#include "ff.h"
#include "render.h"

#include <unistd.h>

#define W 1280
#define H 720

#define OBJ_COUNT 32

#define MAX_DIST 100.0
#define MAX_RAD 10.0
#define MIN_RAD 1.0

#define FOV 90
#define APERTURE 0.8
#define FOCAL_LEN 100
#define SAMPLES_PER_PIXEL 100

#define NELEMS(arr) (sizeof(arr) / sizeof(arr[0]))

static const vec3_t camera_pos = { -100.0, 30.0, -100.0 };
static const vec3_t target = { 0.0, 0.0, 0.0 };

static const vec3_t sky_pos = { 0.6, 0.8, 1.0 };
static const vec3_t sky_neg = { 1.0, 1.0, 1.0 };

static const material_t floor = LAMBERTIAN(1.0, 0.94, 0.80);
static const material_t light = AREA_LIGHT(1.0, 0.8, 0.1, 4.0);
static const material_t gold = REFLECTIVE(1.0, 0.9, 0.5, 0.0);
static const material_t silver = REFLECTIVE(0.9, 0.9, 0.9, 0.0);
static const material_t bronze = REFLECTIVE(0.9, 0.7, 0.5, 0.0);
static const material_t glass = DIELECTRIC(1.5);

static const material_t metals[] = { gold, gold, silver, silver, bronze };

static obj_t objs[OBJ_COUNT] = {
	SPHERE(0.0, -100'000.0, 0.0, 100'000.0, floor),
	SPHERE(-3000.0, 3000.0, -2000.0, 1000.0, light),
};

static pix_t pixbuf[W * H];

static void rand_obj(obj_t *out, rng_t *rng)
{
	material_t material;
	const double rand = rng_canon(rng);
	if (rand < 0.75) {
		const double r = rng_canon(rng);
		const double g = rng_canon(rng);
		const double b = rng_canon(rng);
		material = (material_t)LAMBERTIAN(r, g, b);
	} else if (rand < 0.925) {
		material = glass;
	} else {
		material = metals[rng_uint32(rng) % NELEMS(metals)];
	}

	const double r = MIN_RAD + (MAX_RAD - MIN_RAD) * rng_canon(rng);
	const double x = MAX_DIST * rng_plusminus(rng);
	const double z = MAX_DIST * rng_plusminus(rng);
	*out = (obj_t)SPHERE(x, r, z, r, material);
}

int main()
{
	rng_t rng = rng_init(0);
	for (int i = 2; i < OBJ_COUNT; ++i)
		rand_obj(objs + i, &rng);

	img_t img = { .pix = pixbuf };
	camera_t camera
	    = camera_init(camera_pos, target, FOV, W, H, APERTURE, FOCAL_LEN);

	const scene_t scene = {
		.sky_pos = sky_pos,
		.sky_neg = sky_neg,
		.objs = objs,
		.obj_count = OBJ_COUNT,
	};
	render(&camera, &scene, &img, SAMPLES_PER_PIXEL);

	ff_write(STDOUT_FILENO, img);

	return 0;
}