#include <2geom/circle.h> #include using namespace Geom; class CircleIntersect : public Toy { PointSetHandle psh[2]; void draw(cairo_t *cr, std::ostringstream *notify, int width, int height, bool save, std::ostringstream *timer_stream) override { Rect all(Point(0, 0), Point(width, height)); double r = Geom::distance(psh[0].pts[0], psh[0].pts[1]); Circle circ(psh[0].pts[0], r); Line line(psh[1].pts[0], psh[1].pts[1]); std::vector result = circ.intersect(line); cairo_set_line_width(cr, 1.0); // draw the shapes cairo_set_source_rgb(cr, 0, 0, 0); cairo_arc(cr, circ.center(X), circ.center(Y), circ.radius(), 0, 2*M_PI); draw_line(cr, line, all); cairo_stroke(cr); // draw intersection points cairo_set_source_rgb(cr, 1, 0, 0); for (auto & i : result) { draw_handle(cr, i.point()); } cairo_stroke(cr); // show message if (!result.empty()) { for (auto & i : result) { *notify << i.point() << ", "; } } else { *notify << "No intersection"; } Toy::draw(cr, notify, width, height, save,timer_stream); } public: CircleIntersect(){ psh[0].push_back(200,200); psh[0].push_back(250,200); psh[1].push_back(150,150); psh[1].push_back(250,150); handles.push_back(&psh[0]); handles.push_back(&psh[1]); } }; int main(int argc, char **argv) { init(argc, argv, new CircleIntersect()); 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 :