1 files changed, 63 insertions, 0 deletions
diff --git a/src/toys/sb-zeros.cpp b/src/toys/sb-zeros.cpp
new file mode 100644
index 0000000..ebe3aea
--- /dev/null
+++ b/src/toys/sb-zeros.cpp
@@ -0,0 +1,63 @@
+#include <2geom/d2.h>
+#include <2geom/sbasis.h>
+
+#include <toys/path-cairo.h>
+#include <toys/toy-framework-2.h>
+
+using namespace Geom;
+
+#define SIZE 4
+
+class SBZeros: public Toy {
+    PointSetHandle pB1, pB2;
+    void draw(cairo_t *cr, std::ostringstream *notify, int width, int height, bool save, std::ostringstream *timer_stream) override {
+        D2<SBasis> B1 = pB1.asBezier();
+        D2<SBasis> B2 = pB2.asBezier();
+        Piecewise<D2<SBasis> >B;
+        B.concat(Piecewise<D2<SBasis> >(B1));
+        B.concat(Piecewise<D2<SBasis> >(B2));
+        std::vector<Point> e;
+        std::vector<Piecewise<D2<SBasis> > > s;
+        s.push_back(derivative(B));
+        for(int j = 0; j < 5; j++) s.push_back(derivative(s.back()));
+        for(int j = 0; j <= 5; j++) {
+            for(unsigned d = 0; d < 2; d++) {
+                std::vector<double> r = roots(make_cuts_independent(s[j])[d]);
+                for(double k : r) e.push_back(B.valueAt(k));
+            }
+        }
+        for(auto & i : e) draw_cross(cr, i);
+        
+        cairo_set_line_width (cr, .5);
+        cairo_set_source_rgba (cr, 0., 0.5, 0., 1);
+        cairo_pw_d2_sb(cr, B);
+        cairo_stroke(cr);
+        Toy::draw(cr, notify, width, height, save,timer_stream);
+    }
+
+    public:
+    SBZeros () {
+        for(unsigned i = 0; i < SIZE; i++)
+            pB1.push_back(150+uniform()*300,150+uniform()*300);
+        for(unsigned i = 0; i < SIZE; i++)
+            pB2.push_back(150+uniform()*300,150+uniform()*300);
+        handles.push_back(&pB1);
+        handles.push_back(&pB2);
+    }
+};
+
+int main(int argc, char **argv) {
+    init(argc, argv, new SBZeros());
+    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 :