Draw FramebufferWidgets during step() instead of draw() so we can use the same NanoVG context.

include/widget/FramebufferWidget.hpp

@@ -15,19 +15,24 @@ struct FramebufferWidget : Widget {
 	bool dirty = true;
 	float oversample;
 	NVGLUframebuffer *fb = NULL;
+	/** Scale relative to the world */
+	math::Vec scale;
+	/** Offset in world coordinates */
+	math::Vec offset;
 	/** Pixel dimensions of the allocated framebuffer */
 	math::Vec fbSize;
-	/** Bounding box in world coordinates of where the framebuffer should be painted
+	/** Bounding box in world coordinates of where the framebuffer should be painted.
 	Always has integer coordinates so that blitting framebuffers is pixel-perfect.
 	*/
 	math::Rect fbBox;
-	/** Local scale relative to the world scale */
+	/** Framebuffer's scale relative to the world */
 	math::Vec fbScale;
-	/** Subpixel offset of fbBox in world coordinates */
+	/** Framebuffer's subpixel offset relative to fbBox in world coordinates */
 	math::Vec fbOffset;
 
 	FramebufferWidget();
 	~FramebufferWidget();
+	void step() override;
 	void draw(const DrawArgs &args) override;
 	virtual void drawFramebuffer();
 	int getImageHandle();

include/widget/Widget.hpp

@@ -84,6 +84,7 @@ struct Widget {
 	struct DrawArgs {
 		NVGcontext *vg;
 		math::Rect clipBox;
+		NVGLUframebuffer *fb = NULL;
 	};
 
 	/** Draws the widget to the NanoVG context */

include/window.hpp

@@ -74,8 +74,6 @@ DEPRECATED typedef Svg SVG;
 struct Window {
 	GLFWwindow *win = NULL;
 	NVGcontext *vg = NULL;
-	/** Secondary nanovg context for drawing to framebuffers */
-	NVGcontext *fbVg = NULL;
 	/** The scaling ratio */
 	float pixelRatio = 1.f;
 	/* The ratio between the framebuffer size and the window size reported by the OS.

src/app/LedDisplay.cpp

@@ -17,7 +17,7 @@ void LedDisplay::draw(const DrawArgs &args) {
 	nvgFill(args.vg);
 
 	nvgScissor(args.vg, RECT_ARGS(args.clipBox));
-	widget::Widget::draw(args);
+	Widget::draw(args);
 	nvgResetScissor(args.vg);
 }
 

src/app/ModuleBrowser.cpp

@@ -64,11 +64,11 @@ struct BrowserOverlay : widget::OpaqueWidget {
 		box = parent->box.zeroPos();
 		// Only step if visible, since there are potentially thousands of descendants that don't need to be stepped.
 		if (visible)
-			widget::OpaqueWidget::step();
+			OpaqueWidget::step();
 	}
 
 	void onButton(const event::Button &e) override {
-		widget::OpaqueWidget::onButton(e);
+		OpaqueWidget::onButton(e);
 		if (e.getConsumed() != this)
 			return;
 
@@ -189,6 +189,7 @@ struct ModelBox : widget::OpaqueWidget {
 		if (previewWidget && ++visibleFrames >= 60) {
 			deletePreview();
 		}
+		OpaqueWidget::step();
 	}
 
 	void draw(const DrawArgs &args) override {
@@ -210,7 +211,7 @@ struct ModelBox : widget::OpaqueWidget {
 		nvgFill(args.vg);
 
 		nvgScissor(args.vg, RECT_ARGS(args.clipBox));
-		widget::OpaqueWidget::draw(args);
+		OpaqueWidget::draw(args);
 		nvgResetScissor(args.vg);
 
 		// Translucent overlay when selected
@@ -239,7 +240,7 @@ struct BrowserSearchField : ui::TextField {
 	void step() override {
 		// Steal focus when step is called
 		APP->event->setSelected(this);
-		ui::TextField::step();
+		TextField::step();
 	}
 	void onSelectKey(const event::SelectKey &e) override {
 		if (e.action == GLFW_PRESS) {
@@ -316,7 +317,7 @@ struct BrowserSidebar : widget::Widget {
 		tagScroll->box.size.y = (box.size.y - searchField->box.size.y) / 2;
 		tagScroll->box.size.x = box.size.x;
 		tagList->box.size.x = tagScroll->box.size.x;
-		widget::Widget::step();
+		Widget::step();
 	}
 };
 
@@ -363,12 +364,12 @@ struct ModuleBrowser : widget::OpaqueWidget {
 		modelMargin->box.size.x = modelScroll->box.size.x;
 		modelMargin->box.size.y = modelContainer->getChildrenBoundingBox().size.y + 2 * modelMargin->margin.y;
 
-		widget::OpaqueWidget::step();
+		OpaqueWidget::step();
 	}
 
 	void draw(const DrawArgs &args) override {
 		bndMenuBackground(args.vg, 0.0, 0.0, box.size.x, box.size.y, 0);
-		widget::Widget::draw(args);
+		Widget::draw(args);
 	}
 
 	void setSearch(const std::string &search) {
@@ -388,7 +389,7 @@ struct ModuleBrowser : widget::OpaqueWidget {
 
 
 void ModelBox::onButton(const event::Button &e) {
-	widget::OpaqueWidget::onButton(e);
+	OpaqueWidget::onButton(e);
 	if (e.getConsumed() != this)
 		return;
 

src/app/ModuleWidget.cpp

@@ -148,7 +148,7 @@ void ModuleWidget::draw(const DrawArgs &args) {
 		nvgGlobalAlpha(args.vg, 0.25);
 	}
 
-	widget::Widget::draw(args);
+	Widget::draw(args);
 
 	// Power meter
 	if (module && settings.cpuMeter) {

src/app/ParamWidget.cpp

@@ -21,7 +21,7 @@ struct ParamField : ui::TextField {
 	void step() override {
 		// Keep selected
 		APP->event->setSelected(this);
-		ui::TextField::step();
+		TextField::step();
 	}
 
 	void setParamWidget(ParamWidget *paramWidget) {
@@ -54,7 +54,7 @@ struct ParamField : ui::TextField {
 		}
 
 		if (!e.getConsumed())
-			ui::TextField::onSelectKey(e);
+			TextField::onSelectKey(e);
 	}
 };
 
@@ -73,7 +73,7 @@ struct ParamTooltip : ui::Tooltip {
 		}
 		// Position at bottom-right of parameter
 		box.pos = paramWidget->getAbsoluteOffset(paramWidget->box.size).round();
-		ui::Tooltip::step();
+		Tooltip::step();
 	}
 };
 
@@ -82,7 +82,7 @@ struct ParamLabel : ui::MenuLabel {
 	ParamWidget *paramWidget;
 	void step() override {
 		text = paramWidget->paramQuantity->getString();
-		ui::MenuLabel::step();
+		MenuLabel::step();
 	}
 };
 
@@ -138,11 +138,11 @@ void ParamWidget::step() {
 		}
 	}
 
-	widget::OpaqueWidget::step();
+	OpaqueWidget::step();
 }
 
 void ParamWidget::draw(const DrawArgs &args) {
-	widget::Widget::draw(args);
+	Widget::draw(args);
 
 	// if (paramQuantity) {
 	// 	nvgBeginPath(args.vg);
@@ -185,7 +185,7 @@ void ParamWidget::onButton(const event::Button &e) {
 	}
 
 	if (!e.getConsumed())
-		widget::OpaqueWidget::onButton(e);
+		OpaqueWidget::onButton(e);
 }
 
 void ParamWidget::onDoubleClick(const event::DoubleClick &e) {

src/app/PortWidget.cpp

@@ -45,6 +45,8 @@ void PortWidget::step() {
 			values[i] = module->inputs[portId].plugLights[i].getBrightness();
 	}
 	plugLight->setBrightnesses(values);
+
+	OpaqueWidget::step();
 }
 
 void PortWidget::draw(const DrawArgs &args) {
@@ -54,7 +56,7 @@ void PortWidget::draw(const DrawArgs &args) {
 		if (type == OUTPUT ? cw->outputPort : cw->inputPort)
 			nvgGlobalAlpha(args.vg, 0.5);
 	}
-	widget::Widget::draw(args);
+	Widget::draw(args);
 }
 
 void PortWidget::onButton(const event::Button &e) {

src/app/RackScrollWidget.cpp

@@ -24,12 +24,12 @@ void RackScrollWidget::step() {
 		if (pos.y >= viewport.pos.y + viewport.size.y - margin)
 			offset.y += speed;
 	}
-	ui::ScrollWidget::step();
+	ScrollWidget::step();
 }
 
 
 void RackScrollWidget::draw(const DrawArgs &args) {
-	ui::ScrollWidget::draw(args);
+	ScrollWidget::draw(args);
 }
 
 

src/app/RackWidget.cpp

@@ -55,14 +55,14 @@ struct ModuleContainer : widget::Widget {
 			nvgRestore(args.vg);
 		}
 
-		widget::Widget::draw(args);
+		Widget::draw(args);
 	}
 };
 
 
 struct CableContainer : widget::TransparentWidget {
 	void draw(const DrawArgs &args) override {
-		widget::Widget::draw(args);
+		Widget::draw(args);
 
 		// Draw cable plugs
 		for (widget::Widget *w : children) {
@@ -114,11 +114,11 @@ void RackWidget::step() {
 		rail->box.size = rails->box.size;
 	}
 
-	widget::Widget::step();
+	Widget::step();
 }
 
 void RackWidget::draw(const DrawArgs &args) {
-	widget::Widget::draw(args);
+	Widget::draw(args);
 }
 
 void RackWidget::onHover(const event::Hover &e) {

src/app/Scene.cpp

@@ -51,7 +51,7 @@ void Scene::step() {
 		.plus(math::Vec(500, 500))
 		.div(zoomWidget->zoom);
 
-	widget::OpaqueWidget::step();
+	OpaqueWidget::step();
 
 	zoomWidget->box.size = rackWidget->box.size.mult(zoomWidget->zoom);
 
@@ -88,7 +88,7 @@ void Scene::step() {
 }
 
 void Scene::draw(const DrawArgs &args) {
-	widget::OpaqueWidget::draw(args);
+	OpaqueWidget::draw(args);
 }
 
 void Scene::onHoverKey(const event::HoverKey &e) {
@@ -149,7 +149,7 @@ void Scene::onHoverKey(const event::HoverKey &e) {
 	}
 
 	if (!e.getConsumed())
-		widget::OpaqueWidget::onHoverKey(e);
+		OpaqueWidget::onHoverKey(e);
 }
 
 void Scene::onPathDrop(const event::PathDrop &e) {
@@ -162,7 +162,7 @@ void Scene::onPathDrop(const event::PathDrop &e) {
 	}
 
 	if (!e.getConsumed())
-		widget::OpaqueWidget::onPathDrop(e);
+		OpaqueWidget::onPathDrop(e);
 }
 
 void Scene::runCheckVersion() {

src/app/SvgPanel.cpp

@@ -20,7 +20,7 @@ void SvgPanel::step() {
 		// Small details draw poorly at low DPI, so oversample when drawing to the framebuffer
 		oversample = 2.0;
 	}
-	widget::FramebufferWidget::step();
+	FramebufferWidget::step();
 }
 
 void SvgPanel::setBackground(std::shared_ptr<Svg> svg) {

src/app/Toolbar.cpp

@@ -25,7 +25,7 @@ namespace app {
 struct MenuButton : ui::Button {
 	void step() override {
 		box.size.x = bndLabelWidth(APP->window->vg, -1, text.c_str()) + 1.0;
-		widget::Widget::step();
+		Widget::step();
 	}
 	void draw(const DrawArgs &args) override {
 		bndMenuItem(args.vg, 0.0, 0.0, box.size.x, box.size.y, state, -1, text.c_str());
@@ -680,7 +680,7 @@ void Toolbar::draw(const DrawArgs &args) {
 	bndMenuBackground(args.vg, 0.0, 0.0, box.size.x, box.size.y, BND_CORNER_ALL);
 	bndBevel(args.vg, 0.0, 0.0, box.size.x, box.size.y);
 
-	widget::Widget::draw(args);
+	Widget::draw(args);
 }
 
 

src/ui/List.cpp

@@ -6,7 +6,7 @@ namespace ui {
 
 
 void List::step() {
-	widget::Widget::step();
+	Widget::step();
 
 	// Set positions of children
 	box.size.y = 0.0;

src/ui/MarginLayout.cpp

@@ -7,7 +7,7 @@ namespace ui {
 
 
 void MarginLayout::step() {
-	widget::Widget::step();
+	Widget::step();
 
 	math::Rect childBox = box.zeroPos().grow(margin.neg());
 	for (Widget *child : children) {

src/ui/Menu.cpp

@@ -27,7 +27,7 @@ void Menu::setChildMenu(Menu *menu) {
 }
 
 void Menu::step() {
-	widget::Widget::step();
+	Widget::step();
 
 	// Set positions of children
 	box.size = math::Vec(0, 0);
@@ -51,7 +51,7 @@ void Menu::step() {
 
 void Menu::draw(const DrawArgs &args) {
 	bndMenuBackground(args.vg, 0.0, 0.0, box.size.x, box.size.y, BND_CORNER_NONE);
-	widget::Widget::draw(args);
+	Widget::draw(args);
 }
 
 void Menu::onHoverScroll(const event::HoverScroll &e) {

src/ui/MenuItem.cpp

@@ -34,7 +34,7 @@ void MenuItem::step() {
 	// HACK use APP->window->vg from the window.
 	// All this does is inspect the font, so it shouldn't modify APP->window->vg and should work when called from a widget::FramebufferWidget for example.
 	box.size.x = bndLabelWidth(APP->window->vg, -1, text.c_str()) + bndLabelWidth(APP->window->vg, -1, rightText.c_str()) + rightPadding;
-	widget::Widget::step();
+	Widget::step();
 }
 
 void MenuItem::onEnter(const event::Enter &e) {

src/ui/MenuLabel.cpp

@@ -15,7 +15,7 @@ void MenuLabel::step() {
 	const float rightPadding = 10.0;
 	// HACK use APP->window->vg from the window.
 	box.size.x = bndLabelWidth(APP->window->vg, -1, text.c_str()) + rightPadding;
-	widget::Widget::step();
+	Widget::step();
 }
 
 

src/ui/MenuOverlay.cpp

@@ -14,7 +14,7 @@ void MenuOverlay::step() {
 		child->box = child->box.nudge(box.zeroPos());
 	}
 
-	widget::Widget::step();
+	Widget::step();
 }
 
 void MenuOverlay::onButton(const event::Button &e) {

src/ui/ScrollWidget.cpp

@@ -29,12 +29,12 @@ void ScrollWidget::scrollTo(math::Rect r) {
 
 void ScrollWidget::draw(const DrawArgs &args) {
 	nvgScissor(args.vg, RECT_ARGS(args.clipBox));
-	widget::Widget::draw(args);
+	Widget::draw(args);
 	nvgResetScissor(args.vg);
 }
 
 void ScrollWidget::step() {
-	widget::Widget::step();
+	Widget::step();
 
 	// Clamp scroll offset
 	math::Vec containerCorner = container->getChildrenBoundingBox().getBottomRight();

src/ui/SequentialLayout.cpp

@@ -11,7 +11,7 @@ namespace ui {
 
 
 void SequentialLayout::step() {
-	widget::Widget::step();
+	Widget::step();
 
 	// Sort widgets into rows (or columns if vertical)
 	std::vector<std::vector<widget::Widget*>> rows;

src/ui/Tooltip.cpp

@@ -11,13 +11,13 @@ void Tooltip::step() {
 	// Wrap size to contents
 	box.size.x = bndLabelWidth(APP->window->vg, -1, text.c_str()) + 10.0;
 	box.size.y = bndLabelHeight(APP->window->vg, -1, text.c_str(), INFINITY);
-	widget::Widget::step();
+	Widget::step();
 }
 
 void Tooltip::draw(const DrawArgs &args) {
 	bndTooltipBackground(args.vg, 0.0, 0.0, box.size.x, box.size.y);
 	bndMenuLabel(args.vg, 0.0, 0.0, box.size.x, box.size.y, -1, text.c_str());
-	widget::Widget::draw(args);
+	Widget::draw(args);
 }
 
 

src/widget/FramebufferWidget.cpp

@@ -15,31 +15,18 @@ FramebufferWidget::~FramebufferWidget() {
 		nvgluDeleteFramebuffer(fb);
 }
 
-void FramebufferWidget::draw(const DrawArgs &args) {
-	// Bypass framebuffer rendering if we're already drawing in a framebuffer
-	// In other words, disallow nested framebuffers. They look bad.
-	if (args.vg == APP->window->fbVg) {
-		Widget::draw(args);
-		return;
-	}
-
-	// Get world transform
-	float xform[6];
-	nvgCurrentTransform(args.vg, xform);
-	// Skew and rotate is not supported
-	assert(math::isNear(xform[1], 0.f));
-	assert(math::isNear(xform[2], 0.f));
-	// Extract scale and offset from world transform
-	math::Vec scale = math::Vec(xform[0], xform[3]);
-	math::Vec offset = math::Vec(xform[4], xform[5]);
-	math::Vec offsetI = offset.floor();
+void FramebufferWidget::step() {
+	Widget::step();
 
-	// Render to framebuffer
-	if (dirty) {
+	// Render to framebuffer if dirty.
+	// Also check that scale has been set by `draw()` yet.
+	if (dirty && !scale.isZero()) {
+		// In case we fail drawing the framebuffer, don't try again the next frame, so reset `dirty` here.
 		dirty = false;
 
 		fbScale = scale;
-		// World coordinates, in range [0, 1)
+		// Get subpixel offset in range [0, 1)
+		math::Vec offsetI = offset.floor();
 		fbOffset = offset.minus(offsetI);
 
 		math::Rect localBox;
@@ -50,15 +37,16 @@ void FramebufferWidget::draw(const DrawArgs &args) {
 			localBox = getChildrenBoundingBox();
 		}
 
-		// DEBUG("%g %g %g %g, %g %g, %g %g", RECT_ARGS(localBox), VEC_ARGS(fbOffset), VEC_ARGS(scale));
+		// DEBUG("%g %g %g %g, %g %g, %g %g", RECT_ARGS(localBox), VEC_ARGS(fbOffset), VEC_ARGS(fbScale));
 		// Transform to world coordinates, then expand to nearest integer coordinates
-		math::Vec min = localBox.getTopLeft().mult(scale).plus(fbOffset).floor();
-		math::Vec max = localBox.getBottomRight().mult(scale).plus(fbOffset).ceil();
+		math::Vec min = localBox.getTopLeft().mult(fbScale).plus(fbOffset).floor();
+		math::Vec max = localBox.getBottomRight().mult(fbScale).plus(fbOffset).ceil();
 		fbBox = math::Rect::fromMinMax(min, max);
 		// DEBUG("%g %g %g %g", RECT_ARGS(fbBox));
 
 		math::Vec newFbSize = fbBox.size.mult(APP->window->pixelRatio * oversample);
 
+		// Create framebuffer if a new size is needed
 		if (!fb || !newFbSize.isEqual(fbSize)) {
 			fbSize = newFbSize;
 			// Delete old framebuffer
@@ -66,7 +54,7 @@ void FramebufferWidget::draw(const DrawArgs &args) {
 				nvgluDeleteFramebuffer(fb);
 			// Create a framebuffer from the main nanovg context. We will draw to this in the secondary nanovg context.
 			if (fbSize.isFinite() && !fbSize.isZero())
-				fb = nvgluCreateFramebuffer(args.vg, fbSize.x, fbSize.y, 0);
+				fb = nvgluCreateFramebuffer(APP->window->vg, fbSize.x, fbSize.y, 0);
 		}
 
 		if (!fb)
@@ -76,6 +64,25 @@ void FramebufferWidget::draw(const DrawArgs &args) {
 		drawFramebuffer();
 		nvgluBindFramebuffer(NULL);
 	}
+}
+
+void FramebufferWidget::draw(const DrawArgs &args) {
+	// Draw directly if already drawing in a framebuffer
+	if (args.fb) {
+		Widget::draw(args);
+		return;
+	}
+
+	// Get world transform
+	float xform[6];
+	nvgCurrentTransform(args.vg, xform);
+	// Skew and rotate is not supported
+	assert(math::isNear(xform[1], 0.f));
+	assert(math::isNear(xform[2], 0.f));
+	// Extract scale and offset from world transform
+	scale = math::Vec(xform[0], xform[3]);
+	offset = math::Vec(xform[4], xform[5]);
+	math::Vec offsetI = offset.floor();
 
 	if (!fb)
 		return;
@@ -106,7 +113,7 @@ void FramebufferWidget::draw(const DrawArgs &args) {
 }
 
 void FramebufferWidget::drawFramebuffer() {
-	NVGcontext *vg = APP->window->fbVg;
+	NVGcontext *vg = APP->window->vg;
 
 	float pixelRatio = fbSize.x / fbBox.size.x;
 	nvgBeginFrame(vg, fbBox.size.x, fbBox.size.y, pixelRatio);
@@ -119,6 +126,7 @@ void FramebufferWidget::drawFramebuffer() {
 	DrawArgs args;
 	args.vg = vg;
 	args.clipBox = box.zeroPos();
+	args.fb = fb;
 	Widget::draw(args);
 
 	glViewport(0.0, 0.0, fbSize.x, fbSize.y);

src/window.cpp

@@ -275,15 +275,6 @@ Window::Window() {
 		osdialog_message(OSDIALOG_ERROR, OSDIALOG_OK, "Could not initialize NanoVG. Does your graphics card support OpenGL 2.0 or greater? If so, make sure you have the latest graphics drivers installed.");
 		exit(1);
 	}
-
-#if defined NANOVG_GL2
-	fbVg = nvgCreateGL2(nvgFlags);
-#elif defined NANOVG_GL3
-	fbVg = nvgCreateGL3(nvgFlags);
-#elif defined NANOVG_GLES2
-	fbVg = nvgCreateGLES2(nvgFlags);
-#endif
-	assert(fbVg);
 }
 
 Window::~Window() {
@@ -308,14 +299,6 @@ Window::~Window() {
 	nvgDeleteGLES2(vg);
 #endif
 
-#if defined NANOVG_GL2
-	nvgDeleteGL2(fbVg);
-#elif defined NANOVG_GL3
-	nvgDeleteGL3(fbVg);
-#elif defined NANOVG_GLES2
-	nvgDeleteGLES2(fbVg);
-#endif
-
 	glfwDestroyWindow(win);
 	delete internal;
 }