#pragma once

#include <SDL2/SDL.h>

#define from_fixed(a) ((a) / 16)
#define to_fixed(a) ((a) * 16)

struct hitbox {
	unsigned left, right, top, bottom;
};

static inline int hitbox_overlap(struct hitbox const a, struct hitbox const b) {
	return a.left <= b.right && a.right >= b.left && a.top <= b.bottom && a.bottom >= b.top;
}

struct vec2 {
	signed x, y;
};

struct anim {
	unsigned frame;
	SDL_Rect rect;
	unsigned length;
};

enum factions {
	FACTION_PLAYER,
	FACTION_ENEMY,
};

struct entity {
	int (*update)(struct entity *self);
	int (*hurt)(struct entity *self, int damage);
	int (*draw)(struct entity *self, int camx, int camy);
	void (*free)(struct entity *self);
	int x, y; // unsigned results in a bunch of weird edge cases
	struct vec2 velocity;
	struct hitbox hitbox;
	struct anim anim;
	unsigned state;
	int hp;
	int timer;
	int iframes;
	signed facing;
	enum factions faction;
	void *texture;
	void *ext;
};

struct warp {
	int (*update)(struct warp *);
	unsigned x, y;
	unsigned w, h;
	unsigned tox, toy;
	struct hitbox hitbox;
	unsigned timer;
	void *ext;
};

struct projectile {
	int (*update)(struct projectile *self);
	int (*draw)(struct projectile *self, int camx, int camy);
	void (*free)(struct projectile *self);
	int x, y; // unsigned results in a bunch of weird edge cases
	struct vec2 velocity;
	struct hitbox hitbox;
	struct anim anim;
	unsigned state;
	int hp;
	int timer;
	int iframes;
	signed facing;
	enum factions faction;
	void *texture;
	void *ext;
};

struct particle {
	int x, y;
	struct vec2 velocity;
	struct vec2 acceleration;
	SDL_Rect rect;
	int hp;
};