allow clicking celestial bodies

[blobs.git] / src / math / geometry.hpp

diff --git a/src/math/geometry.hpp b/src/math/geometry.hpp
index 8f062841fe8adf64b05f6c8a0668f3e8a07adf2f..b4a9f50bb43c86c283691a65736f90981b62368a 100644 (file)
--- a/src/math/geometry.hpp
+++ b/src/math/geometry.hpp
@@ -40,6 +40,7 @@ bool Intersect(
        glm::dvec3 &normal,
        double &depth) noexcept;
 
+
 class Ray {
 
 public:
@@ -77,6 +78,32 @@ bool Intersect(
        glm::dvec3 &normal,
        double &dist) noexcept;
 
+
+struct Sphere {
+
+       glm::dvec3 origin;
+       double radius;
+
+};
+
+/// matrix may scale, but only uniformly
+inline Sphere operator *(const glm::dmat4 &m, const Sphere &s) noexcept {
+       glm::dvec4 o(m * glm::dvec4(s.origin, 1.0));
+       glm::dvec4 p(m * glm::dvec4(s.origin + glm::dvec3(s.radius, 0.0, 0.0), 1.0));
+       return Sphere{glm::dvec3(o) / o.w, glm::length((glm::dvec3(p) / p.w) - (glm::dvec3(o) / o.w))};
+}
+
+inline std::ostream &operator <<(std::ostream &out, const Sphere &s) {
+       return out << "Sphere(" << s.origin << ", " << s.radius << ")";
+}
+
+/// oriented ray/sphere intersection test
+bool Intersect(
+       const Ray &,
+       const Sphere &,
+       glm::dvec3 &normal,
+       double &dist) noexcept;
+
 }
 }