From 0c2449dc5eaad5cde9bc3efc0177388d09dd4ca8 Mon Sep 17 00:00:00 2001
From: BZLZHH <admin@bzlzhh.top>
Date: Sun, 15 Jun 2025 10:32:38 +0800
Subject: [PATCH] [Fix] (Diligent/Buffer): Recreate buffer object when the size
 changes.

---
 .../Implementations/GL/Buffer/GL_Buffer.cpp    |  6 +++++-
 .../Implementations/GL/Drawing/GL_Drawing.cpp  | 18 ++++++++++++------
 2 files changed, 17 insertions(+), 7 deletions(-)

diff --git a/MG/MG_GL/Implementations/GL/Buffer/GL_Buffer.cpp b/MG/MG_GL/Implementations/GL/Buffer/GL_Buffer.cpp
index cceb1f35..4171aa6e 100644
--- a/MG/MG_GL/Implementations/GL/Buffer/GL_Buffer.cpp
+++ b/MG/MG_GL/Implementations/GL/Buffer/GL_Buffer.cpp
@@ -223,7 +223,11 @@ namespace MG_GL::GL {
             BuffDesc.Name = name.c_str();
             BuffDesc.Usage = Diligent::USAGE_DEFAULT;
 
-            if (pBuffer == nullptr) {
+            if (!pBuffer || (pBuffer && pBuffer->GetDesc().Size != bufferObj.data.size())) {
+                if (pBuffer) {
+                    pBuffer->Release();
+                    pBuffer = nullptr;
+                }
                 Diligent::BufferData BuffData;
                 // Initial data must not be null for immutable buffers
                 BuffData.pData = BuffDesc.Usage != Diligent::USAGE_IMMUTABLE ? nullptr : bufferObj.data.data();
diff --git a/MG/MG_GL/Implementations/GL/Drawing/GL_Drawing.cpp b/MG/MG_GL/Implementations/GL/Drawing/GL_Drawing.cpp
index 23593eae..bb76a122 100644
--- a/MG/MG_GL/Implementations/GL/Drawing/GL_Drawing.cpp
+++ b/MG/MG_GL/Implementations/GL/Drawing/GL_Drawing.cpp
@@ -465,7 +465,12 @@ namespace MG_GL::GL {
             auto& bufferObj = MG_State_T::bufferState->buffers_[buffer];
 
             Diligent::IBuffer *&pBuffer = MG_Diligent::g_BufferMap[buffer];
-            if (bufferObj.isDynamic && !pBuffer) {
+            if (bufferObj.isDynamic && (!pBuffer || (pBuffer && pBuffer->GetDesc().Size != bufferObj.data.size()))) {
+                if (pBuffer) {
+                    pBuffer->Release();
+                    pBuffer = nullptr;
+                }
+                
                 Diligent::BufferDesc BuffDesc;
                 std::string bufferName = "Dynamic VBO " + std::to_string(buffer);
                 BuffDesc.Name = bufferName.c_str();
@@ -488,7 +493,12 @@ namespace MG_GL::GL {
             auto& bufferObj = MG_State_T::bufferState->buffers_[buffer];
 
             Diligent::IBuffer*& pBuffer = MG_Diligent::g_BufferMap[buffer];
-            if (bufferObj.isDynamic && !pBuffer) {
+            if (bufferObj.isDynamic && (!pBuffer || (pBuffer && pBuffer->GetDesc().Size != bufferObj.data.size()))) {
+                if (pBuffer) {
+                    pBuffer->Release();
+                    pBuffer = nullptr;
+                }
+                
                 Diligent::BufferDesc BuffDesc;
                 std::string bufferName = "Dynamic IBO " + std::to_string(buffer);
                 BuffDesc.Name = bufferName.c_str();
@@ -497,10 +507,6 @@ namespace MG_GL::GL {
                 BuffDesc.BindFlags = Diligent::BIND_INDEX_BUFFER;
                 BuffDesc.CPUAccessFlags = Diligent::CPU_ACCESS_WRITE;
 
-                if (pBuffer) {
-                    pBuffer->Release();
-                }
-
                 MG_Diligent::g_pDevice->CreateBuffer(BuffDesc, nullptr, &pBuffer);
 
                 if (!pBuffer) {