bwidgets/inc/basic_widgets/core/math.hpp

#ifndef BWIDGETS_MATH_HPP
#define BWIDGETS_MATH_HPP

#include <cmath>

#include <SDL2/SDL_rect.h>

#include <basic_widgets/core/type/size.hpp>

namespace bwidgets::core
{
    static inline auto center_rect(int container_size, int rect_size) noexcept -> int
    {
        return (container_size - rect_size) / 2;
    }

    static inline auto distance_sqrd(const SDL_Point& a, const SDL_Point& b) noexcept
      -> float
    {
        return (a.x - b.x) * (a.x - b.x) // NOLINT(bugprone-narrowing-conversions)
             + (a.y - b.y) * (a.y - b.y);
    }

    static inline auto distance(const SDL_Point& a, const SDL_Point& b) noexcept -> float
    {
        return std::sqrt(distance_sqrd(a, b));
    }

    static inline auto rect_in_rect(const SDL_Rect outer, const SDL_Rect inner) noexcept
      -> bool
    {
        SDL_Point top_left {inner.x, inner.y};
        SDL_Point bottom_right {inner.x + inner.w, inner.y + inner.h};

        return (SDL_PointInRect(&top_left, &outer) == SDL_TRUE)
            && (SDL_PointInRect(&bottom_right, &outer) == SDL_TRUE);
    }

    static inline auto rect_margin(const SDL_Rect& r, const Size& margin) noexcept
      -> SDL_Rect
    {
        return {r.x + margin.w, r.y + margin.h, r.w - 2 * margin.w, r.h - 2 * margin.h};
    }

    static inline auto rect_offset(const SDL_Rect& r, const SDL_Rect& offset) noexcept
      -> SDL_Rect
    {
        return {r.x + offset.x, r.y + offset.y, r.w, r.h};
    }
}

#endif