84 lines
2.5 KiB
C
84 lines
2.5 KiB
C
#include <float.h>
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#include <math.h>
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#include <stdbool.h>
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#include <stdio.h>
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#include "color.h"
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#include "hittable.h"
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#include "point3.h"
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#include "ray.h"
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#include "vec3.h"
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Color ray_color(Ray r, Hittable world) {
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HitRecord record;
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if (hittable_hit(&world, r, 0, DBL_MAX, &record)) {
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return (Color){0.5 * (record.normal.x + 1), 0.5 * (record.normal.y + 1),
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0.5 * (record.normal.z + 1)};
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}
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Vec3 unit_direction = vec3_normalize(r.direction);
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double t = 0.5 * (unit_direction.y + 1.0);
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Color gradient1 = {1.0, 1.0, 1.0};
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Color gradient2 = {0.5, 0.7, 1.0};
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return color_lerp(gradient1, gradient2, t);
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}
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int main(void) {
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/* Image parameters */
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const double aspect_ratio = 16.0 / 9.0;
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const int image_width = 256;
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const int image_height = (int)(image_width / aspect_ratio);
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/* World */
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HittableList world = {0};
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hittable_list_add(&world, make_hittable_sphere(&(Sphere){
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.center = (Point3){0, 0, -1},
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.radius = 0.5,
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}));
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hittable_list_add(&world, make_hittable_sphere(&(Sphere){
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.center = (Point3){0, -100.5, -1},
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.radius = 100,
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}));
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/* Camera parameters */
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double viewport_height = 2;
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double viewport_width = aspect_ratio * viewport_height;
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double focal_length = 1.0;
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Point3 origin = {0};
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Vec3 horizontal = {viewport_width, 0, 0};
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Vec3 vertical = {0, viewport_height, 0};
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Vec3 offset = vec3_add(vec3_div(horizontal, 2), vec3_div(vertical, 2));
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offset = vec3_add(offset, (Vec3){0, 0, focal_length});
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Point3 lower_left_corner = point3_add(origin, vec3_neg(offset));
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printf("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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double u = (double)i / (image_width - 1);
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double v = (double)j / (image_height - 1);
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Point3 screen_point =
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point3_add(lower_left_corner,
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vec3_add(vec3_mul(u, horizontal), vec3_mul(v, vertical)));
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Vec3 direction = point3_sub(screen_point, origin);
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Ray r = {origin, direction};
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Color pixel_color = ray_color(r, make_hittable_list(&world));
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color_write(stdout, pixel_color);
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}
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}
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fprintf(stderr, "\nDone.\n");
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hittable_list_free(&world);
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return 0;
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}
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#include "color.c"
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#include "hittable.c"
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#include "point3.c"
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#include "ray.c"
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#include "utils.c"
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#include "vec3.c"
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