10. 2D transformation.cpp

#include <iostream>
#include <math.h>
#include <time.h>
#include <GL/glut.h>
#include <vector>
using namespace std;
int edge;
vector<int> xpoint;
vector<int> ypoint;
int ch;

double round(double d){
return floor(d + 0.5);
}

void init(){
glClearColor(1.0, 1.0, 1.0, 0.0);
glMatrixMode(GL_PROJECTION);
gluOrtho2D(0, 640, 0, 480);
glClear(GL_COLOR_BUFFER_BIT);
}



void rotaion(){
int cx, cy;
cout << "\n Enter Ar point x , y ";
cin >> cx >> cy;
cx = cx + 320;
cy = cy + 240;
glColor3f(0.0, 1.0, 0.0);
glBegin(GL_POINTS);
glVertex2i(cx, cy);
glEnd();
glFlush();
double the;
cout << "\n Enter thetha ";
cin >> the;
the = the * 3.14 / 180;
glColor3f(0, 0, 1.0);
glBegin(GL_POLYGON);
for (int i = 0; i < edge; i++){
glVertex2i(round(((xpoint[i] - cx) * cos(the) - ((ypoint[i] - cy) * sin(the))) +
cx), round(((xpoint[i] - cx) * sin(the) + ((ypoint[i] - cy) * cos(the))) + cy));
}
glEnd();
glFlush();
}

void scale(){
glColor3f(1.0, 0, 0);
glBegin(GL_POLYGON);
for (int i = 0; i < edge; i++){
glVertex2i(xpoint[i] - 320, ypoint[i] - 240);
}
glEnd();
glFlush();
cout << "\n\tIn Scaling whole screen is 1st Qudrant \n";
int sx, sy;
cout << "\t Enter sx, sy \n";
cin >> sx >> sy;// scale the point
for (int i = 0; i < edge; i++){
xpoint[i] = (xpoint[i] - 320) * sx;
ypoint[i] = (ypoint[i] - 240) * sy;
}
glColor3f(0, 0, 1.0);
glBegin(GL_POLYGON);
for (int i = 0; i < edge; i++){
glVertex2i(xpoint[i], ypoint[i]);
}
glEnd();
glFlush();
}

void reflection(){
char reflection;
cout << "Enter Reflection Axis \n";
cin >> reflection;
if (reflection == 'x' || reflection == 'X'){
glColor3f(0.0, 0.0, 1.0);
glBegin(GL_POLYGON);
for (int i = 0; i < edge; i++){
glVertex2i(xpoint[i], (ypoint[i] * -1) + 480);
}
glEnd();
glFlush();
}
else if (reflection == 'y' || reflection == 'Y'){
glColor3f(0.0, 0.0, 1.0);
glBegin(GL_POLYGON);
for (int i = 0; i < edge; i++){
glVertex2i((xpoint[i] * -1) + 640, (ypoint[i]));
}
glEnd();
glFlush();
}
}


void Draw(){if (ch == 2 || ch == 3){
glColor3f(1.0, 0, 0);
glBegin(GL_LINES);
glVertex2i(0, 240);
glVertex2i(640, 240);
glEnd();
glColor3f(1.0, 0, 0);
glBegin(GL_LINES);
glVertex2i(320, 0);
glVertex2i(320, 480);
glEnd();
glFlush();
glColor3f(1.0, 0, 0);
glBegin(GL_POLYGON);
for (int i = 0; i < edge; i++){
glVertex2i(xpoint[i], ypoint[i]);
}
glEnd();
glFlush();
}
if (ch == 1){
scale();
}
else if (ch == 2){
rotaion();
}
else if (ch == 3){
reflection();
}
}
int main(int argc, char **argv){
cout << "\n \t Enter 1) Scaling ";
cout << "\n \t Enter 2) Rotation about arbitrary point";cout << "\n \t Enter 3) Reflection";

cin >> ch;
if (ch == 1 || ch == 2 || ch == 3){
cout << "Enter No of edges \n";
cin >> edge;
int xpointnew, ypointnew;
cout << " Enter" << edge << " point of polygon \n";
for (int i = 0; i < edge; i++){
cout << "Enter " << i << " Point ";
cin >> xpointnew >> ypointnew;
xpoint.push_back(xpointnew + 320);
ypoint.push_back(ypointnew + 240);
}
glutInit(&argc, argv);
glutInitDisplayMode(GLUT_SINGLE | GLUT_RGB);
glutInitWindowSize(640, 480);
glutInitWindowPosition(200, 200);
glutCreateWindow("2D");
init();
glutDisplayFunc(Draw);
glutMainLoop();
return 0;
}
else
{
cout << "\n \t Check Input run again";
return 0;
}
}