#include <GL/freeglut.h>
#include <math.h>
#include <vector>
#include <glm/vec2.hpp>

using namespace std;
using namespace glm;

double Y_AXIS = 5;
double aspectRatio = 1;

vec2 start_point = vec2(2.5,2.4);
double startAngle = 0;
	
double w = (2*M_PI*20)/360; // angular velocity 360:2*PI = 20:x 
int FPS = 60; // frames per sec 	
double alpha = w/FPS ;		

vector<vec2> square;

void getDots(vec2 C, float stranica)
{
	square.clear();
	double alpha2 = 2 * M_PI / 4;
	
	for(int i = 0; i < 4 ; i++)
	{
		vec2 normalised(cos(startAngle + i * alpha2 ), sin(startAngle + i * alpha2));
		vec2 i_vector = normalised * stranica;
		vec2 i_point = C + i_vector;
		square.push_back(i_point);
		
	}
}

vector<vec2> createSquare(vec2 a , double stranica)
{
	vector<vec2> points;
	vec2 ab = vec2( stranica * cos(startAngle), stranica *sin(startAngle));
	vec2 b = a + ab;
	vec2 bc = vec2( stranica * cos(startAngle+M_PI/2), stranica * sin(startAngle+M_PI/2)); 
	vec2 c = b+bc;
	vec2 d = a + bc;
	
	points.push_back(a);
	points.push_back(b);
	points.push_back(c);
	points.push_back(d);
	return points;
}

void draw(GLenum mode, vector<vec2> points)
{
	glColor3f(1.0, 1.0, 1.0);
	glBegin(mode);
	for(int i = 0; i < points.size(); i++) 
		glVertex2d(points[i].x, points[i].y);
	glEnd();
}


void display()
{
	glClear(GL_COLOR_BUFFER_BIT);
	glColor3f(1.0, 1.0, 1.0);
	
	draw(GL_POLYGON,square);

	glFlush();
	glutPostRedisplay();
}

void timer(int v)	
{
	startAngle+=w/FPS;     
	getDots(start_point,0.5);	
	glutTimerFunc(1000/FPS, timer, v);	
	glutPostRedisplay();	
}

void init()
{
	glClearColor (0.0, 0.0, 0.0, 0.0);
	glMatrixMode(GL_PROJECTION);
	glLoadIdentity();
	glOrtho(0.0, Y_AXIS*aspectRatio, 0.0, Y_AXIS, -1.0, 1.0);
}

void mouseClick(int button, int state, int x, int y)
{

}

void keyboardClick(unsigned char key, int x, int y)
{

}

int main(int argc, char** argv)
{
	glutInit(&argc, argv);
	glutInitDisplayMode (GLUT_SINGLE | GLUT_RGB);
	glutInitWindowSize (500, 500);
	glutInitWindowPosition (100, 100);
	glutCreateWindow ("Kvadrat1");
	init();
	
	getDots(start_point,0.5);

	glutDisplayFunc(display);
	glutTimerFunc(100, timer, 0);	

	glutMouseFunc(mouseClick);
	glutKeyboardFunc(keyboardClick);

	glutMainLoop();
    
	return 0;
}