From 51e043f07d2c3068a1f19586f281f66aeb046d77 Mon Sep 17 00:00:00 2001
From: hyzboy <hyzboy@gmail.com>
Date: Wed, 9 Jul 2025 00:45:03 +0800
Subject: [PATCH] =?UTF-8?q?=E6=96=B0=E7=9A=84PrimitiveComponent::GetWorldO?=
 =?UTF-8?q?BBMatrix=E5=87=BD=E6=95=B0=EF=BC=8C=E8=BF=9B=E4=B8=80=E6=AD=A5?=
 =?UTF-8?q?=E5=87=8F=E5=B0=91=E4=B8=AD=E9=97=B4=E8=AE=A1=E7=AE=97=E6=AD=A5?=
 =?UTF-8?q?=E9=AA=A4=EF=BC=8C=E7=9B=B4=E6=8E=A5=E5=87=BAOBBMATRIX?=
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---
 CMSceneGraph                           |  2 +-
 example/Basic/RenderBoundBox.cpp       | 12 +++++------
 inc/hgl/component/PrimitiveComponent.h | 28 ++++++++++++++++++++++++++
 3 files changed, 35 insertions(+), 7 deletions(-)

diff --git a/CMSceneGraph b/CMSceneGraph
index 50f5514a..a4d3950a 160000
--- a/CMSceneGraph
+++ b/CMSceneGraph
@@ -1 +1 @@
-Subproject commit 50f5514aee947cc8cb400cd9bf98b58803fc58a6
+Subproject commit a4d3950af690d892e259865be4559053e007c979
diff --git a/example/Basic/RenderBoundBox.cpp b/example/Basic/RenderBoundBox.cpp
index 70bbfe45..b6cf9a84 100644
--- a/example/Basic/RenderBoundBox.cpp
+++ b/example/Basic/RenderBoundBox.cpp
@@ -240,7 +240,8 @@ private:
         {
             for(int i=0;i<6;i++)
             {
-                cci.mat=AxisYRotate(deg2rad(i*30.0f));
+                cci.mat=AxisYRotate(deg2rad(i*30.0f))*ScaleMatrix((i+1)*1.0f);
+
                 rm_torus->component[i]=CreateComponent<MeshComponent>(&cci,rm_torus->cdp);
                 rm_torus->component[i]->SetOverrideMaterial(solid.mi[i]);
             }
@@ -257,13 +258,12 @@ private:
 
         for(int i=0;i<6;i++)
         {
-            PrimitiveComponent *component=rm_torus->component[i];
+            MeshComponent *component=rm_torus->component[i];
 
-            component->GetWorldOBB(obb);
+            if(!component->GetWorldOBBMatrix(cci.mat))
+                continue;
 
-            cci.mat=obb.GetMatrix();
-
-            CreateComponent<MeshComponent>(&cci,rm_box->cdp);
+            auto *box_component=CreateComponent<MeshComponent>(&cci,rm_box->cdp);
         }
 
         return(true);
diff --git a/inc/hgl/component/PrimitiveComponent.h b/inc/hgl/component/PrimitiveComponent.h
index e3f5d3e5..da7e22dc 100644
--- a/inc/hgl/component/PrimitiveComponent.h
+++ b/inc/hgl/component/PrimitiveComponent.h
@@ -31,6 +31,34 @@ public:
 
         return true;
     }
+
+    const bool GetWorldOBBMatrix(Matrix4f &obb_matrix,const float cube_size=1.0f)
+    {
+        AABB aabb;
+
+        if(!GetLocalAABB(aabb))
+            return false;
+
+        //这两行也是对的
+        //OBB obb(GetLocalToWorldMatrix(),aabb);
+        //obb_matrix=obb.GetMatrix(cube_size);
+
+        // 1. 计算最终的缩放向量
+        const Vector3f scale_vector = aabb.GetLength() * cube_size;
+
+        // 2. 直接构建局部空间的变换矩阵 (Translate * Scale)
+        Matrix4f local_aabb_matrix;
+
+        local_aabb_matrix[0] = Vector4f(scale_vector.x, 0.0f, 0.0f, 0.0f);
+        local_aabb_matrix[1] = Vector4f(0.0f, scale_vector.y, 0.0f, 0.0f);
+        local_aabb_matrix[2] = Vector4f(0.0f, 0.0f, scale_vector.z, 0.0f);
+        local_aabb_matrix[3] = Vector4f(aabb.GetCenter(), 1.0f);
+
+        // 3. 将局部 AABB 矩阵与组件的 LocalToWorld 矩阵相乘，得到最终的世界 OBB 矩阵
+        obb_matrix = GetLocalToWorldMatrix() * local_aabb_matrix;
+
+        return(true);
+    }
 };//class PrimitiveComponent
 
 COMPONENT_NAMESPACE_END