point data type 1.5

Bjarne Stroustrup “Programming Principles and Practice Using C++”
Chapter 10 Drill 6
Using std_lib_facilities.h by Bjarne Stroustrup.

[code language=”cpp”]
// Philipp Siedler
// Bjarne Stroustrup’s PPP
// Chapter 10 Drill 6

#include "std_lib_facilities.h"

class Point {
public:
Point(double _x, double _y);
void set_pt(double _x, double _y);
double get_pt_x() { return x; }
double get_pt_y() { return y; }
private:
double x;
double y;
};

Point::Point(double _x, double _y) {
x = _x;
y = _y;
}

void Point::set_pt(double _x, double _y) {
x = _x;
y = _y;
}

ostream& operator<<(ostream& os, Point& _pt) {
os << "(" << _pt.get_pt_x() << " ," << _pt.get_pt_y() << ")" << endl;
return os;
}

vector<Point> original_pts;
vector<Point> processed_pts;

void fill_vec_pts(vector<Point>& _pts) {
while (true) {
cout << "Enter point pairs in format x,y.\n"
"To end your input type x" << endl;
double x, y;
char comma;
char check;
cin >> check;

if (check == ‘x’) {
break;
}
else {
cin.putback(check);
}

if (cin >> x >> comma >> y) {
if (comma != ‘,’) {
cout << "X and y seperated by comma, not: " << comma << endl;
}
else {
Point pt(x, y);
_pts.push_back(pt);
}
}
else {
cin.clear();
string check1;
cin >> check1;
cout << "Invalid value input: " << check1 << endl;
}
}
}

void print_pts(vector<Point> _pts) {
for (int i = 0; i < _pts.size(); i++) {
cout << _pts[i];
}
}

void output_original_pts(vector<Point> _pts) {
string oname = "pts.txt";
ofstream ost(oname);
if (!ost) error("can’t open output file ", oname);

cout << "Writing file! " << oname << endl;
for (int i = 0; i < _pts.size(); i++) {
ost << _pts[i].get_pt_x() << " " << _pts[i].get_pt_y() << endl;
}
ost.close();
}

void input_original_pts(vector<Point>& _pts) {
string iname = "pts.txt";
ifstream ist(iname);
if (!ist) error("can’t open input file ", iname);

double x;
double y;

while (ist >> x >> y) {
Point p(x, y);
_pts.push_back(p);
}
}

int main()
try
{
fill_vec_pts(original_pts);
output_original_pts(original_pts);
input_original_pts(processed_pts);

cout << "Original pts: " << endl;
print_pts(original_pts);

cout << "Processed pts: " << endl;
print_pts(processed_pts);

keep_window_open();

}
catch (runtime_error e) {
cout << e.what() << endl;
keep_window_open();
}
catch (…) {
cout << "Exiting" << endl;
keep_window_open();
}
[/code]

Output:
Enter point pairs in format x,y.
To end your input type x
6,3
Enter point pairs in format x,y.
To end your input type x
7,3
Enter point pairs in format x,y.
To end your input type x
2,3
Enter point pairs in format x,y.
To end your input type x
x
Writing file! pts.txt
Original pts:
(6 ,3)
(7 ,3)
(2 ,3)
Processed pts:
(6 ,3)
(7 ,3)
(2 ,3)
Please enter a character to exit

Output-File pts.txt:
6 3
7 3
2 3