#ifndef MATERIAL_H
#define MATERIAL_H

#include "ray.h"
#include "rng.h"

#define LAMBERTIAN(r, g, b) \
	{ \
		.scatter = scatter_lambertian, \
		.params = { .lambertian = { .albedo = { r, g, b } } }, \
	}

#define REFLECTIVE(r, g, b) \
	{ \
		.scatter = scatter_reflective, \
		.params = { .reflective = { .tint = { r, g, b } } }, \
	}

typedef struct {
	vec3_t point, normal;
	double t;
	bool front;
} hit_t;

typedef struct {
	vec3_t albedo;
} lambertian_params_t;

typedef struct {
	vec3_t tint;
} reflective_params_t;

typedef union {
	lambertian_params_t lambertian;
	reflective_params_t reflective;
} material_params_t;

typedef bool scatter_fn_t(
    material_params_t params, hit_t hit, rng_t *rng, ray_t *ray,
    vec3_t *atten_out);

typedef struct {
	scatter_fn_t *scatter;
	material_params_t params;
} material_t;

bool scatter_lambertian(
    material_params_t params, hit_t hit, rng_t *rng, ray_t *ray,
    vec3_t *atten_out);
bool scatter_reflective(
    material_params_t params, hit_t hit, rng_t *rng, ray_t *ray,
    vec3_t *atten_out);

#endif