Launching ball phyisics sim [Test] (Just ignore xd)

#include <iostream>
#include <vector>
#include <cmath>
using namespace std;
#define PI 3.14159265

    //int x,y,sizex,sizey;
    //double initialx,initialy,force,angle,mass,gravity,time,timeskip;
    double initialx = 1.0;
    double initialy = 1.0;
    int sizex = 75;
    int sizey = 50;
    double mass = 0.7;
    double gravity = 9.8;
    double time = 20;
    double timeskip = 0.05;


print(vector <vector <bool> >& map) {
    for (int i=map.size()-1; i>=0; --i) {
        for (int j=0; j<map[0].size(); ++j) {
            if (i==initialy and j==initialx) cout<<"x";
            else {
                if (map[i][j]) cout << "*";
                else cout << " ";
            }
        }
        cout<<endl;
    }
    for (int j=0; j<map[0].size(); ++j) cout<<"=";
    cout<<endl;
}

void clear(int n) {for (int i=0; i<n; ++i) cout<<endl;}
//string tolower(string s) {for (int i=0; i<s.length(); i++) tolower(s[i]); return s;}

int main() {
    int x,y;
    double force,angle;
    string s;

mainMenu:
    cout << "Type to select:\n";
    cout << "\n";
    cout << "   [Play]\n";
    cout << " [Settings]\n";
    cin>>s;
    //s = tolower(s);
    if (s=="play") goto Play;
    else if (s=="settings") goto Settings;
    cout << "ERROR: Unknown command. Try writing in lowercase."<<endl;
    goto mainMenu;

Settings:
    clear(50);
    cout<<"  ~ Table size: "<<sizex<<"x"<<sizey<<"               <size>"<<endl;
    cout<<"  ~ Gravity: "<<gravity<<"m/s2              <gravity>"<<endl;
    cout<<"  ~ Ball Mass: "<<mass<<"kg                <mass>"<<endl;
    cout<<"  ~ Simulation Time: "<<time<<"s            <time>"<<endl;
    cout<<"  ~ Time skipping: "<<timeskip<<"s            <skip>"<<endl;
    cout<<"  ~ Launch position: ["<<initialx<<"]["<<initialy<<"]       <position>"<<endl;
    cout<<endl<<endl<<" [Menu]"<<endl;

    cin>>s;
    if (s=="size") {
        cout<<endl<<endl<<"Enter new size: ";
        cin>>sizex>>sizey;
        goto Settings;
    }
    if (s=="gravity") {
        cout<<endl<<endl<<"Enter new gravity: ";
        cin>>gravity;
        goto Settings;
    }
    if (s=="mass") {
        cout<<endl<<endl<<"Enter new mass: ";
        cin>>mass;
        goto Settings;
    }
    if (s=="time") {
        cout<<endl<<endl<<"Enter new time: ";
        cin>>time;
        goto Settings;
    }
    if (s=="skip") {
        cout<<endl<<endl<<"Enter new skip time: ";
        cin>>timeskip;
        goto Settings;
    }
    if (s=="position") {
        cout<<endl<<endl<<"Enter new launch position: ";
        cin>>initialx>>initialy;
        goto Settings;
    }
    if (s=="menu") goto mainMenu;
    else goto Settings;

Play:
    clear(50);
    vector <vector <bool> > map(sizey, vector <bool> (sizex));
    print(map);
    cout << "Angle: ";
    cin >> angle;
    cout << "Force: ";
    cin >> force;
    cout << endl;
    for (double t=0; t<time; t = t + timeskip) {
        //x = initialx + (cos(angle)*force*t*t)/(2*mass));
        x = initialx + (cos(angle*PI/180))*force*t;
        y = initialy + (sin(angle*PI/180))*force*t - (gravity/2)*t*t;
        if (x>=0 and x<map[0].size() and y>=0 and y<map.size()) {
            map[y][x] = true;
            cout << "[" << x << "] [" << y << "]" << endl;
        }
    }

    print(map);
    cout<<endl<<" [Restart]"<<endl<<"  [Menu]"<<endl<<endl;
    cin>>s;
    if (s=="restart") goto Play;
    else if (s=="menu") goto mainMenu;
    else cout << "ERROR: Unknown command. Try writing in lowercase."<<endl;
}