Bjarne Stroustrup “Programming Principles and Practice Using C++”
Chapter 13 Exercise 19
Using GUI library called FLTK (Fast Light Tool Kit, “full tick”).
Output:
[code language=”cpp”]
// Philipp Siedler
// Bjarne Stroustrup’s PP
// Chapter 13 Exercise 19
#define _USE_MATH_DEFINES
#include "Simple_window.h"
#include "Graph.h"
#include <cmath>
using namespace Graph_lib;
ostream& operator<<(ostream& out, Point& a) {
out << "(" << a.x << "," << a.y << ")";
return out;
}
struct Star : Closed_polyline
{
Star(Point origin, int radius, int inner_radius, int segments, Fl_Color linecolor)
: o(origin), r(radius), ir(inner_radius), lc(linecolor)
{
s = (s < 3) ? segments : 3;
generate_points();
};
Star(Point origin, int radius, int segments)
: o(origin), r(radius), lc(Color::black)
{
s = (s < 3) ? segments : 3;
generate_points();
};
void generate_points();
void draw_lines() const;
private:
Point o;
int r;
int ir;
int s;
Fl_Color lc;
};
void Star::generate_points()
{
for (int i = 1; i < s + 1; i++) {
add(Point(r * sin(((2 * M_PI) / s) * i) + o.x, r * cos(((2 * M_PI) / s) * i) + o.y));
add(Point(ir * sin(((2 * M_PI) / s) * i + ((2 * M_PI) / (s * 2))) + o.x, ir * cos(((2 * M_PI) / s) * i + ((2 * M_PI) / (s * 2))) + o.y));
}
};
void Star::draw_lines() const
{
fl_color(lc);
Closed_polyline::draw_lines();
};
int main()
try
{
Point tl(100, 100);
Simple_window win(tl, 720, 400, "Simple Window");
Point center(win.x_max() / 2, win.y_max() / 2);
Star star1(center, 50, 20, 8, FL_RED);
star1.set_fill_color(Color::red);
Star star2(Point(100,300), 70, 20, 10, FL_RED);
star2.set_fill_color(Color::blue);
Star star3(Point(600, 200), 20, 100, 16, FL_RED);
star3.set_fill_color(Color::green);
win.attach(star1);
win.attach(star2);
win.attach(star3);
win.wait_for_button();
}
catch (exception& e) {
cout << e.what() << endl;
return 1;
}
catch (…) {
cout << "Exiting" << endl;
return 2;
}
[/code]
