X-Git-Url: http://git.tdb.fi/?a=blobdiff_plain;ds=sidebyside;f=source%2Flinal%2Fmatrix.h;h=929c48247e517aa47d837df1438c94465e25064a;hb=ffb043ce670d733decc03c6e4240a4e6d980caec;hp=f18eb2f4cfb52504214b84015688e46d0d7be121;hpb=e4b75401bd773201deb00eff672ee34794479671;p=libs%2Fmath.git

diff --git a/source/linal/matrix.h b/source/linal/matrix.h
index f18eb2f..929c482 100644
--- a/source/linal/matrix.h
+++ b/source/linal/matrix.h
@@ -30,6 +30,9 @@ public:
 	T &operator()(unsigned i, unsigned j) { return element(i, j); }
 	const T &operator()(unsigned i, unsigned j) const { return element(i, j); }
 
+	template<unsigned P, unsigned Q>
+	Matrix<T, P, Q> block(unsigned, unsigned) const;
+
 	Matrix &operator*=(T);
 	Matrix &operator/=(T);
 	Matrix &operator+=(const Matrix &);
@@ -81,6 +84,17 @@ inline Matrix<T, M, N> Matrix<T, M, N>::from_rows(const Vector<T, N> *v)
 	return m;
 }
 
+template<typename T, unsigned M, unsigned N>
+template<unsigned P, unsigned Q>
+inline Matrix<T, P, Q> Matrix<T, M, N>::block(unsigned y, unsigned x) const
+{
+	Matrix<T, P, Q> r;
+	for(unsigned j=0; j<P; ++j)
+		for(unsigned i=0; i<Q; ++i)
+			r(j, i) = element(y+j, x+i);
+	return r;
+}
+
 template<typename T, unsigned M, unsigned N>
 inline Matrix<T, M, N> &Matrix<T, M, N>::operator*=(T s)
 {