Check collision between a circle and a rectangle

collision.c

#include <math.h>

typedef float     f32;
typedef struct Vector2
{
    f32 x, y;
} Vector2;

typedef SDL_FRect RectangleF;
typedef struct Circle
{
    Vector2 pos;
    f32 radius;
} Circle;

bool check_collision_circle_rect(Circle* car_hitbox, RectangleF tile)
{
    // Calculate the closest point on the rectangle to the center of the circle
    f32 closest_x = fmaxf(tile.x, fminf(car_hitbox->pos.x, tile.x + tile.w));
    f32 closest_y = fmaxf(tile.y, fminf(car_hitbox->pos.y, tile.y + tile.h));

    // Calculate the distance between the closest point on the rectangle and the center of the circle
    f32 distance_x = car_hitbox->pos.x - closest_x;
    f32 distance_y = car_hitbox->pos.y - closest_y;

    // Calculate the squared distance between the closest point and the center of the circle
    f32 distance_squared = powf(distance_x, 2) + powf(distance_y, 2);

    // If the squared distance is less than or equal to the squared radius, there is a collision
    if (distance_squared <= powf(car_hitbox->radius, 2))
        return true;

    // If the circle's center is outside the rectangle, check if the circle intersects with the rectangle's edges
    if (car_hitbox->pos.x < tile.x)
        distance_x = tile.x - car_hitbox->pos.x;
    else if (car_hitbox->pos.x > tile.x + tile.w)
        distance_x = car_hitbox->pos.x - (tile.x + tile.w);
    else
        distance_x = 0;

    if (car_hitbox->pos.y < tile.y)
        distance_y = tile.y - car_hitbox->pos.y;
    else if (car_hitbox->pos.y > tile.y + tile.h)
        distance_y = car_hitbox->pos.y - (tile.y + tile.h);
    else
        distance_y = 0;

    distance_squared = powf(distance_x, 2) + powf(distance_y, 2);

    // If the squared distance is less than or equal to the squared radius, there is a collision
    return distance_squared <= powf(car_hitbox->radius, 2);
}