CGR Ass 3 - CS Line Clipping

#include <iostream>
#include <graphics.h>
#include <cmath>
using namespace std;

static int LEFT = 1, RIGHT = 2, BOTTOM = 4, TOP = 8, xmin, ymin, xmax, ymax;

int getCode(int x, int y){
    int code = 0;
    if (y > ymax) code |= TOP;
    if (y < ymin) code |= BOTTOM;
    if (x < xmin) code |= LEFT;
    if (x > xmax) code |= RIGHT;
    return code;
}

int main() {
    int gd = DETECT, gm;
    //cout << "Enter Window's max and min values: " << endl;
    //cin >> xmax >> ymax >> xmin >> ymin;
    xmax = 350;
    ymax = 350;
    xmin = 150;
    ymin = 150;

    int x1, y1, x2, y2;
    cout << "Enter Endpoints of the line: " << endl;
    cin >> x1 >> y1 >> x2 >> y2;


    initgraph(&gd, &gm, nullptr);

    rectangle(xmin, ymin, xmax, ymax);
    setcolor(BLUE);
    line(x1, y1, x2, y2);

    int outcode1 = getCode(x1, y1);
    int outcode2 = getCode(x2, y2);
    int accept = 0;

    while (1) {
        float m = (float)(y2 - y1)/(x2 - x1);
        if (outcode1 == 0 && outcode2 == 0) {
            accept = 1;
            break;
        } else if ((outcode1 & outcode2) != 0) {
            break;
        } else {
            int x, y, temp;
            if (outcode1 == 0) {
                temp = outcode2;
            } else {
                temp = outcode1;
            }

            if (temp & TOP) {
                x = x1 + (ymax - y1)/m;
                y = ymax;
            } else if (temp & BOTTOM) {
                x = x1 + (ymin - y1)/m;
                y = ymin;
            } else if (temp & LEFT) {
                x = xmin;
                y = y1 + m*(xmin - x1);
            } else if (temp & RIGHT) {
                x = xmax;
                y = y1 + m*(xmax - x1);
            }

            if (temp == outcode1) {
                x1 = x;
                y1 = y;
                outcode1 = getCode(x1, y1);
            } else {
                x2 = x;
                y2 = y;
                outcode2 = getCode(x2, y2);
            }
        }
    }

    cout << "After Clipping: ";
    if (accept){
        //cleardevice();

    }
    setcolor(WHITE);
    rectangle(xmin, ymin, xmax, ymax);
    setcolor(RED);
    line(x1, y1, x2, y2);
    getch();
    closegraph();

    return 0;
}


/*
Sample Input:
100 400
400 200
*/