#include <GL/glut.h>
#include <bevgrafmath2017.h>

int mainCircleRad = 30, dotsRad = 5, dotsCount = 10;
float circleSpeed = 0.5f;
vec2 dotsPoses[10];

float width = 800, height = 600;
GLint novX = 1, novY=1;
GLint halfSize = 50;
vec2 center = { width/2, height/2 };




void init()
{
    glClearColor(1.0, 1.0, 1.0, 0.0);
    glMatrixMode(GL_PROJECTION);
    gluOrtho2D(0.0, width, 0.0, height);
    glShadeModel(GL_FLAT);
}

void Circle(vec2 center,float r, bool fill = false) {

    int segments = 200;

    glLineWidth(2);
    glColor3ub(0, 0, 0);

    if(fill)
        glBegin(GL_POLYGON);
    else
        glBegin(GL_LINE_LOOP);

    for (float t = 0; t <two_pi(); t += (pi() / 180))
    {
        float x = r * cosf(t) + center[0];
        float y = r * sinf(t) + center[1];

        glVertex2f(x, y);
    }


    glEnd();

    glFlush();
}


void GeneratePoses()
{
    for (int i = 0; i < dotsCount; i++) {

        dotsPoses[i].x = rand();
        while (dotsPoses[i].x  < dotsRad || dotsPoses[i].x  > width- dotsRad)
            dotsPoses[i].x = rand();

        dotsPoses[i].y = rand();
        while (dotsPoses[i].y  < dotsRad || dotsPoses[i].y  > height- dotsRad)
            dotsPoses[i].y = rand();
    }
}

bool lock = false;

void display()
{
    glClear(GL_COLOR_BUFFER_BIT);
    glColor3f(0.0, 0.0, 1.0);
    Circle(center, mainCircleRad);

    if (!lock)
    {
        GeneratePoses();
        lock = true;
    }

    for (int c = 0; c < dotsCount; c++)
    {
        if (dist(dotsPoses[c], center) < mainCircleRad)
        {
            dotsPoses[c] = vec2{ -100,-100 };
            mainCircleRad += 5;
            continue;
        }
        Circle(dotsPoses[c], dotsRad, true);
    }
    glutSwapBuffers();
}

void update(int n)
{
    center[0] += novX * circleSpeed;
    center[1] += novY * circleSpeed;

    if (center[0] + mainCircleRad > width || center[0] - mainCircleRad < 0)
    {
        novX *= -1;
        center[0] += novX * 5;
    }

    if (center[1] + mainCircleRad > height || center[1] - mainCircleRad < 0)
    {
        novY *= -1;
        center[1] += novY * 5;
    }

    glutPostRedisplay();

    glutTimerFunc(5, update, 0);

}

void keyboard(unsigned char key, int x, int y)
{
    switch (key) {
    case 27:
        exit(0);
        break;
    case 'w':
        novX *= -1;
        break;
    case 'd':
        novY *= -1;
        break;
    }
}

int main(int argc, char** argv)
{
    glutInit(&argc, argv);
    glutInitDisplayMode(GLUT_DOUBLE | GLUT_RGB);
    glutInitWindowSize(width, height);
    glutInitWindowPosition(100, 100);
    glutCreateWindow(argv[0]);
    init();
    glutDisplayFunc(display);
    glutKeyboardFunc(keyboard);
    glutTimerFunc(5, update, 0);
    glutMainLoop();
    return 0;
}