#include <GL/glut.h>
#include <math.h>
#define PI 3.141592653589793

void circle(float xc, float yc, float R) {
	double theta;
	glBegin(GL_LINE_STRIP);
		for(theta=0.0; theta<=PI*2.0+0.10; theta=theta+0.10) 
			glVertex2d(xc+R*cos(theta), yc+R*sin(theta));
	glEnd();
}

void mydisplay() {
	glClear(GL_COLOR_BUFFER_BIT); 
	
	glMatrixMode(GL_MODELVIEW);
	glLoadIdentity();  

	glRotatef(45.0, 0.0, 0.0, 1.0);
	glTranslatef(0.4, -0.3, 0.0);
	glScalef(0.5, 0.3, 1.0);

	glBegin(GL_LINE_STRIP);
		glVertex2d(-4.0, 4.0);
		glVertex2d(4.0, -4.0);
	glEnd();

	glBegin(GL_LINE_STRIP);
		glVertex2d(-4.0, 4.0);
		glVertex2d(2.0, -4.0);
	glEnd();

	glBegin(GL_LINE_STRIP);
		glVertex2d(2.0, 0.0);
		glVertex2d(2.1, 4.0);
	glEnd();

	glBegin(GL_LINE_STRIP);
		glVertex2d(0.0, 0.1);
		glVertex2d(2.0, 0.0);
	glEnd();

	glBegin(GL_LINE_STRIP);
		glVertex2d(-4.0, -4.0);
		glVertex2d(-4.0, 4.0);
		glVertex2d(4.0, 4.0);
		glVertex2d(4.0, -4.0);
		glVertex2d(-4.0, -4.0);
	glEnd();

	circle(0.0, 0.0, 2.0);
	circle(0.0, 2.0, 4.0);

	glFlush(); 
}

void init()
{
	glClearColor (1.0, 1.0, 1.0, 1.0);
	glColor3f(0.0, 0.0, 0.0); 

	glViewport((GLsizei)100, (GLsizei)100, (GLsizei)200, (GLsizei)200);
	glMatrixMode(GL_PROJECTION);
	glLoadIdentity();    
	gluOrtho2D(-4.0, 4.0, -4.0, 4.0);  
}

void myreshape(int w, int h) {}	//Empty reshape hack for glViewport

int main(int argc, char** argv)
{
	glutInit(&argc,argv); 
	glutInitDisplayMode(GLUT_SINGLE|GLUT_RGB);      
	glutInitWindowSize(401,401);    	
	glutInitWindowPosition(0, 0); 
	glutCreateWindow("HW1");     
	glutDisplayFunc(mydisplay); 
	glutReshapeFunc(myreshape);
  
	init(); 
   
	glutMainLoop();
}