Second pass idLib integration.

source/shared/idlib/bv/sphere.cpp

@@ -0,0 +1,18 @@
+#include "sphere.h"
+
+bool idSphere::LineIntersection(const idVec3& start, const idVec3& end) const {
+    const idVec3 fromCenter = start - origin;
+    const idVec3 direction = end - start;
+    const float projection = -fromCenter.Dot(direction);
+    if (projection <= 0.0f) return fromCenter.LengthSqr() < radius * radius;
+
+    const float directionLengthSqr = direction.LengthSqr();
+    if (projection >= directionLengthSqr) {
+        const idVec3 endFromCenter = end - origin;
+        return endFromCenter.LengthSqr() < radius * radius;
+    }
+
+    const idVec3 closest = fromCenter
+        + direction * (projection / directionLengthSqr);
+    return closest.LengthSqr() < radius * radius;
+}