Question

Write a Program to implement Bezier Curve

Answer 1

#include <stdio.h>
	#include <graphics.h>
	#include <conio.h>
	#include<stdio.h>
	#include<process.h>
	int gd,gm,maxx,maxy;
	float xxx[4][2];

	/* Function to draw line from relative position
		specified in array xxx-----------------------*/

	void line1(float x2,float y2)
	{
	line(xxx[0][0],xxx[0][1],x2,y2);
	xxx[0][0]=x2;
	xxx[0][1]=y2;
	}
	/* Bezier function
	-------------------- */
	void bezier(float xb,float yb,float xc,float yc,float xd,float yd,int n)
	{
	float xab,yab,xbc,ybc,xcd,ycd;
	float xabc,yabc,xbcd,ybcd;
	float xabcd,yabcd;
	if (n==0)
		{
		 line1(xb,yb);
		 line1(xc,yc);
		 line1(xd,yd);
		}
	else
		{
		 xab = (xxx[0][0]+xb)/2;
		 yab = (xxx[0][1]+yb)/2;
		 xbc = (xb+xc)/2;
		 ybc = (yb+yc)/2;
		 xcd = (xc+xd)/2;
		 ycd = (yc+yd)/2;
		 xabc = (xab+xbc)/2;
		 yabc = (yab+ybc)/2;
		 xbcd = (xbc+xcd)/2;
		 ybcd = (ybc+ycd)/2;
		 xabcd = (xabc+xbcd)/2;
		 yabcd = (yabc+ybcd)/2;
		 n=n-1;
		 bezier(xab,yab,xabc,yabc,xabcd,yabcd,n);
		 bezier(xbcd,ybcd,xcd,ycd,xd,yd,n);
		}
	}

	/* Function to initialise graphics
	----------------------------------- */
	void igraph()
		{
		detectgraph(&gd,&gm);
		if(gd<0)
			{
			puts("CANNOT DETECT A GRAPHICS CARD");
			exit(1);
			}
		initgraph(&gd,&gm,"\\tc\\bgi");
		}
       void  main()
		{
		int i;
		float temp1,temp2;
		igraph();

		/* Read two end points and two control points of the curve
		---------------------------------------------------------- */
		for(i=0;i<4;i++)
		{
		printf("Enter (x,y) coordinates of point%d : ",i+1);
		scanf("%f,%f",&temp1,&temp2);
		xxx[i][0] = temp1;
		xxx[i][1] = temp2;
		}
		bezier(xxx[1][0],xxx[1][1],xxx[2][0],xxx[2][1],xxx[3][0],xxx[3][1],8);
		getch();
		closegraph();
	}