116 lines
3.1 KiB
C++
116 lines
3.1 KiB
C++
#include <iostream>
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#include <limits>
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#include <cstdlib>
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#include "tracer.hpp"
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#define MAX_RECURSION 9
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#define BIAS 0.000001f
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using namespace std;
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using std::numeric_limits;
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using glm::normalize;
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using glm::radians;
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using glm::dot;
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using glm::reflect;
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using glm::refract;
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using glm::clamp;
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using glm::tan;
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using glm::cos;
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static const vec3 BCKG_COLOR = vec3(0.16f, 0.66f, 0.72f);
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static inline float random01() {
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return static_cast<float>(rand()) / static_cast<float>(RAND_MAX);
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}
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static float fresnel(const vec3 & i, const vec3 & n, const float ir1, const float ir2) {
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float cos_t1 = dot(i, n);
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float cos_t2 = dot(normalize(refract(i, n, ir1 / ir2)), n);
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float sin_t2 = (ir1 / ir2) * sqrt(1.0f - (cos_t2 * cos_t2));
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if (sin_t2 >= 1.0f)
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return 1.0f;
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float fr_par = ((ir2 * cos_t1) - (ir1 * cos_t2)) / ((ir2 * cos_t1) + (ir1 * cos_t2));
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float fr_per = ((ir1 * cos_t2) - (ir2 * cos_t1)) / ((ir1 * cos_t2) + (ir2 * cos_t1));
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return ((fr_par * fr_par) + (fr_per * fr_per)) / 2.0f;
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}
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vec2 Tracer::sample_pixel(int i, int j) const {
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float pxNDC;
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float pyNDC;
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float pxS;
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float pyS;
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pyNDC = (static_cast<float>(i) + random01()) / m_h;
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pyS = (1.0f - (2.0f * pyNDC)) * tan(radians(m_fov / 2));
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pxNDC = (static_cast<float>(j) + random01()) / m_w;
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pxS = (2.0f * pxNDC) - 1.0f;
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pxS *= m_a_ratio * tan(radians(m_fov / 2));
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return vec2(pxS, pyS);
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}
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vec3 Tracer::trace_ray(Ray & r, vector<Figure *> & v_figures, vector<Light *> & v_lights, unsigned int rec_level) const {
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float t, _t;
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Figure * _f;
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vec3 n, color, i_pos, ref;
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Ray sr, rr;
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bool vis;
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float kr;
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t = numeric_limits<float>::max();
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_f = NULL;
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for (size_t f = 0; f < v_figures.size(); f++) {
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if (v_figures[f]->intersect(r, _t) && _t < t) {
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t = _t;
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_f = v_figures[f];
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}
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}
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if (_f != NULL) {
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i_pos = r.m_origin + (t * r.m_direction);
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n = _f->normal_at_int(r, t);
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for (size_t l = 0; l < v_lights.size(); l++) {
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vis = true;
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sr = Ray(v_lights[l]->m_position, i_pos + n * BIAS);
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for (size_t f = 0; f < v_figures.size(); f++) {
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if (v_figures[f]->intersect(sr, _t)) {
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vis = false;
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break;
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}
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}
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color += (vis ? 1.0f : 0.0f) * v_lights[l]->shade(n, r, _f->m_mat);
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}
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if (_f->m_mat.m_refract)
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kr = fresnel(r.m_direction, n, r.m_ref_index, _f->m_mat.m_ref_index);
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else
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kr = _f->m_mat.m_rho;
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if (kr > 0.0f && rec_level < MAX_RECURSION) {
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rr = Ray(normalize(reflect(r.m_direction, n)), i_pos + n * BIAS);
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color += _f->m_mat.m_rho * kr * trace_ray(rr, v_figures, v_lights, rec_level + 1);
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} else if (rec_level >= MAX_RECURSION)
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return vec3(BCKG_COLOR);
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if (_f->m_mat.m_refract && kr < 1.0f && rec_level < MAX_RECURSION) {
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rr = Ray(normalize(refract(r.m_direction, n, r.m_ref_index / _f->m_mat.m_ref_index)), i_pos - n * BIAS, _f->m_mat.m_ref_index);
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color += (1.0f - _f->m_mat.m_rho) * (1.0f - kr) * trace_ray(rr, v_figures, v_lights, rec_level + 1);
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} else if (rec_level >= MAX_RECURSION)
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return vec3(BCKG_COLOR);
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return clamp(color, 0.0f, 1.0f);
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} else
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return vec3(BCKG_COLOR);
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}
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