#include <string.h>
#include <stdbool.h>
#include <sys/types.h>

#define VEC_ABS(x) ((x) > 0 ? (x) : -(x))

struct vec2i {
	union {
		struct {
			ssize_t x, y;
		};
		ssize_t dims[2];
	};
};

struct vec3i {
	union {
		struct {
			ssize_t x, y, z;
		};
		ssize_t dims[3];
	};
};

struct vec2f {
	union {
		struct {
			double x, y;
		};
		double dims[2];
	};
};

struct vec3f {
	union {
		struct {
			double x, y, z;
		};
		double dims[3];
	};
};

#define DEFINE_VEC_SET(name, type, dims) \
	static inline void name(type *dst, const type *src) { \
		memcpy(dst, src, sizeof(type)); \
	}

#define DEFINE_VEC_ADD(name, type, n) \
	static inline void name(type *dst, const type *a, const type *b) { \
		for (int i = 0; i < n; i++) \
			dst->dims[i] = a->dims[i] + b->dims[i]; \
	}

#define DEFINE_VEC_SUB(name, type, n) \
	static inline void name(type *dst, const type *a, const type *b) { \
		for (int i = 0; i < n; i++) \
			dst->dims[i] = a->dims[i] - b->dims[i]; \
	}

#define DEFINE_VEC_MUL(name, type, prim, n) \
	static inline void name(type *dst, const type *a, prim b) { \
		for (int i = 0; i < n; i++) \
			dst->dims[i] = a->dims[i] * b; \
	}

#define DEFINE_VEC_EQL(name, type, n) \
	static inline bool name(const type *a, const type *b) { \
		for (int i = 0; i < n; i++) \
			if (a->dims[i] != b->dims[i]) return false; \
		return true; \
	}

DEFINE_VEC_SET(vec2i_set, struct vec2i, 2);
DEFINE_VEC_ADD(vec2i_add, struct vec2i, 2);
DEFINE_VEC_SUB(vec2i_sub, struct vec2i, 2);
DEFINE_VEC_MUL(vec2i_mul, struct vec2i, ssize_t, 2);
DEFINE_VEC_EQL(vec2i_eql, struct vec2i, 2);

static inline void
vec2i_setv(struct vec2i *dst, ssize_t x, ssize_t y)
{
	dst->x = x;
	dst->y = y;
}

static inline ssize_t
vec2i_len(struct vec2i *a)
{
	return VEC_ABS(a->x) + VEC_ABS(a->y);
}

DEFINE_VEC_SET(vec3i_set, struct vec3i, 3);
DEFINE_VEC_ADD(vec3i_add, struct vec3i, 3);
DEFINE_VEC_SUB(vec3i_sub, struct vec3i, 3);
DEFINE_VEC_MUL(vec3i_mul, struct vec3i, ssize_t, 3);
DEFINE_VEC_EQL(vec3i_eql, struct vec3i, 3);

static inline void
vec3i_setv(struct vec3i *dst, ssize_t x, ssize_t y, ssize_t z)
{
	dst->x = x;
	dst->y = y;
	dst->z = z;
}

DEFINE_VEC_SET(vec2f_set, struct vec2f, 2);
DEFINE_VEC_ADD(vec2f_add, struct vec2f, 2);
DEFINE_VEC_SUB(vec2f_sub, struct vec2f, 2);
DEFINE_VEC_MUL(vec2f_mul, struct vec2f, double, 2);

static inline void
vec2f_setv(struct vec2f *dst, double x, double y)
{
	dst->x = x;
	dst->y = y;
}

DEFINE_VEC_SET(vec3f_set, struct vec3f, 3);
DEFINE_VEC_ADD(vec3f_add, struct vec3f, 3);
DEFINE_VEC_SUB(vec3f_sub, struct vec3f, 3);
DEFINE_VEC_MUL(vec3f_mul, struct vec3f, double, 3);

static inline void
vec3f_setv(struct vec3f *dst, double x, double y, double z)
{
	dst->x = x;
	dst->y = y;
	dst->z = z;
}

static inline void
vec3i_add_2i(struct vec3i *dst, const struct vec3i *a, const struct vec2i *b)
{
	dst->x = a->x + b->x;
	dst->y = a->y + b->y;
	dst->z = a->z;
}

#undef DEFINE_VEC_SET
#undef DEFINE_VEC_ADD
#undef DEFINE_VEC_SUB
#undef DEFINE_VEC_MUL