libakgl/include/akgl/util.h

/**
 * @file util.h
 * @brief Declares the public util API.
 */

#ifndef _UTIL_H_
#define _UTIL_H_

#include <akerror.h>
#include <akgl/staticstring.h>

/** @brief Represents a two-dimensional point. */
typedef struct point {
  int x;
  int y;
  int z;
} point;

/** @brief Stores the corners of an axis-aligned rectangle. */
typedef struct RectanglePoints {
  point topleft;
  point topright;
  point bottomleft;
  point bottomright;
} RectanglePoints;

#define AKGL_COLLIDE_RECTANGLES(r1x, r1y, r1w, r1h, r2x, r2y, r2w, r2h) ((r1x < (r2x + r2w)) || ((r1x + r1w) > r2x)

/**
 * @brief Rectangle points.
 * @param dest Output destination populated by the function.
 * @param rect Rectangle whose corner points are calculated.
 * @return `NULL` on success, otherwise an error context owned by the caller.
 * @throws AKERR_NULLPOINTER When the corresponding validation or operation fails.
 */
akerr_ErrorContext AKERR_NOIGNORE *akgl_rectangle_points(RectanglePoints *dest, SDL_FRect *rect);
/**
 * @brief Collide point rectangle.
 * @param p Point to test for containment.
 * @param r Rectangle corner data used for collision testing.
 * @param collide Output set to whether the tested geometry intersects.
 * @return `NULL` on success, otherwise an error context owned by the caller.
 * @throws AKERR_NULLPOINTER When the corresponding validation or operation fails.
 */
akerr_ErrorContext AKERR_NOIGNORE *akgl_collide_point_rectangle(point *p, RectanglePoints *r, bool *collide);
/**
 * @brief Collide rectangles.
 * @param r1 First rectangle to compare.
 * @param r2 Second rectangle to compare.
 * @param collide Output set to whether the tested geometry intersects.
 * @return `NULL` on success, otherwise an error context owned by the caller.
 * @throws AKERR_NULLPOINTER When the corresponding validation or operation fails.
 */
akerr_ErrorContext AKERR_NOIGNORE *akgl_collide_rectangles(SDL_FRect *r1, SDL_FRect *r2, bool *collide);

/**
 * @brief Path relative.
 * @param root Base directory used to resolve the path.
 * @param path Path to resolve or transform.
 * @param dst Output destination populated by the function.
 * @return `NULL` on success, otherwise an error context owned by the caller.
 * @throws AKERR_NULLPOINTER When the corresponding validation or operation fails.
 */
akerr_ErrorContext AKERR_NOIGNORE *akgl_path_relative(char *root, char *path, akgl_String *dst);

// These are REALLY slow routines that are only useful in testing harnesses
/**
 * @brief Compare sdl surfaces.
 * @param s1 First SDL surface to compare.
 * @param s2 Second SDL surface to compare.
 * @return `NULL` on success, otherwise an error context owned by the caller.
 * @throws AKERR_NULLPOINTER When the corresponding validation or operation fails.
 * @throws AKERR_VALUE When the corresponding validation or operation fails.
 */
akerr_ErrorContext AKERR_NOIGNORE *akgl_compare_sdl_surfaces(SDL_Surface *s1, SDL_Surface *s2);
/**
 * @brief Render and compare.
 * @param t1 First texture to render for comparison.
 * @param t2 Second texture to render for comparison.
 * @param x Horizontal destination coordinate.
 * @param y Vertical destination coordinate.
 * @param w Destination width.
 * @param h Destination height.
 * @param writeout Optional filename for the rendered diagnostic image.
 * @return `NULL` on success, otherwise an error context owned by the caller.
 * @throws AKERR_IO When the corresponding validation or operation fails.
 * @throws AKERR_NULLPOINTER When the corresponding validation or operation fails.
 * @throws AKGL_ERR_SDL When the corresponding validation or operation fails.
 */
akerr_ErrorContext AKERR_NOIGNORE *akgl_render_and_compare(SDL_Texture *t1, SDL_Texture *t2, int x, int y, int w, int h, char *writeout);

#endif // _UTIL_H_