//Fedor Zsombor
//OFAPYD
//2014.10.23.
//A forráskódhoz segítségül az InfoC SDL grafika oldalon lévő rajzolós programot használtam.
/////////////////////////////////////////////////////////////////////////////////////////////
#include <SDL/SDL.h>
//#include <SDL_image/SDL_image.h>
#include <SDL_gfx/SDL_gfxPrimitives.h>
#include <stdio.h>
#include <math.h>

typedef struct
{
    int x;
    int y;
}Pont;

double Pont_tav(Pont p1, Pont p2){
    return  sqrt((p1.x-p2.x)*(p1.x-p2.x) + (p1.y-p2.y)*(p1.y-p2.y));
}

void ellipszis(Pont p1, Pont p2, int tav, SDL_Surface *screen)
{
    int i, j;
    int eps=4;

    for (i=1; i<=800; i++)
    {
        for (j=1; j<=600; j++)
        {
            Pont pp = {i,j};
            int a=Pont_tav(pp, p1) + Pont_tav(pp, p2);
            if (a < tav+eps && a > tav-eps)
            {
                pixelRGBA(screen, i,j, 70,130,180,255);
            }
        }
    }
}

void Pont_rajzolas(Pont p1, SDL_Surface *screen)
{
    filledCircleRGBA(screen, p1.x, p1.y, 10, 0, 255, 0, 255);
}

void szoveg(Pont p1, Pont p2, int tav, SDL_Surface *screen)
{
    char tav_s[10];
    char p1x_s[10];
    char p1y_s[10];
    char p2x_s[10];
    char p2y_s[10];
    sprintf(tav_s, "%d", tav);
    sprintf(p1x_s, "%d", p1.x);
    sprintf(p1y_s, "%d", p1.y);
    sprintf(p2x_s, "%d", p2.x);
    sprintf(p2y_s, "%d", p2.y);

    stringRGBA(screen, 770, 0,  tav_s,       0 , 0, 0, 255);
    stringRGBA(screen, 740, 10, p1x_s,       0, 0, 0, 255);
    stringRGBA(screen, 770, 10, p1y_s,       0, 0, 0, 255);
    stringRGBA(screen, 740, 20, p2x_s,       0, 0, 0, 255);
    stringRGBA(screen, 770, 20, p2y_s,       0, 0, 0, 255);
    stringRGBA(screen, 702, 0,  "Tav:",      0, 0, 0, 255);
    stringRGBA(screen, 670, 10, "1. Pont:",  0, 0, 0, 255);
    stringRGBA(screen, 670, 20, "2. Pont:",  0, 0, 0, 255);
    stringRGBA(screen, 692, 30, "Fedor Zsombor", 0, 0, 0, 255);
}

int main(int argc, char *argv[])
{
    SDL_Event event;
    SDL_Surface *screen;
    int tav=600;
    Pont p1, p2;
    p1.x=200;
    p1.y=300;
    p2.x=600;
    p2.y=300;
    int click, quit;

    // SDL inicializálása és ablak megnyitása
    SDL_Init(SDL_INIT_VIDEO);
    screen=SDL_SetVideoMode(800, 600, 0, SDL_ANYFORMAT);
    if (!screen) {
        fprintf(stderr, "Nem sikerult megnyitni az ablakot!\n");
        exit(1);
    }
    SDL_WM_SetCaption("Ellipszis", "Ellipszis");

    SDL_FillRect(screen, NULL, 0xDCDCDCFF);

    //A fókuszpontok kirajzolása
    filledCircleRGBA(screen, p1.x, p1.y, 10, 0,206,209,255);
    filledCircleRGBA(screen, p2.x, p2.y, 10, 64,224,208,255);

    //Az ellipszis kirajzolása
    ellipszis(p1, p2, tav, screen);

    //Szöveg kiirítása
    szoveg(p1, p2, tav, screen);

    //Az eddigi dolgok kirajzolása
    SDL_Flip(screen);

    quit = 0;
    click = 0;
    while (!quit) {
        SDL_WaitEvent(&event);
        switch (event.type) {
                //Egér kattintás
            case SDL_MOUSEBUTTONDOWN:
                if (event.button.button == SDL_BUTTON_LEFT)
                {
                    click = 1;
                }
                break;
                //Egérgomb elengedése
            case SDL_MOUSEBUTTONUP:
                if (event.button.button == SDL_BUTTON_LEFT)
                {
                    click = 0;
                }
                break;
                //Egér mozdulat
            case SDL_MOUSEMOTION:
                if(click)
                {
                    Pont p_eger={event.button.x, event.button.y};

                    if (event.button.x<p1.x+10 && event.button.x>p1.x-10)
                    {
                        if (event.button.y<p1.y+10 && event.button.y>p1.y-10)
                        {
                            p1.x=event.button.x;
                            p1.y=event.button.y;

                            SDL_FillRect(screen, NULL, 0xDCDCDCFF);
                            filledCircleRGBA(screen, p1.x, p1.y, 10, 0,206,209,255);
                            filledCircleRGBA(screen, p2.x, p2.y, 10, 64,224,208,255);
                            ellipszis(p1, p2, tav, screen);
                            szoveg(p1, p2, tav, screen);
                            SDL_Flip(screen);
                        }
                    } else if (event.button.x<p2.x+10 && event.button.x>p2.x-10)
                    {
                        if (event.button.y<p2.y+10 && event.button.y>p2.y-10)
                        {
                            p2.x=event.button.x;
                            p2.y=event.button.y;

                            SDL_FillRect(screen, NULL, 0xDCDCDCFF);
                            filledCircleRGBA(screen, p1.x, p1.y, 10, 0,206,209,255);
                            filledCircleRGBA(screen, p2.x, p2.y, 10, 64,224,208,255);
                            ellipszis(p1, p2, tav, screen);
                            szoveg(p1, p2, tav, screen);

                            SDL_Flip(screen);
                        }
                    } else if(Pont_tav(p_eger, p1)+Pont_tav(p_eger, p2)<tav+10 && Pont_tav(p_eger, p1)+Pont_tav(p_eger, p2)>tav-10)
                    {
                        tav = Pont_tav(p_eger, p1)+Pont_tav(p_eger, p2);
                        SDL_FillRect(screen, NULL, 0xDCDCDCFF);
                        filledCircleRGBA(screen, p1.x, p1.y, 10, 0,206,209,255);
                        filledCircleRGBA(screen, p2.x, p2.y, 10, 64,224,208,255);
                        ellipszis(p1, p2, tav, screen);
                        szoveg(p1, p2, tav, screen);

                        SDL_Flip(screen);
                    }
                }
                break;
                //Bezárás
            case SDL_QUIT:
                quit=1;
                break;
        }
    }
    return 0;
}