From f3744c4ba3ddadd47e280a1ef5fbd002d357d10a Mon Sep 17 00:00:00 2001
From: Ilya Fedin <fedin-ilja2010@ya.ru>
Date: Sun, 5 Mar 2023 15:23:26 +0400
Subject: [PATCH] Use paintGL instead of paintEvent

Hopefully making GL code less crashy by using the respective initialization code
---
 ui/gl/gl_surface.cpp | 19 +++----------------
 1 file changed, 3 insertions(+), 16 deletions(-)

diff --git a/ui/gl/gl_surface.cpp b/ui/gl/gl_surface.cpp
index fc45dd6..cd57156 100644
--- a/ui/gl/gl_surface.cpp
+++ b/ui/gl/gl_surface.cpp
@@ -12,7 +12,6 @@
 #include <QtGui/QtEvents>
 #include <QtGui/QOpenGLContext>
 #include <QtGui/QWindow>
-#include <QtGui/QPaintEngine>
 #include <QOpenGLWidget>
 
 namespace Ui::GL {
@@ -31,7 +30,7 @@ public:
 private:
 	void initializeGL() override;
 	void resizeGL(int w, int h) override;
-	void paintEvent(QPaintEvent *e) override;
+	void paintGL() override;
 	void callDeInit();
 
 	const std::unique_ptr<Renderer> _renderer;
@@ -55,6 +54,7 @@ SurfaceOpenGL::SurfaceOpenGL(
 	std::unique_ptr<Renderer> renderer)
 : RpWidgetBase<QOpenGLWidget, SurfaceTraits>(parent)
 , _renderer(std::move(renderer)) {
+	setUpdateBehavior(QOpenGLWidget::PartialUpdate);
 }
 
 SurfaceOpenGL::~SurfaceOpenGL() {
@@ -79,30 +79,17 @@ void SurfaceOpenGL::resizeGL(int w, int h) {
 	_renderer->resize(this, *context()->functions(), w, h);
 }
 
-void SurfaceOpenGL::paintEvent(QPaintEvent *e) {
+void SurfaceOpenGL::paintGL() {
 	if (!updatesEnabled() || size().isEmpty() || !isValid()) {
 		return;
 	}
-	auto redirectOffset = QPoint();
-	const auto rpd = redirected(&redirectOffset);
-	const auto device = rpd ? rpd : static_cast<QPaintDevice*>(this);
-	const auto engine = device->paintEngine();
-	if (!engine) {
-		return;
-	}
-	engine->begin(device);
-	if (!isValid()) { // The call above could lose the context.
-		return;
-	}
 	const auto f = context()->functions();
 	if (const auto bg = _renderer->clearColor()) {
 		f->glClearColor(bg->redF(), bg->greenF(), bg->blueF(), bg->alphaF());
 		f->glClear(GL_COLOR_BUFFER_BIT);
 	}
 	f->glDisable(GL_BLEND);
-	f->glViewport(0, 0, device->width(), device->height());
 	_renderer->paint(this, *f);
-	engine->end();
 }
 
 void SurfaceOpenGL::callDeInit() {