo_set_source_rgba (cr, 0., 0.5, 0., 1);
cairo_d2_sb(cr, B);
cairo_stroke(cr);
Coord offset = -100;
plot_offset(cr,B,offset,11);
cairo_set_source_rgba (cr, 0, 0, 1, 1);
cairo_stroke(cr);
cairo_set_source_rgba (cr, 0.5, 0.2, 0., 0.8);
Piecewise<D2<SBasis> > n = rot90(unitVector(derivative(B)));
Piecewise<D2<SBasis> > offset_curve = Piecewise<D2<SBasis> >(B)+n*offset;
PathVector offset_path = path_from_piecewise(offset_curve, 0.1);
cairo_path(cr, offset_path);
cairo_stroke(cr);
for(const auto & pi : offset_path) {
Crossings cs = self_crossings(pi);
for(auto & c : cs) {
draw_cross(cr, pi.pointAt(c.ta));
std::stringstream s;
Point Pa = pi.pointAt(c.ta);
Point Pb = pi.pointAt(c.tb);
s << L1(Pa - Pb) << std::endl;
std::string ss = s.str();
draw_text(cr, Pa+Point(3,3), ss.c_str(), false, "Serif 6");
}
}
for(unsigned i = 0; i < n.size()+1;i++){
Point ptA=B(n.cuts[i]), ptB;
if (i==n.size())
ptB=ptA+n.segs[i-1].at1()*offset;
else
ptB=ptA+n.segs[i].at0()*offset;
cairo_move_to(cr,ptA);
cairo_line_to(cr,ptB);
cairo_set_source_rgba (cr, 1, 0, 0, 1);
cairo_stroke(cr);
}
Piecewise<SBasis> alpha = atan2(derivative(B),1e-2,3);
plot(cr,alpha,75/M_PI);
Piecewise<D2<SBasis> >n2 = sectionize(D2<Piecewise<SBasis> >(sin(alpha),cos(alpha)));
cairo_pw_d2_sb(cr,Piecewise<D2<SBasis> >(B)+n2*offset*.9);
cairo_set_source_rgba (cr, 0.5, 0.2, 0.5, 0.8);
cairo_stroke(cr);
Piecewise<SBasis> k = curvature(B);
cairo_pw_d2_sb(cr,Piecewise<D2<SBasis> >(B)+k*n*100);
cairo_set_source_rgba (cr, 0.5, 0.2, 0.5, 0.8);
cairo_stroke(cr);
*notify << "Total length: " << length(B) << endl;
*notify << "(nb of cuts of unitVector: " << n.size()-1 << ")" << endl;
*notify << "(nb of cuts of cos,sin(atan2): " << n2.size()-1 << ")" << endl;
Toy::draw(cr, notify, width, height, save,timer_stream);
}
public:
OffsetTester(int order) {
handles.push_back(&psh);
for(int i = 0; i < order; i++)
psh.push_back(200+50*i,300+70*uniform());
}
};
int main(int argc, char **argv) {
int A_bez_ord = 6;
if(argc > 1)
sscanf(argv[1], "%d", &A_bez_ord);
init(argc, argv, new OffsetTester(A_bez_ord));
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 = 8:softtabstop = 4:encoding = utf-8:textwidth = 99 :
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