1 files changed, 47 insertions, 0 deletions
diff --git a/src/libnr/nr-point-matrix-ops.h b/src/libnr/nr-point-matrix-ops.h
new file mode 100644
index 000000000..58e06fc6d
--- /dev/null
+++ b/src/libnr/nr-point-matrix-ops.h
@@ -0,0 +1,47 @@
+/** \file operator functions over (NR::Point, NR::Matrix). */
+#ifndef SEEN_NR_POINT_MATRIX_OPS_H
+#define SEEN_NR_POINT_MATRIX_OPS_H
+
+#include "libnr/nr-point.h"
+#include "libnr/nr-matrix.h"
+
+namespace NR {
+
+inline Point operator*(Point const &v, Matrix const &m)
+{
+#if 1  /* Which code makes it easier to see what's happening? */
+    NR::Point const xform_col0(m[0],
+                               m[2]);
+    NR::Point const xform_col1(m[1],
+                               m[3]);
+    NR::Point const xlate(m[4], m[5]);
+    return ( Point(dot(v, xform_col0),
+                   dot(v, xform_col1))
+             + xlate );
+#else
+    return Point(v[X] * m[0]  +  v[Y] * m[2]  +  m[4],
+                 v[X] * m[1]  +  v[Y] * m[3]  +  m[5]);
+#endif
+}
+
+inline Point &Point::operator*=(Matrix const &m)
+{
+    *this = *this * m;
+    return *this;
+}
+
+} /* namespace NR */
+
+
+#endif /* !SEEN_NR_POINT_MATRIX_OPS_H */
+
+/*
+  Local Variables:
+  mode:c++
+  c-file-style:"stroustrup"
+  c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
+  indent-tabs-mode:nil
+  fill-column:99
+  End:
+*/
+// vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:encoding=utf-8:textwidth=99 :