Rotirea unui patrat fata de un punct

rotire_patrat.cpp

#include <iostream>
#define PI 3.14

struct Punct
{
    float x;
    float y;
};

int main(int argc, char const *argv[])
{
    float unghiRotire = 75;
    float unghiRotireRadian = unghiRotire * PI / 180;
    float laturaPatrat = 250;
    Punct centruPatrat; // citit de la tastatura
    Punct colturiPatrat[4]; // vor fi calculate
    Punct punctulFix(320,240);
    
    // citire centru patrat
    std::cin >> centruPatrat.x >> centruPatrat.y;

    // calculare colturi
    colturiPatrat[0].x = colturiPatrat[3].x = centruPatrat.x - laturaPatrat / 2;
    colturiPatrat[1].x = colturiPatrat[2].x = centruPatrat.x + laturaPatrat / 2;
    colturiPatrat[0].y = colturiPatrat[1].y = centruPatrat.y - laturaPatrat / 2;
    colturiPatrat[2].y = colturiPatrat[3].y = centruPatrat.y + laturaPatrat / 2;

    // schimbam pozitia colturilor cu 75 grade fata de punctul fix
    for (int i = 0; i < 4; ++i)
    {
        float x = colturiPatrat[i].x;
        float y = colturiPatrat[i].y;

        colturiPatrat[i].x = x * cos(unghiRotireRadian) - y * sin(unghiRotireRadian) 
                             + punctulFix.x - punctulFix.x * cos(unghiRotireRadian)
                             + punctulFix.y * sin(unghiRotireRadian);

        colturiPatrat[i].y = x * sin(unghiRotireRadian) + y * cos(unghiRotireRadian)
                             + punctulFix.y - punctulFix.x * sin(unghiRotireRadian)
                             - punctulFix.y * cos(unghiRotireRadian);
    }

    return 0;
}