From 50390e9198ee2953e44ff2435b8c7627163bf990 Mon Sep 17 00:00:00 2001
From: GranMinigun <11149380+GranMinigun@users.noreply.github.com>
Date: Thu, 22 Feb 2024 19:06:19 +0500
Subject: [PATCH 1/6] Platform: Core: Replace GLEW with glad

---
 CMakeLists.txt                                   |  2 +-
 src/platform/core/CMakeLists.txt                 | 16 ++++++++++++----
 .../include/platform/device/ogl_video_device.hpp |  2 +-
 .../core/src/device/ogl_video_device.cpp         |  2 --
 src/platform/qt/src/widget/screen.cpp            | 11 ++++++++---
 5 files changed, 22 insertions(+), 11 deletions(-)

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 2e26c039..98f4154f 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -1,5 +1,5 @@
 cmake_minimum_required(VERSION 3.11...3.28)
-project(NanoBoyAdvance LANGUAGES CXX)
+project(NanoBoyAdvance LANGUAGES C CXX)
 
 set(CMAKE_CXX_STANDARD 17)
 set(CMAKE_CXX_STANDARD_REQUIRED ON)
diff --git a/src/platform/core/CMakeLists.txt b/src/platform/core/CMakeLists.txt
index 3a211153..2bc6d8c3 100644
--- a/src/platform/core/CMakeLists.txt
+++ b/src/platform/core/CMakeLists.txt
@@ -15,12 +15,21 @@ else()
 endif()
 
 find_package(OpenGL REQUIRED)
-find_package(GLEW REQUIRED)
+
+include(FetchContent)
+FetchContent_Declare(glad
+  GIT_REPOSITORY https://github.com/Dav1dde/glad.git
+  GIT_TAG        adc3d7a1d704e099581ca25bc5bbdf728c2db67b # v2.0.5-2-gadc3d7a
+  SOURCE_SUBDIR  cmake
+)
+FetchContent_MakeAvailable(glad)
+glad_add_library(glad_gl_core_33 STATIC
+  LANGUAGE c REPRODUCIBLE API gl:core=3.3 EXTENSIONS NONE
+)
 
 if(USE_SYSTEM_TOML11)
   find_package(toml11 3.7 REQUIRED)
 else()
-  include(FetchContent)
   FetchContent_Declare(toml11
     GIT_REPOSITORY https://github.com/ToruNiina/toml11.git
     GIT_TAG        dcfe39a783a94e8d52c885e5883a6fbb21529019 # v3.7.1
@@ -37,7 +46,6 @@ else()
   set(USE_SYSTEM_ZLIB OFF CACHE BOOL "" FORCE)
   set(BUILD_SHARED_LIBS OFF CACHE BOOL "" FORCE)
 
-  include(FetchContent)
   FetchContent_Declare(unarr
     GIT_REPOSITORY https://github.com/selmf/unarr.git
     GIT_TAG        b211040df83dee513362cdeb9bd87afa26fd5e38 # v1.1.1
@@ -104,5 +112,5 @@ endif()
 
 target_link_libraries(platform-core
   PRIVATE unarr::unarr
-  PUBLIC nba toml11::toml11 OpenGL::GL GLEW::GLEW
+  PUBLIC nba toml11::toml11 OpenGL::GL glad_gl_core_33
 )
diff --git a/src/platform/core/include/platform/device/ogl_video_device.hpp b/src/platform/core/include/platform/device/ogl_video_device.hpp
index 1b7f3d1b..ebcf1602 100644
--- a/src/platform/core/include/platform/device/ogl_video_device.hpp
+++ b/src/platform/core/include/platform/device/ogl_video_device.hpp
@@ -8,8 +8,8 @@
 #pragma once
 
 #include <array>
+#include <glad/gl.h>
 #include <nba/device/video_device.hpp>
-#include <GL/glew.h>
 #include <platform/config.hpp>
 #include <string>
 #include <utility>
diff --git a/src/platform/core/src/device/ogl_video_device.cpp b/src/platform/core/src/device/ogl_video_device.cpp
index 3fb65e63..05e6dffa 100644
--- a/src/platform/core/src/device/ogl_video_device.cpp
+++ b/src/platform/core/src/device/ogl_video_device.cpp
@@ -47,8 +47,6 @@ OGLVideoDevice::~OGLVideoDevice() {
 }
 
 void OGLVideoDevice::Initialize() {
-  glewInit();
-
   // Create a fullscreen quad to render to the viewport.
   glGenVertexArrays(1, &quad_vao);
   glGenBuffers(1, &quad_vbo);
diff --git a/src/platform/qt/src/widget/screen.cpp b/src/platform/qt/src/widget/screen.cpp
index b8546474..cc827998 100644
--- a/src/platform/qt/src/widget/screen.cpp
+++ b/src/platform/qt/src/widget/screen.cpp
@@ -5,10 +5,11 @@
  * Refer to the included LICENSE file.
  */
 
-#include <GL/glew.h>
-
 #include "widget/screen.hpp"
 
+#include <glad/gl.h>
+#include <QOpenGLContext> // Has to go after glad.
+
 Screen::Screen(
   QWidget* parent,
   std::shared_ptr<QtConfig> config
@@ -93,8 +94,12 @@ void Screen::UpdateViewport() {
   ogl_video_device.SetViewport(viewport_x, viewport_y, viewport_width, viewport_height);
 }
 
+static auto get_proc_address(const char* proc_name) {
+  return QOpenGLContext::currentContext()->getProcAddress(proc_name);
+}
+
 void Screen::initializeGL() {
-  makeCurrent();
+  gladLoadGL(get_proc_address);
   ogl_video_device.Initialize();
 }
 

From 0c037a06c6f93fa711253b01625a35d6321f6960 Mon Sep 17 00:00:00 2001
From: GranMinigun <11149380+GranMinigun@users.noreply.github.com>
Date: Sun, 10 Mar 2024 21:10:01 +0500
Subject: [PATCH 2/6] CI: Bump actions

---
 .github/workflows/build.yml | 16 ++++++++--------
 1 file changed, 8 insertions(+), 8 deletions(-)

diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
index 6a017a9a..9b7a9a6b 100644
--- a/.github/workflows/build.yml
+++ b/.github/workflows/build.yml
@@ -9,7 +9,7 @@ jobs:
       run:
         shell: msys2 {0}
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
       - uses: msys2/setup-msys2@v2
         with:
           install: make mingw-w64-x86_64-gcc mingw-w64-x86_64-cmake mingw-w64-x86_64-SDL2 mingw-w64-x86_64-glew mingw-w64-x86_64-qt5-static
@@ -31,7 +31,7 @@ jobs:
           mkdir upload
           cp -r build/bin/qt/{NanoBoyAdvance.exe,config.toml} upload
       - name: Upload artifacts
-        uses: actions/upload-artifact@v3
+        uses: actions/upload-artifact@v4
         with:
           name: NanoBoyAdvance-win64
           path: upload
@@ -40,7 +40,7 @@ jobs:
   build-linux:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
       - name: Setup dependencies
         run: |
           sudo apt-get update -qq
@@ -55,7 +55,7 @@ jobs:
           mkdir upload
           cp -r build/bin/qt/{NanoBoyAdvance,config.toml} upload
       - name: Upload artifacts
-        uses: actions/upload-artifact@v3
+        uses: actions/upload-artifact@v4
         with:
           name: NanoBoyAdvance-linux
           path: upload
@@ -64,7 +64,7 @@ jobs:
   build-macOS:
     runs-on: macos-latest
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
       - name: Setup dependencies
         env:
           HOMEBREW_NO_ANALYTICS: 1
@@ -94,7 +94,7 @@ jobs:
             -ov -format UDBZ \
             NanoBoyAdvance.dmg
       - name: Upload artifacts
-        uses: actions/upload-artifact@v3
+        uses: actions/upload-artifact@v4
         with:
           name: NanoBoyAdvance-${{ runner.os }}-x64
           path: NanoBoyAdvance.dmg
@@ -103,7 +103,7 @@ jobs:
   build-macOS-arm:
     runs-on: macos-14
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
       - name: Setup dependencies
         env:
           HOMEBREW_NO_ANALYTICS: 1
@@ -133,7 +133,7 @@ jobs:
             -ov -format UDBZ \
             NanoBoyAdvance.dmg
       - name: Upload artifacts
-        uses: actions/upload-artifact@v3
+        uses: actions/upload-artifact@v4
         with:
           name: NanoBoyAdvance-${{ runner.os }}-arm64
           path: NanoBoyAdvance.dmg

From c2bf6defe62b5d5d70b5804b189d748461e603ae Mon Sep 17 00:00:00 2001
From: GranMinigun <11149380+GranMinigun@users.noreply.github.com>
Date: Tue, 27 Feb 2024 19:37:31 +0500
Subject: [PATCH 3/6] CI: Remove GLEW and add dependencies of glad

---
 .github/workflows/build.yml | 26 +++++++++++++++++---------
 1 file changed, 17 insertions(+), 9 deletions(-)

diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
index 9b7a9a6b..17c739b7 100644
--- a/.github/workflows/build.yml
+++ b/.github/workflows/build.yml
@@ -12,7 +12,7 @@ jobs:
       - uses: actions/checkout@v4
       - uses: msys2/setup-msys2@v2
         with:
-          install: make mingw-w64-x86_64-gcc mingw-w64-x86_64-cmake mingw-w64-x86_64-SDL2 mingw-w64-x86_64-glew mingw-w64-x86_64-qt5-static
+          install: make mingw-w64-x86_64-gcc mingw-w64-x86_64-cmake mingw-w64-x86_64-python-jinja mingw-w64-x86_64-python-lxml mingw-w64-x86_64-SDL2 mingw-w64-x86_64-qt5-static
       - name: Build NanoBoyAdvance
         run: |
           cmake \
@@ -20,9 +20,9 @@ jobs:
             -G"Unix Makefiles" \
             -DCMAKE_BUILD_TYPE=Release \
             -DCMAKE_CXX_FLAGS="-s" \
+            -DPython_EXECUTABLE="$(which python3)" \
             -DPLATFORM_QT_STATIC=ON \
             -DUSE_STATIC_SDL=ON \
-            -DGLEW_USE_STATIC_LIBS=ON \
             -DQT5_STATIC_DIR="/c/tools/msys64/mingw64/qt5-static"
           cd build
           make -j$NUMBER_OF_PROCESSORS
@@ -44,7 +44,7 @@ jobs:
       - name: Setup dependencies
         run: |
           sudo apt-get update -qq
-          sudo apt-get install -y libsdl2-dev libglew-dev qtbase5-dev
+          sudo apt-get install -y python3-jinja2 python3-lxml libsdl2-dev qtbase5-dev
       - name: Build NanoBoyAdvance
         run: |
           cmake -Bbuild -DCMAKE_BUILD_TYPE=Release
@@ -65,18 +65,22 @@ jobs:
     runs-on: macos-latest
     steps:
       - uses: actions/checkout@v4
+      - uses: actions/setup-python@v5
+        with:
+          python-version: '3.x'
       - name: Setup dependencies
         env:
           HOMEBREW_NO_ANALYTICS: 1
-        run: brew install sdl2 glew qt@5
+        run: |
+          brew install sdl2 qt@5
+          python3 -m pip install Jinja2
       - name: Build NanoBoyAdvance
         run: |
           cmake -Bbuild \
             -DCMAKE_CXX_FLAGS="-s" \
             -DUSE_STATIC_SDL=ON \
-            -DGLEW_USE_STATIC_LIBS=ON \
             -DCMAKE_BUILD_TYPE=Release \
-            -DCMAKE_PREFIX_PATH="$(brew --prefix qt@5);$(brew --prefix glew)" \
+            -DCMAKE_PREFIX_PATH="$(brew --prefix qt@5)" \
             -DMACOS_BUILD_APP_BUNDLE=ON \
             -DMACOS_BUNDLE_QT=ON
           cd build
@@ -104,18 +108,22 @@ jobs:
     runs-on: macos-14
     steps:
       - uses: actions/checkout@v4
+      - uses: actions/setup-python@v5
+        with:
+          python-version: '3.x'
       - name: Setup dependencies
         env:
           HOMEBREW_NO_ANALYTICS: 1
-        run: brew install sdl2 glew qt@5
+        run: |
+          brew install sdl2 qt@5
+          python3 -m pip install Jinja2
       - name: Build NanoBoyAdvance
         run: |
           cmake -Bbuild \
             -DCMAKE_CXX_FLAGS="-s" \
             -DUSE_STATIC_SDL=ON \
-            -DGLEW_USE_STATIC_LIBS=ON \
             -DCMAKE_BUILD_TYPE=Release \
-            -DCMAKE_PREFIX_PATH="$(brew --prefix qt@5);$(brew --prefix glew)" \
+            -DCMAKE_PREFIX_PATH="$(brew --prefix qt@5)" \
             -DMACOS_BUILD_APP_BUNDLE=ON \
             -DMACOS_BUNDLE_QT=ON
           cd build

From 44523312e623d71fdd5335b4c10350aa0a1fd71b Mon Sep 17 00:00:00 2001
From: GranMinigun <11149380+GranMinigun@users.noreply.github.com>
Date: Sun, 10 Mar 2024 16:12:46 +0500
Subject: [PATCH 4/6] Docs: Update compiling instructions

---
 docs/COMPILING.md | 19 ++++++++++---------
 1 file changed, 10 insertions(+), 9 deletions(-)

diff --git a/docs/COMPILING.md b/docs/COMPILING.md
index 36462cc5..2706d9b9 100644
--- a/docs/COMPILING.md
+++ b/docs/COMPILING.md
@@ -4,10 +4,10 @@ NanoBoyAdvance can be compiled on Windows, Linux, and macOS.
 
 - Clang or GCC with C++17 support
 - CMake 3.11 or higher
+- Python modules Jinja and (optionally) lxml
 - OpenGL (usually provided by the operating system)
-- SDL2 library
-- GLEW library
-- Qt5 library
+- SDL 2 library
+- Qt 5 library
 
 ### Source Code
 
@@ -28,13 +28,13 @@ Here is a list of commands for popular distributions and macOS:
 ##### Arch Linux
 
 ```bash
-pacman -S cmake sdl2 glew qt5-base
+pacman -S cmake python-jinja python-lxml sdl2 qt5-base
 ```
 
 ##### Ubuntu or other Debian-derived distribution
 
 ```bash
-apt install cmake libsdl2-dev libglew-dev qtbase5-dev libqt5opengl5-dev
+apt install cmake python3-jinja2 python3-lxml libsdl2-dev qtbase5-dev libqt5opengl5-dev
 ```
 
 ##### macOS
@@ -42,14 +42,15 @@ apt install cmake libsdl2-dev libglew-dev qtbase5-dev libqt5opengl5-dev
 Get [Brew](https://brew.sh/) and run:
 
 ``` bash
-brew install cmake sdl2 glew qt@5
+brew install cmake python@3 sdl2 qt@5
+python3 -m pip install Jinja2
 ```
 
 ##### FreeBSD
 
 ```bash
 su
-pkg install cmake git sdl2 glew qt5 qt5-opengl
+pkg install cmake git py39-Jinja2 py39-lxml sdl2 qt5 qt5-opengl
 ```
 
 #### 2. Setup CMake build directory
@@ -67,7 +68,7 @@ NOTE: the location and name of the `build` directory is arbitrary.
 
 ```
 cd /somewhere/on/your/system/NanoBoyAdvance
-cmake -S . -B build -DCMAKE_BUILD_TYPE=Release -DCMAKE_PREFIX_PATH="$(brew --prefix qt@5);$(brew --prefix glew)"
+cmake -S . -B build -DCMAKE_BUILD_TYPE=Release -DCMAKE_PREFIX_PATH="$(brew --prefix qt@5)"
 ```
 
 NOTE: the location and name of the `build` directory is arbitrary.
@@ -94,7 +95,7 @@ This guide uses [MSYS2](https://www.msys2.org/) to install Mingw-w64 and other d
 In your MSYS2 command line, run:
 
 ```bash
-pacman -S make mingw-w64-x86_64-gcc mingw-w64-x86_64-cmake mingw-w64-x86_64-SDL2 mingw-w64-x86_64-glew mingw-w64-x86_64-qt5-static
+pacman -S make mingw-w64-x86_64-gcc mingw-w64-x86_64-cmake mingw-w64-x86_64-python-jinja mingw-w64-x86_64-python-lxml mingw-w64-x86_64-SDL2 mingw-w64-x86_64-qt5-static
 ```
 
 #### 2. Setup CMake build directory

From 64127069a5de9955a524811325f0578126b556c7 Mon Sep 17 00:00:00 2001
From: GranMinigun <11149380+GranMinigun@users.noreply.github.com>
Date: Mon, 26 Feb 2024 03:49:11 +0500
Subject: [PATCH 5/6] Qt: Replace QOpenGLWidget with QWidget

---
 .../core/src/device/ogl_video_device.cpp      |  7 +-
 src/platform/qt/CMakeLists.txt                |  4 +-
 src/platform/qt/src/widget/main_window.cpp    | 22 ++---
 src/platform/qt/src/widget/screen.cpp         | 82 ++++++++++++-------
 src/platform/qt/src/widget/screen.hpp         | 18 ++--
 5 files changed, 77 insertions(+), 56 deletions(-)

diff --git a/src/platform/core/src/device/ogl_video_device.cpp b/src/platform/core/src/device/ogl_video_device.cpp
index 05e6dffa..a4a68711 100644
--- a/src/platform/core/src/device/ogl_video_device.cpp
+++ b/src/platform/core/src/device/ogl_video_device.cpp
@@ -62,8 +62,7 @@ void OGLVideoDevice::Initialize() {
   glGenFramebuffers(1, &fbo);
   glGenTextures(textures.size(), textures.data());
 
-  glClearColor(0, 0, 0, 1);
-  glClear(GL_COLOR_BUFFER_BIT);
+  glClearColor(0.0, 0.0, 0.0, 1.0);
 
   ReloadConfig();
 }
@@ -352,14 +351,16 @@ void OGLVideoDevice::Draw(u32* buffer) {
       copy_area_y      = view_y;
       copy_area_width  = view_width;
       copy_area_height = view_height;
+      glBindFramebuffer(GL_READ_FRAMEBUFFER, default_fbo);
+      glReadBuffer(GL_BACK);
     } else {
       glBindFramebuffer(GL_READ_FRAMEBUFFER, fbo);
       glFramebufferTexture2D(GL_READ_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, textures[output_index], 0);
+      glReadBuffer(GL_COLOR_ATTACHMENT0);
     }
 
     glActiveTexture(GL_TEXTURE0);
     glBindTexture(GL_TEXTURE_2D, textures[history_index]);
-    glReadBuffer(GL_COLOR_ATTACHMENT0);
     glCopyTexSubImage2D(GL_TEXTURE_2D, 0, 0, 0, copy_area_x, copy_area_y, copy_area_width, copy_area_height);
   }
 }
diff --git a/src/platform/qt/CMakeLists.txt b/src/platform/qt/CMakeLists.txt
index 056419e4..a28a2833 100644
--- a/src/platform/qt/CMakeLists.txt
+++ b/src/platform/qt/CMakeLists.txt
@@ -47,8 +47,8 @@ option(USE_QT6 "Use Qt 6" OFF)
 option(PORTABLE_MODE "Portable Mode" ON)
 
 if(USE_QT6)
-  find_package(Qt6 COMPONENTS Core Gui Widgets OpenGL OpenGLWidgets REQUIRED)
-  set(QT_DEPS Qt6::Core Qt6::Gui Qt6::Widgets Qt6::OpenGL Qt6::OpenGLWidgets)
+  find_package(Qt6 COMPONENTS Core Gui Widgets OpenGL REQUIRED)
+  set(QT_DEPS Qt6::Core Qt6::Gui Qt6::Widgets Qt6::OpenGL)
 else()
   find_package(Qt5 COMPONENTS Core Gui Widgets OpenGL REQUIRED)
   set(QT_DEPS Qt5::Core Qt5::Gui Qt5::Widgets Qt5::OpenGL)
diff --git a/src/platform/qt/src/widget/main_window.cpp b/src/platform/qt/src/widget/main_window.cpp
index 9085f4b3..a13d9d92 100644
--- a/src/platform/qt/src/widget/main_window.cpp
+++ b/src/platform/qt/src/widget/main_window.cpp
@@ -20,6 +20,7 @@
 #include <QKeyEvent>
 #include <QLocale>
 #include <QStatusBar>
+#include <QWindow>
 #include <unordered_map>
 
 #include "widget/main_window.hpp"
@@ -40,10 +41,12 @@ MainWindow::MainWindow(
   setWindowTitle(base_window_title);
   setAcceptDrops(true);
 
+  config->Load();
+
   screen = std::make_shared<Screen>(this, config);
   setCentralWidget(screen.get());
-
-  config->Load();
+  screen->windowHandle()->create();
+  screen->Initialize();
 
   auto menu_bar = new QMenuBar(this);
   setMenuBar(menu_bar);
@@ -694,10 +697,6 @@ void MainWindow::ApplyPauseState() {
   const bool window_inactive_and_should_pause = !isActiveWindow() && config->window.pause_emulator_when_inactive;
   const bool paused = pause_action->isChecked() || window_inactive_and_should_pause;
 
-  if(!paused) {
-    screen->SetForceClear(false);
-  }
-
   emu_thread->SetPause(paused);
   config->audio_dev->SetPause(paused);
 }
@@ -706,7 +705,9 @@ void MainWindow::Stop() {
   if(emu_thread->IsRunning()) {
     core = emu_thread->Stop();
     config->audio_dev->Close();
-    screen->SetForceClear(true);
+
+    // Clear the screen.
+    screen->Draw(nullptr);
 
     // Clear the list of save state slots:
     game_loaded = false;
@@ -832,13 +833,6 @@ void MainWindow::LoadROM(std::u16string const& path) {
   core->Reset();
   emu_thread->Start(std::move(core));
 
-  /**
-   * If the the emulator is paused we force-clear the screen to avoid 
-   * presenting the last frame from before pausing, since that could be confusing.
-   * In the other case we explicitly disable force-clear, because it is currently enabled (due to the call to Stop() at the top).
-   */
-  screen->SetForceClear(pause_action->isChecked());
-
   UpdateSolarSensorLevel();
   UpdateMenuBarVisibility();
 }
diff --git a/src/platform/qt/src/widget/screen.cpp b/src/platform/qt/src/widget/screen.cpp
index cc827998..867c3155 100644
--- a/src/platform/qt/src/widget/screen.cpp
+++ b/src/platform/qt/src/widget/screen.cpp
@@ -9,26 +9,42 @@
 
 #include <glad/gl.h>
 #include <QOpenGLContext> // Has to go after glad.
+#include <QWindow>
 
 Screen::Screen(
   QWidget* parent,
   std::shared_ptr<QtConfig> config
-)   : QOpenGLWidget(parent)
+)   : QWidget(parent)
     , ogl_video_device(config)
     , config(config) {
   connect(this, &Screen::RequestDraw, this, &Screen::OnRequestDraw);
+  setAttribute(Qt::WA_NativeWindow);
+  setAttribute(Qt::WA_OpaquePaintEvent);
+  setAttribute(Qt::WA_PaintOnScreen);
+  windowHandle()->setSurfaceType(QWindow::OpenGLSurface);
 }
 
-void Screen::Draw(u32* buffer) {
-  emit RequestDraw(buffer);
+static auto get_proc_address(const char* proc_name) {
+  return QOpenGLContext::currentContext()->getProcAddress(proc_name);
 }
 
-void Screen::SetForceClear(bool force_clear) {
-  this->force_clear = force_clear;
-  update();
+void Screen::Initialize() {
+  context = new QOpenGLContext();
+  context->create();
+  context->makeCurrent(this->windowHandle());
+
+  gladLoadGL(get_proc_address);
+  ogl_video_device.Initialize();
+
+  context->doneCurrent();
+}
+
+void Screen::Draw(u32* buffer) {
+  emit RequestDraw(buffer);
 }
 
 void Screen::ReloadConfig() {
+  context->makeCurrent(this->windowHandle());
   ogl_video_device.ReloadConfig();
   UpdateViewport();
 }
@@ -38,7 +54,36 @@ void Screen::OnRequestDraw(u32* buffer) {
   update();
 }
 
+void Screen::paintEvent([[maybe_unused]] QPaintEvent* event) {
+  Render();
+}
+
+void Screen::resizeEvent([[maybe_unused]] QResizeEvent* event) {
+  UpdateViewport();
+}
+
+void Screen::Render() {
+  if(!context) {
+    return;
+  }
+
+  context->makeCurrent(this->windowHandle());
+  glClear(GL_COLOR_BUFFER_BIT);
+
+  if(buffer) {
+    ogl_video_device.SetDefaultFBO(context->defaultFramebufferObject());
+    ogl_video_device.Draw(buffer);
+  }
+
+  context->swapBuffers(this->windowHandle());
+  context->doneCurrent();
+}
+
 void Screen::UpdateViewport() {
+  if(!context) {
+    return;
+  }
+
   auto dpr = devicePixelRatio();
   int width  = size().width()  * dpr;
   int height = size().height() * dpr;
@@ -91,28 +136,7 @@ void Screen::UpdateViewport() {
   viewport_x = (width  - viewport_width ) / 2;
   viewport_y = (height - viewport_height) / 2;
 
+  context->makeCurrent(this->windowHandle());
   ogl_video_device.SetViewport(viewport_x, viewport_y, viewport_width, viewport_height);
-}
-
-static auto get_proc_address(const char* proc_name) {
-  return QOpenGLContext::currentContext()->getProcAddress(proc_name);
-}
-
-void Screen::initializeGL() {
-  gladLoadGL(get_proc_address);
-  ogl_video_device.Initialize();
-}
-
-void Screen::paintGL() {
-  if(force_clear) {
-    glClearColor(0.0, 0.0, 0.0, 0.0);
-    glClear(GL_COLOR_BUFFER_BIT);
-  } else if(buffer != nullptr) {
-    ogl_video_device.SetDefaultFBO(defaultFramebufferObject());
-    ogl_video_device.Draw(buffer);
-  }
-}
-
-void Screen::resizeGL(int width, int height) {
-  UpdateViewport();
+  context->doneCurrent();
 }
diff --git a/src/platform/qt/src/widget/screen.hpp b/src/platform/qt/src/widget/screen.hpp
index 02c50ac5..ed16feaa 100644
--- a/src/platform/qt/src/widget/screen.hpp
+++ b/src/platform/qt/src/widget/screen.hpp
@@ -8,19 +8,21 @@
 #pragma once
 
 #include <platform/device/ogl_video_device.hpp>
-#include <QOpenGLWidget>
+#include <QOpenGLContext>
+#include <QWidget>
 
 #include "config.hpp"
 
-struct Screen : QOpenGLWidget, nba::VideoDevice {
-  Screen(
+struct Screen : QWidget, nba::VideoDevice {
+  explicit Screen(
     QWidget* parent,
     std::shared_ptr<QtConfig> config
   );
 
+  void Initialize();
   void Draw(u32* buffer) final;
-  void SetForceClear(bool force_clear);
   void ReloadConfig();
+  QPaintEngine* paintEngine() const override { return nullptr; }; // Silence Qt.
 
 signals:
   void RequestDraw(u32* buffer);
@@ -29,19 +31,19 @@ private slots:
   void OnRequestDraw(u32* buffer);
 
 protected:
-  void initializeGL() override;
-  void paintGL() override;
-  void resizeGL(int width, int height) override;
+  void paintEvent(QPaintEvent* event) override;
+  void resizeEvent(QResizeEvent* event) override;
 
 private:
   static constexpr int kGBANativeWidth = 240;
   static constexpr int kGBANativeHeight = 160;
   static constexpr float kGBANativeAR = static_cast<float>(kGBANativeWidth) / static_cast<float>(kGBANativeHeight);
 
+  void Render();
   void UpdateViewport();
 
   u32* buffer = nullptr;
-  bool force_clear = false;
+  QOpenGLContext* context = nullptr;
   nba::OGLVideoDevice ogl_video_device;
   std::shared_ptr<QtConfig> config;
 

From 0fb4517a398c8667319b0440225e01cc51c46bf9 Mon Sep 17 00:00:00 2001
From: GranMinigun <11149380+GranMinigun@users.noreply.github.com>
Date: Thu, 14 Mar 2024 18:52:58 +0500
Subject: [PATCH 6/6] Qt: Check version of created OpenGL context

---
 src/platform/qt/src/main.cpp               |  6 +++++
 src/platform/qt/src/widget/main_window.cpp | 15 +++++++++--
 src/platform/qt/src/widget/main_window.hpp |  1 +
 src/platform/qt/src/widget/screen.cpp      | 31 +++++++++++++++++++---
 src/platform/qt/src/widget/screen.hpp      |  2 +-
 5 files changed, 48 insertions(+), 7 deletions(-)

diff --git a/src/platform/qt/src/main.cpp b/src/platform/qt/src/main.cpp
index 9a4a6b96..e85cc979 100644
--- a/src/platform/qt/src/main.cpp
+++ b/src/platform/qt/src/main.cpp
@@ -48,6 +48,9 @@ auto create_window(QApplication& app, int argc, char** argv) -> std::unique_ptr<
   }
 
   auto window = std::make_unique<MainWindow>(&app);
+  if(!window->Initialize()) {
+    return nullptr;
+  }
 
   if(!rom.empty()) {
     window->LoadROM(rom.u16string());
@@ -104,6 +107,9 @@ int main(int argc, char** argv) {
   QGuiApplication::setDesktopFileName("io.github.nba_emuNanoBoyAdvance");
 
   auto window = create_window(app, argc, argv);
+  if(!window) {
+    return EXIT_FAILURE;
+  }
 
   return app.exec();
 }
diff --git a/src/platform/qt/src/widget/main_window.cpp b/src/platform/qt/src/widget/main_window.cpp
index a13d9d92..222e3c17 100644
--- a/src/platform/qt/src/widget/main_window.cpp
+++ b/src/platform/qt/src/widget/main_window.cpp
@@ -45,8 +45,6 @@ MainWindow::MainWindow(
 
   screen = std::make_shared<Screen>(this, config);
   setCentralWidget(screen.get());
-  screen->windowHandle()->create();
-  screen->Initialize();
 
   auto menu_bar = new QMenuBar(this);
   setMenuBar(menu_bar);
@@ -93,6 +91,19 @@ MainWindow::~MainWindow() {
   delete controller_manager;
 }
 
+bool MainWindow::Initialize() {
+  screen->windowHandle()->create();
+  if(!screen->Initialize()) {
+    QMessageBox::critical(this, QApplication::instance()->applicationName(),
+                          tr("Failed to initialize graphics subsystem.\n\n"
+                          "Make sure that your hardware supports OpenGL 3.3 or later, "
+                          "and you have the latest driver version installed."));
+    return false;
+  }
+
+  return true;
+}
+
 void MainWindow::CreateFileMenu() {
   auto file_menu = menuBar()->addMenu(tr("File"));
 
diff --git a/src/platform/qt/src/widget/main_window.hpp b/src/platform/qt/src/widget/main_window.hpp
index a5ddead8..32c0be86 100644
--- a/src/platform/qt/src/widget/main_window.hpp
+++ b/src/platform/qt/src/widget/main_window.hpp
@@ -39,6 +39,7 @@ struct MainWindow : QMainWindow {
 
  ~MainWindow();
 
+  bool Initialize();
   void LoadROM(std::u16string const& path);
 
 signals:
diff --git a/src/platform/qt/src/widget/screen.cpp b/src/platform/qt/src/widget/screen.cpp
index 867c3155..8c5a8b45 100644
--- a/src/platform/qt/src/widget/screen.cpp
+++ b/src/platform/qt/src/widget/screen.cpp
@@ -28,15 +28,38 @@ static auto get_proc_address(const char* proc_name) {
   return QOpenGLContext::currentContext()->getProcAddress(proc_name);
 }
 
-void Screen::Initialize() {
+bool Screen::Initialize() {
   context = new QOpenGLContext();
-  context->create();
-  context->makeCurrent(this->windowHandle());
+  if(!context->create()) {
+    delete context;
+    context = nullptr;
+    return false;
+  }
+  if(context->format().majorVersion() < 3 ||
+     context->format().majorVersion() == 3 && context->format().minorVersion() < 3) {
+    delete context;
+    context = nullptr;
+    return false;
+  }
+
+  if(!context->makeCurrent(this->windowHandle())) {
+    delete context;
+    context = nullptr;
+    return false;
+  }
+
+  if(!gladLoadGL(get_proc_address)) {
+    delete context;
+    context = nullptr;
+    return false;
+  }
 
-  gladLoadGL(get_proc_address);
   ogl_video_device.Initialize();
+  UpdateViewport();
 
   context->doneCurrent();
+
+  return true;
 }
 
 void Screen::Draw(u32* buffer) {
diff --git a/src/platform/qt/src/widget/screen.hpp b/src/platform/qt/src/widget/screen.hpp
index ed16feaa..b69bfb74 100644
--- a/src/platform/qt/src/widget/screen.hpp
+++ b/src/platform/qt/src/widget/screen.hpp
@@ -19,7 +19,7 @@ struct Screen : QWidget, nba::VideoDevice {
     std::shared_ptr<QtConfig> config
   );
 
-  void Initialize();
+  bool Initialize();
   void Draw(u32* buffer) final;
   void ReloadConfig();
   QPaintEngine* paintEngine() const override { return nullptr; }; // Silence Qt.