Cohen Sutherland Line Clipping Algorithm

#include <graphics.h>
#include <stdio.h>
#include <conio.h>
#define IN 0
#define TOP 8
#define BOTTOM 4
#define RIGHT 2
#define LEFT 1

float XMIN=20, XMAX=90, YMIN=20, YMAX=70, m;
int ax=10, ay=10, bx=100, by = 90;
int count=0;
float f[2][2];

void startgraphics(){
    int gd = DETECT, gm;
    initgraph(&gd, &gm, "");
    cleardevice();
}

void clipit(float x, float y){
    if(count==2) return;
    f[count][0]=x;
    f[count][1]=y;
    count++;
}

int getCode(float x, float y){
    int code=IN;
    if(x < XMIN) code |= LEFT;
    else if(x > XMAX) code |= RIGHT;

    if(y < YMIN) code |= BOTTOM;
    else if(y > YMAX) code |= TOP;

    return code;
}

void calcF(int code){
    if(code & TOP)
        clipit(1/m*(YMAX-ay)+ax, YMAX);
    else if(code & BOTTOM)
        clipit(1/m*(YMIN-ay)+ax,YMIN);
    else if(code & RIGHT)
        clipit(XMAX, m*(XMAX-ax)+ay);
    else if(code & LEFT)
        clipit(XMIN, m*(XMIN-ax)+ay);
}

void main(){
    int codeA=0, codeB=0;
    float xnew, ynew;
    int i, j;
    m=(float)(by-ay)/(bx-ax);
    clrscr();

    printf("Windows: (%f, %f) and (%f, %f)\n", XMIN, YMIN, XMAX, YMAX);
    printf("Line: (%d, %d) to (%d, %d)", ax, ay, bx, by);
    codeA=getCode(ax, ay);
    if(codeA==0) clipit((float)ax, (float)ay);
    codeB=getCode(bx, by);
    if(codeB==0) clipit((float)bx, (float)by);
    printf("\ncodeA = %d\ncodeB = %d",codeA, codeB);

    if((codeA|codeB) == 0) printf("\n %d In!\n", codeA|codeB);
    else if(codeA & codeB) printf("\nOut!\n");
    else{
        if(codeA)calcF(codeA);
        if(codeB)calcF(codeB);
        printf("\n\n%d/%d = m = %f", by-ay, bx-ax, m);
        if(count>0){
        printf("\nPartially Visible!\nThe clipping points are:-\n");
        for(i=0; i<2; i++)
                printf("\n%f\t%f\n", f[i][0], f[i][1]);
        } else printf("\nNot Visible!");
    }
    getch();

    startgraphics();
    rectangle(XMIN, YMIN, XMAX, YMAX);
    setcolor(GREEN);
    line((int)ax, (int)ay, (int)bx, (int)by);
    getch();

    cleardevice();
    rectangle(XMIN, YMIN, XMAX, YMAX);
    setcolor(RED);
    line((int)f[0][0], (int)f[0][1], (int)f[1][0], (int)f[1][1]);
    getch();

    closegraph();
}