96 lines
2.1 KiB
C
96 lines
2.1 KiB
C
#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 <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 VP_H 2.0
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#define VP_W (VP_H * W / H)
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#define FOCLEN 1.0
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#define NELEMS(arr) (sizeof(arr) / sizeof(arr[0]))
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typedef struct {
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vec3_t centre;
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double rad;
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} sphere_t;
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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 = { 0, 0, 0 };
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static const vec3_t vp_disp = { 0, 0, FOCLEN };
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static const vec3_t vp_u = { VP_W, 0, 0 };
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static const vec3_t vp_v = { 0, -VP_H, 0 };
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static const vec3_t pix_x_step = { VP_W / W, 0, 0 };
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static const vec3_t pix_y_step = { 0, -VP_H / H, 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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};
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static pix_t pix[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))
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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 = pix };
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const vec3_t vp_topleft = vec3_sub(
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vec3_sub(vec3_sub(camera, vp_disp), vec3_scale(vp_u, 0.5)),
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vec3_scale(vp_v, 0.5));
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const vec3_t pix_orig = vec3_add(
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vec3_add(vp_topleft, vec3_scale(pix_x_step, 0.5)),
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vec3_scale(pix_y_step, 0.5));
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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 = vec3_add(pix_orig, vec3_scale(pix_y_step, y));
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for (unsigned x = 0; x < W; ++x) {
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const ray_t ray = {
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.orig = camera,
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.dir = vec3_unit(vec3_add(row, vec3_scale(pix_x_step, x))),
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};
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const vec3_t col = raycol(ray);
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setpix(col, 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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