Bjarne Stroustrup “Programming Principles and Practice Using C++”
Chapter 14 Exercise 13
Using GUI library called FLTK (Fast Light Tool Kit, “full tick”).
Output:
[code language=”cpp”]
// Philipp Siedler
// Bjarne Stroustrup’s PP
// Chapter 14 Exercise 13
#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;
}
//———————–ARROW CLASS——————————–
struct MyArrow : public Shape
{
MyArrow(Point start, Point end, bool s, bool e, int size, Color col);
~MyArrow() {}
void draw_lines() const;
double pointVecMag(Point vec);
private:
//Line
Point start;
Point end;
//Arrowhead at start
Point c;
Point cUnit;
Point cTrans;
Point cPerp;
double cMag;
Point arrowhead01;
Point arrowhead02;
//Arrowhead at end
Point d;
Point dUnit;
Point dTrans;
Point dPerp;
double dMag;
Point arrowhead03;
Point arrowhead04;
bool s;
bool e;
int size;
Color flc;
};
MyArrow::MyArrow(Point start, Point end, bool s, bool e, int size, Color col)
:start(start), end(end), s(s), e(e), size(size), flc(col)
{
if (s) {
//end-start vector: c
c = Point(end.x – start.x, end.y – start.y);
cMag = pointVecMag(c);
cUnit = Point(c.x / cMag * size, c.y / cMag * size);
cTrans = Point(cUnit.x, cUnit.y);
//Arrow Head Start
cPerp = Point(-cTrans.y, cTrans.x);
arrowhead01 = Point(start.x + cPerp.x + cTrans.x, start.y + cPerp.y + cTrans.y);
arrowhead02 = Point(start.x – cPerp.x + cTrans.x, start.y – cPerp.y + cTrans.y);
}
if (e) {
//start-end vector: d
d = Point(start.x – end.x, start.y – end.y);
dMag = pointVecMag(d);
dUnit = Point(d.x / dMag * size, d.y / dMag * size);
dTrans = Point(dUnit.x, dUnit.y);
//Arrow Head End
dPerp = Point(-dTrans.y, dTrans.x);
arrowhead03 = Point(end.x + dPerp.x + dTrans.x, end.y + dPerp.y + dTrans.y);
arrowhead04 = Point(end.x – dPerp.x + dTrans.x, end.y – dPerp.y + dTrans.y);
}
}
double MyArrow::pointVecMag(Point vec) {
return sqrt(pow(vec.x, 2) + pow(vec.y, 2));;
}
void MyArrow::draw_lines() const {
fl_color(flc.as_int());
if (color().visibility()) {
//Line
fl_line(start.x, start.y, end.x, end.y);
//Arrowhead at start
if (s) {
fl_line(start.x, start.y, arrowhead01.x, arrowhead01.y);
fl_line(start.x, start.y, arrowhead02.x, arrowhead02.y);
}
//Arrowhead at end
if (e) {
fl_line(end.x, end.y, arrowhead03.x, arrowhead03.y);
fl_line(end.x, end.y, arrowhead04.x, arrowhead04.y);
}
}
}
//———————–BINARY TREE CLASS——————————–
enum line_type { arrow_up = 0, arrow_down, arrow_both_ways, line };
class Binary_tree : public Shape
{
public:
Binary_tree(Point root, int levels, line_type line_type, Color col)
:r(root), l(levels), lt(line_type), col(col)
{
initialize_nodes();
}
~Binary_tree() {}
void initialize_nodes();
void draw_lines() const;
private:
Point r;
int l;
vector<Point> node_points;
line_type lt;
Color col;
};
void Binary_tree::initialize_nodes()
{
double nodes = 1.0;
double tree_w = l * 100;
for (int i = 0; i < l; i++) {
for (double j = -(nodes / 2); j < (nodes / 2); j++) {
if (i == 0) {
node_points.push_back(Point(r.x + j, r.y + i * 30));
}
else {
node_points.push_back(Point(r.x + (double(tree_w / nodes) / 2) + (j * double(tree_w / nodes)), r.y + i * 30));
}
}
nodes *= 2;
}
}
void Binary_tree::draw_lines() const
{
// draw nodes
for (int i = 0; i < node_points.size(); i++) {
Circle c(node_points[i], 5);
c.set_style(Line_style(Line_style::solid, 2));
c.draw();
}
// draw connecting lines
int node = 2;
for (int i = 0; i < node_points.size() – ((node_points.size() + 1) / 2); i++) {
for (int j = 1; j < 3; j++) {
Point from(node_points[i].x, node_points[i].y + 5);
Point to(node_points[i * node + j].x, node_points[i * node + j].y – 5);
//enum line_type { arrow_up, arrow_down, arrow_both_ways, line };
switch (lt)
{
case arrow_up:
MyArrow(from, to, true, false, 5, col).draw_lines();
break;
case arrow_down:
MyArrow(from, to, false, true, 5, col).draw_lines();
break;
case arrow_both_ways:
MyArrow(from, to, true, true, 5, col).draw_lines();
break;
case line:
Line l(from, to);
l.set_color(col);
l.draw();
break;
}
}
}
}
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);
Binary_tree tree(Point(center.x, 20), 7, line_type::arrow_down, Color::blue);
tree.set_color(Color::red);
win.attach(tree);
win.wait_for_button();
}
catch (exception& e) {
cout << e.what() << endl;
return 1;
}
catch (…) {
cout << "Exiting" << endl;
return 2;
}
[/code]
