356 lines
12 KiB
C
356 lines
12 KiB
C
#include <errno.h>
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#include <float.h>
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#include <stdio.h>
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#include <stdlib.h>
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#include <string.h>
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#include <time.h>
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#include "arena.h"
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#include "camera.h"
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#include "color.h"
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#include "hittable.h"
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#include "material.h"
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#include "perlin.h"
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#include "point3.h"
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#include "ray.h"
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#include "texture.h"
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#include "utils.h"
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#include "vec3.h"
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#define SCENE_RANDOM 0
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#define SCENE_TWO_SPHERES 1
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#define SCENE_TWO_PERLIN_SPHERES 2
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#define SCENE_EARTH 3
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#define SCENE_SIMPLE_LIGHT 4
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#define SCENE_CORNELL_BOX 5
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#ifndef SCENE_SELECT
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#define SCENE_SELECT SCENE_CORNELL_BOX
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#endif
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static Color ray_color(Ray r, Color background_color, const Hittable *world,
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int depth) {
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if (depth <= 0)
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return (Color){0, 0, 0};
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HitRecord record;
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if (!hittable_hit(world, r, 0.001, DBL_MAX, &record))
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return background_color;
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Ray scattered;
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Color attenuation;
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Color emitted =
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material_emitted(record.material, record.u, record.v, record.p);
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if (!material_scatter(record.material, r, &record, &attenuation, &scattered))
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return emitted;
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return color_add(emitted,
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color_mul(attenuation, ray_color(scattered, background_color,
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world, depth - 1)));
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}
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static const Hittable *generate_random_scene(Arena *arena) {
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Hittable *world = hittable_create_hittable_list(arena);
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const Texture *checker = texture_create_checker_solid_color(
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(Color){0.2, 0.3, 0.1}, (Color){0.9, 0.9, 0.9}, 10.0, arena);
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const Material *ground_material = material_create_lambertian(checker, arena);
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const Hittable *ground_sphere = hittable_create_sphere(
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(Point3){0.0, -1000.0, 0.0}, 1000.0, ground_material, arena);
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hittable_list_add(&world->list, ground_sphere, arena);
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const Material *glass = material_create_dielectric(1.5, arena);
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for (int a = -11; a < 11; ++a) {
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for (int b = -11; b < 11; ++b) {
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double choose_material = random_double();
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Point3 center = {a + 0.9 * random_double(), 0.2,
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b + 0.9 * random_double()};
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if (vec3_length(point3_sub(center, (Point3){4.0, 0.2, 0.0})) > 0.9) {
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if (choose_material < 0.8) {
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const Material *material = material_create_lambertian_color(
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color_mul(color_random(), color_random()), arena);
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const Hittable *sphere =
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hittable_create_sphere(center, 0.2, material, arena);
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hittable_list_add(&world->list, sphere, arena);
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} else if (choose_material < 0.95) {
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const Material *material = material_create_metal_color(
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color_random_in_range(0.5, 1), random_double_in_range(0.5, 1.0),
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arena);
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const Hittable *sphere =
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hittable_create_sphere(center, 0.2, material, arena);
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hittable_list_add(&world->list, sphere, arena);
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} else {
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const Hittable *sphere =
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hittable_create_sphere(center, 0.2, glass, arena);
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hittable_list_add(&world->list, sphere, arena);
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}
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}
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}
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}
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const Material *lambertian =
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material_create_lambertian_color((Color){0.4, 0.2, 0.1}, arena);
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const Material *metal =
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material_create_metal_color((Color){0.7, 0.6, 0.5}, 0.0, arena);
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const Hittable *sphere1 =
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hittable_create_sphere((Point3){0.0, 1.0, 0.0}, 1.0, glass, arena);
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hittable_list_add(&world->list, sphere1, arena);
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const Hittable *sphere2 =
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hittable_create_sphere((Point3){-4.0, 1.0, 0.0}, 1.0, lambertian, arena);
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hittable_list_add(&world->list, sphere2, arena);
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const Hittable *sphere3 =
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hittable_create_sphere((Point3){4.0, 1.0, 0.0}, 1.0, metal, arena);
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hittable_list_add(&world->list, sphere3, arena);
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Hittable *bvh_root = hittable_create_bvh_node(
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world->list.objects, 0, world->list.size, 0.0, 1.0, arena);
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return bvh_root;
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}
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static Hittable *two_spheres(Arena *arena) {
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Hittable *world = hittable_create_hittable_list(arena);
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Texture *checker = texture_create_checker_solid_color(
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(Color){0.2, 0.3, 0.1}, (Color){0.9, 0.9, 0.9}, 10.0, arena);
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hittable_list_add(
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&world->list,
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hittable_create_sphere((Point3){0.0, -10.0, 0.0}, 10.0,
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material_create_lambertian(checker, arena), arena),
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arena);
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hittable_list_add(
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&world->list,
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hittable_create_sphere((Point3){0.0, 10.0, 0.0}, 10.0,
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material_create_lambertian(checker, arena), arena),
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arena);
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return world;
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}
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static Hittable *two_perlin_spheres(Arena *arena) {
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Hittable *world = hittable_create_hittable_list(arena);
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Texture *perlin_texture =
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texture_create_perlin_noise(4.0, PERLIN_DEFAULT_POINT_COUNT, arena);
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hittable_list_add(
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&world->list,
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hittable_create_sphere((Point3){0.0, -1000.0, 0.0}, 1000.0,
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material_create_lambertian(perlin_texture, arena),
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arena),
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arena);
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hittable_list_add(
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&world->list,
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hittable_create_sphere((Point3){0.0, 2.0, 0.0}, 2.0,
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material_create_lambertian(perlin_texture, arena),
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arena),
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arena);
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return world;
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}
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static Hittable *earth(Arena *arena) {
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Texture *earth_texture = texture_create_image("assets/earthmap.jpg", arena);
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Material *earth_surface = material_create_lambertian(earth_texture, arena);
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Hittable *globe = hittable_create_sphere((Point3){0.0, 0.0, 0.0}, 2.0,
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earth_surface, arena);
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return globe;
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}
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static Hittable *simple_light(Arena *arena) {
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Hittable *world = hittable_create_hittable_list(arena);
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Texture *perlin_texture =
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texture_create_perlin_noise(4.0, PERLIN_DEFAULT_POINT_COUNT, arena);
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hittable_list_add(
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&world->list,
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hittable_create_sphere((Point3){0.0, -1000.0, 0.0}, 1000.0,
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material_create_lambertian(perlin_texture, arena),
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arena),
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arena);
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hittable_list_add(
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&world->list,
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hittable_create_sphere((Point3){0.0, 2.0, 0.0}, 2.0,
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material_create_lambertian(perlin_texture, arena),
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arena),
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arena);
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Material *diffuse_light =
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material_create_diffuse_light_color((Color){4.0, 4.0, 4.0}, arena);
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hittable_list_add(&world->list,
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hittable_create_xy_rectangle(3.0, 5.0, 1.0, 3.0, -2.0,
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diffuse_light, arena),
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arena);
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return world;
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}
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static Hittable *cornell_box(Arena *arena) {
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Hittable *world = hittable_create_hittable_list(arena);
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Material *red =
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material_create_lambertian_color((Color){0.65, 0.05, 0.05}, arena);
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Material *white =
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material_create_lambertian_color((Color){0.73, 0.73, 0.73}, arena);
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Material *green =
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material_create_lambertian_color((Color){0.12, 0.45, 0.15}, arena);
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Material *light =
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material_create_diffuse_light_color((Color){15.0, 15.0, 15.0}, arena);
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hittable_list_add(
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&world->list,
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hittable_create_yz_rectangle(0, 555, 0, 555, 555, green, arena), arena);
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hittable_list_add(&world->list,
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hittable_create_yz_rectangle(0, 555, 0, 555, 0, red, arena),
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arena);
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hittable_list_add(
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&world->list,
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hittable_create_xz_rectangle(213, 343, 227, 332, 554, light, arena),
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arena);
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hittable_list_add(
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&world->list,
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hittable_create_xz_rectangle(0, 555, 0, 555, 0, white, arena), arena);
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hittable_list_add(
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&world->list,
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hittable_create_xz_rectangle(0, 555, 0, 555, 555, white, arena), arena);
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hittable_list_add(
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&world->list,
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hittable_create_xy_rectangle(0, 555, 0, 555, 555, white, arena), arena);
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Hittable *box1 = hittable_create_box((Point3){0, 0, 0},
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(Point3){165, 330, 165}, white, arena);
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box1 = hittable_create_y_rotation(box1, 15, arena);
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box1 = hittable_create_translation(box1, (Vec3){265, 0, 295}, arena);
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hittable_list_add(&world->list, box1, arena);
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Hittable *box2 = hittable_create_box((Point3){0, 0, 0},
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(Point3){165, 165, 165}, white, arena);
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box2 = hittable_create_y_rotation(box2, -18, arena);
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box2 = hittable_create_translation(box2, (Vec3){130, 0, 65}, arena);
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hittable_list_add(&world->list, box2, arena);
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Hittable *bvh_root = hittable_create_bvh_node(
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world->list.objects, 0, world->list.size, 0.0, 1.0, arena);
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return bvh_root;
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}
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int main(int argc, char *argv[]) {
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srand(time(0));
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if (argc < 2) {
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fprintf(stderr, "Expected output file name\n");
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return 1;
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}
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FILE *output_file = fopen(argv[1], "wb");
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if (!output_file) {
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fprintf(stderr, "Failed to open output file %s: %s", argv[1],
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strerror(errno));
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return 1;
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}
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/* Memory management */
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const unsigned int buffer_size = 1 * 1024 * 1024;
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void *buffer = malloc(buffer_size);
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if (!buffer)
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abort();
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Arena arena = {0};
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arena_init(&arena, buffer, buffer_size);
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/* Image parameters */
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double aspect_ratio = 16.0 / 9.0;
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int image_width = 400;
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int samples_per_pixel = 400;
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const int max_depth = 50;
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Point3 look_from = {0.0, 0.0, 1.0};
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Point3 look_at = {0.0, 0.0, 0.0};
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double vfov = 40.0;
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double aperture = 0.0;
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double dist_to_focus = 10.0;
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Color background_color = {0.0, 0.0, 0.0};
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/* World */
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const Hittable *world = 0;
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#if SCENE_SELECT == SCENE_RANDOM
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world = generate_random_scene(&arena);
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background_color = (Color){0.7, 0.8, 1.0};
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look_from = (Point3){13.0, 2.0, 3.0};
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look_at = (Point3){0.0, 0.0, 0.0};
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vfov = 20.0;
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aperture = 0.1;
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#elif SCENE_SELECT == SCENE_TWO_SPHERES
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world = two_spheres(&arena);
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background_color = (Color){0.7, 0.8, 1.0};
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look_from = (Point3){13.0, 2.0, 3.0};
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look_at = (Point3){0.0, 0.0, 0.0};
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vfov = 20.0;
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#elif SCENE_SELECT == SCENE_TWO_PERLIN_SPHERES
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world = two_perlin_spheres(&arena);
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background_color = (Color){0.7, 0.8, 1.0};
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look_from = (Point3){13.0, 2.0, 3.0};
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look_at = (Point3){0.0, 0.0, 0.0};
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vfov = 20.0;
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#elif SCENE_SELECT == SCENE_EARTH
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world = earth(&arena);
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background_color = (Color){0.7, 0.8, 1.0};
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look_from = (Point3){13.0, 2.0, 3.0};
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look_at = (Point3){0.0, 0.0, 0.0};
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vfov = 20.0;
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#elif SCENE_SELECT == SCENE_SIMPLE_LIGHT
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world = simple_light(&arena);
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background_color = (Color){0.0, 0.0, 0.0};
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look_from = (Point3){26.0, 3.0, 6.0};
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look_at = (Point3){0.0, 2.0, 0.0};
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vfov = 20.0;
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#elif SCENE_SELECT == SCENE_CORNELL_BOX
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world = cornell_box(&arena);
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aspect_ratio = 1.0;
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image_width = 600;
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samples_per_pixel = 1000;
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background_color = (Color){0.0, 0.0, 0.0};
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look_from = (Point3){278.0, 278.0, -800.0};
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look_at = (Point3){278.0, 278.0, 0.0};
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vfov = 40.0;
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#else
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#error Unknown scene selected
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#endif
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int image_height = (int)(image_width / aspect_ratio);
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Vec3 up = {0.0, 1.0, 0.0};
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Camera camera;
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camera_init(&camera, look_from, look_at, up, vfov, aspect_ratio, aperture,
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dist_to_focus, 0.0, 1.0);
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fprintf(output_file, "P3\n%u %u\n255\n", image_width, image_height);
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for (int j = image_height - 1; j >= 0; --j) {
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fprintf(stderr, "\rScanlines remaining: %d ", j);
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for (int i = 0; i < image_width; ++i) {
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Color pixel_color = {0, 0, 0};
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for (int s = 0; s < samples_per_pixel; ++s) {
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double u = (i + random_double()) / (image_width - 1);
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double v = (j + random_double()) / (image_height - 1);
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Ray r = camera_get_ray(&camera, u, v);
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pixel_color = color_add(
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pixel_color, ray_color(r, background_color, world, max_depth));
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}
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color_write(output_file, pixel_color, samples_per_pixel);
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}
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}
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fprintf(stderr, "\nDone.\n");
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free(buffer);
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fclose(output_file);
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return 0;
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}
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