WINDOWING TO VIEWPORT MAPPING

WINDOWING TO VIEWPORT MAPPING

#include<stdio.h>

#include<conio.h>

#include<graphics.h>

#include<math.h>

main()

  {

                    float sx,sy;

                    int w1,w2,w3,w4,x1,x2,x3,x4,y1,y2,y3,y4,v1,v2,v3,v4;

                    int gd=DETECT,gm;

                    initgraph(&gd,&gm,"c:\\tc\\bgi");

                    printf("Enter The Coordinate x1,y1,x2,y2,x3,y3\n");

                    scanf("%d%d%d%d%d%d",&x1,&y1,&x2,&y2,&x3,&y3);

                    cleardevice();

                    w1=5;

                    w2=5;

                    w3=635;

                    w4=465;

                    rectangle(w1,w2,w3,w4);

                    line(x1,y1,x2,y2);

                    line(x2,y2,x3,y3);

                    line(x3,y3,x1,y1);

                    getch();

                    v1=425;

                    v2=75;

                    v3=550;

                    v4=250;

                    sx=(float)(v3-v1)/(w3-w1);

                    sy=(float)(v4-v2)/(w4-w2);

                    rectangle(v1,v2,v3,v4);

                    x1=v1+floor(((float)(x1-w1)*sx)+.5);

                    x2=v1+floor(((float)(x2-w1)*sx)+.5);

                    x3=v1+floor(((float)(x3-w1)*sx)+.5);

                    y1=v2+floor(((float)(y1-w2)*sy)+.5);

                    y2=v2+floor(((float)(y2-w2)*sy)+.5);

                    y3=v2+floor(((float)(y3-w2)*sy)+.5);

                    line(x1,y1,x2,y2);

                    line(x2,y2,x3,y3);

                    line(x3,y3,x1,y1);

                    getch();

                    return 0;

 }

OUTPUT

Enter The Coordinate x1,y1,x2,y2,x3,y3

100

200

300

400

500

350

 

 

         

        

COHEN-SUTHERLAND 2D LINE CLIPPING

#include<stdio.h>

#include<conio.h>

#include<graphics.h>

#include<math.h>

float cxl,cxr,cyt,cyb;

code(float ,float);

void clip(float ,float,float,float);

void  rect(float ,float,float,float);

 main()

    {

                    float x1,y1,x2,y2;

                    int g=0,d;

                    initgraph(&g,&d,"c:\\tc\\bin");

                    settextstyle(1,0,1);

                    outtextxy(40,15,"BEFORE CLIPPING");

                    printf("\n Please Enter Left,Bottom,Right,Top Of Clip Window");

                    scanf("%f%f%f%f",&cxl,&cyb,&cxr,&cyt);

rect(cxl,cyb,cxr,cyt);

                    getch();

printf("\n Enter  The Line Coordinate");

                    scanf("%f%f%f%f",&x1,&y1,&x2,&y2);

line(x1,y1,x2,y2);

                    getch();

                    cleardevice();

                    settextstyle(1,0,1);

                    outtextxy(40,15,"AFTER CLIPPING");

                    clip(x1,y1,x2,y2);

                    getch();

                    closegraph();

   }

void clip(float x1,float y1,float x2,float y2)

 {

                    int c,c1,c2;

                    float x,y;

                    c1=code(x1,y1);

                    c2=code(x2,y2);

                    getch();

         

                    while((c1!=0)||(c2!=0))

                     {

                             if((c1&c2)!=0)

                             goto out;

                             c=c1;

                              if(c==0)

                                       c=c2;

                             if((c&1)==1)

                                {

                                       y=y1+(y2-y1)*(cxl-x1);

                                       x=cxl;

                               }

                             else

                             if((c&2)==2)

                               {

                                       y=y1+(y2-y1)*(cxl-x1)/(x2-x1);

                                       x=cxr;

                                }

                             else

                             if((c&8)==8)

                                {

                                       x=x1+(x2-x1)*(cyb-y1)/(y2-y1);

                                       y=cyb;

                              }

                             else

                             if((c&4)==4)

                              {

                                       x=x1+(x2-x1)*(cyt-y1)/(y2-y1);

                                       y=cyt;

                               }

                            if(c==c1)

                             {

                                       x1=x;

                                       y1=y;

                                       c1=code(x,y);

                             }

                             else

                             {

                                       x2=x;

                                       y2=y;

                                       c2=code(x,y);

                             }

                     }

                   

out:

                              rect(cxl,cyb,cxr,cyt);

                             line(x1,y1,x2,y2);

    }

code(float x ,float y)

 {

                    int c=0;

                    if(x<cxl)                          c=1;

                    else

                              if(x>cxr)               c=2;

                    else

                              if(y<cyb)               c=c|8;

                    else

                              if(y>cyt)               c=c|4;

                    return c;

}

void rect(float xl,float yb,float xr,float yt)

  {

                    line(xl,yb,xr,yb);

                    line(xr,yb,xr,yt);

                    line(xr,yt,xl,yt);

                    line(xl,yt,xl,yb);

 }

OUTPUT

BEFORE CLIPPING

Please Enter Left , Bottom , Right , Top Of The Clip window

200

200

400

400

         

Please Enter The Line Coordinates (X1, Y1, X2, Y2)

150

300

400

450

 

AFTER CLIPPING

 

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dda line drawing algorithm in c

DDA Line drawing Algorithm

The digital differential analyzer (DDA)  is a scan-conversion line algorithm. In this algorithm, we sample the line at unit intervals in one coordinate and determine corresponding integer values nearest the line path of the other coordinate and plot those coordinate (pixel) in computer screen. Consider first a line with positive slope. If the slope is less than or equal to 1, we sample at unit x intervals (dx = 1) and computer each successive y value as y(k+1) = y(k) + m. Subscript k takes integer values starting from 1, for the first point, and increases by 1 until the final endpoint is reached. For lines with a positive slope greater than 1, we reverse the roles of x and y.That is, we sample at unit y intervals (dy = 1) and calculate each succeeding x value as x(k+1) = x(k) + (1/m)




Program

#include<stdio.h>
#include<conio.h>
#include<graphics.h>
void DDA(int x1,int y1,int x2,int y2,int col,int del);
void main()
{
int gd=DETECT,gm,x1,x2,y1,y2;
initgraph(&gd,&gm,"");
printf("Enter (x1,y1) and (x2,y2) : ");
scanf("%d%d%d%d",&x1,&y1,&x2,&y2);
DDA(x1,y1,x2,y2,14,20);
getch();
closegraph();
}
void DDA(int x1,int y1,int x2,int y2,int col,int del)
{
int dx,dy,s,i,xi,yi,x,y;
x=x1,y=y1;
dx=x2-x1;
dy=y2-y1;
if(dx>dy)
s=dx;
else
s=dy;
xi=dx/s;
yi=dy/s;
putpixel(x,y,col);
for(i=0;i<s;i++)
{
x+=xi;
y+=yi;

putpixel(x,y,col);

delay(del);

}

}

Output

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bresenham’s ellipse drawing algorithm c program

         

BRESENHAM’S ELLIPSE DRAWING ALGORITHM

#include "stdio.h"

#include "conio.h"

#include "math.h"

#include "graphics.h"

main()

{

                    int gd=DETECT,gm;

                    int xcenter,ycenter,rx,ry;

                    int p,x,y,px,py,rx1,ry1,rx2,ry2;

                    initgraph(&gd,&gm,"c:\\tc\\bgi");

                    printf("Enter The Radius Value:\n");

                    scanf("%d%d",&rx,&ry);

                    printf("Enter The xcenter and ycenter Values:\n");

                    scanf("%d%d",&xcenter,&ycenter);

                    ry1=ry*ry;

                    rx1=rx*rx;

                    ry2=2*ry1;

                    rx2=2*rx1;

/* REGION 1 */

x=0;

                    y=ry;

                    plotpoints(xcenter,ycenter,x,y);

                    p=(ry1-rx1*ry+(0.25*rx1));

                    px=0;

                    py=rx2*y;

                    while(px<py)

                    {

                              x=x+1;

                             px=px+ry2;

                             if(p>=0)

                                       y=y-1;

                                       py=py-rx2;

                               if(p<0)

                                       p=p+ry1+px;

                              else

                                        p=p+ry1+px-py;

                    plotpoints(xcenter,ycenter,x,y);

/* REGION 2*/

                  

p=(ry1*(x+0.5)*(x+0.5)+rx1*(y-1)*(y-1)-rx1*ry1);

                   while(y>0)

                   {

                             y=y-1;

                             py=py-rx2;

                              if(p<=0)

                             {

                                       x=x+1;

                                       px=px+ry2;

                              }

                              if(p>0)

                                       p=p+rx1-py;

                             else

                                      p=p+rx1-py+px;

                     plotpoints(xcenter,ycenter,x,y);

                   }

               }

                    getch();

                    return(0);

            }

int plotpoints(int xcenter,int ycenter,int x,int y)

{

                    putpixel(xcenter+x,ycenter+y,6);

                    putpixel(xcenter-x,ycenter+y,6);

                    putpixel(xcenter+x,ycenter-y,6);

                    putpixel(xcenter-x,ycenter-y,6);

}

OUTPUT

Enter The Radius Value(Rx,Ry)           :     10      30

                   

Enter The xcenter and ycenter Values  :     300    150

         

RESULT:

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