From 7589d62732b68b99de1bec561b1703dd2b043c03 Mon Sep 17 00:00:00 2001
From: hyzboy <hyzboy@gmail.com>
Date: Thu, 1 Aug 2024 01:39:33 +0800
Subject: [PATCH] Added GetRotateQuat()

---
 inc/hgl/math/Matrix.h |  3 ++-
 src/Math/Matrix4f.cpp | 17 +++++++++++++++++
 2 files changed, 19 insertions(+), 1 deletion(-)

diff --git a/inc/hgl/math/Matrix.h b/inc/hgl/math/Matrix.h
index e88bc31..bf361fe 100644
--- a/inc/hgl/math/Matrix.h
+++ b/inc/hgl/math/Matrix.h
@@ -215,7 +215,8 @@ namespace hgl
         return root*child;
     }
 
-    const Matrix4f GetRotateMatrix(const Vector3f &world_position,const Vector3f &cur_direction,const Vector3f &new_direction);
+    const Matrix4f GetRotateMatrix(const Vector3f &world_position,const Vector3f &cur_direction,const Vector3f &new_direction);    
+    const Quatf GetRotateQuat(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
diff --git a/src/Math/Matrix4f.cpp b/src/Math/Matrix4f.cpp
index 5da0110..4d58b45 100644
--- a/src/Math/Matrix4f.cpp
+++ b/src/Math/Matrix4f.cpp
@@ -195,4 +195,21 @@ namespace hgl
 
         return glm::rotate(Matrix4f(1.0f),angle,axis);
     }
+
+    /**
+    * 计算一个方向旋转成另一个方向的四元数
+    */
+    const Quatf GetRotateQuat(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 Quatf(1.0f,0.0f,0.0f,0.0f);
+
+        axis=glm::normalize(axis);
+
+        float angle=acos(glm::dot(cur_direction,new_direction));
+
+        return glm::angleAxis(angle,axis);
+    }
 }//namespace hgl