scaling.cpp

#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); 
 	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; 
 	 	default:  return; 
 	} 
 	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);     	
     glMatrixMode(GL_PROJECTION);  	 
     	gluOrtho2D(0.0,400.0,0.0,400.0);  
 
}  
int main(int argc, char**argv)  
{  
 	glutInit(&argc,argv);  	 
 	glutInitDisplayMode(GLUT_SINGLE | GLUT_RGB);    	
     glutInitWindowSize(400,400);   	
     glutInitWindowPosition(500,100);    	
 	glutCreateWindow("2d Scaling");  	 
 	init();  	 	 	 	 	 	
 	glutDisplayFunc(display);  	 	 	   	
     glutMainLoop();  
}