Added GetRotateMatrix() in Matrix.h

inc/hgl/math/Matrix.h

@@ -215,6 +215,8 @@ namespace hgl
         return root*child;
     }
 
+    const Matrix4f GetRotateMatrix(const Vector3f &world_position,const Vector3f &cur_direction,const Vector3f &new_direction);
+
     /**
      * 带误差的比较两个浮点矩阵是否相等
      * @param m1 矩阵1

src/Math/Matrix4f.cpp

@@ -178,4 +178,21 @@ namespace hgl
 
         return result;
     }
+    
+    /**
+    * 计算一个方向旋转成另一个方向的变换矩阵
+    */
+    const Matrix4f GetRotateMatrix(const Vector3f &world_position,const Vector3f &cur_direction,const Vector3f &new_direction)
+    {
+        Vector3f axis=glm::cross(cur_direction,new_direction);
+
+        if(glm::length2(axis)<0.0001)
+            return Matrix4f(1.0f);
+
+        axis=glm::normalize(axis);
+
+        float angle=acos(glm::dot(cur_direction,new_direction));
+
+        return glm::rotate(Matrix4f(1.0f),angle,axis);
+    }
 }//namespace hgl