C code to use Be'zier curves to draw Bengali Scripts

/*
 C code to display Bengali Script on the DOS prompt
 Sandipan Dey
 BCSE, JU, Kolkata
 2002
*/

#include <math.h>
#include <graphics.h>
#include <stdio.h>
#include <conio.h>
#include <stdlib.h>
#include <dos.h>
#define MAX 10

struct Point{
    double x,y;
};

double pow(double x,int i) {
    if (i==0) return 1;                 //0**0=1,for Jn,0(0)=1,i=0
    else if(x<=0 || i<0)return 0;
    else {
        double p=1;
        for(int j=0;j<i;++j)p*=x;
        return p;
    }
}

double fact(int n) {
    double f=1;
    for(int i=1;i<=n;++i)
    f=f*i;
    return f;
}

double C(int n,int i) {
    if(i<0 || n<0 || i>n)return 0;
    else if(i==0 || i==n)return 1;
    else return fact(n)/(fact(i)*fact(n-i));
}

double J(int n,int i,double t) {   //Bernstein Basis Function
    return C(n,i)*pow(t,i)*pow(1-t,n-i);
}

Point P(Point* B,int n,double t) {
    Point p={0,0};
    for(int i=0;i<=n;++i) {
        p.x+=B[i].x*J(n,i,t);
        p.y+=B[i].y*J(n,i,t);
    }
    return p;
}

void PatternP(int lt=100,int tp=100,int color=15) {
    int n=4;
    double t;
    Point B[MAX]={{lt,tp+30},{lt+50,tp+45},{lt+50,tp+80},{lt,tp+100}},p;
    for(t=0;t<=1;t+=0.005) {
        p=P(B,n-1,t);putpixel(p.x,p.y,color);
    } //Draw Be'zier Curve of Degree n-1
    B[0].x=lt;B[0].y=tp+30;
    B[1].x=lt+70;B[1].y=tp+10;
    B[2].x=lt+50;B[2].y=tp+50;
    B[3].x=lt+100;B[3].y=tp+100;
    for(t=0;t<=1;t+=0.005){
        p=P(B,n-1,t);putpixel(p.x,p.y,color);
    } //Draw Be'zier Curve of Degree n-1
    B[0].x=lt;B[0].y=tp+100;
    B[1].x=lt+70;B[1].y=tp+100;
    B[2].x=lt+50;B[2].y=tp+50;
    B[3].x=lt+100;B[3].y=tp+100;
    for(t=0;t<=1;t+=0.005){
        p=P(B,n-1,t);putpixel(p.x,p.y,color);
    } //Draw Be'zier Curve of Degree n-1
    line(lt+100,tp+10,lt+100,tp+180);
    line(lt+95,tp+20,lt+130,tp+20);
}

void PatternB(int lt=100,int tp=100,int color=15) {
    int n=3;
    double t;
    Point B[MAX]={{lt,tp+100},{lt+50,tp+70},{lt+100,tp+180}},p;
    for(t=0;t<=1;t+=0.005) {
        p=P(B,n-1,t);putpixel(p.x,p.y,color);
    } //Draw Be'zier Curve of Degree n-1
    line(lt+100,tp+20,lt+100,tp+180);
    line(lt+100,tp+20,lt,tp+100);
    line(lt,tp+20,lt+120,tp+20);
}

void PatternJ(int lt=100,int tp=100,int color=15) {
    int n=3;
    double t;
    Point B[MAX]={{lt,tp+120},{lt+50,tp+90},{lt+100,tp+180}},p;
    for(t=0;t<=1;t+=0.005) {
        p=P(B,n-1,t);putpixel(p.x,p.y,color);
    } //Draw Be'zier Curve of Degree n-1
    line(lt+100,tp+20,lt+100,tp+180);
    line(lt+5,tp+20,lt+60,tp+75);
    line(lt+60,tp+75,lt,tp+120);
    line(lt,tp+20,lt+110,tp+20);
}

void PatternR(int lt=100,int tp=100,int color=15) {
    PatternB(lt,tp,color);
    circle(lt+50,tp+140,15);
}

void PatternD(int lt=100,int tp=100,int color=15) {
    int n=4;
    double t;
    Point B[MAX]={{lt+20,tp+100},{lt+60,tp+60},{lt+80,tp+60},{lt+100,tp+100}},p;
    for(t=0;t<=1;t+=0.005) {
        p=P(B,n-1,t);putpixel(p.x,p.y,color);
    } //Draw Be'zier Curve of Degree n-1
    B[0].x=lt+100;B[0].y=tp+100;
    B[1].x=lt+50;B[1].y=tp+110;
    B[2].x=lt+50;B[2].y=tp+140;
    B[3].x=lt+90;B[3].y=tp+170;
    for(t=0;t<=1;t+=0.005) {
        p=P(B,n-1,t);putpixel(p.x,p.y,color);
    } //Draw Be'zier Curve of Degree n-1
    line(lt,tp+20,lt+110,tp+20);
    line(lt+20,tp+20,lt+20,tp+100);
}

void PatternU(int lt=100,int tp=100,int color=15) {
    int n=4;
    double t;
    Point B[MAX]={{lt+10,tp},{lt,tp+50},{lt+40,tp+50},{lt+70,tp}},p;
    for(t=0;t<=1;t+=0.005) {
        p=P(B,n-1,t);putpixel(p.x,p.y,color);
    } //Draw Be'zier Curve of Degree n-1
    B[0].x=lt+10;B[0].y=tp;
    B[1].x=lt+70;B[1].y=tp-50;
    B[2].x=lt+70;B[2].y=tp+70;
    B[3].x=lt+200;B[3].y=tp+50;
    for(t=0;t<=1;t+=0.005) {
        p=P(B,n-1,t);putpixel(p.x,p.y,color);
    } //Draw Be'zier Curve of Degree n-1
}

void Line(int lt=100,int tp=100,int color=15) {
    setcolor(color);
    line(lt,tp+10,lt,tp+180);
    line(lt-20,tp+20,lt+20,tp+20);
}

void Name() {
    rectangle(515,375,630,415);
    outtextxy(520,380,"SANDIPAN DEY");
    outtextxy(520,390,"BCSE-IV");
    outtextxy(520,400,"Roll-99710");
}

void main() {
    int xm,ym;
    clrscr();
    int gd=DETECT,gm;
    initgraph(&gd,&gm,"");
    xm=getmaxx();ym=getmaxy();
    int i=1;
    Name();
    while(!kbhit()) {
        //setcolor(i);
        PatternJ(0,100,i);
        Line(125);
        //setcolor(i);
        PatternD(140,100,i);
        PatternB(250,100,i);
        PatternP(375,100,i);
        PatternU(410,280,i);
        PatternR(500,100,i);
        i=(i+1)%15+1;
        delay(1000);
    }
    getch();
    closegraph();
}