1 files changed, 129 insertions, 0 deletions
diff --git a/src/3rdparty/2geom/src/toys/conic-4.cpp b/src/3rdparty/2geom/src/toys/conic-4.cpp
new file mode 100644
index 0000000..0dbecd6
--- /dev/null
+++ b/src/3rdparty/2geom/src/toys/conic-4.cpp
@@ -0,0 +1,129 @@
+/**
+ * elliptics via 5 point w-pi basis. (njh)
+ * Affine, endpoint, tangent, exact circle
+ * full circle.  Convex containment implies small circle.
+ * Also represents lumpy polar type curves
+ */
+
+#include <2geom/d2.h>
+#include <2geom/sbasis.h>
+#include <2geom/sbasis-math.h>
+#include <2geom/bezier-to-sbasis.h>
+
+#include <toys/path-cairo.h>
+#include <toys/toy-framework-2.h>
+
+using std::vector;
+using namespace Geom;
+
+const double w = 1./3;
+const double cwp = cos(w*M_PI);
+const double swp = sin(w*M_PI);
+/*double phi(double t, double w) { return sin(w*t) - w*sin(t); }
+double phih(double t, double w) { return sin(w*t) + w*sin(t); }
+double b4(double t, double w) {return phi(t/2,w)*phih(t/2,w)/(swp*swp);}
+double b3(double t, double w) {return cwp*phi(t,w)/(2*swp) - cwp*cwp*b4(t,w); }
+double b2(double t, double w) {return 2*w*w*sin(t/2)*sin(t/2);}
+double b1(double t, double w) {return b3(2*M_PI - t, w);}
+double b0(double t, double w) {return b4(2*M_PI - t, w);}*/
+
+class arc_basis{
+public:
+    Piecewise<SBasis> basis[5];
+    double w;
+    
+    Piecewise<SBasis> phi(Piecewise<SBasis> const &d, double w) { 
+        return sin(d*w) - sin(d)*w; 
+    }
+    Piecewise<SBasis> phih(Piecewise<SBasis> const &d, double w) { 
+        return sin(d*w) + sin(d)*w; 
+    }
+    Piecewise<SBasis> b4(Piecewise<SBasis> const &d, double w) {
+        return phi(d*.5,w)/(swp*swp)*phih(d*.5,w);
+    }
+    Piecewise<SBasis> b3(Piecewise<SBasis> const &d, double w) {
+        return phi(d,w)*(cwp/(2*swp)) - b4(d,w)*(cwp*cwp); 
+    }
+
+    Piecewise<SBasis> b2(Piecewise<SBasis> const &d, double w) {
+        return sin(d*.5)*(2*w*w)*sin(d*.5);
+    }
+    Piecewise<SBasis> b1(Piecewise<SBasis> const &d, double w) {
+        return b3(reverse(d), w);
+    }
+    Piecewise<SBasis> b0(Piecewise<SBasis> const &d, double w) {
+        return b4(reverse(d), w);
+    }
+    
+    
+    arc_basis(double w) {
+        Piecewise<SBasis> dom(Linear(0, 2*M_PI));
+        basis[0] = b4(dom, w);
+        basis[1] = b3(dom, w);
+        basis[2] = b2(dom, w);
+        basis[3] = b1(dom, w);
+        basis[4] = b0(dom, w);
+    }
+
+};
+
+class Conic4: public Toy {
+    PointSetHandle psh;
+    public:
+    Conic4 () {
+        double sc = 30;
+        Geom::Point c(6*sc, 6*sc);
+        psh.push_back(sc*Geom::Point(0,0)+c);
+        psh.push_back(sc*Geom::Point(tan(w*M_PI)/w, 0)+c);
+        psh.push_back(sc*Geom::Point(0, 1/(w*w))+c);
+        psh.push_back(sc*Geom::Point(-tan(w*M_PI)/w, 0)+c);
+        psh.push_back(sc*Geom::Point(0,0)+c);
+        handles.push_back(&psh);
+    }
+
+    void draw(cairo_t *cr, std::ostringstream *notify, int width, int height, bool save, std::ostringstream *timer_stream) override {
+        std::vector<Geom::Point> e_h = psh.pts;
+        for(int i = 0; i < 5; i++) {
+            Geom::Point p = e_h[i];
+        
+            if(i)
+                cairo_line_to(cr, p);
+            else
+                cairo_move_to(cr, p);
+        }
+        cairo_set_source_rgba (cr, 0., 0., 0, 1);
+        cairo_set_line_width (cr, 1);
+        cairo_stroke(cr);
+        
+        arc_basis ab(1./3);
+        D2<Piecewise<SBasis> > B;
+        
+        for(unsigned dim  = 0; dim < 2; dim++)
+            for(unsigned i  = 0; i < 5; i++)
+                B[dim] += ab.basis[i]*e_h[i][dim];
+        
+        cairo_d2_pw_sb(cr, B);
+        cairo_set_source_rgba (cr, 1., 0.5, 0, 1);
+        cairo_set_line_width (cr, 1);
+        cairo_stroke(cr);
+
+        Toy::draw(cr, notify, width, height, save,timer_stream);
+    }
+};
+
+int main(int argc, char **argv) {
+    init(argc, argv, new Conic4());
+
+    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 :