From bac87e9c4c61a69c5d315f331031d0745ee9d8d2 Mon Sep 17 00:00:00 2001 From: Keuin Date: Sat, 16 Apr 2022 14:30:48 +0800 Subject: Add object::is_on to check whether a point is on the object's surface. --- object.h | 3 +++ sphere.h | 4 ++++ 2 files changed, 7 insertions(+) diff --git a/object.h b/object.h index 26548c5..c679d83 100644 --- a/object.h +++ b/object.h @@ -28,6 +28,9 @@ public: return hit(r, t, t1, std::numeric_limits::infinity()); } + // If given position is on the object's surface. + virtual bool is_on(const vec3d &p) const = 0; + // Given a point on the surface, returns the normalized outer normal vector on that point. virtual vec3d normal_vector(const vec3d &where) const = 0; diff --git a/sphere.h b/sphere.h index fa181e7..a5a935e 100644 --- a/sphere.h +++ b/sphere.h @@ -81,6 +81,10 @@ public: return hit; } + bool is_on(const vec3d &p) const override { + return ((p - center).mod2() - radius * radius) < 1e-10; + } + pixel8b color() const override { return pixel8b::from_normalized(1.0, 0.0, 0.0); } -- cgit v1.2.3