Fix composite shape ray intersection logic

[libs/math.git] / source / geometry / halfspace.h

diff --git a/source/geometry/halfspace.h b/source/geometry/halfspace.h
index 4adc0dff45694726f399b7a07a3afff0cedcdb2c..b439851bd5adaf3a7067c7f91f5bf8308bb01166 100644 (file)
--- a/source/geometry/halfspace.h
+++ b/source/geometry/halfspace.h
@@ -7,8 +7,8 @@ namespace Msp {
 namespace Geometry {
 
 /**
-An infinite shape consisting of the space on one side of a plane.  Mostly
-useful when composited with other shapes.
+An unbounded shape consisting of the space on one side of a plane.  Mostly
+useful when intersected with other shapes.
 */
 template<typename T, unsigned D>
 class HalfSpace: public Shape<T, D>
@@ -76,6 +76,7 @@ inline unsigned HalfSpace<T, D>::get_intersections(const Ray<T, D> &ray, Surface
                        points[0].position = ray.get_start()+ray.get_direction()*x;
                        points[0].normal = normal;
                        points[0].distance = x;
+                       points[0].entry = (c<T(0));
                }
 
                return 1;