83 lines
1.8 KiB
C
83 lines
1.8 KiB
C
#include "camera.h"
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#include "ff.h"
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#include "obj.h"
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#include "ray.h"
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#include "vec3.h"
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#include <float.h>
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#include <limits.h>
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#include <math.h>
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#include <stdio.h>
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#include <unistd.h>
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#define W 800
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#define H 600
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#define FOCAL_LEN 1.0
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#define VIEWPORT_H 2.0
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#define NELEMS(arr) (sizeof(arr) / sizeof(arr[0]))
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static const vec3_t lightblue = { 0.4, 0.6, 1.0 };
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static const vec3_t white = { 1.0, 1.0, 1.0 };
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static const vec3_t red = { 1.0, 0.1, 0.2 };
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static const vec3_t camera_pos = { 0.0, 0.0, 0.0 };
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static const obj_t scene[] = {
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SPHERE(1.0, 0.0, -3.0, 1.0),
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SPHERE(-2.0, 0.0, -5.0, 1.0),
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SPHERE(0.0, -1001.0, 0.0, 1000.0),
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};
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static pix_t pixbuf[W * H];
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static vec3_t raycol(ray_t ray)
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{
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hit_t hit;
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for (unsigned i = 0; i < NELEMS(scene); ++i) {
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if (scene[i].intersect(scene[i].params, ray, &hit, 0.0, DBL_MAX))
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return vec3_scale(vec3_add(hit.normal, white), 0.5);
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}
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const double a = (ray.dir.y + 1.0) / 2.0;
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return vec3_add(vec3_scale(lightblue, a), vec3_scale(white, 1 - a));
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}
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static void setpix(vec3_t col, pix_t *out)
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{
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out->r = UINT16_MAX * col.x;
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out->g = UINT16_MAX * col.y;
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out->b = UINT16_MAX * col.z;
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out->a = UINT16_MAX;
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}
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int main()
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{
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img_t img = { .w = W, .h = H, .pix = pixbuf };
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camera_t camera = camera_init(camera_pos, FOCAL_LEN, VIEWPORT_H, W, H);
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for (unsigned y = 0; y < H; ++y) {
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fprintf(stderr, "\r[%3d/%3d]", y, H);
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fflush(stderr);
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const vec3_t row
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= vec3_add(camera.pix_origin, vec3_scale(camera.y_step, y));
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for (unsigned x = 0; x < W; ++x) {
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const vec3_t pix = vec3_add(row, vec3_scale(camera.x_step, x));
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const ray_t ray = {
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.orig = camera.pos,
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.dir = vec3_unit(pix),
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};
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const vec3_t col = raycol(ray);
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setpix(col, img.pix + (W * y + x));
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}
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}
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fprintf(stderr, "\r[%3d/%3d]\n", H, H);
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ff_write(STDOUT_FILENO, img);
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return 0;
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}
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