/**
 * oif.c - source file for just testing basic optics-related functions.
 *
 * Copyright (C) 2025 https://optics-design.com
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Affero General Public License as
 * published by the Free Software Foundation, either version 3 of the
 * License, or (at your option) any later version.
 *
 * See the COPYING file for the full license text.
 */
#include <stdio.h>
#include <stdlib.h>

int main(int argc, char *argv[]) {
    if (argc != 4){
        printf("This program calculates relations between object, image and focal length.\nIt requires you to provide two of these and leave the third one as any char in the form of O I F.\nExample: 90 x 50 will output 112.5");
        return 1;
    }
    char *po, *pi, *pf;
    float o,i,f;

    o =  strtof(argv[1], &po);
    i =  strtof(argv[2], &pi);
    f =  strtof(argv[3], &pf);
    if (*po && !*pi && !*pf) {
        o = i*f/(i-f); 
    }
    else if (!*po && *pi && !*pf) {
        i = o*f/(o-f); 
    }
    else if (!*po && !*pi && *pf) {
        f = o*i/(o+i); 
    }
    else {
        printf("Wrong usage of the program! Refer to help");
        return 1;
    }
    printf("Object Distance: %.5f\nImage Distance: %.5f\nFocal Length: %.5f\n",o,i,f);
    return 0;
}