diff options
| -rw-r--r-- | main_simple_scanner.cpp | 33 |
1 files changed, 25 insertions, 8 deletions
diff --git a/main_simple_scanner.cpp b/main_simple_scanner.cpp index 99fed35..51870eb 100644 --- a/main_simple_scanner.cpp +++ b/main_simple_scanner.cpp @@ -5,6 +5,7 @@ #include <cstdint> #include <iostream> #include <vector> +#include <limits> #include <memory> #include <cstdlib> @@ -17,8 +18,13 @@ class object { public: - // Will the given ray hit. Returns time t if hits. - virtual bool hit(const ray3d &r, double &t) const = 0; + // Will the given ray hit. Returns time t if hits in range [t1, t2]. + virtual bool hit(const ray3d &r, double &t, double t1, double t2) const = 0; + + // With t2 = infinity + inline bool hit(const ray3d &r, double &t, double t1) const { + return hit(r, t, t1, std::numeric_limits<double>::infinity()); + } // Given a point on the surface, returns the normalized outer normal vector on that point. virtual vec3d normal_vector(const vec3d &where) const = 0; @@ -46,7 +52,7 @@ public: return (where - center) / radius; } - bool hit(const ray3d &r, double &t) const override { + bool hit(const ray3d &r, double &t, double t1, double t2) const override { // Ray: {Source, Direction, time} // Sphere: {Center, radius} // sphere hit formula: |Source + Direction * time - Center| = radius @@ -64,11 +70,22 @@ public: // delta_q = H^2 - AC (quarter delta) const double delta_q = h * h - a * c; - const auto hit = delta_q >= 0; - if (hit) { - // the smaller root is the first point the ray hits, so return that one + bool hit = false; + if (delta_q >= 0) { + // return the root in range [t1, t2] // t = ( -H +- sqrt{ delta_q } ) / A - t = (-h - sqrt(delta_q)) / a; + double root; + root = (-h - sqrt(delta_q)) / a; + if (root >= t1 && root <= t2) { + hit = true; + t = root; + } else { + root = (-h + sqrt(delta_q)) / a; + if (root >= t1 && root <= t2) { + hit = true; + t = root; + } + } } return hit; } @@ -88,7 +105,7 @@ class viewport { // Detect hits double hit_t; for (const auto &obj: objects) { - if (obj->hit(r, hit_t)) { + if (obj->hit(r, hit_t, 0.0)) { // normal vector on hit point const auto nv = obj->normal_vector(r.at(hit_t)); // return obj->color(); |