From d025adb453702b91963bcce6a076e922d4ecc4dd Mon Sep 17 00:00:00 2001
From: Nomango <nomango@qq.com>
Date: Tue, 30 Jul 2019 13:05:16 +0800
Subject: [PATCH] fix potential errors in matrix multiplication

---
 kiwano/2d/Node.cpp     |  2 +-
 kiwano/math/Matrix.hpp | 22 +++++++++++++++++-----
 2 files changed, 18 insertions(+), 6 deletions(-)

diff --git a/kiwano/2d/Node.cpp b/kiwano/2d/Node.cpp
index cf77abc7..52d18492 100644
--- a/kiwano/2d/Node.cpp
+++ b/kiwano/2d/Node.cpp
@@ -220,7 +220,7 @@ namespace kiwano
 
 		if (parent_)
 		{
-			transform_matrix_ = transform_matrix_ * parent_->transform_matrix_;
+			transform_matrix_ *= parent_->transform_matrix_;
 		}
 
 		// update children's transform
diff --git a/kiwano/math/Matrix.hpp b/kiwano/math/Matrix.hpp
index dd251212..5c3f7194 100644
--- a/kiwano/math/Matrix.hpp
+++ b/kiwano/math/Matrix.hpp
@@ -78,8 +78,8 @@ namespace kiwano
 			{
 			}
 
-			template <typename T>
-			MatrixT(T const& other)
+			template <typename _MTy>
+			MatrixT(_MTy const& other)
 			{
 				for (int i = 0; i < 6; i++)
 					m[i] = other[i];
@@ -95,12 +95,24 @@ namespace kiwano
 				return m[index];
 			}
 
-			template <typename _Lty, typename _Rty>
-			inline MatrixT& operator= (MatrixMultiply<value_type, _Lty, _Rty> const& other)
+			inline MatrixT& operator= (MatrixT const& other)
 			{
 				for (int i = 0; i < 6; i++)
 					m[i] = other[i];
-				return *this;
+				return (*this);
+			}
+
+			template <typename _Lty, typename _Rty>
+			inline MatrixT& operator= (MatrixMultiply<value_type, _Lty, _Rty> const& other)
+			{
+				MatrixT result(other);
+				(*this) = result;
+				return (*this);
+			}
+
+			inline MatrixT& operator*= (MatrixT const& other)
+			{
+				return operator=((*this) * other);
 			}
 
 			inline void Identity()