1 files changed, 112 insertions, 0 deletions
diff --git a/src/toys/path-along-path.cpp b/src/toys/path-along-path.cpp
new file mode 100644
index 0000000..a2a6a1b
--- /dev/null
+++ b/src/toys/path-along-path.cpp
@@ -0,0 +1,112 @@
+#include <2geom/d2.h>
+#include <2geom/piecewise.h>
+#include <2geom/sbasis.h>
+#include <2geom/sbasis-geometric.h>
+#include <2geom/bezier-to-sbasis.h>
+
+#include <toys/path-cairo.h>
+#include <toys/toy-framework-2.h>
+
+#include <algorithm>
+using std::vector;
+using namespace Geom;
+
+class PathAlongPathToy: public Toy {
+    PointSetHandle skel_handles, pat_handles;
+    PointHandle origin_handle;
+    bool should_draw_numbers() override{return false;}
+
+    void draw(cairo_t *cr, std::ostringstream *notify, int width, int height, bool save, std::ostringstream *timer_stream) override {
+        D2<SBasis> skeleton = skel_handles.asBezier();
+        D2<SBasis> pattern  = pat_handles.asBezier();
+
+
+        cairo_set_line_width(cr,1.);
+        cairo_pw_d2_sb(cr, Piecewise<D2<SBasis> >(skeleton));
+        cairo_set_source_rgba(cr,0.0,0.0,1.0,1.0);
+        cairo_stroke(cr);
+
+        cairo_pw_d2_sb(cr, Piecewise<D2<SBasis> >(pattern));
+        cairo_set_source_rgba(cr,1.0,0.0,1.0,1.0);
+        cairo_stroke(cr);
+
+        origin_handle.pos[0]=150;
+        Geom::Point origin = origin_handle.pos;
+
+        Piecewise<D2<SBasis> > uskeleton = arc_length_parametrization(Piecewise<D2<SBasis> >(skeleton),2,.1);
+        uskeleton = remove_short_cuts(uskeleton,.01);
+        Piecewise<D2<SBasis> > n = rot90(derivative(uskeleton));
+        n = force_continuity(remove_short_cuts(n,.1));
+        
+        Piecewise<SBasis> x=Piecewise<SBasis>(pattern[0]-origin[0]);
+        Piecewise<SBasis> y=Piecewise<SBasis>(pattern[1]-origin[1]);
+        Interval pattBnds = *bounds_exact(x);
+        int nbCopies = int(uskeleton.cuts.back()/pattBnds.extent());
+
+        //double pattWidth = uskeleton.cuts.back()/nbCopies;
+        double pattWidth = pattBnds.extent();
+        
+        double offs = 0;
+        x-=pattBnds.min();
+        //x*=pattWidth/pattBnds.extent();
+        
+        Piecewise<D2<SBasis> >output;
+        for (int i=0; i<nbCopies; i++){
+            output.concat(compose(uskeleton,x+offs)+y*compose(n,x+offs));
+            offs+=pattWidth;
+        }
+
+        //Perform cut for last segment
+        double tt = uskeleton.cuts.back() - offs;
+        if(tt > 0.) {
+            vector<double> rs = roots(x - tt);
+            rs.push_back(0); rs.push_back(1);  //regard endpoints
+            std::sort(rs.begin(), rs.end());
+            std::unique(rs.begin(), rs.end());
+            //enumerate indices of sections to the left of the line
+            for(unsigned i = (x[0].at0()>tt ? 1 : 0); i < rs.size()-1; i+=2) {
+                Piecewise<SBasis> port = portion(x+offs, rs[i], rs[i+1]);
+                output.concat(compose(uskeleton,port)+portion(y, rs[i], rs[i+1])*compose(n,port));
+            }
+        }
+
+        cairo_pw_d2_sb(cr, output);
+        cairo_set_source_rgba(cr,1.0,0.0,1.0,1.0);
+        cairo_stroke(cr);
+
+        Toy::draw(cr, notify, width, height, save,timer_stream);
+    }        
+
+public:
+    PathAlongPathToy() : origin_handle(150,150) {
+        if(handles.empty()) {
+            handles.push_back(&skel_handles);
+            handles.push_back(&pat_handles);
+            for(int i = 0; i < 8; i++)
+                skel_handles.push_back(200+50*i,400);
+            for(int i = 0; i < 4; i++)
+                pat_handles.push_back(100+uniform()*400,
+                                      150+uniform()*100);
+
+            handles.push_back(&origin_handle);
+        }
+    }
+};
+
+
+int main(int argc, char **argv) {
+    init(argc, argv, new PathAlongPathToy);
+    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:fileencoding=utf-8:textwidth=99 :
+