Adding upstream version 1.3.upstream/1.3upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 916 insertions, 0 deletions

diff --git a/src/toys/line-toy.cpp b/src/toys/line-toy.cpp
new file mode 100644
index 0000000..0090d3a
--- /dev/null
+++ b/src/toys/line-toy.cpp
@@ -0,0 +1,916 @@
+/*
+ * Line Toy
+ *
+ * Copyright 2008  Marco Cecchetti <mrcekets at gmail.com>
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it either under the terms of the GNU Lesser General Public
+ * License version 2.1 as published by the Free Software Foundation
+ * (the "LGPL") or, at your option, under the terms of the Mozilla
+ * Public License Version 1.1 (the "MPL"). If you do not alter this
+ * notice, a recipient may use your version of this file under either
+ * the MPL or the LGPL.
+ *
+ * You should have received a copy of the LGPL along with this library
+ * in the file COPYING-LGPL-2.1; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ * You should have received a copy of the MPL along with this library
+ * in the file COPYING-MPL-1.1
+ *
+ * The contents of this file are subject to the Mozilla Public License
+ * Version 1.1 (the "License"); you may not use this file except in
+ * compliance with the License. You may obtain a copy of the License at
+ * http://www.mozilla.org/MPL/
+ *
+ * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY
+ * OF ANY KIND, either express or implied. See the LGPL or the MPL for
+ * the specific language governing rights and limitations.
+ */
+
+
+#include <2geom/line.h>
+#include <toys/path-cairo.h>
+#include <toys/toy-framework-2.h>
+
+#include <2geom/angle.h>
+
+#include <vector>
+#include <string>
+#include <optional>
+
+using namespace Geom;
+
+
+
+std::string angle_formatter(double angle)
+{
+    return default_formatter(decimal_round(deg_from_rad(angle),2));
+}
+
+
+
+class LineToy : public Toy
+{
+    enum menu_item_t
+    {
+        SHOW_MENU = 0,
+        TEST_CREATE,
+        TEST_PROJECTION,
+        TEST_ORTHO,
+        TEST_DISTANCE,
+        TEST_POSITION,
+        TEST_SEG_BISEC,
+        TEST_ANGLE_BISEC,
+        TEST_COLLINEAR,
+        TEST_INTERSECTIONS,
+        TEST_COEFFICIENTS,
+        TEST_SEGMENT_INSIDE,
+        TOTAL_ITEMS // this one must be the last item
+    };
+
+    enum handle_label_t
+    {
+    };
+
+    enum toggle_label_t
+    {
+    };
+
+    enum slider_label_t
+    {
+        END_SHARED_SLIDERS = 0,
+        ANGLE_SLIDER = END_SHARED_SLIDERS,
+        A_COEFF_SLIDER = END_SHARED_SLIDERS,
+        B_COEFF_SLIDER,
+        C_COEFF_SLIDER
+    };
+
+    static const char* menu_items[TOTAL_ITEMS];
+    static const char keys[TOTAL_ITEMS];
+
+    void first_time(int /*argc*/, char** /*argv*/) override
+    {
+        draw_f = &LineToy::draw_menu;
+    }
+
+    void init_common()
+    {
+        set_common_control_geometry = true;
+        set_control_geometry = true;
+
+        sliders.clear();
+        toggles.clear();
+        handles.clear();
+    }
+
+
+    virtual void draw_common( cairo_t *cr, std::ostringstream *notify,
+                              int width, int height, bool /*save*/ )
+    {
+        init_common_ctrl_geom(cr, width, height, notify);
+    }
+
+
+    void init_create()
+    {
+        init_common();
+
+        p1.pos = Point(400, 50);
+        p2.pos = Point(450, 450);
+        O.pos = Point(50, 400);
+
+        sliders.emplace_back(0, 2*M_PI, 0, 0, "angle");
+        sliders[ANGLE_SLIDER].formatter(&angle_formatter);
+
+        handles.push_back(&p1);
+        handles.push_back(&p2);
+        handles.push_back(&O);
+        handles.push_back(&(sliders[ANGLE_SLIDER]));
+    }
+
+    void draw_create(cairo_t *cr, std::ostringstream *notify,
+                      int width, int height, bool save, std::ostringstream */*timer_stream*/)
+    {
+        draw_common(cr, notify, width, height, save);
+        init_create_ctrl_geom(cr, notify, width, height);
+
+        Line l1(p1.pos, p2.pos);
+        Line l2(O.pos, sliders[ANGLE_SLIDER].value());
+
+        cairo_set_source_rgba(cr, 0.0, 0.0, 0.0, 1.0);
+        cairo_set_line_width(cr, 0.3);
+        draw_line(cr, l1);
+        draw_line(cr, l2);
+        cairo_stroke(cr);
+
+        draw_label(cr, p1, "P1");
+        draw_label(cr, p2, "P2");
+        draw_label(cr, O, "O");
+        draw_label(cr, l1, "L(P1,P2)");
+        draw_label(cr, l2, "L(O,angle)");
+    }
+
+
+    void init_projection()
+    {
+        init_common();
+        p1.pos = Point(400, 50);
+        p2.pos = Point(450, 450);
+        p3.pos = Point(100, 250);
+        p4.pos = Point(200, 450);
+        O.pos = Point(50, 150);
+
+        handles.push_back(&p1);
+        handles.push_back(&p2);
+        handles.push_back(&p3);
+        handles.push_back(&p4);
+        handles.push_back(&O);
+    }
+
+    void draw_projection(cairo_t *cr, std::ostringstream *notify,
+                      int width, int height, bool save, std::ostringstream */*timer_stream*/)
+    {
+        draw_common(cr, notify, width, height, save);
+
+        Line l1(p1.pos, p2.pos);
+        LineSegment ls(p3.pos, p4.pos);
+
+        Point np = projection(O.pos, l1);
+        LineSegment lsp = projection(ls, l1);
+
+        cairo_set_source_rgba(cr, 0.3, 0.3, 0.3, 1.0);
+        cairo_set_line_width(cr, 0.2);
+        draw_line(cr, l1);
+        draw_segment(cr, ls);
+        cairo_stroke(cr);
+
+        cairo_set_line_width(cr, 0.3);
+        cairo_set_source_rgba(cr, 0.0, 0.0, 1.0, 1.0);
+        draw_segment(cr, lsp);
+        draw_handle(cr, lsp[0]);
+        draw_handle(cr, lsp[1]);
+        cairo_stroke(cr);
+
+        cairo_set_source_rgba(cr, 0.8, 0.0, 0.0, 1.0);
+        draw_circ(cr, np);
+        cairo_stroke(cr);
+
+        cairo_set_source_rgba(cr, 0.5, 0.5, 0.5, 1.0);
+        draw_label(cr, p1, "P1");
+        draw_label(cr, p2, "P2");
+        draw_label(cr, ls, "S");
+        draw_label(cr, lsp, "prj(S)");
+        draw_label(cr, O, "P");
+        draw_text(cr, np, "prj(P)");
+
+        cairo_stroke(cr);
+    }
+
+
+    void init_ortho()
+    {
+        init_common();
+        p1.pos = Point(400, 50);
+        p2.pos = Point(450, 450);
+        p3.pos = Point(100, 50);
+        p4.pos = Point(150, 450);
+
+        handles.push_back(&p1);
+        handles.push_back(&p2);
+        handles.push_back(&p3);
+        handles.push_back(&p4);
+    }
+
+    void draw_ortho(cairo_t *cr, std::ostringstream *notify,
+                      int width, int height, bool save, std::ostringstream */*timer_stream*/)
+    {
+        draw_common(cr, notify, width, height, save);
+
+        Line l1(p1.pos, p2.pos);
+        Line l2 = make_orthogonal_line(p3.pos, l1);
+        Line l3 = make_parallel_line(p4.pos, l1);
+
+        cairo_set_source_rgba(cr, 0.0, 0.0, 0.0, 1.0);
+        cairo_set_line_width(cr, 0.3);
+        draw_line(cr, l1);
+        draw_line(cr, l2);
+        draw_line(cr, l3);
+        cairo_stroke(cr);
+
+        draw_label(cr, p1, "P1");
+        draw_label(cr, p2, "P2");
+        draw_label(cr, p3, "O1");
+        draw_label(cr, p4, "O2");
+
+        draw_label(cr, l1, "L");
+        draw_label(cr, l2, "L1 _|_ L");
+        draw_label(cr, l3, "L2 // L");
+
+    }
+
+
+    void init_distance()
+    {
+        init_common();
+        p1.pos = Point(400, 50);
+        p2.pos = Point(450, 450);
+        p3.pos = Point(100, 250);
+        p4.pos = Point(200, 450);
+        p5.pos = Point(50, 150);
+        p6.pos = Point(480, 60);
+        O.pos = Point(300, 300);
+
+        handles.push_back(&p1);
+        handles.push_back(&p2);
+        handles.push_back(&p3);
+        handles.push_back(&p4);
+        handles.push_back(&p5);
+        handles.push_back(&p6);
+        handles.push_back(&O);
+    }
+
+    void draw_distance(cairo_t *cr, std::ostringstream *notify,
+                      int width, int height, bool save, std::ostringstream */*timer_stream*/)
+    {
+        draw_common(cr, notify, width, height, save);
+
+        Line l1(p1.pos, p2.pos);
+        LineSegment ls(p3.pos, p4.pos);
+        Ray r1(p5.pos, p6.pos);
+
+        Point q1 = l1.pointAt(l1.nearestTime(O.pos));
+        Point q2 = ls.pointAt(ls.nearestTime(O.pos));
+        Point q3 = r1.pointAt(r1.nearestTime(O.pos));
+
+        double d1 = distance(O.pos, l1);
+        double d2 = distance(O.pos, ls);
+        double d3 = distance(O.pos, r1);
+
+        cairo_set_source_rgba(cr, 0.0, 0.0, 0.0, 1.0);
+        cairo_set_line_width(cr, 0.3);
+        draw_line(cr, l1);
+        draw_segment(cr, ls);
+        draw_ray(cr, r1);
+        cairo_stroke(cr);
+
+
+        draw_label(cr, l1, "L");
+        draw_label(cr, ls, "S");
+        draw_label(cr, r1, "R");
+        draw_label(cr, O, "P");
+        cairo_stroke(cr);
+
+        cairo_set_source_rgba(cr, 0.5, 0.5, 0.8, 1.0);
+        cairo_set_line_width(cr, 0.2);
+        draw_segment(cr, O.pos, q1);
+        draw_segment(cr, O.pos, q2);
+        draw_segment(cr, O.pos, q3);
+        cairo_stroke(cr);
+
+        cairo_set_source_rgba(cr, 0.8, 0.0, 0.0, 1.0);
+        cairo_set_line_width(cr, 0.3);
+        draw_handle(cr, q1);
+        draw_handle(cr, q2);
+        draw_handle(cr, q3);
+        cairo_stroke(cr);
+
+        *notify << "  distance(P,L) = " << d1 << std::endl;
+        *notify << "  distance(P,S) = " << d2 << std::endl;
+        *notify << "  distance(P,R) = " << d3 << std::endl;
+    }
+
+
+    void init_position()
+    {
+        init_common();
+        p1.pos = Point(400, 50);
+        p2.pos = Point(450, 450);
+        p3.pos = Point(100, 50);
+        p4.pos = Point(150, 450);
+
+        handles.push_back(&p1);
+        handles.push_back(&p2);
+        handles.push_back(&p3);
+        handles.push_back(&p4);
+    }
+
+    void draw_position(cairo_t *cr, std::ostringstream *notify,
+                      int width, int height, bool save, std::ostringstream */*timer_stream*/)
+    {
+        draw_common(cr, notify, width, height, save);
+
+        Line l1(p1.pos, p2.pos);
+        Line l2(p3.pos, p4.pos);
+
+        bool b1 = are_same(l1, l2, 0.01);
+        bool b2 = are_parallel(l1, l2, 0.01);
+        bool b3 = are_orthogonal(l1, l2, 0.01);
+
+        double a = angle_between(l1,l2);
+
+        cairo_set_source_rgba(cr, 0.0, 0.0, 0.0, 1.0);
+        cairo_set_line_width(cr, 0.3);
+        draw_line(cr, l1);
+        draw_line(cr, l2);
+        cairo_stroke(cr);
+
+        draw_label(cr, l1, "A");
+        draw_label(cr, l2, "B");
+        cairo_stroke(cr);
+
+        if (b1)
+        {
+            *notify << "  A is coincident with B" << std::endl;
+        }
+        else if (b2)
+        {
+            *notify << "  A is parallel to B" << std::endl;
+        }
+        else if (b3)
+        {
+            *notify << "  A is orthogonal to B" << std::endl;
+        }
+        else
+        {
+            *notify << "  A is incident with B:  angle(A,B) = " << angle_formatter(a) << std::endl;
+        }
+    }
+
+
+    void init_seg_bisec()
+    {
+        init_common();
+        p1.pos = Point(100, 50);
+        p2.pos = Point(150, 450);
+
+        handles.push_back(&p1);
+        handles.push_back(&p2);
+    }
+
+    void draw_seg_bisec(cairo_t *cr, std::ostringstream *notify,
+                      int width, int height, bool save, std::ostringstream */*timer_stream*/)
+    {
+        draw_common(cr, notify, width, height, save);
+
+        LineSegment ls(p1.pos, p2.pos);
+        Line l = make_bisector_line(ls);
+        Point M = middle_point(p1.pos, p2.pos);
+
+        cairo_set_source_rgba(cr, 0.0, 0.0, 0.0, 1.0);
+        cairo_set_line_width(cr, 0.3);
+        draw_label(cr, p1, "P");
+        draw_label(cr, p2, "Q");
+        draw_label(cr, M, "M");
+        draw_segment(cr, ls);
+        draw_line(cr, l);
+        cairo_stroke(cr);
+
+        draw_label(cr, l, "axis");
+        cairo_stroke(cr);
+    }
+
+
+    void init_angle_bisec()
+    {
+        init_common();
+        p1.pos = Point(100, 50);
+        p2.pos = Point(150, 450);
+        O.pos = Point(50, 200);
+
+        handles.push_back(&p1);
+        handles.push_back(&p2);
+        handles.push_back(&O);
+    }
+
+    void draw_angle_bisec(cairo_t *cr, std::ostringstream *notify,
+                      int width, int height, bool save, std::ostringstream */*timer_stream*/)
+    {
+        draw_common(cr, notify, width, height, save);
+
+        Ray r1(O.pos, p1.pos);
+        Ray r2(O.pos, p2.pos);
+        Ray rb = make_angle_bisector_ray(r1, r2);
+
+        double a1 = angle_between(r1,rb);
+        double a2 = angle_between(rb,r2);
+
+        cairo_set_source_rgba(cr, 0.0, 0.0, 0.0, 1.0);
+        cairo_set_line_width(cr, 0.3);
+        draw_label(cr, O, "O");
+        draw_ray(cr, r1);
+        draw_ray(cr, r2);
+        draw_ray(cr, rb);
+        cairo_stroke(cr);
+
+        draw_label(cr, r1, "R1");
+        draw_label(cr, r2, "R2");
+        draw_label(cr, rb, "bisector ray");
+
+        *notify << "  angle(R1, bisector ray) = " << angle_formatter(a1)
+                << "    angle(bisector ray, R2) = " << angle_formatter(a2)
+                << std::endl;
+    }
+
+
+    void init_collinear()
+    {
+        init_common();
+        p1.pos = Point(100, 50);
+        p2.pos = Point(450, 450);
+        p3.pos = Point(400, 50);
+
+        handles.push_back(&p1);
+        handles.push_back(&p2);
+        handles.push_back(&p3);
+    }
+
+    void draw_collinear(cairo_t *cr, std::ostringstream *notify,
+                      int width, int height, bool save, std::ostringstream */*timer_stream*/)
+    {
+        draw_common(cr, notify, width, height, save);
+
+        Point A = p1.pos;
+        Point B = p2.pos;
+        Point C = p3.pos;
+
+        LineSegment AB(A, B);
+        LineSegment BC(B, C);
+        Line l(A, C);
+
+        cairo_set_source_rgba(cr, 0.0, 0.0, 0.0, 1.0);
+        cairo_set_line_width(cr, 0.3);
+        draw_label(cr, p1, "A");
+        draw_label(cr, p2, "B");
+        draw_label(cr, p3, "C");
+        cairo_stroke(cr);
+
+
+        double turn = cross(C, B) - cross(C, A) + cross(B, A);
+        //*notify << "  turn: " << turn << std::endl;
+
+        bool collinear = are_collinear(A, B, C, 200);
+        if (collinear)
+        {
+            cairo_set_source_rgba(cr, 0.0, 0.0, 0.0, 1.0);
+            cairo_set_line_width(cr, 0.3);
+            draw_line(cr, l);
+            cairo_stroke(cr);
+            *notify << "  A,B,C are collinear!" << std::endl;
+        }
+        else
+        {
+            cairo_set_source_rgba(cr, 0.5, 0.5, 0.8, 1.0);
+            cairo_set_line_width(cr, 0.2);
+            draw_segment(cr, AB);
+            draw_segment(cr, BC);
+            cairo_stroke(cr);
+            if (turn < 0)
+                *notify << "  A,B,C is a left turn:  " << turn << std::endl;
+            else
+                *notify << "  A,B,C is a right turn: " << turn << std::endl;
+        }
+
+    }
+
+
+    void init_intersections()
+    {
+        init_common();
+        p1.pos = Point(400, 50);
+        p2.pos = Point(450, 450);
+        p3.pos = Point(100, 250);
+        p4.pos = Point(200, 450);
+        p5.pos = Point(50, 150);
+        p6.pos = Point(480, 60);
+
+        handles.push_back(&p1);
+        handles.push_back(&p2);
+        handles.push_back(&p3);
+        handles.push_back(&p4);
+        handles.push_back(&p5);
+        handles.push_back(&p6);
+    }
+
+    void draw_intersections(cairo_t *cr, std::ostringstream *notify,
+                            int width, int height, bool save, std::ostringstream */*timer_stream*/)
+    {
+        draw_common(cr, notify, width, height, save);
+
+        Line l1(p1.pos, p2.pos);
+        Ray r1(p3.pos, p4.pos);
+        LineSegment s1(p5.pos, p6.pos);
+
+        std::vector<ShapeIntersection> cl1r1 = l1.intersect(r1);
+        std::vector<ShapeIntersection> cl1s1 = l1.intersect(s1);
+        std::vector<ShapeIntersection> cr1s1 = Line(r1).intersect(s1);
+        filter_ray_intersections(cr1s1, true, false);
+
+        std::vector<Point> ip;
+
+        if (!cl1r1.empty()) {
+            ip.push_back(l1.pointAt(cl1r1[0].first));
+        }
+        if (!cl1s1.empty()) {
+            ip.push_back(l1.pointAt(cl1s1[0].first));
+        }
+        if (!cr1s1.empty()) {
+            ip.push_back(r1.pointAt(cr1s1[0].first));
+        }
+
+        cairo_set_source_rgba(cr, 0.2, 0.2, 0.2, 1.0);
+        cairo_set_line_width(cr, 0.3);
+        draw_line(cr, l1);
+        draw_ray(cr, r1);
+        draw_segment(cr, s1);
+        cairo_stroke(cr);
+
+
+        draw_label(cr, l1, "L");
+        draw_label(cr, r1, "R");
+        draw_label(cr, s1, "S");
+        cairo_stroke(cr);
+
+        std::string label("A");
+        cairo_set_source_rgba(cr, 1.0, 0.0, 0.0, 1.0);
+        cairo_set_line_width(cr, 0.5);
+        for (auto & i : ip)
+        {
+            draw_handle(cr, i);
+            draw_text(cr, i+op, label.c_str());
+            label[0] += 1;
+        }
+        cairo_stroke(cr);
+
+    }
+
+
+    void init_coefficients()
+    {
+        init_common();
+        p1.pos = Point(400, 50);
+        p2.pos = Point(450, 450);
+
+        Line l(p1.pos, p2.pos);
+        std::vector<double> coeff = l.coefficients();
+        sliders.emplace_back(-1, 1, 0, coeff[0], "A");
+        sliders.emplace_back(-1, 1, 0, coeff[1], "B");
+        sliders.emplace_back(-500, 500, 0, coeff[2], "C");
+
+        handles.push_back(&p1);
+        handles.push_back(&p2);
+        handles.push_back(&(sliders[A_COEFF_SLIDER]));
+        handles.push_back(&(sliders[B_COEFF_SLIDER]));
+        handles.push_back(&(sliders[C_COEFF_SLIDER]));
+    }
+
+    void draw_coefficients(cairo_t *cr, std::ostringstream *notify,
+                            int width, int height, bool save, std::ostringstream */*timer_stream*/)
+    {
+        draw_common(cr, notify, width, height, save);
+        init_coefficients_ctrl_geom(cr, notify, width, height);
+
+        Line l1(p1.pos, p2.pos);
+        std::vector<double> coeff1 = l1.coefficients();
+        Line l2(sliders[A_COEFF_SLIDER].value(),
+                sliders[B_COEFF_SLIDER].value(),
+                sliders[C_COEFF_SLIDER].value());
+
+        cairo_set_source_rgba(cr, 0.0, 0.0, 0.0, 1.0);
+        cairo_set_line_width(cr, 0.8);
+        draw_line(cr, l1);
+        cairo_stroke(cr);
+
+        cairo_set_source_rgba(cr, 1.0, 0.0, 0.0, 1.0);
+        cairo_set_line_width(cr, 0.4);
+        draw_line(cr, l2);
+        cairo_stroke(cr);
+
+        cairo_set_source_rgba(cr, 0.0, 0.0, 0.0, 1.0);
+        draw_label(cr, p1, "P");
+        draw_label(cr, p2, "Q");
+        //draw_label(cr, l1, "L(P,Q)");
+        cairo_stroke(cr);
+
+        cairo_set_source_rgba(cr, 1.0, 0.0, 0.0, 1.0);
+        draw_label(cr, l2, "L(A, B, C)");
+        cairo_stroke(cr);
+
+        *notify << "  L(P,Q):  a = " << coeff1[0]
+                << ", b = " << coeff1[1]
+                << ", c = " << coeff1[2] << std::endl;
+
+    }
+
+    void init_segment_inside()
+    {
+        init_common();
+        p1.pos = Point(200, 300);
+        p2.pos = Point(400, 200);
+        p3.pos = Point(250, 200);
+        p4.pos = Point(350, 300);
+
+        handles.push_back(&p1);
+        handles.push_back(&p2);
+        handles.push_back(&p3);
+        handles.push_back(&p4);
+    }
+
+    void draw_segment_inside(cairo_t *cr, std::ostringstream *notify,
+                             int width, int height, bool save, std::ostringstream */*timer_stream*/)
+    {
+        draw_common(cr, notify, width, height, save);
+        Line l(p1.pos, p2.pos);
+        Rect r(p3.pos, p4.pos);
+
+        cairo_set_source_rgba(cr, 0, 0, 0, 1);
+        cairo_set_line_width(cr, 0.5);
+        draw_line(cr, l);
+        cairo_stroke(cr);
+
+        cairo_set_source_rgba(cr, 0, 0, 1, 1);
+        cairo_rectangle(cr, r);
+        cairo_stroke(cr);
+
+        std::optional<LineSegment> seg = l.clip(r);
+        if (seg) {
+            cairo_set_source_rgba(cr, 1, 0, 0, 1);
+            draw_line_seg(cr, seg->initialPoint(), seg->finalPoint());
+            cairo_stroke(cr);
+        }
+    }
+
+
+    void init_common_ctrl_geom(cairo_t* /*cr*/, int /*width*/, int /*height*/, std::ostringstream* /*notify*/)
+    {
+        if ( set_common_control_geometry )
+        {
+            set_common_control_geometry = false;
+        }
+    }
+
+    void init_create_ctrl_geom(cairo_t* /*cr*/, std::ostringstream* /*notify*/, int /*width*/, int height)
+    {
+        if ( set_control_geometry )
+        {
+            set_control_geometry = false;
+
+            sliders[ANGLE_SLIDER].geometry(Point(50, height - 50), 180);
+        }
+    }
+
+    void init_coefficients_ctrl_geom(cairo_t* /*cr*/, std::ostringstream* /*notify*/, int /*width*/, int height)
+    {
+        if ( set_control_geometry )
+        {
+            set_control_geometry = false;
+
+            sliders[A_COEFF_SLIDER].geometry(Point(50, height - 160), 400);
+            sliders[B_COEFF_SLIDER].geometry(Point(50, height - 110), 400);
+            sliders[C_COEFF_SLIDER].geometry(Point(50, height - 60), 400);
+        }
+    }
+
+
+    void draw_segment(cairo_t* cr, Point const& p1, Point const&  p2)
+    {
+        cairo_move_to(cr, p1);
+        cairo_line_to(cr, p2);
+    }
+
+    void draw_segment(cairo_t* cr, Point const& p1, double angle, double length)
+    {
+        Point p2;
+        p2[X] = length * std::cos(angle);
+        p2[Y] = length * std::sin(angle);
+        p2 += p1;
+        draw_segment(cr, p1, p2);
+    }
+
+    void draw_segment(cairo_t* cr, LineSegment const& ls)
+    {
+        draw_segment(cr, ls[0], ls[1]);
+    }
+
+    void draw_ray(cairo_t* cr, Ray const& r)
+    {
+        double angle = r.angle();
+        draw_segment(cr, r.origin(), angle, m_length);
+    }
+
+    void draw_line(cairo_t* cr, Line const& l)
+    {
+        double angle = l.angle();
+        draw_segment(cr, l.origin(), angle, m_length);
+        draw_segment(cr, l.origin(), angle, -m_length);
+    }
+
+    void draw_label(cairo_t* cr, PointHandle const& ph, const char* label)
+    {
+        draw_text(cr, ph.pos+op, label);
+    }
+
+    void draw_label(cairo_t* cr, Line const& l, const char* label)
+    {
+        draw_text(cr, projection(Point(m_width/2-30, m_height/2-30), l)+op, label);
+    }
+
+    void draw_label(cairo_t* cr, LineSegment const& ls, const char* label)
+    {
+        draw_text(cr, middle_point(ls[0], ls[1])+op, label);
+    }
+
+    void draw_label(cairo_t* cr, Ray const& r, const char* label)
+    {
+        Point prj = r.pointAt(r.nearestTime(Point(m_width/2-30, m_height/2-30)));
+        if (L2(r.origin() - prj) < 100)
+        {
+            prj = r.origin() + 100*r.vector();
+        }
+        draw_text(cr, prj+op, label);
+    }
+
+    void init_menu()
+    {
+        handles.clear();
+        sliders.clear();
+        toggles.clear();
+    }
+
+    void draw_menu( cairo_t * /*cr*/, std::ostringstream *notify,
+                    int /*width*/, int /*height*/, bool /*save*/,
+                    std::ostringstream */*timer_stream*/ )
+    {
+        *notify << std::endl;
+        for (int i = SHOW_MENU; i < TOTAL_ITEMS; ++i)
+        {
+            *notify << "   " << keys[i] << " -  " <<  menu_items[i] << std::endl;
+        }
+    }
+
+    void key_hit(GdkEventKey *e) override
+    {
+        char choice = std::toupper(e->keyval);
+        switch ( choice )
+        {
+            case 'A':
+                init_menu();
+                draw_f = &LineToy::draw_menu;
+                break;
+            case 'B':
+                init_create();
+                draw_f = &LineToy::draw_create;
+                break;
+            case 'C':
+                init_projection();
+                draw_f = &LineToy::draw_projection;
+                break;
+            case 'D':
+                init_ortho();
+                draw_f = &LineToy::draw_ortho;
+                break;
+            case 'E':
+                init_distance();
+                draw_f = &LineToy::draw_distance;
+                break;
+            case 'F':
+                init_position();
+                draw_f = &LineToy::draw_position;
+                break;
+            case 'G':
+                init_seg_bisec();
+                draw_f = &LineToy::draw_seg_bisec;
+                break;
+            case 'H':
+                init_angle_bisec();
+                draw_f = &LineToy::draw_angle_bisec;
+                break;
+            case 'I':
+                init_collinear();
+                draw_f = &LineToy::draw_collinear;
+                break;
+            case 'J':
+                init_intersections();
+                draw_f = &LineToy::draw_intersections;
+                break;
+            case 'K':
+                init_coefficients();
+                draw_f = &LineToy::draw_coefficients;
+                break;
+            case 'L':
+                init_segment_inside();
+                draw_f = &LineToy::draw_segment_inside;
+        }
+        redraw();
+    }
+
+    void draw( cairo_t *cr, std::ostringstream *notify,
+                       int width, int height, bool save, std::ostringstream *timer_stream) override
+    {
+        m_width = width;
+        m_height = height;
+        m_length = (m_width > m_height) ? m_width : m_height;
+        m_length *= 2;
+        (this->*draw_f)(cr, notify, width, height, save, timer_stream);
+        Toy::draw(cr, notify, width, height, save, timer_stream);
+    }
+
+  public:
+    LineToy()
+    {
+        op = Point(5,5);
+    }
+
+  private:
+    typedef void (LineToy::* draw_func_t) (cairo_t*, std::ostringstream*, int, int, bool, std::ostringstream*);
+    draw_func_t draw_f;
+    bool set_common_control_geometry;
+    bool set_control_geometry;
+    PointHandle p1, p2, p3, p4, p5, p6, O;
+    std::vector<Toggle> toggles;
+    std::vector<Slider> sliders;
+    Point op;
+    double m_width, m_height, m_length;
+
+}; // end class LineToy
+
+
+const char* LineToy::menu_items[] =
+{
+    "show this menu",
+    "line generation",
+    "projection on a line",
+    "make orthogonal/parallel",
+    "distance",
+    "position",
+    "segment bisector",
+    "angle bisector",
+    "collinear",
+    "intersection",
+    "coefficients",
+    "segment inside"
+};
+
+const char LineToy::keys[] =
+{
+     'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J', 'K', 'L'
+};
+
+
+
+int main(int argc, char **argv)
+{
+    init( argc, argv, new LineToy());
+    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 :