M src/platform/qt/Display.cpp → src/platform/qt/Display.cpp

@@ -64,7 +64,7 @@ }
 
 void Display::resizeEvent(QResizeEvent* event) {
 	if (m_painter) {
-		m_painter->resize(event->size());
+		QMetaObject::invokeMethod(m_painter, "resize", Qt::BlockingQueuedConnection, Q_ARG(QSize, event->size()));
 	}
 }
 
@@ -86,6 +86,11 @@ }
 
 void Painter::resize(const QSize& size) {
 	m_size = size;
+	m_gl->makeCurrent();
+	glViewport(0, 0, m_size.width() * m_gl->devicePixelRatio(), m_size.height() * m_gl->devicePixelRatio());
+	glDrawArrays(GL_TRIANGLE_FAN, 0, 4);
+	m_gl->swapBuffers();
+	m_gl->doneCurrent();
 }
 
 void Painter::start() {

M src/platform/qt/Display.h → src/platform/qt/Display.h

@@ -39,12 +39,12 @@
 	void setContext(GBAThread*);
 	void setBacking(const uint32_t*);
 	void setGLContext(QGLWidget*);
-	void resize(const QSize& size);
 
 public slots:
 	void draw();
 	void start();
 	void stop();
+	void resize(const QSize& size);
 
 private:
 	QTimer* m_drawTimer;