townengine/include/twn_util.h

#ifndef TWN_UTIL_H
#define TWN_UTIL_H

#include "twn_types.h"
#include "twn_engine_api.h"

#include <stdint.h>
#include <stddef.h>
#include <stdbool.h>
#include <math.h>


#ifndef M_PI
#define M_PI 3.14159265358979323846264338327950288   /**< pi */
#endif

/* multiply by these to convert degrees <---> radians */
#define DEG2RAD (M_PI / 180)
#define RAD2DEG (180 / M_PI)

#ifndef TWN_NOT_C

    TWN_API void *cmalloc(size_t size);
    TWN_API void *crealloc(void *ptr, size_t size);
    TWN_API void *ccalloc(size_t num, size_t size);

#endif /* TWN_NOT_C */


TWN_API void log_info(const char *restrict format, ...);
TWN_API void log_critical(const char *restrict format, ...);
TWN_API void log_warn(const char *restrict format, ...);


/* TODO: this is why generics were invented. sorry, i'm tired today */
TWN_API double clamp(double d, double min, double max);
TWN_API float clampf(float f, float min, float max);
TWN_API int clampi(int i, int min, int max);


/* sets buf_out to a pointer to a byte buffer which must be freed. */
/* returns the size of this buffer. */
TWN_API int64_t file_to_bytes(const char *path, unsigned char **buf_out);

/* returns a pointer to a string which must be freed */
TWN_API char *file_to_str(const char *path);

/* returns true if the file exists in the filesystem */
TWN_API bool file_exists(const char *path);


/* saves all texture atlases as BMP files in the write directory */
TWN_API void textures_dump_atlases(void);


/* returns true if str ends with suffix */
TWN_API TWN_API bool strends(const char *str, const char *suffix);


/*                      */
/* GAME LOGIC UTILITIES */
/*                      */

/* calculates the overlap of two rectangles and places it in result. */
/* result may be NULL. if this is the case, it will simply be ignored. */
/* returns true if the rectangles are indeed intersecting. */
TWN_API bool overlap_rect(const Recti *a, const Recti *b, Recti *result);
TWN_API bool overlap_frect(const Rect *a, const Rect *b, Rect *result);

/* returns true if two rectangles are intersecting */
TWN_API bool intersect_rect(const Recti *a, const Recti *b);
TWN_API bool intersect_frect(const Rect *a, const Rect *b);

/* TODO: generics and specials (see m_vec2_from() for an example)*/
TWN_API Rect to_frect(Recti rect);

TWN_API Vec2 frect_center(Rect rect);


/* decrements an lvalue (which should be an int), stopping at 0 */
/* meant for tick-based timers in game logic */
/*
 * example:
 * tick_timer(&player->jump_air_timer);
 */
TWN_API void tick_timer(int *value);

/* decrements a floating point second-based timer, stopping at 0.0 */
/* meant for poll based real time logic in game logic */
/* note that it should be decremented only on the next tick after its creation */
TWN_API void tick_ftimer(float *value);

/* same as `tick_ftimer` but instead of clamping it repeats */
/* returns true if value was cycled */
TWN_API bool repeat_ftimer(float *value, float at);

#endif