8. Write a program to create (without using built in function) a triangle by implementing scaling algorithm by zooming/un-zooming along 1. X-axis, 2.Y-axis and 3. X and Y plane.

#include <GL/glut.h>
#include<math.h>
#include<stdio.h>
void scaling(float , float);
typedef struct Point
{
float x, y;
};
Point p[3]={ {50, 50}, {150, 50}, {100, 125}};
void drawTriangle(Point p[3])
{
glColor3f(0.0, 0.0, 0.0);
glBegin(GL_LINE_LOOP);
glVertex2i(p[0].x, p[0].y);
glVertex2i(p[1].x, p[1].y);
glVertex2i(p[2].x, p[2].y);
glEnd();
glFlush();
}
void display()
{
int opt;
float sx, sy;
glClearColor(1.0, 1.0, 1.0, 1.0);
glClear(GL_COLOR_BUFFER_BIT);
drawTriangle(p);
for(;;)
{
printf("************ Traingle Scaling ***************");
printf("\n1. Scale along x-axis \n 2. Scale along y-axis \n 3. Scale along both x-axis and y-axis \n");
printf("Enter your option:");
scanf("%d", & opt);
switch(opt)
{
case 1: printf("\n Enter value for sx: ");
scanf("%f", &sx);
scaling(sx, 0);
break;
case 2: printf("\n Enter value for sy: ");
scanf("%f", &sy);
scaling(0, sy);
break;
case 3: printf("\n Enter value for sx : ");
scanf("%f", &sx);
printf("\n Enter value for sy : ");
scanf("%f", &sy);
scaling(sx, sy);
break;
case 4:exit(0);
default: printf("Invalid choice");
               break;
}
}
glFlush();
}
void scaling(float sx, float sy)
{ int i;
Point new_p[3];
for(i=0;i<3;i++)
{
if(sx !=0)
new_p[i].x = p[i].x * sx;
else
new_p[i].x=p[i].x;
if(sy!=0)
new_p[i].y = p[i].y * sy;
else
new_p[i].y=p[i].y;
}
drawTriangle(new_p);
}
void init(void)
{
glClearColor(1.0,1.0,1.0,0.0); //set display-window background color to white
glMatrixMode(GL_PROJECTION); //set projection paramaters
gluOrtho2D(0.0,400.0,0.0,400.0);
}
void main(int argc, char**argv)
{
glutInit(&argc,argv); //initialize GLUT
glutInitDisplayMode(GLUT_SINGLE | GLUT_RGB); //initialize display mode
glutInitWindowSize(400,400); //set display-window width & height
glutInitWindowPosition(500,100); //set display-window upper-left position
glutCreateWindow("Triangle Scaling"); //create display-window
init(); //initialize OpenGL
glutDisplayFunc(display);
glutMainLoop();
}