diff --git a/Makefile.am b/Makefile.am
index ce581deb..00df58f3 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -77,6 +77,8 @@ UTIL_FILES = \
json/tree.hpp \
lerp.cpp \
lerp.hpp \
+ line.cpp \
+ line.hpp \
log.cpp \
log.hpp \
log.ipp \
@@ -239,6 +241,7 @@ TEST_BIN = \
test/hton \
test/ip \
test/json_types \
+ test/line \
test/maths \
test/maths_matrix \
test/matrix \
diff --git a/line.cpp b/line.cpp
new file mode 100644
index 00000000..90e66883
--- /dev/null
+++ b/line.cpp
@@ -0,0 +1,60 @@
+/*
+ * This file is part of libgim.
+ *
+ * libgim is free software: you can redistribute it and/or modify it under the
+ * terms of the GNU General Public License as published by the Free Software
+ * Foundation, either version 3 of the License, or (at your option) any later
+ * version.
+ *
+ * libgim is distributed in the hope that it will be useful, but WITHOUT ANY
+ * WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
+ * FOR A PARTICULAR PURPOSE. See the GNU General Public License for more
+ * details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with libgim. If not, see .
+ *
+ * Copyright 2015 Danny Robson
+ */
+
+#include "line.hpp"
+
+#include "debug.hpp"
+
+
+//-----------------------------------------------------------------------------
+template
+util::line::line (util::point _p,
+ util::vector _d):
+ p (_p),
+ d (_d)
+{
+ CHECK_EQ (d.magnitude2 (), 1);
+}
+
+
+///----------------------------------------------------------------------------
+/// returns the distance alone the line in a line-plane intersection
+///
+/// returns inf if parallel
+/// returns 0 if colinear
+template
+T
+util::line::intersect (plane rhs) const
+{
+ return dot (rhs.p - p, rhs.n) / dot (d, rhs.n);
+}
+
+
+//-----------------------------------------------------------------------------
+template
+util::point
+util::line::at (T t) const
+{
+ return p + d * t;
+}
+
+
+//-----------------------------------------------------------------------------
+template struct util::line<2,float>;
+template struct util::line<3,float>;
diff --git a/line.hpp b/line.hpp
new file mode 100644
index 00000000..3a13b94a
--- /dev/null
+++ b/line.hpp
@@ -0,0 +1,46 @@
+/*
+ * This file is part of libgim.
+ *
+ * libgim is free software: you can redistribute it and/or modify it under the
+ * terms of the GNU General Public License as published by the Free Software
+ * Foundation, either version 3 of the License, or (at your option) any later
+ * version.
+ *
+ * libgim is distributed in the hope that it will be useful, but WITHOUT ANY
+ * WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
+ * FOR A PARTICULAR PURPOSE. See the GNU General Public License for more
+ * details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with libgim. If not, see .
+ *
+ * Copyright 2015 Danny Robson
+ */
+
+#ifndef __UTIL_LINE_HPP
+#define __UTIL_LINE_HPP
+
+#include "point.hpp"
+#include "vector.hpp"
+#include "plane.hpp"
+
+namespace util {
+ template
+ struct line {
+ line (util::point place,
+ util::vector direction);
+
+ T intersect (plane) const;
+
+ util::point at (T) const;
+
+ util::point p;
+ util::vector d;
+ };
+
+
+ typedef line<2,float> line2f;
+ typedef line<3,float> line3f;
+}
+
+#endif
diff --git a/test/line.cpp b/test/line.cpp
new file mode 100644
index 00000000..4527e5e1
--- /dev/null
+++ b/test/line.cpp
@@ -0,0 +1,13 @@
+#include "line.hpp"
+#include "plane.hpp"
+#include "debug.hpp"
+
+int
+main (void)
+{
+ // trivial case: origin line facing z, plane at unit z facing -z.
+ util::line3f l ({0,0,0}, {0,0, 1});
+ util::plane3f p ({0,0,1}, {0,0,-1});
+
+ CHECK_EQ (l.intersect (p), 1);
+}