/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * *\
*   All of the functions declared in this file and          *
*   defined in vector2d.c are from the SDL2 source code.    *
*   They are just renamed.                                  *
*    => https://github.com/libsdl-org/SDL                   *
\* * * * * * * * * * * * * * * * * * * * * * * * * * * * * */

#ifndef VECTOR2D_H
#define VECTOR2D_H

#include <gint/defs/types.h>

/* vector2d_t: A point in space
   This struct is the base for storing 2D positions.

   @x   X pos of the vector
   @y   Y pos of the vector */
typedef struct vector2d_t {
    float x, y;
} vector2d_t;

/* vector2d_t: A point in space
   This struct is the base for storing 2D positions.

   @x   X pos of the rectangle
   @y   Y pos of the rectangle
   @w   Width of the rectangle
   @h   Height of the rectangle */
typedef struct rect_t {
    float x, y;
    float w, h;
} rect_t;

#define EPSILON 0.000001f

__attribute__((const)) float fabsf(float x);

#define is_equal_to_zero(X) (fabsf(X) <= EPSILON)

#define is_not_zero(X) (fabsf(X) > EPSILON)

/* point_in_rect(): Verify if a point is in a rectangle
   This function is useful for verify if a point is in a rectangle.

   @P   A Vector2d
   @R   A rectangle
   Return true if the condition is validated else false. */
#define point_in_rect(P, R) (((P)->x >= (R)->x) && ((P)->x < ((R)->x + (R)->w)) && \
                             ((P)->y >= (R)->y) && ((P)->y < ((R)->y + (R)->h)))

/* rect_empty(): Verify if a rectangle is empty
   This function is useful for verify if a rectangle exists.

   @R   A rectangle
   Return true if the condition is validated else false. */
#define rect_empty(R) ((!(R)) || (is_equal_to_zero((R)->w)) || (is_equal_to_zero((R)->h)))

/* has_intersection(): Verify if there is a intersction between two rectangles
   This function is useful for verify intersection between two rectangles.

   @A   A rectangle
   @B   Another rectangle
   Return true if the condition is validated else false. */
bool has_intersection(const rect_t *, const rect_t *);

/* intersect_rect(): Like has_intersection but has a result rectangle
   This function is useful for verify intersection between two rectangles
   and get the intersection rectangle.

   @A       A rectangle
   @B       Another rectangle
   @result  The intersection rectangle
   Return true if the condition is validated else false. */
bool intersect_rect(const rect_t *, const rect_t *, rect_t *);

#endif // VECTOR2D_H