Write C++/Java program to draw inscribed and Circumscribed circles in the triangle,

Second Year Computer Engineering Computer Graphics Programs:

Computer Graphics Lab:

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Practical 7:

         Write C++/Java program to draw inscribed and Circumscribed circles in the triangle as shown as an example below. (Use any Circle drawing and Line drawing algorithms)

#include <iostream>

#include <stdlib.h>

#include <graphics.h>

#include <math.h>

using namespace std;

int xmax,ymax,xmid,ymid;

class Line

{

public:

int x1,x2,y1,y2;

void dda(int x1,int y1,int x2,int y2)

{

float x,y,dx,dy,length;

int i;

dx = abs(x2-x1);

dy = abs(y2-y1);

if(dx>dy)

{length = dx;}

else

{length = dy;}

dx = (x2-x1)/length;

dy = (y2-y1)/length;

x = x1 + 0.5;

y = y1 + 0.5;

i=1;

while(i<=length)

{

putpixel(x,y,12);

x = x + dx;

y = y + dy;

i++;

}

putpixel(x,y,12);

}

};

class Circle

{

public:

void plot(int x,int y,int x1,int y1)

{

putpixel(xmid+x+x1,ymid-(y+y1),12);

putpixel(xmid+y+x1,ymid-(x+y1),12);

putpixel(xmid-x+x1,ymid-(y+y1),12);

putpixel(xmid+y+x1,ymid-(-x+y1),12);

putpixel(xmid+x+x1,ymid-(-y+y1),12);

putpixel(xmid-y+x1,ymid-(x+y1),12);

putpixel(xmid-x+x1,ymid-(-y+y1),12);

putpixel(xmid-y+x1,ymid-(-x+y1),12);

}

void drawcircle(float x1,float y1,int r)

{

float x,y,d;

d = 3 - (2 * r);

x=0;

y=r;

while(x<=y)

{

plot(x,y,x1,y1);

if(d<0)

d = d + (4 * x) + 6;

else

{

d = d + (4 * (x - y)) + 10;

y=y-1;

}

x=x+1;

}

}

};

void display(int x1,int y1,int x2,int y2,int x3,int y3)

{

Line obj;

obj.dda(x1+xmid,ymid-y1,x2+xmid,ymid-y2);delay(300);

obj.dda(x2+xmid,ymid-y2,x3+xmid,ymid-y3);delay(300);

obj.dda(x3+xmid,ymid-y3,x1+xmid,ymid-y1);delay(300);

}

int main()

{

Circle obj2;

int gd=DETECT,gm;

int x1=50,y1=50,x2=150,y2=50,x3=100,y3=175;

initgraph(&gd,&gm,NULL);

xmax=getmaxx();

ymax=getmaxy();

xmid=xmax/2;

ymid=ymax/2;

display(x1,y1,x2,y2,x3,y3);

float a,b,c,incenterx,incentery,inradius,s;

a = sqrt((x2-x1)*(x2-x1)+(y2-y1)*(y2-y1));

b = sqrt((x3-x2)*(x3-x2)+(y3-y2)*(y3-y2));

c = sqrt((x3-x1)*(x3-x1)+(y3-y1)*(y3-y1));

incenterx = ((a*x3)+(b*x1)+(c*x2))/(a+b+c);

incentery = ((a*y3)+(b*y1)+(c*y2))/(a+b+c);

inradius = 0.5*sqrt(((a+b-c)*(a+c-b)*(c+b-a))/(a+b+c));

obj2.drawcircle(incenterx,incentery,inradius);

float circenterx,circentery,cerradius;

cerradius = (a*b*c)/(4*((a+b+c)*(0.5))*inradius);

float A,B,C;

A = acos(((c*c)+(a*a)-(b*b))/(2*a*c));

B = acos(((b*b)+(a*a)-(c*c))/(2*a*b));

C = acos(((c*c)+(b*b)-(a*a))/(2*c*b));

circenterx = ((x1*sin(2*A))+(x2*sin(2*B))+(x3*sin(2*C)))/(sin(2*A)+sin(2*B)+sin(2*C));

circentery = ((y1*sin(2*A))+(y2*sin(2*B))+(y3*sin(2*C)))/(sin(2*A)+sin(2*B)+sin(2*C));

obj2.drawcircle(circenterx,circentery,cerradius);

delay(1000);

closegraph();

system("clear");

return 0;

}

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