#include <GL/glut.h>
#include <cstdlib>
#include <iostream>
using namespace std;

const GLfloat Pi=3.1415926536;
const GLfloat sqrt2=1.4142135624;

GLint transform = 0;

void myInit()
{
	glClearColor(1.0,1.0,1.0,0.0);

	glColor3f( 0 , 0 , 0 );

	glMatrixMode(GL_PROJECTION);
	glLoadIdentity();
	gluOrtho2D( -200 , 200 , -200 , 200 );
	glMatrixMode(GL_MODELVIEW);
}

void drawSquare(GLint length) {
	glColor3f(1,0,0);
	glBegin(GL_POLYGON);
		glVertex2f(0,0);
		glVertex2f(length,0);
		glVertex2f(length,length);
		glVertex2f(0,length);
	glEnd();
}

void display() {

	glClear(GL_COLOR_BUFFER_BIT);


	if (transform == 1) {
		

	}
		
	drawSquare(50);
	

	// this code renders a set of axes anchored at the origin
	glPushMatrix();
	glLoadIdentity();
	glColor3f(0,0,0);
	glBegin(GL_LINES);
		glVertex2f(0,0);
		glVertex2f(0,100);
		glVertex2f(0,0);
		glVertex2f(100,0);
	glEnd();

	// this code renders a several points used in the lab
	glPointSize(5.0);
	glBegin(GL_POINTS);
		glColor3f(1,0,0);
		glVertex2f(50,0);
		glColor3f(0,1,0);
		glVertex2f(35,35);
		glColor3f(0,0,1);
		glVertex2f(70,35);
		glColor3f(1,0,0);
		glVertex2f(-50,0);
	glEnd();
	glPopMatrix();


	glFlush();
}

//clicking on the left mouse button will toggle the transform flag and post a redisplay
void mouse (GLint btn, GLint state, GLint x, GLint y)
{
	if (btn==GLUT_LEFT_BUTTON && state==GLUT_DOWN) {
		transform=1;
		glutPostRedisplay();
	}
}


// set up the keyboard callback
void keyboard (unsigned char key , int x, int y)
{
	if ( key=='q' || key=='Q' ) {
		exit( 0 );
	}
}


int main( int argc , char **argv )
{
	glutInit(&argc,argv);
	glutInitDisplayMode (GLUT_SINGLE | GLUT_RGB);
    glutInitWindowSize(400,400);
    glutInitWindowPosition(0,0);
    glutCreateWindow("Transforms");
    
	myInit();
	
	glutDisplayFunc(display); 
	glutMouseFunc(mouse);
	glutKeyboardFunc(keyboard);
    glutMainLoop();
	
	return 0;
}