dda.cpp

#include <iostream>
#include <graphics.h>
#include <stdlib.h>
using namespace std;
class dcircle
{
private:
    int x0, y0;

public:
    dcircle()
    {
        x0 = 0;
        y0 = 0;
    }
    void setoff(int xx, int yy)
    {
        x0 = xx;
        y0 = yy;
    }
    void drawc(int x1, int y1, int r)
    {
        float d;
        int x, y;
        x = 0;
        y = r;
        d = 3 - 2 * r;
        do
        {
            putpixel(x1 + x0 + x, y0 + y - y1, 15);
            putpixel(x1 + x0 + y, y0 + x - y1, 15);
            putpixel(x1 + x0 + y, y0 - x - y1, 15);
            putpixel(x1 + x0 + x, y0 - y - y1, 15);
            putpixel(x1 + x0 - x, y0 - y - y1, 15);
            putpixel(x1 + x0 - y, y0 - x - y1, 15);
            putpixel(x1 + x0 - y, y0 + x - y1, 15);
            putpixel(x1 + x0 - x, y0 + y - y1, 15);
            if (d <= 0)
            {
                d = d + 4 * x + 6;
            }
            else
            {
                d = d + 4 * (x - y) + 10;
                y = y - 1;
            }
            x = x + 1;
        } while (x < y);
    }
};

class pt
{
protected:
    int xco, yco, color;

public:
    pt()
    {
        xco = 0, yco = 0, color = 15;
    }
    void setco(int x, int y)
    {
        xco = x;
        yco = y;
    }
    void setcolor(int c)
    {
        color = c;
    }
    void draw()
    {
        putpixel(xco, yco, color);
    }
};
class dline : public pt
{
private:
    int x2, y2;

public:
    dline() : pt()
    {
        x2 = 0;
        y2 = 0;
    }
    void setline(int x, int y, int xx, int yy)
    {
        pt::setco(x, y);
        x2 = xx;
        y2 = yy;
    }
    void drawl(int colour)
    {
        float x, y, dx, dy, length;
        int i;
        pt::setcolor(colour);
        dx = abs(x2 - xco);
        dy = abs(y2 - yco);
        if (dx >= dy)
        {
            length = dx;
        }
        else
        {
            length = dy;
        }
        dx = (x2 - xco) / length;
        dy = (y2 - yco) / length;
        x = xco + 0.5;
        y = yco + 0.5;
        i = 1;
        while (i <= length)
        {
            pt::setco(x, y);
            pt::draw();
            x = x + dx;
            y = y + dy;
            i = i + 1;
        }
        pt::setco(x, y);
        pt::draw();
    }
};
int main()
{
    int gd = DETECT, gm;
    initgraph(&gd, &gm, NULL);
    int x, y, r, x1, x2, y1, y2, xmax, ymax, xmid, ymid, n, i;
    dcircle c;
    cout << "\nenter coordinates of centre of circle : ";
    cout << "\n enter the value of x : ";
    cin >> x;
    cout << "\nenter the value of y : ";
    cin >> y;
    cout << "\nenter the value of radius : ";
    cin >> r;
    xmax = getmaxx();
    ymax = getmaxy();
    xmid = xmax / 2;
    ymid = ymax / 2;
    setcolor(1);
    c.setoff(xmid, ymid);
    line(xmid, 0, xmid, ymax);
    line(0, ymid, xmax, ymid);
    setcolor(15);
    c.drawc(x, y, r);
    pt p1;
    p1.setco(100, 100);
    p1.setcolor(14);
    dline l;
    l.setline(x1 + xmid, ymid - y1, x2 + xmid, ymid - y2);
    cout << "Enter Total Number of lines : ";
    cin >> n;
    for (i = 0; i < n; i++)
    {
        cout << "Enter co-ordinates of point x1 : ";
        cin >> x1;
        cout << "enter coordinates of point y1 : ";
        cin >> y1;
        cout << "Enter co-ordinates of point x2 : ";
        cin >> x2;
        cout << "enter coordinates of point y2 : ";
        cin >> y2;
        l.setline(x1 + xmid, ymid - y1, x2 + xmid, ymid - y2);
        l.drawl(15);
    }
    cout << "\nEnter coordinates of centre of circle : ";
    cout << "\n Enter the value of x : ";
    cin >> x;
    cout << "\nEnter the value of y : ";
    cin >> y;
    cout << "\nEnter the value of radius : ";
    cin >> r;
    setcolor(5);
    c.drawc(x, y, r);
    getch();
    delay(200);
    closegraph();
    return 0;
}