Computer Graphics- Lab Project 4 : 2D Transformation

Computer Graphics (ITEC-613)

Lab Project 4 : 2D Transformation

BSIT P-IV
By: Dr. Zeeshan Bhatti

Task 1: Search and write how Matrices are used in Matlab and in CPP or JAVA. How to Solve simple Matrices using these programming languages.

Programming Task: Write code to Solve 2D Transformation using any programming language. Write code to solve Translation, Rotation, Scaling, and Shear.

Download the Lab Handout: https://www.scribd.com/doc/309742677/Computer-Graphics-Lab-Project-4-2D-Transformation

Task 2: Write a program to implement 2D Scaling

Coding:

#include<stdio.h>

#include<conio.h>

#include<graphics.h>

#include<process.h>

#include<math.h>

int x1,y1,x2,y2,x3,y3,mx,my;

void draw();

void scale();

void main()

{

int gd=DETECT,gm;

int c;

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

printf("Enter the 1st point for the triangle:");

scanf("%d%d",&x1,&y1);

printf("Enter the 2nd point for the triangle:");

scanf("%d%d",&x2,&y2);

printf("Enter the 3rd point for the triangle:");

scanf("%d%d",&x3,&y3);

draw();

scale();

}

void draw()

{

line(x1,y1,x2,y2);

line(x2,y2,x3,y3);

line(x3,y3,x1,y1);

}

void scale()

{

int x,y,a1,a2,a3,b1,b2,b3;

int mx,my;

printf("Enter the scalling coordinates");

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

mx=(x1+x2+x3)/3;

my=(y1+y2+y3)/3;

cleardevice();

a1=mx+(x1-mx)*x;

b1=my+(y1-my)*y;

a2=mx+(x2-mx)*x;

b2=my+(y2-my)*y;

a3=mx+(x3-mx)*x;

b3=my+(y3-my)*y;

line(a1,b1,a2,b2);

line(a2,b2,a3,b3);

line(a3,b3,a1,b1);

draw();

getch();

}

Task 3: Write a program to implement 2D Rotation

Coding:

include<stdio.h>

#include<conio.h>

#include<graphics.h>

#include<process.h>

#include<math.h>

void TriAngle(int x1,int y1,int x2,int y2,int x3,int y3);

void Rotate(int x1,int y1,int x2,int y2,int x3,int y3);

void main()

{

int gd=DETECT,gm;

int x1,y1,x2,y2,x3,y3;

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

printf("Enter the 1st point for the triangle:");

scanf("%d%d",&x1,&y1);

printf("Enter the 2nd point for the triangle:");

scanf("%d%d",&x2,&y2);

printf("Enter the 3rd point for the triangle:");

scanf("%d%d",&x3,&y3);

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

getch();

cleardevice();

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

setcolor(1);

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

getch();

}

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

{

line(x1,y1,x2,y2);

line(x2,y2,x3,y3);

line(x3,y3,x1,y1);

}

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

{

int x,y,a1,b1,a2,b2,a3,b3,p=x2,q=y2;

float Angle;

printf("Enter the angle for rotation:");

scanf("%f",&Angle);

cleardevice();

Angle=(Angle*3.14)/180;

a1=p+(x1-p)*cos(Angle)-(y1-q)*sin(Angle);

b1=q+(x1-p)*sin(Angle)+(y1-q)*cos(Angle);

a2=p+(x2-p)*cos(Angle)-(y2-q)*sin(Angle);

b2=q+(x2-p)*sin(Angle)+(y2-q)*cos(Angle);

a3=p+(x3-p)*cos(Angle)-(y3-q)*sin(Angle);

b3=q+(x3-p)*sin(Angle)+(y3-q)*cos(Angle);

printf("Rotate");

TriAngle(a1,b1,a2,b2,a3,b3);

}

Task 4: Write a program to implement 2D Translation Triangle Program 

 Coding:

#include<stdio.h>

#include<conio.h>

#include<graphics.h>

#include<process.h>

#include<math.h>

int x1,y1,x2,y2,x3,y3,mx,my;

void draw();

void tri();

void main()

{

int gd=DETECT,gm;

int c;

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

printf("Enter the 1st point for the triangle:");

scanf("%d%d",&x1,&y1);

printf("Enter the 2nd point for the triangle:");

scanf("%d%d",&x2,&y2);

printf("Enter the 3rd point for the triangle:");

scanf("%d%d",&x3,&y3);

cleardevice();

draw();

getch();

tri();

getch();

}

void draw()

{

line(x1,y1,x2,y2);

line(x2,y2,x3,y3);

line(x3,y3,x1,y1);

}

void tri()

{

int x,y,a1,a2,a3,b1,b2,b3;

printf("Enter the Transaction coordinates");

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

cleardevice();

a1=x1+x;

b1=y1+y;

a2=x2+x;

b2=y2+y;

a3=x3+x;

b3=y3+y;

line(a1,b1,a2,b2);

line(a2,b2,a3,b3);

line(a3,b3,a1,b1);

}

 Task 5: 2D Translation Using Matlab

%Simple demo of 2D Translation in dx,dy in MATLAB

dx = 3; % set translation values

dy = 2;

% create a simple box to draw and manipulate

% row 1 is x coords row 2 is y coords

pts = [1 1 4 4 1;1 4 4 1 1];

[n m] = size(pts);

% Plot box

figure(1)

plot(pts(1,1:end),pts(2,1:end),'b*-');

axis([0 5 0 5])

shg

% create a 2D Translation in dx, dy NEED TO MAKE A HOMOGENEOUS COORDS matrix

trans = [1 0 dx;0 1 dy; 0 0 1];

% Do Translation

% Make PTS HOMOGENEOUS

homogeneous_pts = [pts; ones(1,5)];

%Translate

trans_pts = trans*homogeneous_pts;

% Plot Translated box

% just extract out X and Y points to plot ignore third dimension

hold on

plot(trans_pts(1,1:end),trans_pts(2,1:end),'r*-');

axis([0 10 0 10]);

 

Task 6: 2D Rotation Using Matlab

%Simple demo of 2D rotation in MATLAB

% create a simple box to draw and manipulate

% row 1 is x coords row 2 is y coords

pts = [1 1 4 4 1;1 4 4 1 1];

% Plot box

figure(1)

plot(pts(1,1:end),pts(2,1:end),'b*-');

axis([0 5 0 5])

shg

% create a 2D rotation matrix

rot = [cos_deg(30) sin_deg(30);-sin_deg(30) cos_deg(30)]

% Do Rotation

rot_pts = rot*pts

% Plot Rotated box

hold on

plot(rot_pts(1,1:end),rot_pts(2,1:end),'r*-');

axis([-8 8 -8 8]);

Task 7: 2D Shear using Matlab

% shear_demo_2D.m

close all

clear all

%Simple demo of 2D Shear in X in MATLAB

k = 3; % shear factor

% create a simple box to draw and manipulate

% row 1 is x coords row 2 is y coords

pts = [1 1 4 4 1;1 4 4 1 1];

% Plot box

figure(1)

plot(pts(1,1:end),pts(2,1:end),'b*-');

axis([0 5 0 5])

shg

% create a 2D Shear in X matrix

shear = [1 k;0 1]

% Do Shear

shear_pts = shear*pts;

% Plot Sheared box

hold on

plot(shear_pts(1,1:end),shear_pts(2,1:end),'r*-');

axis([0 20 0 5]);

 

 

Computer Graphics- Lab Project 4 : 2D Transformation