9. Bezier Curve

/********************************************************************************
TITLE : PROGRAM TO IMPLEMENT THE BEZIER CURVE.
********************************************************************************/

#include <stdio.h>
#include <graphics.h>
#include <math.h>
#include <conio.h>

int main()
{
    int gd = DETECT, gm; //Detects the graphics drivers automatically
    initgraph (&gd, &gm, " "); //Initialize to graphics mode

    int x[4],y[4],i;
    double put_x,put_y,t;

    //To plot the quadrants
    line(0,240,639,240);
    line(320,0,320,479);
    outtextxy(295,243,"0,0");
    setcolor(WHITE);

    printf("\n ===========================BEZIER CURVE============================\n");
    printf("\n Enter the x and y coordinates of the four control points : \n ");

    for (i=0; i<4; i++)
    {
        scanf("%d%d", &x[i],&y[i]);
        putpixel (320+x[i],240-y[i],14);  // Plots the control points
    }

    //To plot the BEZIER CURVE
    for (t = 0.0; t < 1.0; t += 0.001)  // t always lies between 0 and 1
    {
        put_x = pow(1-t,3)*x[0] + 3*t*pow(1-t,2)*x[1] + 3*pow(t,2)*(1-t)*x[2] + pow(t,3)*x[3];
        put_y = pow(1-t,3)*y[0] + 3*t*pow(1-t,2)*y[1] + 3*pow(t,2)*(1-t)*y[2] + pow(t,3)*y[3];
        putpixel(320+put_x,240-put_y,1); //Plots the BEZIER CURVE
		
    }

    getch(); //Pauses the Output Console until a key is pressed
    closegraph(); //Closes the graphics mode
    return 0;
}