init: create git repo

2022-12-17 18:22:51 +01:00
commit e7bc9882e6
11 changed files with 860 additions and 0 deletions
--- a/include/raytrace.hpp
+++ b/include/raytrace.hpp
@@ -0,0 +1,82 @@
+#pragma once
+
+#include <vector>
+#include "./vec.hpp"
+
+struct Screen {
+    const int W, H;
+    const choice_t ASPECT_RATIO;
+    constexpr Screen(int W, int H, choice_t ASPECT_RATIO)
+	: W(W), H(H), ASPECT_RATIO(ASPECT_RATIO) {}
+};
+
+struct Camera {
+    v3 pos; v3 rotation; v3 translation{0,0,0};
+    choice_t zoom = 0.5;
+    choice_t exposure = -0.6;
+    choice_t dynamic_range = 1;
+};
+
+struct Material {
+    choice_t specular = 0.1;
+    choice_t roughness = 0.5;
+    choice_t ior = 1.2;
+    choice_t transparency = 0.8;
+    v3 colour;
+};
+
+struct Renderable {
+    Material specs;
+
+    Renderable(const Material& specs);
+
+    virtual int intersect(const v3& eye, const v3& dir, choice_t& hit_dist, v3& hit_loc, v3& hit_normal)=0;
+
+    /**
+       Like #intersect, but for transmission rays inside the object. #eye must
+       be on the surface of the object.
+     */
+    virtual int transmit(const v3& eye, const v3& dir, choice_t& hit_dist, v3& hit_loc, v3& hit_normal) { return -1; }
+};
+
+/**
+   Shoots a ray from #eye in direction #dir, (possibly) hitting the closest object from #objs.
+   Expects #dir to be normalised.
+
+   The hit object's distance, location, normal and type will be written in the
+   references so-aptly named. If nothing was hit, the contents of those variables is UB.
+
+   Returns the pointer to the object it hit, or `nullptr' otherwise.
+
+   Respects the initial value of #hit_dist, et al.
+
+   Optional parameter #self is a pointer to an object considered 'self' that
+   will be skipped during collision checks. The objects are compared by pointer
+   address.
+ */
+Renderable* shoot_ray_into_objects(const v3& eye, const v3& dir, const std::vector<Renderable*>& objs,
+				   choice_t& hit_dist, v3& hit_loc, v3& hit_normal, int& hit_type,
+				   Renderable* self = nullptr);
+
+/**
+   Shoots a ray from #eye in (unit) direction #dir into a #scene and returns the
+   colour of that ray.
+
+   #scene must be #objects u #lights.
+
+   #depth is how much the ray tracer is allowed to recurse.
+ */
+v3 ray_trace(const v3& eye, const v3& dir,
+	     const std::vector<Renderable*>& scene,
+	     const std::vector<Renderable*>& objects,
+	     const std::vector<Renderable*>& lights, int depth,
+	     Renderable* skip = nullptr,
+	     choice_t* dist_to_hit = nullptr);
+
+choice_t ggx_ndf(const v3& dir, const v3& h, const v3& normal, choice_t roughness);
+choice_t blinn_phong_ndf(const v3& dir, const v3& h, const v3& normal, choice_t roughness);
+choice_t cook_torrance_gaf(const v3& dir, const v3& h, const v3& normal, const v3& light);
+choice_t cook_torrance_fresnel(const v3& dir, const v3& h, choice_t ior);
+
+v3 cook_torrance(const v3& dir, const v3& normal, const v3& light, choice_t specular, choice_t roughness,
+		 choice_t ior, const v3& light_colour, const v3& surface_colour);