@@ -121,6 +121,7 @@ - GB Memory: Support manual SRAM editing (fixes mgba.io/i/1580)
  - GBA: Trim non-movie ROMs to 32 MiB if applicable
  - GBA Audio: Redo channel 4 batching for GBA only
  - GBA I/O: Stop logging several harmless invalid register reads
+ - GBA Video: Changing OpenGL scaling no longer requires restart
  - Debugger: Separate aliases from main commands
  - Debugger: Print break-/watchpoint ID when breaking in CLI
  - Debugger: Minor interface cleanup

@@ -196,6 +196,7 @@ int scale;
 };
 
 void GBAVideoGLRendererCreate(struct GBAVideoGLRenderer* renderer);
+void GBAVideoGLRendererSetScale(struct GBAVideoGLRenderer* renderer, int scale);
 
 #endif
 

@@ -347,6 +347,20 @@ gba->allowOpposingDirections = fakeBool;
 		}
 		return;
 	}
+#if defined(BUILD_GLES2) || defined(BUILD_GLES3)
+	struct GBACore* gbacore = (struct GBACore*) core;
+	if (strcmp("videoScale", option) == 0) {
+		if (config != &core->config) {
+			mCoreConfigCopyValue(&core->config, config, "videoScale");
+		}
+		if (gbacore->glRenderer.outputTex != (unsigned) -1 && mCoreConfigGetIntValue(&core->config, "hwaccelVideo", &fakeBool) && fakeBool) {
+			int scale;
+			mCoreConfigGetIntValue(config, "videoScale", &scale);
+			GBAVideoGLRendererSetScale(&gbacore->glRenderer, scale);
+		}
+		return;
+	}
+#endif
 }
 
 static void _GBACoreDesiredVideoDimensions(struct mCore* core, unsigned* width, unsigned* height) {

@@ -755,19 +755,7 @@ static void _initFramebufferTexture(GLuint tex, GLenum format, GLenum attachment, int scale) {
 	_initFramebufferTextureEx(tex, format, format, GL_UNSIGNED_BYTE, attachment, scale);
 }
 
-void GBAVideoGLRendererInit(struct GBAVideoRenderer* renderer) {
-	struct GBAVideoGLRenderer* glRenderer = (struct GBAVideoGLRenderer*) renderer;
-	glRenderer->temporaryBuffer = NULL;
-
-	glGenFramebuffers(GBA_GL_FBO_MAX, glRenderer->fbo);
-	glGenTextures(GBA_GL_TEX_MAX, glRenderer->layers);
-
-	glGenTextures(1, &glRenderer->vramTex);
-	glBindTexture(GL_TEXTURE_2D, glRenderer->vramTex);
-	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
-	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
-	glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA4, 256, 192, 0, GL_RGBA, GL_UNSIGNED_SHORT_4_4_4_4, 0);
-
+static void _initFramebuffers(struct GBAVideoGLRenderer* glRenderer) {
 	glBindFramebuffer(GL_FRAMEBUFFER, glRenderer->fbo[GBA_GL_FBO_OBJ]);
 	_initFramebufferTexture(glRenderer->layers[GBA_GL_TEX_OBJ_COLOR], GL_RGBA, GL_COLOR_ATTACHMENT0, glRenderer->scale);
 	_initFramebufferTextureEx(glRenderer->layers[GBA_GL_TEX_OBJ_FLAGS], GL_RGBA8I, GL_RGBA_INTEGER, GL_BYTE, GL_COLOR_ATTACHMENT1, glRenderer->scale);
@@ -784,7 +772,28 @@
 	glBindFramebuffer(GL_FRAMEBUFFER, glRenderer->fbo[GBA_GL_FBO_OUTPUT]);
 	_initFramebufferTexture(glRenderer->outputTex, GL_RGB, GL_COLOR_ATTACHMENT0, glRenderer->scale);
 
+	int i;
+	for (i = 0; i < 4; ++i) {
+		struct GBAVideoGLBackground* bg = &glRenderer->bg[i];
+		glBindFramebuffer(GL_FRAMEBUFFER, bg->fbo);
+		_initFramebufferTexture(bg->tex, GL_RGBA, GL_COLOR_ATTACHMENT0, glRenderer->scale);
+		_initFramebufferTextureEx(bg->flags, GL_RGBA8I, GL_RGBA_INTEGER, GL_BYTE, GL_COLOR_ATTACHMENT1, glRenderer->scale);
+	}
 	glBindFramebuffer(GL_FRAMEBUFFER, 0);
+}
+
+void GBAVideoGLRendererInit(struct GBAVideoRenderer* renderer) {
+	struct GBAVideoGLRenderer* glRenderer = (struct GBAVideoGLRenderer*) renderer;
+	glRenderer->temporaryBuffer = NULL;
+
+	glGenFramebuffers(GBA_GL_FBO_MAX, glRenderer->fbo);
+	glGenTextures(GBA_GL_TEX_MAX, glRenderer->layers);
+
+	glGenTextures(1, &glRenderer->vramTex);
+	glBindTexture(GL_TEXTURE_2D, glRenderer->vramTex);
+	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
+	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
+	glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA4, 256, 192, 0, GL_RGBA, GL_UNSIGNED_SHORT_4_4_4_4, 0);
 
 	glGenBuffers(1, &glRenderer->vbo);
 	glBindBuffer(GL_ARRAY_BUFFER, glRenderer->vbo);
@@ -817,11 +826,9 @@ bg->affine.sy = 0;
 		glGenFramebuffers(1, &bg->fbo);
 		glGenTextures(1, &bg->tex);
 		glGenTextures(1, &bg->flags);
-		glBindFramebuffer(GL_FRAMEBUFFER, bg->fbo);
-		_initFramebufferTexture(bg->tex, GL_RGBA, GL_COLOR_ATTACHMENT0, glRenderer->scale);
-		_initFramebufferTextureEx(bg->flags, GL_RGBA8I, GL_RGBA_INTEGER, GL_BYTE, GL_COLOR_ATTACHMENT1, glRenderer->scale);
 	}
-	glBindFramebuffer(GL_FRAMEBUFFER, 0);
+
+	_initFramebuffers(glRenderer);
 
 	char log[2048];
 	const GLchar* shaderBuffer[4];
@@ -1849,6 +1856,19 @@ glUniform4iv(uniforms[GBA_GL_WIN_WIN0], GBA_VIDEO_VERTICAL_PIXELS, renderer->winNHistory[0]);
 	glUniform4iv(uniforms[GBA_GL_WIN_WIN1], GBA_VIDEO_VERTICAL_PIXELS, renderer->winNHistory[1]);
 	glDrawBuffers(1, (GLenum[]) { GL_COLOR_ATTACHMENT0 });
 	glDrawArrays(GL_TRIANGLE_FAN, 0, 4);
+}
+
+void GBAVideoGLRendererSetScale(struct GBAVideoGLRenderer* renderer, int scale) {
+	if (scale == renderer->scale) {
+		return;
+	}
+	if (renderer->temporaryBuffer) {
+		mappedMemoryFree(renderer->temporaryBuffer, GBA_VIDEO_HORIZONTAL_PIXELS * GBA_VIDEO_VERTICAL_PIXELS * renderer->scale * renderer->scale * BYTES_PER_PIXEL);
+		renderer->temporaryBuffer = NULL;
+	}
+	renderer->scale = scale;
+	_initFramebuffers(renderer);
+	renderer->paletteDirty = true;
 }
 
 #endif

@@ -51,6 +51,7 @@ virtual bool isDrawing() const = 0;
 	virtual bool supportsShaders() const = 0;
 	virtual VideoShader* shaders() = 0;
 	virtual int framebufferHandle() { return -1; }
+	virtual void setVideoScale(int scale) {}
 
 	virtual void setVideoProxy(std::shared_ptr<VideoProxy> proxy) { m_videoProxy = proxy; }
 	std::shared_ptr<VideoProxy> videoProxy() { return m_videoProxy; }

@@ -218,11 +218,19 @@ void DisplayGL::clearShaders() {
 	QMetaObject::invokeMethod(m_painter, "clearShaders");
 }
 
-
 void DisplayGL::resizeContext() {
 	if (m_drawThread) {
 		m_isDrawing = false;
 		CoreController::Interrupter interrupter(m_context);
+		QMetaObject::invokeMethod(m_painter, "resizeContext", Qt::BlockingQueuedConnection);
+	}
+}
+
+void DisplayGL::setVideoScale(int scale) {
+	if (m_drawThread) {
+		m_isDrawing = false;
+		CoreController::Interrupter interrupter(m_context);
+		mCoreConfigSetIntValue(&m_context->thread()->core->config, "videoScale", scale);
 		QMetaObject::invokeMethod(m_painter, "resizeContext", Qt::BlockingQueuedConnection);
 	}
 }
@@ -347,6 +355,9 @@ void PainterGL::resizeContext() {
 	if (!m_context) {
 		return;
 	}
+
+	mCore* core = m_context->thread()->core;
+	core->reloadConfigOption(core, "videoScale", NULL);
 
 	QSize size = m_context->screenDimensions();
 	m_backend->setDimensions(m_backend, size.width(), size.height());

@@ -62,6 +62,7 @@ void framePosted() override;
 	void setShaders(struct VDir*) override;
 	void clearShaders() override;
 	void resizeContext() override;
+	void setVideoScale(int scale) override;
 
 protected:
 	virtual void paintEvent(QPaintEvent*) override { forceDraw(); }

@@ -494,7 +494,7 @@ }
 
 	int videoScale = m_controller->getOption("videoScale", 1).toInt();
 	int hwaccelVideo = m_controller->getOption("hwaccelVideo").toInt();
-	if (videoScale != m_ui.videoScale->value() || hwaccelVideo != m_ui.hwaccelVideo->currentIndex()) {
+	if (hwaccelVideo != m_ui.hwaccelVideo->currentIndex()) {
 		emit videoRendererChanged();
 	}
 	saveSetting("videoScale", m_ui.videoScale);

@@ -1617,6 +1617,13 @@ m_display->showOSDMessages(value.toBool());
 		}
 	}, this);
 
+	ConfigOption* videoScale = m_config->addOption("videoScale");
+	videoScale->connect([this](const QVariant& value) {
+		if (m_display) {
+			m_display->setVideoScale(value.toInt());
+		}
+	}, this);
+
 	m_actions.addHiddenAction(tr("Exit fullscreen"), "exitFullScreen", this, &Window::exitFullScreen, "frame", QKeySequence("Esc"));
 
 	m_actions.addHeldAction(tr("GameShark Button (held)"), "holdGSButton", [this](bool held) {