Draw a Circle : Bresenham’s Circle Algorithm


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C Program

#include <stdio.h>
#include <dos.h>
#include <graphics.h>
void plotPoints(int cx, int cy, int x, int y) {
	putpixel(cx+x, cy+y, RED);
	putpixel(cx-x, cy+y, RED);
	putpixel(cx+x, cy-y, RED);
	putpixel(cx-x, cy-y, RED);
	putpixel(cx+y, cy+x, RED);
	putpixel(cx-y, cy+x, RED);
	putpixel(cx+y, cy-x, RED);
	putpixel(cx-y, cy-x, RED);
}
void main() {
	int cx, cy, x = 0, y, r, p;
	int gd = DETECT, gm;
	clrscr();
	printf("Enter the coordinates of centre of the circle: ");
	scanf("%d %d", &cx, &cy);
	printf("Enter radius of : ");
	scanf("%d", &r);
	y = r;
	p = 3 - 2 * r;
	initgraph(&gd, &gm, "");
	cleardevice();
	while (x < y) {
		plotPoints(cx, cy, x, y);
		x++;
		if (p < 0)
					p = p + 4 * x + 6; else {
			y--;
			p = p + 4 * (x - y) + 10;
		}
		plotPoints(cx, cy, x, y);
		delay(200);
	}
	getch();
}





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