From 55db06bf5c2ab9c28519311b972a003515c841e4 Mon Sep 17 00:00:00 2001
From: Swung0x48 <swung0x48@outlook.com>
Date: Mon, 17 Nov 2025 17:36:42 +0800
Subject: [PATCH] [Feat] (MG_Backend/DirectGLES): implement `glGenerateMipmap`

---
 MobileGL/MG_Backend/DirectGLES/DirectGLES.cpp | 53 +++++++++++++++----
 MobileGL/MG_Backend/DirectGLES/DirectGLES.h   |  1 +
 .../GLImpl/Framebuffer/GL_Framebuffer.cpp     |  8 +--
 3 files changed, 49 insertions(+), 13 deletions(-)

diff --git a/MobileGL/MG_Backend/DirectGLES/DirectGLES.cpp b/MobileGL/MG_Backend/DirectGLES/DirectGLES.cpp
index 58769417..36f924ad 100644
--- a/MobileGL/MG_Backend/DirectGLES/DirectGLES.cpp
+++ b/MobileGL/MG_Backend/DirectGLES/DirectGLES.cpp
@@ -112,6 +112,19 @@ namespace MobileGL::MG_Backend::DirectGLES {
     } // namespace VertexArrayImpl
 
     namespace TextureImpl {
+        SharedPtr<BackendTextureObject> SyncTextureObjectToBackend(SharedPtr<MG_State::GLState::ITextureObject>& textureObject) {
+            const auto& backendTextureIt = g_backendTextureObjects.find(textureObject);
+            SharedPtr<BackendTextureObject> backendTextureObject;
+            if (backendTextureIt == g_backendTextureObjects.end()) {
+                backendTextureObject = MakeShared<BackendTextureObject>();
+                g_backendTextureObjects[textureObject] = backendTextureObject;
+            } else {
+                backendTextureObject = backendTextureIt->second;
+            }
+            backendTextureObject->SyncToBackend(textureObject);
+            return backendTextureObject;
+        }
+
         void SyncNeccessaryTextures() {
             // All textures we need are:
             //   1. textures bound to texture units (TODO: only sync ones that are used in current program)
@@ -144,15 +157,7 @@ namespace MobileGL::MG_Backend::DirectGLES {
 
             // Do real sync
             for (auto& textureObject : texturesToSync) {
-                const auto& backendTextureIt = g_backendTextureObjects.find(textureObject);
-                SharedPtr<BackendTextureObject> backendTextureObject;
-                if (backendTextureIt == g_backendTextureObjects.end()) {
-                    backendTextureObject = MakeShared<BackendTextureObject>();
-                    g_backendTextureObjects[textureObject] = backendTextureObject;
-                } else {
-                    backendTextureObject = backendTextureIt->second;
-                }
-                backendTextureObject->SyncToBackend(textureObject);
+                SyncTextureObjectToBackend(textureObject);
             }
         }
     } // namespace TextureImpl
@@ -486,14 +491,30 @@ namespace MobileGL::MG_Backend::DirectGLES {
 
     void BlitFramebuffer(GLint srcX0, GLint srcY0, GLint srcX1, GLint srcY1, GLint dstX0, GLint dstY0, GLint dstX1,
                          GLint dstY1, GLbitfield mask, GLenum filter) {
+        DebugImpl::ErrorLopper errorLopper;
+
         TextureImpl::SyncNeccessaryTextures();
+        errorLopper.Loop([file = __FILE__, line = __LINE__](auto err) {
+            MGLOG_D("ES error (%s:%d): %s", file, line, MG_Util::ConvertGLEnumToString(err).c_str());
+        });
         FramebufferImpl::SyncCurrentFBO();
+        errorLopper.Loop([file = __FILE__, line = __LINE__](auto err) {
+            MGLOG_D("ES error (%s:%d): %s", file, line, MG_Util::ConvertGLEnumToString(err).c_str());
+        });
         RenderStateImpl::SyncRenderState();
+        errorLopper.Loop([file = __FILE__, line = __LINE__](auto err) {
+            MGLOG_D("ES error (%s:%d): %s", file, line, MG_Util::ConvertGLEnumToString(err).c_str());
+        });
 
         BindCurrentFBO(FramebufferTarget::Draw);
         BindCurrentFBO(FramebufferTarget::Read);
-
+        errorLopper.Loop([file = __FILE__, line = __LINE__](auto err) {
+            MGLOG_D("ES error (%s:%d): %s", file, line, MG_Util::ConvertGLEnumToString(err).c_str());
+        });
         MG_External::GLES::glBlitFramebuffer(srcX0, srcY0, srcX1, srcY1, dstX0, dstY0, dstX1, dstY1, mask, filter);
+        errorLopper.Loop([file = __FILE__, line = __LINE__](auto err) {
+            MGLOG_D("ES error (%s:%d): %s", file, line, MG_Util::ConvertGLEnumToString(err).c_str());
+        });
     }
 
     void CopyTexImage2D(GLenum target, GLint level, GLenum internalformat, GLint x, GLint y, GLsizei width,
@@ -662,6 +683,18 @@ namespace MobileGL::MG_Backend::DirectGLES {
         }
     }
 
+    void GenerateMipmap(GLenum target) {
+        auto unitIndex = MG_State::pGLContext->GetActiveTextureUnit();
+        auto& unit = MG_State::pGLContext->GetTextureUnitObject(unitIndex);
+        auto& slot = unit.GetBindingSlot(MG_Util::ConvertGLEnumToTextureTarget(target));
+        auto texture = slot.GetBoundObject();
+        auto backendTexture = TextureImpl::SyncTextureObjectToBackend(texture);
+
+        TextureImpl::BackendTextureBindingProtector protector(target);
+        backendTexture->Bind(target);
+        MG_External::GLES::glGenerateMipmap(target);
+    }
+
     const GLubyte* GetString(GLenum name) {
         return MG_External::GLES::glGetString(name);
     }
diff --git a/MobileGL/MG_Backend/DirectGLES/DirectGLES.h b/MobileGL/MG_Backend/DirectGLES/DirectGLES.h
index 6e4562e8..6814ebf1 100644
--- a/MobileGL/MG_Backend/DirectGLES/DirectGLES.h
+++ b/MobileGL/MG_Backend/DirectGLES/DirectGLES.h
@@ -20,5 +20,6 @@ namespace MobileGL::MG_Backend::DirectGLES {
                         GLsizei height, GLint border);
     void CopyTexSubImage2D(GLenum target, GLint level, GLint xoffset, GLint yoffset, GLint x, GLint y,
                                    GLsizei width, GLsizei height);
+    void GenerateMipmap(GLenum target);
     const GLubyte* GetString(GLenum name);
 } // namespace MobileGL::MG_Backend::DirectGLES
\ No newline at end of file
diff --git a/MobileGL/MG_Impl/GLImpl/Framebuffer/GL_Framebuffer.cpp b/MobileGL/MG_Impl/GLImpl/Framebuffer/GL_Framebuffer.cpp
index f9d5ce40..d44c7358 100644
--- a/MobileGL/MG_Impl/GLImpl/Framebuffer/GL_Framebuffer.cpp
+++ b/MobileGL/MG_Impl/GLImpl/Framebuffer/GL_Framebuffer.cpp
@@ -46,8 +46,10 @@ namespace MobileGL {
             // TODO: implement
         }
 
-        void GenerateMipmap_State(GLenum target) {
-            // TODO: implement
+        void GenerateMipmap_Backend(GLenum target) {
+#if MOBILEGL_BACKEND == MOBILEGL_BACKEND_TYPE_DIRECT_GLES
+            MG_Backend::DirectGLES::GenerateMipmap(target);
+#endif
         }
 
         void GenRenderbuffers_State(GLsizei n, GLuint* renderbuffers) {
@@ -325,7 +327,7 @@ namespace MobileGL {
         }
 
         void GenerateMipmap(GLenum target) {
-            GenerateMipmap_State(target);
+            GenerateMipmap_Backend(target);
         }
 
         void GenRenderbuffers(GLsizei n, GLuint* renderbuffers) {