#define GLM_ENABLE_EXPERIMENTAL
#include <GL/freeglut.h>
#include <math.h>
#include <vector>
#include <glm/vec3.hpp>
#include <glm/vec4.hpp>
#include <glm/glm.hpp>
#include <glm/gtc/matrix_transform.hpp>
#include <glm/gtx/transform.hpp>

using namespace std;
using namespace glm;

float Y_AXIS = 5;
float aspectRatio = 1;

vec3 start_point = vec3(2.5,2.4,0.0);
float startAngle = 0;
	
float w = (2*M_PI*20)/360; // angular velocity 360:2*PI = 20:x 
int FPS = 60; // frames per sec 	
float alpha = w/FPS ;		

vector<vec4> square;
mat4 T;

vector<vec4> createSquare(vec3 a , float stranica)
{
	vec4 a4 = vec4( a, 1.0 );

	vector<vec4> points;
	vec4 ab = vec4( stranica * cos(startAngle), stranica *sin(startAngle), 0, 0);
	vec4 b = a4 + ab;
	vec4 bc = vec4( stranica * cos(startAngle+M_PI/2), stranica * sin(startAngle+M_PI/2), 0, 0); 
	vec4 c = b + bc;
	vec4 d = a4 + bc;
	
	points.push_back(a4);
	points.push_back(b);
	points.push_back(c);
	points.push_back(d);

	return points;
}

void draw(GLenum mode, vector<vec4> 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 transform( vector<vec4> &o, mat4 T )
{
	for ( auto it = o.begin(); it != o.end(); it ++ )
		*it = T * *it;
}

void timer(int v)	
{
	transform( square, T );	

	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();
	
	square = createSquare(start_point,0.5);
	
	mat4 MT = translate( -start_point );
	mat4 MR = rotate( w/FPS, vec3(0,0,1) );
	mat4 MTP = translate( start_point );

	T = MTP * MR * MT;

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

	glutMouseFunc(mouseClick);
	glutKeyboardFunc(keyboardClick);

	glutMainLoop();
    
	return 0;
}