Graphics Manual 12

8/4/2019 Graphics Manual 12

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LINE DRAWING USING DDA ALGORITHM

AIM:

To write a C program to draw a line using DDA algorithm.

ALGORITHM:

1. Start the program.2. Read the starting and ending coordinates xa, ya, xb, and yb.3. Find the x-coordinate difference and y-coordinate difference.

dx=xb-xa & dy=yb-ya.

4.Compare the difference and decide the step value.if(dx>dy)

step=dx

else

step=dy

5. Find the increment values of coordinates.xi=dx/step

yi=dy/step

6. Display the starting point using the function putpixel(xa,ya,4).7. Find adjacent pixels using the formula xa=xa+xi & ya=ya+yi.8.

Repeat the steps till reaching the endpoints i.e, ya=yb & xa=xb.

9. Stop the program.


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PROGRAM:

#include#include

#include

#include

void main()

{

int gd=DETECT,gm;

float xadj,yadj,xa,ya,xb,yb,dx,dy,step,xi,yi,d,t1,t2;

initgraph(&gd,&gm,"");

d=1;printf("Enter the starting coordinates:");

scanf("%f %f",&xa,&ya);

printf("Enter the ending coordinates:");

scanf("%f %f",&xb,&yb);

dx=xb-xa;

dy=yb-ya;

if(abs(dx)>abs(dy))

step=abs(dx);

else

step=abs(dy);

xi=dx/step;

yi=dy/step;

while(d==1)

{

putpixel(xa,ya,4);

xadj=xa+xi;

yadj=ya+yi;

xa=xadj;

ya=yadj;if((xa==xb)&&(ya==yb))

d=0;

}

getch();

closegraph();

}


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OUTPUT:

Enter the starting coordinates: 100 100

Enter the ending coordinates: 200 200

RESULT:

Thus a line is drawn successfully using DDA algorithm in C.


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LINE DRAWING USING BRESENHAMS ALGORITHM

AIM:

To write a program in C to draw a line using Bresenhams

algorithm.

ALGORITHM:

1. Start the program.2. Read the starting and ending coordinates xa, ya, xb, yb.3. Find the x-coordinate difference and y-difference.

dx=xb-xa & dy=yb-ya

4. Calculate decision parameter p value.p= 2dy-dx

5. Fix the starting and ending coordinates.xstart=xa

if(xa


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PROGRAM:

#include#include

#include

void main()

{

int gd=DETECT,gm;

int xa, xb, ya, yb, dx, dy, x, y, xstart, ystart, xend, yend, p;

initgraph(&gd,&gm,""); clrscr();

printf("Enter the xa & ya value:"); scanf("%d %d",&xa,&ya);

printf("Enter the xb & yb value:"); scanf("%d %d",&xb,&yb);dx=abs(xa-xb);

dy=abs(ya-yb);

p=2*dy-dx;

if(xa


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OUTPUT:

Enter the xa & ya value: 200 200Enter the xb & yb value: 350 450

RESULT:

Thus a line is drawn successfully using Bresenhams algorithm in C.


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CIRCLE DRAWING USING BRESENHAMS CIRCLE ALGORITHM

AIM:

To draw a circle using Bresenhams circle drawing algorithm in C.

ALGORITHM:

1. Start the program.2. Get the radius and center of the circle r, xc, yc.3. Obtain the first point on the circumference of a circle centered on the origin

as (X0,Y0)=(0,r)

4. Calculate the initial value of the decision parameter as p =5/4-r5. At each xk position, starting at k=0, perform the following test

if(pk=y.9.

Stop the program.


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PROGRAM:

#include#include

#include

float xc, yc, r, x, y, p;

void plotpoint();

void main()

{

int gd=DETECT,gm;


printf("Enter the xc value:");scanf("%f",&xc);

printf("Enter the yc value:");

scanf("%f",&yc);

printf("Enter the radius:");

scanf("%f",&r);

x=0;

y=r;

plotpoint();

p=1-r;

while(x


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void plotpoint()

{

putpixel(xc+x,yc+y,1);

putpixel(xc-x,yc+y,1);

putpixel(xc+x,yc-y,1);

put pixel(xc-x,yc-y,1);

putpixel(xc+y,yc+x,1);

putpixel(xc-y,yc+x,1);

putpixel(xc+y,yc-x,1);

putpixel(xc-y,yc-x,1);

}


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OUTPUT:

Enter the xa value: 200Enter the ya value: 200

Enter the radius: 50

RESULT:

Thus a circle is drawn successfully using Bresenhams circle drawing

algorithm in C.


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ELLIPSE DRAWING ALGORITHM

AIM:

To write a program in C to draw an ellipse using midpoint ellipse

drawing algorithm.

ALGORITHM:

1. Start the program.2. Get the radius rx, ry and center of the ellipse xc, yc.3. Obtain the first point on the ellipse centered on the origin as (x0,y0)=(0,ry)4. Calculate the initial value of the decision parameter in region1 as

p10=ry2-rx

2ry+1/4rx

2.

5. At each xk position in region1,starting at k=0,perform the following testIf(p1k0), the next point along the ellipse centered on (0,0) is (xk, yk+1) and

p2k+1=p2k-2rx2yk+1+rx

2

Otherwise the next point along the ellipse is (xk+1,yk+1) andP2k+1=p2k+2ry

2xk+1+rx

2-2rx

2yk+1, using the same incremental

calculations for x & y as in region2.

8. Determine the symmetry points in other three quadrants.9. Move each calculated pixel position (x,y) onto the elliptical path centered on

(xc,yc) and plot the coordinate values, x=x+xc & y=y+yc.

10.Repeat the steps for region1 until 2ry2x>2rx2y.11.Stop the program.


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PROGRAM:

#include#include

#include

#define round(a) (int)(a+0.5)

float xc, yc, x, y;

void plotpoint();

void main()

{

int gd=DETECT,gm;

float rx, ry, p, px, py, rx2, ry2, tworx2, twory2;initgraph(&gd,&gm,"");

clrscr();

printf("Enter the xc value:");

scanf("%f",&xc);

printf("Enter the yc value:");

scanf("%f",&yc);

printf("Enter the x radius:");

scanf("%f",&rx);

printf("Enter the y radius:");

scanf("%f",&ry);

ry2=ry*ry;

rx2=rx*rx;

twory2=2*ry2;

tworx2=2*rx2;

x=0;

y=ry;

plotpoint();

p=round(ry2 - rx2 * ry + (0.25 * rx2));

px=0;py=tworx2*y;

while(px=0){

y=y-1;

py=py-tworx2; }


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if(p0)

{

y=y-1;

py=py-tworx2;

if(p0)

p=p+rx2-py;

else

p=p+rx2-py+px;

plotpoint();

}

getch();

closegraph();

}

void plotpoint()

{

putpixel(xc+x,yc+y,1);

putpixel(xc-x,yc+y,1);

putpixel(xc+x,yc-y,1);

putpixel(xc-x,yc-y,1);

}


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OUTPUT:

Enter the xa value: 200Enter the ya value: 200

Enter the x radius: 100

Enter the y radius: 50

RESULT:

Thus an ellipse is drawn successfully using midpoint ellipse drawing

algorithm in C.


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IMPLEMENTATION OF LINE, CIRCLE AND ELLIPSE ATTRIBUTES

AIM:

To write a C Program to display the various output primitives with its

attributes.

ALGORITHM:

1. Start the program.2. Initialize the variables.3. Call the initgraph() function4. Set color for the output primitives.5. Using outtextxy() display the chosen particular primitives.6. Using switch cases mention the various primitives and their attributes.7. The various primitives are arc, line, circle, rectangle and ellipse.8. Close the graph and run the program.9. Stop the program.


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PROGRAM:

#include#include

#include

#include

void main()

{

char ch;

int gd=DETECT,gm,x1,y1,x2,y2,rad,sa,ea,xrad,yrad,i;


printf("enter the choice:"); scanf("%c",ch);

do

{

cleardevice(); setbkcolor(9);

outtextxy(100,150,"Enter 1 to get line");

outtextxy(100,170,"2.Circle");

outtextxy(100,190,"3.Box");

outtextxy(100,210,"4.Arc");

outtextxy(100,230,"5.Ellipse");

outtextxy(100,250,"6.Rectangle");

outtextxy(100,270,"7.Exit");

ch=getch(); cleardevice();

switch(ch)

{

case '1':

setlinestyle(SOLID_LINE,0,1);

line(100,200,300,400);

break;

case '2':setfillstyle(SOLID_FILL,8);

circle(200,200,75);

break;

case '3':

setfillstyle(7,4);

bar(100,300,200,100);

break;


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case '4':

setfillstyle(5,4);

arc(200,200,100,300,100);

break;

case '5':

setfillstyle(5,4);

fillellipse(100,100,50,100);

break;

case '6':

settextstyle(DEFAULT_FONT,0,2);

outtextxy(120,140,"Graphics");

line(100,100,100,300);line(300,300,100,300);

line(100,100,300,100);

line(300,100,300,300);

break;

case '7':

closegraph();

return;

}

}

while(ch=='y'|| ch=='Y');

getch();

}


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OUTPUT:

Enter Choice: yEnter 1 to get line

2. Circle

3. Box

4. Arc

5. Ellipse

6. Rectangle

7. Exit

1 2


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RESULT:

Thus the program for implementing line, circle and ellipse attributes was

executed successfully.

Graphics

4

6


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BASIC 2D TRANSFORMATIONS

AIM:

To write a program to perform the basic 2D transformations like

translation, rotation and scaling using transformation equation in C.

ALGORITHM:

1. Start the program.2. Obtain the coordinates of the line xa,ya,xb,yb.3. Get the translation factors tx, ty, rotation angle a & scaling factors sx, sy.4. Find the translated coordinates by applying the angle as

x1=x+tx & y

1=y+ty.

5. Get the rotation coordinates by applying the angle asX

1=abs(xa-xb)cosa-abs(ya-yb)sina

Y1

=abs(xa-xb)sina+abs(ya-yb)cosa

6. Scaling is applied asX

1=x*sx

Y1=y*sy

7. Draw the transformed line with the new coordinates (x1,y1).8. Stop the program.


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PROGRAM:

#include#include

#include

#include

void getdata();

int x1, y1, x2, y2;

void main()

{

int gd=DETECT,gm;

int x3, x4, y3, y4, tx, ty, ch;float sx, sy, a, t;


clrscr(); setcolor(1);

do

{

printf("1.Translation\t2.Scaling\t3.Rotation\t4.Exit\nEnter your choice:");

scanf("%d",&ch);

switch(ch)

{

case 1:

getdata();

printf("Enter the translation factor in x-axis:");

scanf("%d",&tx);

printf("Enter the translation factor in y-axis:");

scanf("%d",&ty);

x3=x1+tx; x4=x2+tx;

y3=y1+ty; y4=y2+ty;

line(x3,y3,x4,y4);

getch(); cleardevice();break;

case 2:

getdata();

printf("Enter the scaling factor in x-axis:");

scanf("%f",&sx);

printf("Enter the scaling factor in y-axis:");

scanf("%f",&sy);

x3=x1*sx;


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x4=x2*sx;

y3=y1*sy;

y4=y2*sy;

line(x3,y3,x4,y4);

getch();

cleardevice();

break;

case 3:

getdata();

printf("Enter the rotation angle:");

scanf("%f",&a);

t=a*(3.14159/180);x4=x1+abs(x2-x1)*cos(t)-abs(y2-y1)*sin(t);

y4=y1+abs(x2-x1)*sin(t)+abs(y2-y1)*cos(t);

line(x1,y1,x4,y4);

getch();

cleardevice();

break;

case 4:

exit(0);

break;

}

}while(ch


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OUTPUT:

1.Translation 2.Scaling 3.Rotation 4.ExitEnter the choice: 1

Enter the x1 value: 100

Enter the y1 value: 100



Enter the translation factor in x-axis: 50

Enter the translation factor in y-axis: 0

1.Translation 2.Scaling 3.Rotation 4.Exit

Enter the choice: 2





Enter the scaling factor in x-axis: 1

Enter the scaling factor in y-axis: 2


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1.Translation 2.Scaling 3.Rotation 4.Exit

Enter the choice: 3

Enter the x1 value: 100Enter the y1 value: 100



Enter the rotation angle: 45

RESULT:

Thus the program for performing basic 2D transformations using

transformation equation is successfully executed in C.


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2D TRANSFORMATIONS (REFLECTION AND SHEARING)

AIM:

To write a program to perform the other 2D transformations like

reflection and shearing in C.

ALGORITHM:

1. Start the program.2. For reflection obtain the coordinates of the triangle xa, ya, xb, yb, xc, yc.3. Calculate the reflection as, x`=x+2*(320-x) y`=y+2*(240-y)4. For shearing obtain the coordinates of the square xa, ya, xb, yb, xc, yc, xd, yd.5. Shearing points can be calculated as x`=x+shx & y`=y+shy, where shx, shy

are the shearing factors.

6. Draw the transformed objects with the new coordinates (x`, y`).7. Stop the program.


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PROGRAM:

#include#include

#include

void reflection();

void shearing();

void main()

{

int gd=DETECT,gm,ch;


do{

cleardevice();

printf("1.Reflection\t2.Shearing\t3.Exit\nEnter your choice:");

scanf("%d",&ch);

switch(ch)

{

case 1:

cleardevice();

reflection();

break;

case 2:

cleardevice();

shearing();

break;

case 3:

exit(0);

break;

}

}while(ch


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printf("Enter the xb&yb values:");

scanf("%d\n%d",&xb,&yb);

printf("Enter the xc&yc values:");

scanf("%d\n%d",&xc,&yc);

line(xa,ya,xb,yb);

line(xb,yb,xc,yc);

line(xc,yc,xa,ya);

do

{

printf("1.About x-axis\t2.About y-axis\t3.About both\t4.exit\nEnter the

choice:");

scanf("%d",&ch);switch(ch)

{

case 1:

cleardevice();

line(xa,ya,xb,yb);

line(xb,yb,xc,yc);

line(xc,yc,xa,ya);

y1=ya+2*(getmaxy()/2-ya);

y2=yb+2*(getmaxy()/2-yb);

y3=yc+2*(getmaxy()/2-yc);

line(xa,y1,xb,y2);

line(xb,y2,xc,y3);

line(xc,y3,xa,y1);

break;

case 2:

cleardevice();

line(xa,ya,xb,yb);

line(xb,yb,xc,yc);

line(xc,yc,xa,ya);

x1=xa+2*(getmaxy()/2-xa);

x2=xb+2*(getmaxy()/2-xb);

x3=xc+2*(getmaxy()/2-xc);

line(x1,ya,x2,yb);

line(x2,yb,x3,yc);

line(x3,yc,x1,ya);

break;


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case 3:

cleardevice();

line(xa,ya,xb,yb);

line(xb,yb,xc,yc);

line(xc,yc,xa,ya);

x1=xa+2*(getmaxy()/2-xa);

x2=xb+2*(getmaxy()/2-xb);

x3=xc+2*(getmaxy()/2-xc);

y1=ya+2*(getmaxy()/2-ya);

y2=yb+2*(getmaxy()/2-yb);

y3=yc+2*(getmaxy()/2-yc);

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

line(x3,y3,x1,y1);

break;

case 4:

break;

}

}

while(ch


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switch(ch)

{

case 1:

cleardevice();

line(xa,ya,xb,yb);

line(xb,yb,xc,yc);

line(xc,yc,xd,yd);

line(xd,yd,xa,ya);

printf("Enter the shearing factor for x:");

scanf("%f",&shx);

xe=xc+shx;

xf=xd+shx;line(xa,ya,xb,yb);

line(xb,yb,xe,yc);

line(xe,yc,xf,yd);

line(xf,yd,xa,ya);

break;

case 2:

cleardevice();

printf("Enter the shearing factor for y:");

scanf("%f",&shy);

ye=yb+shy;

yf=yc+shy;

line(xa,ya,xb,ye);

line(xb,ye,xc,yf);

line(xc,yf,xd,yd);

line(xd,yd,xa,ya);

break;

case 3:

cleardevice();

printf("Enter the shearing factor for x:");

scanf("%f",&shx);

printf("Enter the shearing factor for y:");

scanf("%f",&shy);

xe=xc+shx;

xf=xd+shx;

ye=yb+shy;

yf=yc+shy;


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line(xa,ya,xb,ye);

line(xb,ye,xe,yf);

line(xe,yf,xf,yd);

line(xf,yd,xa,ya);

break;

case 4:

break;

}

}

while(ch


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OUTPUT:

1.Reflection 2.Shearing 3.ExitEnter the choice: 1

Enter the xa&ya value: 200 100

Enter the xb&yb value: 200 200

Enter the xc&yc value: 100 200

1.About x-axis 2.About y-axis 3.About both 4.Exit

Enter the choice: 1


Enter the choice: 2

1.About x-axis 2.About y-axis 3.About both 4.ExitEnter the choice: 3


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Enter the choice: 4

1.Reflection 2.Shearing 3.Exit

Enter the choice: 2

Enter the xa&ya value: 200 200

Enter the xb&yb value: 300 200

Enter the xc&yc value: 300 300

Enter the xd&yd value: 200 300


Enter the choice: 1

Enter the shearing factor for x:50


Enter the choice: 2

Enter the shearing factor for y:50


Enter the choice: 3

Enter the shearing factor for x: 50

Enter the shearing factor for y: 50


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Enter the choice: 4

Enter the choice: 3

RESULT:

Thus the program for performing 2D transformations reflection and

shearing is successfully executed in C.


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COMPOSITE 2D TRANSFORMATIONS

AIM:

To write a program to perform the composite 2D transformations like

successive translation, rotation and scaling using transformation equation in

C.

ALGORITHM:

1. Start the program.2.

Obtain the coordinates of the line xa,ya,xb,yb.

3. Get the translation factors tx1, ty1, tx2, ty2 rotation angles a1, a2 & scalingfactors sx1, sy1, sx2, sy2.

4. Find the translated coordinates by applying the formula as below.x

1=x+(tx1+tx2) & y

1=y+(ty1+ty2).

It possesses associative property and successive translations are additive.

5. Get the rotation coordinates by applying the formula asX

1=abs(xa-xb)cos(a1+a2)-abs(ya-yb)sin(a1+a2)

Y1=abs(xa-xb)sin(a1+a2)+abs(ya-yb)cos(a1+a2)

It possesses associative property and successive rotations are additive.

6. Scaling is applied asX

1=x*(sx1*sx2)

Y1=y*(sy1*sy2)

It possesses associative property and successive scaling is multiplicative.

7. Draw the transformed line with the new coordinates (x1,y1).8. Stop the program.


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PROGRAM:

#include#include

#include

#include

void getdata();

int x1, y1, x2, y2;

void main()

{

int gd=DETECT, gm;

int x3, x4, y3, y4, tx1, ty1, tx2, ty2, ch;float sx1, sy1, sx2, sy2, a1, a2, t1, t2;


clrscr();

setcolor(1);

do

{

printf("1.Successive Translation\t2.Successive Scaling\t3.Successive

Rotation\t4.Exit\nEnter your choice:");

scanf("%d",&ch);

switch(ch)

{

case 1:

getdata();

printf("Enter the translation factors in x-axis:");

scanf("%d%d",&tx1,&tx2);

printf("Enter the translation factors in y-axis:");

scanf("%d%d",&ty1,&ty2);

x3=x1+tx1+tx2;

x4=x2+tx1+tx2;y3=y1+ty1+ty2;

y4=y2+ty1+ty2;

line(x3,y3,x4,y4);

getch();

cleardevice();

break;


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case 2:

getdata();

printf("Enter the scaling factors in x-axis:");

scanf("%f%f",&sx1,&sx2);

printf("Enter the scaling factors in y-axis:");

scanf("%f%f",&sy1,&sy2);

x3=x1*sx1*sx2;

x4=x2*sx1*sx2;

y3=y1*sy1*sy2;

y4=y2*sy1*sy2;

line(x3,y3,x4,y4);

getch();cleardevice();

break;

case 3:

getdata();

printf("Enter the rotation angle:");

scanf("%f%f",&a1,&a2);

t1=a1*(3.14159/180);

t2= a2*(3.14159/180);

x4=x1+abs(x2-x1)*cos(t1+t2)-abs(y2-y1)*sin(t1+t2);

y4=y1+abs(x2-x1)*sin(t1+t2)+abs(y2-y1)*cos(t1+t2);

line(x1,y1,x4,y4);

getch();

cleardevice();

break;

case 4:

exit(0);

break;

}

}

while(ch


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printf("Enter the x1 value:");

scanf("%d",&x1);

printf("Enter the y1 value:");

scanf("%d",&y1);

printf("Enter the x2 value:");

scanf("%d",&x2);

printf("Enter the y2 value:");

scanf("%d",&y2);

line(x1,y1,x2,y2);

}


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OUTPUT:

1.Successive Translation 2. Successive Scaling 3. Successive Rotation4.Exit

Enter the choice: 1





Enter the translation factor in x-axis: 25 25

Enter the translation factor in y-axis: 0 0

1.Successive Translation 2. Successive Scaling 3. Successive Rotation

4.Exit

Enter the choice: 2





Enter the scaling factor in x-axis: 0.5 0.5

Enter the scaling factor in y-axis: 1 1


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1.Successive Translation 2. Successive Scaling 3. Successive Rotation

4.Exit

Enter the choice: 3Enter the x1 value: 100




Enter the rotation angle: 20 25

RESULT:

Thus the program for performing composite 2D transformations using

transformation equation is successfully executed in C.


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LINE CLIPPING USING COHEN-SUTHERLAND ALGORITHM

AIM:

To write a program in C to clip a line using Cohen-Sutherland line

clipping algorithm.

ALGORITHM:

1.

Start the program.2. Obtain the coordinates of the clipping window xmin,ymin,xmax,ymax.3. Get the coordinates of the line to be clipped xa,ya,xb,yb.4. Region codes are assigned to the line end points according to relative position

with respect to the clipping rectangle.

5. The two region codes of the line end points which passes through the clippingrectangle are ANDed.

6. If the result is one (1 1 1 1),then the line is entirely outside the clippingwindow.

7. If the result is zero (0 0 0 0), then the line is completely inside the windowhence we can save it for display.

8. For the intermediate results we have to find intersection point using lineequation. The slope of the line is given by the equation m=(yb-ya)/(xb-xa).

9. The point at which the line intersects the clipping window can be obtainedusing the equation x


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PROGRAM:

#include#include

#include

#include

void main()

{

int gd=DETECT,gm;

float xmin,ymin,xmax,ymax,x1,y1,x2,y2,x,y,slope,yl1,yr1,xa1,xb1;

float xa2, xr2;

float yl2,xb2,xl2,xe,ye,yr2;int l1,r1,b1,a1,l2,r2,b2,a2,l,r,b,a;


clrscr();

printf("Enter the coordinates for rectangle:");

scanf("%f\n%f\n%f\n%f",&xmin,&ymin,&xmax,&ymax);

printf("Enter the coordinates for line:");

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

setcolor(3);

rectangle(xmin,ymin,xmax,ymax);

line(x1,y1,x2,y2);

if((x1-xmin)


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if((x2-xmin)


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else

xa1=x1+(ymin-y1)/slope;

getch(); cleardevice();


line(xa1,ymin,x2,y2);

xe=xa1; ye=ymin;

}

if(x1xmax)

{

yr1=y1+slope*(xmax-x1);

getch();

cleardevice();


line(xmax,yr1,x2,y2);

xe=xmax;

ye=yr1;

}

if(y1>ymax)

{

xb1=x1+(ymax-y1)/slope;

getch();

cleardevice();


line(xb1,ymax,x2,y2);

xe=xb1;

ye=ymax;

}

if(y2


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else

xa2=x2+(ymin-y2)/slope;

getch();

cleardevice();


line(xa2,ymin,xe,ye);

}

if(x2>xmax)

{

yr2=y2+slope*(xmax-x2);

getch();

cleardevice();rectangle(xmin,ymin,xmax,ymax);

line(xmax,yr2,xe,ye);

}

if(x2ymax)

{

if((x2-x1)==0)

xb2=x2;

else

xb2=x2+(ymax-y2)/slope;

getch();

cleardevice();


line(xb2,ymax,xe,ye);

}

getch();

closegraph();

}


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OUTPUT:Enter the coordinates for rectangle: 200 200 300 300

Enter the coordinates for line:150 200 350 450

*

*

*

RESULT:

Thus the program to clip a line using Cohen-Sutherland algorithm has

written and successfully executed in C.


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IMPLEMENTATION OF SUTHERLAND HODGEMAN POLYGONCLIPPING ALGORITHM

AIM:

To write a C program to implement Sutherland Hodgeman polygon

clipping algorithm.

ALGORITHM:

1. Start the program.2. Declare the variables for defining clip window & polygon.3. While clipping a polygon following four possible cases to be considered:

If the first vertex is outside the window boundary and the secondvertex inside.

If the first vertex is inside the window boundary and the second vertexoutside

If both are outside If both are inside

4. Clip the polygon against the window boundary in the order left, right, bottom& above using intersection calculation.

5. Check the vertices that formed the polygon lies inside or on the boundary. Ifthat is inside or on the boundary save that point otherwise discard it.



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PROGRAM:

#include #include

#include

#include

#include

#define TRUE 1

#define FALSE 0

typedef unsigned int outcode;

outcode CompOutCode(float x,float y);

enum {

TOP = 0x1,

BOTTOM = 0x2,

RIGHT = 0x4,

LEFT = 0x8

};

float xmin,xmax,ymin,ymax;

void clip(float x0,float y0,float x1,float y1)

{

outcode outcode0,outcode1,outcodeOut;

int accept = FALSE,done = FALSE;outcode0 = CompOutCode(x0,y0);

outcode1 = CompOutCode(x1,y1);

do

{

if(!(outcode0|outcode1))

{

accept = TRUE;

done = TRUE;

}else if(outcode0 & outcode1)

done = TRUE;

else

{

float x,y;

outcodeOut = outcode0?outcode0:outcode1;


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if(outcodeOut & TOP)

{

x = x0+(x1-x0)*(ymax-y0)/(y1-y0);

y = ymax;

}

else if(outcodeOut & BOTTOM)

{

x = x0+(x1-x0)*(ymin-y0)/(y1-y0);

y = ymin;

}

else if(outcodeOut & RIGHT)

{y = y0+(y1-y0)*(xmax-x0)/(x1-x0);

x = xmax;

}

else

{

y = y0+(y1-y0)*(xmin-x0)/(x1-x0);

x = xmin;

}

if(outcodeOut==outcode0)

{

x0 = x;

y0 = y;


}

else

{

x1 = x;

y1 = y;


}

}

}while(done==FALSE);

if(accept)

line(x0,y0,x1,y1);

outtextxy(150,20,"POLYGON AFTER CLIPPING");


}


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outcode CompOutCode(float x,float y)

{

outcode code = 0;

if(y>ymax)

code|=TOP;

else if(yxmax)

code|=RIGHT;

else if(x


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OUTPUT:Enter the no of sides of polygon:5

Enter the coordinates of polygon50

50

200

100

350

350

80

200

40

80

Enter the rectangular coordinates of clipping window150

150

300

300

POLYGON BEFORE CLIPPING

POLYGON AFTER CLIPPING

RESULT:Thus the C program to implement Sutherland Hodgeman polygon clipping was

executed and verified.


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3D TRANSFORMATION(TRANSLATION,ROTATION AND SCALING)

AIM:

To write a C program to perform translation,rotation and scaling on

3D objects.

ALGORITHM:

1. Start the program.2. Store the coordinate values in a homogeneous matrix.3. Draw a 3D object with a specified coordinate value stored in a homogeneous

matrix.

4. Perform Translation with the use of translation matrix given below1 0 0 tx

0 1 0 ty

0 0 1 tz

0 0 0 1

where tx,ty,tz are the translation factors.

5. Perform rotation with the rotation matrix given by1 0 0 0

0 cost -sint 0

0 sint cost 0

0 0 0 0

6. Perform scaling with the scaling matrix given bysx 0 0 0

0 sy 0 0

0 0 sz 00 0 0 1

where sx,sy,sz are scaling factors.



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PROGRAM:

#include#include

#include

#include

void main()

{

int tx,ty,z[4][4],t1,i,j,p,k,l,shx;

float a,zr[4][4],yf,xf,zf,m,n,sx,sy,sz;

int pts[10],pts1[10],ch,x[10],y[10];

int gd=DETECT,gm;void scaling();


do

{

cleardevice();

printf("3D-TRANSFORMATION\n");

printf("1.Translation\t2.Rotation\t3.Scaling\t4.Exit\n");

printf("Enter the choice:");

scanf("%d",&ch);

switch(ch)

{

case 1:

cleardevice();

pts[0]=50;pts[1]=50;pts[2]=250;pts[3]=50;pts[4]=250;

pts[5]=150;pts[6]=50;pts[7]=150;pts[8]=50;pts[9]=50;

printf("Enter the vector:");

scanf("%d %d",&tx,&ty);

for(i=0;i


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for(k=0;k


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for(l=0;l


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case 3:

scaling();

break;

case 4:

exit(0);

}

}

while(ch!=5);

closegraph();

}

void scaling()

{int xx1,yy1,xx2,yy2,xx3,yy3,xx4,yy4,tx,ty, x1,y1,x2,y2,x3,y3,x4,y4;

x1=100;y1=100;x2=50;y2=150;x3=100;y3=125;x4=150;y4=150;

printf("Enter the scaling factor:"); scanf("%d %d",&tx,&ty);

cleardevice(); settextstyle(0,0,2);

outtextxy(200,50,"scaling");

line(x1,y1,x2,y2);

line(x1,y1,x4,y4);

line(x2,y2,x4,y4);

setlinestyle(1,1,1);

line(x2,y2,x3,y3);

line(x3,y3,x1,y1);

line(x3,y3,x4,y4);

xx1=x1*tx; yy1=y1*ty;





line(xx1,yy1,xx2,yy2);







getch();

}


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OUTPUT:

3D-TRANSFORMATIONS

1.Translation 2.Rotation 3.Scaling 4.ExitEnter the choice: 1

1.Translation 2.Rotation 3.Scaling 4.Exit

Enter the choice: 2


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Enter the choice: 3


Enter the choice: 4

RESULT:

Thus the program to perform translation, rotation and scaling on 3D

objects were written and executed successfully in C.


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COMPOSITE 3D- TRANSFORMATIONS

AIM:

To perform Composite 3D transformations such as successive translation &

rotation, fixed point scaling.

ALGORITHM:

1. Start the program.2. Use the function draw cube to draw a cube using eight points by means of

line functions.

3. Declare the variables x1,y1,x2,y2,x3,y3, in array type which of data type int.4. Declare the necessary variables for performing transformations.5. Initialize graphics functions.6. Input the first point in the cube.7. Input the size of the edge.8. Using switch operation selects the operation to perform successive translation,

successive rotation, and fixed point scaling.

9. Successive Translationa) input the translation vector tx1, ty1, tz1 & tx2, ty2, tz2.b) calculate points using formula

x3[i]=x1[i]+tx1+tx2.

y3[i]=y1[i]+ty1+ty2z3[i]=z1[i]+tz1+tz2.

x4[i]=x3[i]+z3[i]/2

y4[i]=y3[i]+z3[i]/2

c) using the function line, display the object before and after translation.


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10.Successive Rotation:

a) input the rotation anglesb) Using formula theta=((theta1+theta2)*3.14)/180c) If the direction is along z axis,

z3[i]=z1[i].

x3[i]=x1[i]*cos(theta)-y1[i]*sin(theta).

y3[i]=x1[i]*sin(theta)-y1[i]*cos(theta).

Apply cyclic permutation and compute for the rest of the directions.

d) Calculate the points using the formulax4[i]=x3[i]+z3[i]/2

y4[i]=y3[i]+z3[i]/2

e) Using the function line, display the object before and after rotation.12.Fixed Point Scaling:

a) Input the scaling factor and reference pointb) Calculate coordinates point using formula

x3[i]=xf+(x1[i]*sx+xf*(1-sx),

y3 [i] =yf+ (y1[i]*sy+yf*(1-sy)

z3 [i] =zf+ (z1[i]*sz+zf*(1-sz)

c) Calculate the points using the formulax4[i]=x3[i]+z3[i]/2

y4[i]=y3[i]+z3[i]/2

d) Using the function line, display the object before and after scaling.13.Stop the program.


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PROGRAM:

#include#include

#include

#include

void drawcube(int x1[],int y1[]);

void main()

{

int i,x1[8],y1[8],x2[8],y2[8],z1[8],x3[8],y3[8],z3[8],x4[8],y4[8],t,t1,t2,op;

int ch,tx1,ty1,tz1,tx2,ty2,tz2,sx,sy,sz,xf,yf,zf,x,y,z,s;

int driver=DETECT;int mode;

initgraph(&driver,&mode,"");

printf("Enter the points on the cube:");

scanf("%d%d%d",&x,&y,&z);

printf("Enter the size of the edge:");

scanf("%d",&s);

x1[0]=x1[3]=x;

x1[1]=x1[2]=x+s;

x1[4]=x1[7]=x;

x1[5]=x1[6]=x+s;

y1[0]=y1[1]=y;

y1[2]=y1[3]=y+s;

y1[4]=y1[5]=y;

y1[6]=y1[7]=y+s;

z1[1]=z1[2]=z1[3]=z1[0]=z;

z1[4]=z1[5]=z1[6]=z1[7]=z-s;

for(i=0;i


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do

{

printf("menu");

printf("\n1.Successive Transformation\n2.Successive Rotation \n

3.Fixed Point Scaling\n4.exit\n");

printf("Enter thr choice:");

scanf("%d",&ch);

switch(ch)

{

case 1:

printf("Enter thr translation vectors:");

scanf("%d%d%d%d%d%d",&tx1, &ty1, &tz1, &tx2,&ty2, &tz2);

for(i=0;i


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t=((t1+t2)*3.14)/180;

printf("Enter the dirrection");

printf("\n1.Rotation about x-axis\n2.Rotation about y-

axis\n3.Rotation about z axis");

scanf("%d",&op);

if(op==1)

{

for(i=0;i


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drawcube(x2,y2);

getch();

cleardevice();

printf("After Rotation");

drawcube(x4,y4);

getch();

cleardevice();

break;

case 3:

printf("Enter the scaling factor");

scanf("%d%d%d",&sx,&sy,&sz);

printf("Enter the reference point");scanf("%d%d%d",&xf,&yf,&zf);

for(i=0;i


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}

while(op!=4);

getch();

}

void drawcube(int x1[],int y1[])

{

int i;

for(i=0;i


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DRAWING 3D- OBJECTS

AIM:

To write a C program to compose a scene by using three dimensional

objects.

ALGORITHM:

1. Start the program.2. Initialize graphics functions.3. Use the function bar3d to depict three dimensional bars on the screen.4. Call sphere in the program by specifying necessary variables.5. Compose a scene in which the bars and the sphere move on the screen by using

the relevant control structure.



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PROGRAM:

#include#include

#include

void main()

{

int gd=DETECT,gm,i,j;


bar3d(200,200,325,250,31,1);

getch();for(i=1;i


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bar3d(i+300,i-100,i+125,i-150,31,1);

setcolor(8);

setfillstyle(LINE_FILL,8);

bar3d(i-400,i+200,i-525,i+250,31,1);

setcolor(5);

setfillstyle(BKSLASH_FILL,5);

bar3d(i+100,i-200,i+250,i-250,31,1);

setcolor(3);

setfillstyle(SOLID_FILL,3);

fillellipse(i+100,100,50,50);

fillellipse(450-i,400,50,50);

setcolor(6);setfillstyle(SOLID_FILL,6);

fillellipse(100,i+100,50,50);

fillellipse(450,i-500,50,50);

setcolor(2);

setfillstyle(SOLID_FILL,2);

fillellipse(i+100,i+100,50,50);

fillellipse(450-i,i-400,50,50);

delay(25);

}

getch();

closegraph();

}


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OUTPUT:

RESULT:

Thus a C program for composing a scene using three dimensional

objects was executed and verified.


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GENERATING FRACTALS

AIM:

To write a C program to generate a fractal image.

ALGORITHM:

1. Start the program.2. Initialize graphics functions.3. In this program a sierpinski gasket is chosen as a fractal image and is drawn

using the function drawsierpinski().

4. Sierpinski triangle is created by infinite removals. Each triangle is divided intofour smaller triangles, each of them half the length (height, etc.) of the original.

5.

Each smaller triangle is reduced iteratively in linear dimension from the originalby a factor of n=2, and keep k=3 smaller triangles at each step. Hence the

Sierpinski Triangle has a dimension of 1.5850



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PROGRAM:

#include#include

#include

#include

#include

void DrawSierpinski(void);

void main()

{

int gd=VGA;

int gm=VGAHI;initgraph(&gd,&gm,"\\tc\\bgi");

DrawSierpinski();

getch();

}

void DrawSierpinski(void)

{

char Direct;

int iterate;

unsigned int x1,y1,x2,y2;

x1=x2=320;

y1=y2=0;

for(iterate=0;iterate


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OUTPUT:

Graphics Manual 12

Documents

Transcript of Graphics Manual 12