From 5142f3c72ba39a74ac3c98932a4ffa63c1ec2816 Mon Sep 17 00:00:00 2001
From: Swung0x48 <swung0x48@outlook.com>
Date: Thu, 8 May 2025 20:53:42 +0800
Subject: [PATCH] [Fix] (TextureState, GL_Drawing): mark dirty textures to skip
 uploading unmodified ones

---
 MG/MG_GL/Implementations/GL/Drawing/GL_Drawing.cpp | 3 +++
 MG/MG_GL/State/Texture/TextureState.cpp            | 5 +++--
 MG/MG_GL/State/Texture/TextureState.h              | 1 +
 3 files changed, 7 insertions(+), 2 deletions(-)

diff --git a/MG/MG_GL/Implementations/GL/Drawing/GL_Drawing.cpp b/MG/MG_GL/Implementations/GL/Drawing/GL_Drawing.cpp
index b465ca50..484a0498 100644
--- a/MG/MG_GL/Implementations/GL/Drawing/GL_Drawing.cpp
+++ b/MG/MG_GL/Implementations/GL/Drawing/GL_Drawing.cpp
@@ -416,6 +416,9 @@ namespace MG_GL::GL {
             }
 
             for (auto& [level, mip] : texObj.params.mipmapData) {
+                if (!mip.dirty)
+                    continue;
+                mip.dirty = false;
                 const void* data = !mip.pixelData.empty() ? mip.pixelData.data() : nullptr;
                 switch (target) {
                     case GL_TEXTURE_2D: {
diff --git a/MG/MG_GL/State/Texture/TextureState.cpp b/MG/MG_GL/State/Texture/TextureState.cpp
index ba7fe964..78f552f3 100644
--- a/MG/MG_GL/State/Texture/TextureState.cpp
+++ b/MG/MG_GL/State/Texture/TextureState.cpp
@@ -258,7 +258,7 @@ GLenum TextureState::Upload2D(GLenum target, GLint level, GLint internalFormat,
     if (isProxyTexture) {
         MG_Util::Debug::LogD("MG_State: Texture: Upload2D proxy texture detected");
         TextureObject& proxyTex = proxyTextures_[target];
-        TextureParams::MipmapLevel mip{};
+        auto& mip = proxyTex.params.mipmapData[level];
         mip.width = width;
         mip.height = height;
         mip.internalFormat = internalFormat;
@@ -266,7 +266,6 @@ GLenum TextureState::Upload2D(GLenum target, GLint level, GLint internalFormat,
         mip.type = type;
         proxyTex.generated = true;
         proxyTex.target = target;
-        proxyTex.params.mipmapData[level] = mip;
         return GL_NO_ERROR;
     }
 
@@ -280,6 +279,7 @@ GLenum TextureState::Upload2D(GLenum target, GLint level, GLint internalFormat,
     mip.internalFormat = internalFormat;
     mip.format = format;
     mip.type = type;
+    mip.dirty = true;
 
     if (data == nullptr) {
         mip.hasData = false;
@@ -491,6 +491,7 @@ GLenum TextureState::UpdateRegion2D(GLenum target, GLint level, GLint xoffset,
 //    }
 
     mip.hasData = true;
+    mip.dirty = true;
     MG_Util::Debug::LogD("MG_State: Texture: UpdateRegion2D succeeded");
     return GL_NO_ERROR;
 }
diff --git a/MG/MG_GL/State/Texture/TextureState.h b/MG/MG_GL/State/Texture/TextureState.h
index 63cff3ef..ea0de3af 100644
--- a/MG/MG_GL/State/Texture/TextureState.h
+++ b/MG/MG_GL/State/Texture/TextureState.h
@@ -31,6 +31,7 @@ struct TextureParams {
         GLenum type = GL_UNSIGNED_BYTE;
         std::vector<GLubyte> pixelData;
         bool hasData = false;
+        bool dirty = false; // TODO: encapsulate this with an public API to RHI
     };
     unordered_map<GLint, MipmapLevel> mipmapData;
 };