CG (Computer Graphics )Programs in Mumbai University’s Semester 3 Engineering

In this article i have shared all programs of computer graphics that i done during my practicals and it will surely help you

1 To implement DDA Algorithm for Drawing a Line Segment between two Given end Points A(x1,y1) and B(x2,y2) . { Computer Graphics }

#include<stdio.h>
#include<graphics.h>
#include<math.h>
void main()
{
float x,y,x1,y1,x2,y2,dx,dy,length;
int i,gd,gm;
clrscr();
printf("Enter the value of x1 :\t");
scanf("%f",&x1);
printf("Enter the value of y1 :\t");
scanf("%f",&y1);
printf("Enter the value of x2 :\t");
scanf("%f",&x2);
printf("Enter the value of y2 :\t");
scanf("%f",&y2);

detectgraph(&gd,&gm);
initgraph(&gd,&gm,"\\tc\\BGI");

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;  
putpixel (x, y, 15);
i = 1;  
while(i <= length)
{
x = x + dx;
y = y + dy;
putpixel (x, y, 15);
i = i + 1;
delay(100);  
}
getch();
closegraph();
}

2 To implement Bresenham’s Line Drawing Algorithm

#include<stdio.h>
#include<graphics.h>
#include<math.h>
#include<conio.h>
void main()
{
float x,y,x1,y1,x2,y2,dx,dy,e;
int i,gd,gm;
clrscr(); 
printf("Enter the value of x1 :\t");
scanf("%f",&x1);
printf("Enter the value of y1 :\t");
scanf("%f",&y1);
printf("Enter the value of x2 :\t");
scanf("%f",&x2);
printf("Enter the value of y2 :\t");
scanf("%f",&y2); 
detectgraph(&gd,&gm);
initgraph(&gd,&gm,"c:\\tc\\BGI");

dx=abs(x2-x1);
dy=abs(y2-y1); 
x = x1;
y = y1;
putpixel (x, y, 15) ;

e = 2 * dy-dx;

i = 1; 
do
{
while(e >= 0)
{
y = y + 1;
e = e - 2 * dx;
}
x = x + 1;
e = e + 2 * dy;
i = i + 1;
putpixel (x, y, 15);
}
while( i <= dx);
getch();
closegraph();
}

3 To implement Midpoint circle

#include<stdio.h>
#include<graphics.h>
#include<math.h>
void main()
{
float p;
int i,gd,gm,x,y;
int r; 
detectgraph(&gd,&gm);
initgraph(&gd,&gm,"\\tc\\bgi");

printf("Enter the radius of the circle :");
scanf("%d",&r);

x=0;
y=r;
p = 1.25 - r;
do
{
putpixel(200+x,200+y,15);
putpixel(200+y,200+x,15);
putpixel(200+x,200-y,15);
putpixel(200+y,200-x,15);
putpixel(200-x,200-y,15);

putpixel(200-x,200+y,15);
putpixel(200-y,200+x,15);
putpixel(200-y,200-x,15);

if (p < 0)
{
x = x+1;
y = y;
p = p + 2*x + 1;
}
else
{
x= x+1;
y= y-1;
p = p + 2*(x-y) + 1;
}
delay(100);
}
while(x < y);
getch();
closegraph();
}

4 To implement area filling (flood fill)

#include<stdio.h>
#include<graphics.h>
#include<conio.h>

void flood(int, int, int, int);
void main()
{int gd,gm;

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

rectangle(50,50,100,100);
flood(55,55,4,15);
getch();
closegraph();
}

void flood(int seed_x,int seed_y,int foreground_col,int background_col)
{
if(getpixel(seed_x,seed_y)!= background_col &&
getpixel(seed_x,seed_y)!= foreground_col)
{
putpixel(seed_x,seed_y,foreground_col);
flood(seed_x+1,seed_y,foreground_col,background_col);
flood(seed_x-1,seed_y,foreground_col,background_col);
flood(seed_x,seed_y+1,foreground_col,background_col);
flood(seed_x,seed_y-1,foreground_col,background_col);

flood(seed_x+1,seed_y+1,foreground_col,background_col);
flood(seed_x-1,seed_y-1,foreground_col,background_col);
flood(seed_x+1,seed_y-1,foreground_col,background_col);
flood(seed_x-1,seed_y+1,foreground_col,background_col);
}
}

5 To implement bit map method for given character Genration

#include<stdio.h>
#include<conio.h>
#include<graphics.h>
void main()
{
int gd=DETECT,gm,i,j;
int a[20][20]=
{{0,0,0,1,1,1,0,0,0,0,0,0,0,0,1,1,1,1,0,0},
{0,0,1,0,0,0,1,0,0,0,0,0,0,1,0,0,0,0,1,0},
{0,1,0,0,0,0,0,1,0,0,0,0,1,0,0,0,0,0,0,1},
{1,0,0,0,0,0,0,0,0,0,0,1,0,0,0,0,0,0,0,0},
{1,0,0,0,0,0,0,0,0,0,0,1,0,0,0,0,0,0,0,0},
{1,0,0,0,0,0,0,0,0,0,0,1,0,0,0,1,1,1,1,0},
{1,0,0,0,0,0,0,0,0,0,0,1,0,0,0,0,0,0,1,0},
{0,1,0,0,0,0,0,1,0,0,0,1,0,0,0,0,0,0,1,0},
{0,0,1,0,0,0,1,0,0,0,0,0,1,0,0,0,0,1,0,0},
{0,0,0,1,1,1,0,0,0,0,0,0,0,1,1,1,1,0,0,0}};

initgraph(&gd,&gm,"c:\\tc\\bgi");
for(i=0;i<19;i++)
{
for(j=0;j<19;j++)
{
if(a[i][j]==1)
putpixel(100+j,200+i,WHITE);
}
}
getch();

}

6 To apply Basic 2D Transformation(Translation , rotation , Scaling

#include<graphics.h>
#include<conio.h>
#include<math.h>
#include<stdio.h>

   int main()
   {
   int i, x, y, tx, ty, sx, sy, angle=10, xmax, ymax, xmid, ymid, op;
   int gd,gm;
   float p1[10]=  {    50,50,
            100,50,
            100,100,
            50,100,
            50,50,
           };
   int pi[10];
   float b[3][3]={    1,0,0,
            0,1,0,
            0,0,1
        };
   int c[1][1];
   float a[1][1];
      printf("\nSelect the transformation : ");
      printf("\n1 : Traslation");
      printf("\n2 : Rotation");
      printf("\n3 : Scaling");
      printf("\n4 : Rotation about arbitrary point");
      printf( "\nEnter the option : ");
      scanf("%d",&op);
      switch(op)
      {
        case 1: printf("\nEnter x traslation : ");
                scanf("%d",&tx);
                printf("\nEnter y traslation : ");
                scanf("%d",&ty);

        b[0][0] = 1;
        b[0][1] = 0;
        b[0][2] = 0;

        b[1][0] = 0;
        b[1][1] = 1;
        b[1][2] = 0;

        b[2][0] = tx;
        b[2][1] = ty;
        b[2][2] = 1;

        break;
    case 2:     printf("\nEnter Rotation angle : ");
                scanf("%d",&angle);
        b[0][0] =cos(angle*3.142/180);
        b[0][1] =sin(angle*3.142/180);
        b[0][2] = 0;

        b[1][0] =-sin(angle*3.142/180);
        b[1][1] = cos(angle*3.142/180);
        b[1][2] = 0;

        b[2][0] = 0;
        b[2][1] = 0;
        b[2][2] = 1;

        break;
    case 3:     printf("\nEnter x scaling : ");
        scanf("%d",&sx);
        printf("\nEnter y scaling : ");
        scanf("%d",&sy);

        b[0][0] = sx;
        b[0][1] = 0;
        b[0][2] = 0;

        b[1][0] = 0;
        b[1][1] = sy;
        b[1][2] = 0;

        b[2][0] = 0;
        b[2][1] = 0;
        b[2][2] = 1;

        break;
    case 4:     printf("\nEnter x coordinate of arbitrary point : ");
        scanf("%d",&x);
        printf("\nEnter y coordinate of arbitrary point : ");
        scanf("%d",&y);
        printf("\nEnter Rotation angle : ");
        scanf("%d",&angle);

        tx = x;
        ty = y;

        b[0][0] =cos(angle*3.142/180);
        b[0][1] =sin(angle*3.142/180);
        b[0][2] = 0;

        b[1][0] =-sin(angle*3.142/180);
        b[1][1] = cos(angle*3.142/180);
        b[1][2] = 0;

        b[2][0] = -tx* cos(angle*3.142/180) + ty*sin(angle*3.142/180)+tx;
        b[2][1] = -tx* sin(angle*3.142/180) - ty*cos(angle*3.142/180)+ty;
        b[2][2] = 1;

      }
        detectgraph(&gd,&gm);
        initgraph(&gd,&gm,"\\tc\\bgi"); // Initialize graphics
    xmax = getmaxx();       // Get maximum x coordinate
    ymax = getmaxy();       // Get maximum y coordinate
    xmid = xmax/2;      // Get the center x coordinate
    ymid = ymax/2;      // Get the center y coordinate

    setcolor(1);
    line(xmid,0,xmid,ymax); // Draw y coordinate
    line(0, ymid, xmax, ymid);  // Draw x coordinate

      setcolor(4);
      for (i=0; i<8;i=i+2)
      {
      line(p1[i]+xmid,ymid-p1[i+1],xmid+p1[i+2],ymid-p1[i+3]);
      }
      for(i=0;i<9;i=i+2)
      {     a[0][0]=p1[i];
        a[0][1]=p1[i+1];
        c[0][0] = a[0][0]*b[0][0]+a[0][1]*b[1][0]+b[2][0];
        c[0][1] = a[0][0]*b[0][1]+a[0][1]*b[1][1]+b[2][1];
        pi[i]=c[0][0];
        pi[i+1]=c[0][1];
      }
  setcolor(15);
      for (i=0; i<8;i=i+2)
      {
      line(xmid+pi[i],ymid-pi[i+1],xmid+pi[i+2],ymid-pi[i+3]);
      }
      getch();
      closegraph();
      return 0;
   }

7 To implement Cohen sutherland Line Clipping Algorithm

#include<stdio.h>
    #include<conio.h>
    #include<stdlib.h>
    #include<dos.h>
    #include<math.h>
    #include<graphics.h>
     typedef struct coordinate
    {
    int x,y;
    char code[4];
    }PT;
    void drawwindow();
    void drawline (PT p1,PT p2,int cl);
    PT setcode(PT p);
    int visibility (PT p1,PT p2);
    PT resetendpt (PT p1,PT p2);
    main()
    {
    int gd=DETECT, gm,v;
    PT p1,p2,ptemp;
    initgraph(&gd,&gm,"\\tc\\bgi");
    cleardevice();
    printf("\n\n\t\tENTER END-POINT 1 (x,y): ");
    scanf("%d,%d",&p1.x,&p1.y);
    printf("\n\n\t\tENTER END-POINT 2 (x,y): ");
    scanf("%d,%d",&p2.x,&p2.y);
    cleardevice();
    drawwindow();
    getch();
    drawline(p1,p2,15);
    getch();
    p1=setcode(p1);
    p2=setcode(p2);
    v=visibility(p1,p2);
    switch(v)
        {
        case 0: cleardevice(); /* Line completely visible*/
                drawwindow();
                drawline(p1,p2,15);
                break;
        case 1: cleardevice(); /* Line completely invisible */
                drawwindow();
                break;
        case 2: cleardevice();  /* line partly visible */
                p1=resetendpt (p1,p2);
                p2=resetendpt(p2,p1);
                drawwindow();
                drawline(p1,p2,15);
                break;
        }
    getch();
    closegraph();
    return(0);
    }
 void drawwindow()
    {
    setcolor(RED);
    line(150,100,450,100);
    line(450,100,450,350);
    line(450,350,150,350);
    line(150,350,150,100);
    }
     void drawline (PT p1,PT p2,int cl)
    {
    setcolor(cl);
    line(p1.x,p1.y,p2.x,p2.y);
    }
     PT setcode(PT p)
    {
    PT ptemp;
    if(p.y<100)
    ptemp.code[0]='1'; /* TOP */
    else
    ptemp.code[0]='0';
    if(p.y>350)
    ptemp.code[1]='1'; /* BOTTOM */
    else
    ptemp.code[1]='0';
    if (p.x>450)
    ptemp.code[2]='1'; /* RIGHT */
    else
    ptemp.code[2]='0';
    if (p.x<150) /* LEFT */
    ptemp.code[3]='1';
    else
    ptemp.code[3]='0';
    ptemp.x=p.x;
    ptemp.y=p.y;
    return(ptemp);
    }
     int visibility (PT p1,PT p2)
    {
    int i,flag=0;
    for(i=0;i<4;i++)
    {
    if((p1.code[i]!='0')||(p2.code[i]!='0'))
    flag=1;
    }
    if(flag==0)
    return(0);
    for(i=0;i<4;i++)
    {
    if((p1.code[i]==p2.code[i]) &&(p1.code[i]=='1'))
    flag=0;
    }
    if(flag==0)
    return(1);
    return(2);
    }
     PT resetendpt (PT p1,PT p2)
    {
    PT temp;
    int x,y,i;
    float m,k;
    if( p1.code[3]=='1') /* Cutting LEFT Edge  */
    x=150;
    if(p1.code[2]=='1')  /* Cutting RIGHT Edge */
    x=450;
    if((p1.code[3]=='1')||(p1.code[2]=='1'))
    {
    m=(float) (p2.y-p1.y)/(p2.x-p1.x);
    k=(p1.y+(m*(x-p1.x)));
    temp.y=k;
    temp.x=x;
    for(i=0;i<4;i++)
    temp.code[i]=p1.code[i];
    if(temp.y<=350&&temp.y>=100)
    return(temp);
    }
    if(p1.code[0]=='1')  /* Cutting TOP Edge */
    y=100;
    if(p1.code [1]=='1') /* Cutting BOTTOM Edge */
    y=350;
    if((p1.code[0]=='1')||(p1.code[1]=='1'))
    {
    m=(float)(p2.y-p1.y)/(p2.x-p1.x);
    k=(float)p1.x+(float)(y-p1.y)/m;
    temp.x=k;
    temp.y=y;
    for(i=0;i<4;i++)
    temp.code[i]=p1.code[i];
    return(temp);
    }
    else
    return(p1);
    }

8 To implement Bezier Curve

#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();
    }

9 To implement Fractal Genration (koch Curve)

#include<stdio.h>
#include<graphics.h>
#include<stdlib.h>
#define SIN 0.86602540   // sin(60 degrees)


void koch(int x1, int y1, int x2, int y2, int m)
{
int xx, yy, x[5], y[5], lx, ly, offx = 50, offy = 300;

        lx = (x2-x1)/3;
        ly = (y2-y1)/3;
        x[0] = x1;              // Store point p0
        y[0] = y1;
        x[4] = x2;                               // Store point p4
        y[4] = y2;
        x[1] = x[0] + lx;                             // Store point p1
        y[1] = y[0] + ly;
        x[3] = x[0] + 2*lx;                      // Store point p3
        y[3] = y[0] + 2*ly;
        xx =  x[3] - x[1];                      // Translate point p2 to origin
        yy =  y[3] - y[1];
        x[2] =  xx*(0.5) + yy*(SIN);        // Perform rotation for point p3
        y[2] = - xx*(SIN) + yy*(0.5);
        x[2] = x[2] + x[1];                       // Perform inverse translation
        y[2] = y[2] + y[1];
    if(m>0)
    {
        koch(x[0], y[0], x[1], y[1], m-1);  // Recursive call to Draw part1
        koch(x[1], y[1], x[2], y[2], m-1);  // Recursive call to Draw part2
        koch(x[2], y[2], x[3], y[3], m-1);  // Recursive call to Draw part3
        koch(x[3], y[3], x[4], y[4], m-1);  // Recursive call to Draw part4
    }
    else
    {
        line(offx + x[0], offy + y[0] , offx + x[1], offy + y[1]);
        line(offx + x[1], offy + y[1] , offx + x[2], offy + y[2]);
        line(offx + x[2], offy + y[2] , offx + x[3], offy + y[3]);
        line(offx + x[3], offy + y[3] , offx + x[4], offy + y[4]);

    }
}
void main()
{
int n, gd, gm;
int x1 = 0, x2 = 550, y1= 0, y2 = 0;
/* Initialise graphics mode
---------------------------------- */
printf("\n Enter the level of curve generation : ");
scanf("%d", &n);
detectgraph(&gd,&gm);
initgraph(&gd,&gm,"\\tc\\bgi");
koch(x1, y1, x2, y2, n);             // Draw Koch curve

getch();
closegraph();
}

10 To implement program for projection of 3d object on projection Plane

#include <stdio.h>
#include <stdlib.h>
#include<graphics.h>
#include<conio.h>
void draw3d(int s,int x[20],int y[20],int d);
void main()
{
    int gd=DETECT,gm;
    int x[20],y[20],i,s,d;
    initgraph(&gd,&gm,"");
    printf("Enter the No of sides : ");
    scanf("%d",&s);
    for(i=0;i<s;i++)
    {
        printf("(x%d,y%d) :",i,i);
        scanf("%d%d",&x[i],&y[i]);
    }
    printf("Depth :");
    scanf("%d",&d);
    draw3d(s,x,y,d);
    getch();
    setcolor(14);
    for(i=0;i<s-1;i++)
    {
        line(x[i]+200,y[i],x[i+1]+200,y[i+1]);
    }
    line(x[i]+200,y[i],x[0]+200,y[0]);
    getch();//top view
    for(i=0;i<s-1;i++)
    {
        line(x[i],300,x[i+1],300);
        line(x[i],300+d*2,x[i+1],300+d*2);
        line(x[i],300,x[i],300+d*2);
        line(x[i+1],300,x[i+1],300+d*2);
    }
    getch();//side view
    for(i=0;i<s-1;i++)
    {
        line(10,y[i],10,y[i+1]);
        line(10+d*2,y[i],10+d*2,y[i+1]);
        line(10,y[i],10+d*2,y[i]);
        line(10,y[i+1],10+d*2,y[i+1]);
    }
    getch();
    closegraph();
}
void draw3d(int s,int x[20],int y[20],int d)
{
    int i,j,k=0;
    for(j=0;j<2;j++)
    {
        for(i=0;i<s-1;i++)
            line(x[i]+k,y[i]-k,x[i+1]+k,y[i+1]-k);
        line(x[i]+k,y[i]-k,x[0]+k,y[0]-k);
        k=d;
    }
    for(i=0;i<s;i++)
        line(x[i],y[i],x[i]+d,y[i]-d);
}

Ajink Gupta
Ajink Gupta

Ajink Gupta is a software developer from Dombivli, Maharashtra, India. He has expertise in a variety of technologies including web development, mobile app development, and blockchain. He works with languages and frameworks like JavaScript, Python, Flutter, React, and Django.

Ajink Gupta is also active on several platforms where he shares his work and engages with the community. You can find his projects and contributions on GitHub and follow his tutorials and updates on his YouTube channel​ . He also has a personal website where he showcases his portfolio and ongoing projects at ajinkgupta.vercel.app

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