Make FramebufferWidget draw the framebuffer in draw() instead of step().

include/widget/FramebufferWidget.hpp

@@ -31,7 +31,6 @@ struct FramebufferWidget : Widget {
 	int getImageHandle();
 	NVGLUframebuffer* getFramebuffer();
 	math::Vec getFramebufferSize();
-	void setScale(math::Vec scale);
 	void onContextCreate(const ContextCreateEvent& e) override;
 	void onContextDestroy(const ContextDestroyEvent& e) override;
 };

include/window.hpp

@@ -50,6 +50,7 @@ struct Window {
 
 	GLFWwindow* win = NULL;
 	NVGcontext* vg = NULL;
+	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/widget/FramebufferWidget.cpp

@@ -10,15 +10,6 @@ namespace widget {
 struct FramebufferWidget::Internal {
 	NVGLUframebuffer* fb = NULL;
 
-	// Set by draw()
-
-	/** Scale relative to the world */
-	math::Vec scale;
-	/** Subpixel offset in world coordinates */
-	math::Vec offsetF;
-
-	// Set by step() and drawFramebuffer()
-
 	/** Pixel dimensions of the allocated framebuffer */
 	math::Vec fbSize;
 	/** Bounding box in world coordinates of where the framebuffer should be painted.
@@ -60,115 +51,11 @@ void FramebufferWidget::onDirty(const DirtyEvent& e) {
 
 void FramebufferWidget::step() {
 	Widget::step();
-
-	// It's more important to not lag the frame than to draw the framebuffer
-	if (APP->window->getFrameTimeOverdue() > 0.0)
-		return;
-
-	// Check that scale has been set by `draw()` yet.
-	if (internal->scale.isZero())
-		return;
-
-	// Only redraw if FramebufferWidget is dirty
-	if (!dirty)
-		return;
-
-	// In case we fail drawing the framebuffer, don't try again the next frame, so reset `dirty` here.
-	dirty = false;
-	NVGcontext* vg = APP->window->vg;
-
-	internal->fbScale = internal->scale;
-	internal->fbOffsetF = internal->offsetF;
-
-	math::Rect localBox;
-	if (children.empty()) {
-		localBox = box.zeroPos();
-	}
-	else {
-		localBox = getVisibleChildrenBoundingBox();
-	}
-
-	// DEBUG("rendering FramebufferWidget localBox (%g %g %g %g) fbOffset (%g %g) fbScale (%g %g)", RECT_ARGS(localBox), VEC_ARGS(internal->fbOffsetF), VEC_ARGS(internal->fbScale));
-	// Transform to world coordinates, then expand to nearest integer coordinates
-	math::Vec min = localBox.getTopLeft().mult(internal->fbScale).plus(internal->fbOffsetF).floor();
-	math::Vec max = localBox.getBottomRight().mult(internal->fbScale).plus(internal->fbOffsetF).ceil();
-	internal->fbBox = math::Rect::fromMinMax(min, max);
-	// DEBUG("%g %g %g %g", RECT_ARGS(internal->fbBox));
-
-	math::Vec newFbSize = internal->fbBox.size.mult(APP->window->pixelRatio).ceil();
-
-	// Create framebuffer if a new size is needed
-	if (!internal->fb || !newFbSize.equals(internal->fbSize)) {
-		internal->fbSize = newFbSize;
-		// Delete old framebuffer
-		if (internal->fb) {
-			nvgluDeleteFramebuffer(internal->fb);
-			internal->fb = NULL;
-		}
-		// Create a framebuffer
-		if (internal->fbSize.isFinite() && !internal->fbSize.isZero()) {
-			internal->fb = nvgluCreateFramebuffer(vg, internal->fbSize.x, internal->fbSize.y, 0);
-			// DEBUG("Created framebuffer of size (%f, %f)", VEC_ARGS(internal->fbSize));
-		}
-	}
-	if (!internal->fb) {
-		WARN("Framebuffer of size (%f, %f) could not be created for FramebufferWidget %p.", VEC_ARGS(internal->fbSize), this);
-		return;
-	}
-
-	// Render to framebuffer
-	if (oversample == 1.0) {
-		// If not oversampling, render directly to framebuffer.
-		nvgluBindFramebuffer(internal->fb);
-		drawFramebuffer();
-		nvgluBindFramebuffer(NULL);
-	}
-	else {
-		NVGLUframebuffer* fb = internal->fb;
-		// If oversampling, create another framebuffer and copy it to actual size.
-		math::Vec oversampledFbSize = internal->fbSize.mult(oversample).ceil();
-		NVGLUframebuffer* oversampledFb = nvgluCreateFramebuffer(vg, oversampledFbSize.x, oversampledFbSize.y, 0);
-
-		if (!oversampledFb) {
-			WARN("Oversampled framebuffer of size (%f, %f) could not be created for FramebufferWidget %p.", VEC_ARGS(oversampledFbSize), this);
-			return;
-		}
-
-		// Render to oversampled framebuffer.
-		nvgluBindFramebuffer(oversampledFb);
-		internal->fb = oversampledFb;
-		drawFramebuffer();
-		internal->fb = fb;
-		nvgluBindFramebuffer(NULL);
-
-		// Use NanoVG for resizing framebuffers
-		nvgluBindFramebuffer(internal->fb);
-
-		nvgBeginFrame(vg, internal->fbBox.size.x, internal->fbBox.size.y, 1.0);
-
-		// Draw oversampled framebuffer
-		nvgBeginPath(vg);
-		nvgRect(vg, 0.0, 0.0, internal->fbSize.x, internal->fbSize.y);
-		NVGpaint paint = nvgImagePattern(vg, 0.0, 0.0,
-			internal->fbSize.x, internal->fbSize.y,
-			0.0, oversampledFb->image, 1.0);
-		nvgFillPaint(vg, paint);
-		nvgFill(vg);
-
-		glViewport(0.0, 0.0, internal->fbSize.x, internal->fbSize.y);
-		glClearColor(0.0, 0.0, 0.0, 0.0);
-		glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT | GL_STENCIL_BUFFER_BIT);
-		nvgEndFrame(vg);
-		nvgReset(vg);
-
-		nvgluBindFramebuffer(NULL);
-		nvgluDeleteFramebuffer(oversampledFb);
-	}
 }
 
 
 void FramebufferWidget::draw(const DrawArgs& args) {
-	// Draw directly if already drawing in a framebuffer
+	// Draw directly if bypassed or already drawing in a framebuffer
 	if (bypassed || args.fb) {
 		Widget::draw(args);
 		return;
@@ -184,30 +71,132 @@ void FramebufferWidget::draw(const DrawArgs& args) {
 	}
 
 	// Extract scale and offset from world transform
-	internal->scale = math::Vec(xform[0], xform[3]);
+	math::Vec scale = math::Vec(xform[0], xform[3]);
 	math::Vec offset = math::Vec(xform[4], xform[5]);
 	math::Vec offsetI = offset.floor();
-	internal->offsetF = offset.minus(offsetI);
+	math::Vec offsetF = offset.minus(offsetI);
 
 	// If drawing to a new subpixel location, rerender in the next frame.
 	// Anything less than 0.1 pixels isn't noticeable.
-	math::Vec offsetFDelta = internal->offsetF.minus(internal->fbOffsetF);
+	math::Vec offsetFDelta = offsetF.minus(internal->fbOffsetF);
 	if (offsetFDelta.square() >= std::pow(0.1f, 2) && dirtyOnSubpixelChange && APP->window->fbDirtyOnSubpixelChange()) {
-		// DEBUG("%p dirty subpixel (%f, %f) (%f, %f)", this, VEC_ARGS(internal->offsetF), VEC_ARGS(internal->fbOffsetF));
+		// DEBUG("%p dirty subpixel (%f, %f) (%f, %f)", this, VEC_ARGS(offsetF), VEC_ARGS(internal->fbOffsetF));
 		setDirty();
 	}
-	if (!internal->scale.equals(internal->fbScale)) {
+	if (!scale.equals(internal->fbScale)) {
 		// If rescaled, rerender in the next frame.
 		// DEBUG("%p dirty scale", this);
 		setDirty();
 	}
 
-	math::Vec scaleRatio = math::Vec(1, 1);
-	if (!internal->fbScale.isZero() && !internal->scale.equals(internal->fbScale)) {
-		// Continue to draw with the last framebuffer, but stretch it to rescale.
-		scaleRatio = internal->scale.div(internal->fbScale);
+	// Draw to framebuffer if dirty
+	auto redraw = [&]() {
+		// It's more important to not lag the frame than to draw the framebuffer
+		if (APP->window->getFrameTimeOverdue() > 0.0)
+			return;
+
+		// Check that scale has been set by `draw()` yet.
+		if (scale.isZero())
+			return;
+
+		// In case we fail drawing the framebuffer, don't try again the next frame, so reset `dirty` here.
+		dirty = false;
+		NVGcontext* vg = APP->window->vg;
+		NVGcontext* fbVg = APP->window->fbVg;
+
+		internal->fbScale = scale;
+		internal->fbOffsetF = offsetF;
+
+		math::Rect localBox;
+		if (children.empty()) {
+			localBox = box.zeroPos();
+		}
+		else {
+			localBox = getVisibleChildrenBoundingBox();
+		}
+
+		// DEBUG("rendering FramebufferWidget localBox (%g %g %g %g) fbOffset (%g %g) fbScale (%g %g)", RECT_ARGS(localBox), VEC_ARGS(internal->fbOffsetF), VEC_ARGS(internal->fbScale));
+		// Transform to world coordinates, then expand to nearest integer coordinates
+		math::Vec min = localBox.getTopLeft().mult(internal->fbScale).plus(internal->fbOffsetF).floor();
+		math::Vec max = localBox.getBottomRight().mult(internal->fbScale).plus(internal->fbOffsetF).ceil();
+		internal->fbBox = math::Rect::fromMinMax(min, max);
+		// DEBUG("%g %g %g %g", RECT_ARGS(internal->fbBox));
+
+		math::Vec newFbSize = internal->fbBox.size.mult(APP->window->pixelRatio).ceil();
+
+		// Create framebuffer if a new size is needed
+		if (!internal->fb || !newFbSize.equals(internal->fbSize)) {
+			internal->fbSize = newFbSize;
+			// Delete old framebuffer
+			if (internal->fb) {
+				nvgluDeleteFramebuffer(internal->fb);
+				internal->fb = NULL;
+			}
+			// Create a framebuffer
+			if (internal->fbSize.isFinite() && !internal->fbSize.isZero()) {
+				internal->fb = nvgluCreateFramebuffer(vg, internal->fbSize.x, internal->fbSize.y, 0);
+				// DEBUG("Created framebuffer of size (%f, %f)", VEC_ARGS(internal->fbSize));
+			}
+		}
+		if (!internal->fb) {
+			WARN("Framebuffer of size (%f, %f) could not be created for FramebufferWidget %p.", VEC_ARGS(internal->fbSize), this);
+			return;
+		}
+
+		DEBUG("Drawing to framebuffer of size (%f, %f)", VEC_ARGS(internal->fbSize));
+
+		// Render to framebuffer
+		if (oversample == 1.0) {
+			// If not oversampling, render directly to framebuffer.
+			nvgluBindFramebuffer(internal->fb);
+			drawFramebuffer();
+			nvgluBindFramebuffer(NULL);
+		}
+		else {
+			NVGLUframebuffer* fb = internal->fb;
+			// If oversampling, create another framebuffer and copy it to actual size.
+			math::Vec oversampledFbSize = internal->fbSize.mult(oversample).ceil();
+			NVGLUframebuffer* oversampledFb = nvgluCreateFramebuffer(fbVg, oversampledFbSize.x, oversampledFbSize.y, 0);
+
+			if (!oversampledFb) {
+				WARN("Oversampled framebuffer of size (%f, %f) could not be created for FramebufferWidget %p.", VEC_ARGS(oversampledFbSize), this);
+				return;
+			}
+
+			// Render to oversampled framebuffer.
+			nvgluBindFramebuffer(oversampledFb);
+			internal->fb = oversampledFb;
+			drawFramebuffer();
+			internal->fb = fb;
+			nvgluBindFramebuffer(NULL);
+
+			// Use NanoVG for resizing framebuffers
+			nvgluBindFramebuffer(internal->fb);
+
+			nvgBeginFrame(fbVg, internal->fbBox.size.x, internal->fbBox.size.y, 1.0);
+
+			// Draw oversampled framebuffer
+			nvgBeginPath(fbVg);
+			nvgRect(fbVg, 0.0, 0.0, internal->fbSize.x, internal->fbSize.y);
+			NVGpaint paint = nvgImagePattern(fbVg, 0.0, 0.0,
+				internal->fbSize.x, internal->fbSize.y,
+				0.0, oversampledFb->image, 1.0);
+			nvgFillPaint(fbVg, paint);
+			nvgFill(fbVg);
+
+			glViewport(0.0, 0.0, internal->fbSize.x, internal->fbSize.y);
+			glClearColor(0.0, 0.0, 0.0, 0.0);
+			glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT | GL_STENCIL_BUFFER_BIT);
+			nvgEndFrame(fbVg);
+			nvgReset(fbVg);
+
+			nvgluBindFramebuffer(NULL);
+			nvgluDeleteFramebuffer(oversampledFb);
+		}
+	};
+	if (dirty) {
+		redraw();
 	}
-	// DEBUG("%f %f %f %f", scaleRatio.x, scaleRatio.y, offsetF.x, offsetF.y);
 
 	if (!internal->fb)
 		return;
@@ -216,6 +205,13 @@ void FramebufferWidget::draw(const DrawArgs& args) {
 	nvgSave(args.vg);
 	nvgResetTransform(args.vg);
 
+	math::Vec scaleRatio = math::Vec(1, 1);
+	if (!internal->fbScale.isZero() && !scale.equals(internal->fbScale)) {
+		// Continue to draw with the last framebuffer, but stretch it to rescale.
+		scaleRatio = scale.div(internal->fbScale);
+	}
+	// DEBUG("%f %f %f %f", scaleRatio.x, scaleRatio.y, offsetF.x, offsetF.y);
+
 	// DEBUG("%f %f %f %f, %f %f", RECT_ARGS(internal->fbBox), VEC_ARGS(internal->fbSize));
 	nvgBeginPath(args.vg);
 	nvgRect(args.vg,
@@ -242,7 +238,7 @@ void FramebufferWidget::draw(const DrawArgs& args) {
 
 
 void FramebufferWidget::drawFramebuffer() {
-	NVGcontext* vg = APP->window->vg;
+	NVGcontext* vg = APP->window->fbVg;
 	nvgSave(vg);
 
 	float pixelRatio = internal->fbSize.x * oversample / internal->fbBox.size.x;
@@ -289,11 +285,6 @@ math::Vec FramebufferWidget::getFramebufferSize() {
 }
 
 
-void FramebufferWidget::setScale(math::Vec scale) {
-	internal->scale = scale;
-}
-
-
 void FramebufferWidget::onContextCreate(const ContextCreateEvent& e) {
 	setDirty();
 	Widget::onContextCreate(e);

src/window.cpp

@@ -318,6 +318,8 @@ Window::Window() {
 	int nvgFlags = NVG_ANTIALIAS;
 #if defined NANOVG_GL2
 	vg = nvgCreateGL2(nvgFlags);
+	// TODO Instead of creating a whole other NanoVG context, create one that uses the same fonts and framebuffers as `fb`.
+	fbVg = nvgCreateGL2(nvgFlags);
 #elif defined NANOVG_GL3
 	vg = nvgCreateGL3(nvgFlags);
 #elif defined NANOVG_GLES2
@@ -328,6 +330,8 @@ Window::Window() {
 		exit(1);
 	}
 
+	// fbVg = nvgClone(vg);
+
 	// Load default Blendish font
 	uiFont = loadFont(asset::system("res/fonts/DejaVuSans.ttf"));
 	bndSetFont(uiFont->handle);
@@ -345,8 +349,11 @@ Window::~Window() {
 		APP->scene->onContextDestroy(e);
 	}
 
+	// nvgDeleteClone(fbVg);
+
 #if defined NANOVG_GL2
 	nvgDeleteGL2(vg);
+	nvgDeleteGL2(fbVg);
 #elif defined NANOVG_GL3
 	nvgDeleteGL3(vg);
 #elif defined NANOVG_GLES2
@@ -523,12 +530,16 @@ void Window::screenshotModules(const std::string& screenshotsDir, float zoom) {
 			// Create widgets
 			widget::FramebufferWidget* fbw = new widget::FramebufferWidget;
 			fbw->oversample = 2;
-			fbw->setScale(math::Vec(zoom, zoom));
+
+			widget::ZoomWidget* zw = new widget::ZoomWidget;
+			zw->setZoom(zoom);
+			fbw->addChild(zw);
 
 			app::ModuleWidget* mw = model->createModuleWidget(NULL);
-			fbw->addChild(mw);
+			zw->box.size = mw->box.size.mult(zoom);
+			zw->addChild(mw);
 
-			// Hack the frame time so FramebufferWidgets are never overdue and therefore guaranteed to draw
+			// HACK: Set the frame time so FramebufferWidgets are never overdue and therefore guaranteed to draw
 			internal->lastFrameTime = INFINITY;
 
 			// Draw to framebuffer