Add DrawContext::clipBox for drawing children widgets only when they intersect with the clipBox.

include/math.hpp

@@ -258,17 +258,17 @@ struct Rect {
 	}
 
 	/** Returns whether this Rect contains an entire point, inclusive on the top/left, non-inclusive on the bottom/right */
-	bool contains(Vec v) const {
+	bool isContaining(Vec v) const {
 		return pos.x <= v.x && v.x < pos.x + size.x
 			&& pos.y <= v.y && v.y < pos.y + size.y;
 	}
 	/** Returns whether this Rect contains an entire Rect */
-	bool contains(Rect r) const {
+	bool isContaining(Rect r) const {
 		return pos.x <= r.pos.x && r.pos.x + r.size.x <= pos.x + size.x
 			&& pos.y <= r.pos.y && r.pos.y + r.size.y <= pos.y + size.y;
 	}
 	/** Returns whether this Rect overlaps with another Rect */
-	bool intersects(Rect r) const {
+	bool isIntersecting(Rect r) const {
 		return (pos.x + size.x > r.pos.x && r.pos.x + r.size.x > pos.x)
 			&& (pos.y + size.y > r.pos.y && r.pos.y + r.size.y > pos.y);
 	}
@@ -313,13 +313,22 @@ struct Rect {
 		r.pos.y = math::clampSafe(pos.y, bound.pos.y, bound.pos.y + bound.size.y - size.y);
 		return r;
 	}
-	/** Expands this Rect to contain `other` */
-	Rect expand(Rect other) const {
+	/** Expands this Rect to contain `b` */
+	Rect expand(Rect b) const {
 		Rect r;
-		r.pos.x = std::min(pos.x, other.pos.x);
-		r.pos.y = std::min(pos.y, other.pos.y);
-		r.size.x = std::max(pos.x + size.x, other.pos.x + other.size.x) - r.pos.x;
-		r.size.y = std::max(pos.y + size.y, other.pos.y + other.size.y) - r.pos.y;
+		r.pos.x = std::min(pos.x, b.pos.x);
+		r.pos.y = std::min(pos.y, b.pos.y);
+		r.size.x = std::max(pos.x + size.x, b.pos.x + b.size.x) - r.pos.x;
+		r.size.y = std::max(pos.y + size.y, b.pos.y + b.size.y) - r.pos.y;
+		return r;
+	}
+	/** Returns the intersection of `this` and `b` */
+	Rect intersect(Rect b) const {
+		Rect r;
+		r.pos.x = std::max(pos.x, b.pos.x);
+		r.pos.y = std::max(pos.y, b.pos.y);
+		r.size.x = std::min(pos.x + size.x, b.pos.x + b.size.x) - r.pos.x;
+		r.size.y = std::min(pos.y + size.y, b.pos.y + b.size.y) - r.pos.y;
 		return r;
 	}
 	/** Returns a Rect with its position set to zero */
@@ -335,6 +344,10 @@ struct Rect {
 		r.size = size.plus(delta.mult(2.f));
 		return r;
 	}
+
+	DEPRECATED bool contains(Vec v) const {return isContaining(v);}
+	DEPRECATED bool contains(Rect r) const {return isContaining(r);}
+	DEPRECATED bool intersects(Rect r) const {return isIntersecting(r);}
 };
 
 

include/widgets/Widget.hpp

@@ -11,7 +11,8 @@ namespace rack {
 
 
 struct DrawContext {
-	mutable NVGcontext *vg;
+	NVGcontext *vg;
+	math::Rect clipBox = math::Rect(math::Vec(), math::Vec(INFINITY, INFINITY));
 };
 
 
@@ -101,7 +102,7 @@ struct Widget {
 			// Filter child by visibility and position
 			if (!child->visible)
 				continue;
-			if (!child->box.contains(e.pos))
+			if (!child->box.isContaining(e.pos))
 				continue;
 
 			// Clone event and adjust its position

src/app/ModuleBrowser.cpp

@@ -22,7 +22,10 @@ static std::set<Model*> sFavoriteModels;
 
 struct ModuleBox : OpaqueWidget {
 	Model *model;
-	bool initialized = false;
+	/** Lazily created */
+	Widget *previewWidget = NULL;
+	/** Number of frames since draw() has been called */
+	int visibleFrames = 0;
 
 	void setModel(Model *model) {
 		this->model = model;
@@ -47,9 +50,17 @@ struct ModuleBox : OpaqueWidget {
 		addChild(pluginLabel);
 	}
 
+	void step() override {
+		if (previewWidget && ++visibleFrames >= 60) {
+			removeChild(previewWidget);
+			delete previewWidget;
+			previewWidget = NULL;
+		}
+	}
+
 	void draw(const DrawContext &ctx) override {
 		// Lazily create ModuleWidget when drawn
-		if (!initialized) {
+		if (!previewWidget) {
 			Widget *transparentWidget = new TransparentWidget;
 			addChild(transparentWidget);
 
@@ -71,7 +82,8 @@ struct ModuleBox : OpaqueWidget {
 			zoomWidget->box.size.y = RACK_GRID_HEIGHT;
 			float width = std::ceil(zoomWidget->box.size.x);
 			box.size.x = std::max(box.size.x, width);
-			initialized = true;
+
+			previewWidget = transparentWidget;
 		}
 
 		OpaqueWidget::draw(ctx);
@@ -113,6 +125,7 @@ ModuleBrowser::ModuleBrowser() {
 	moduleLayout->spacing = math::Vec(10, 10);
 	moduleScroll->container->addChild(moduleLayout);
 
+	for (int i = 0; i < 100; i++)
 	for (Plugin *plugin : plugin::plugins) {
 		for (Model *model : plugin->models) {
 			ModuleBox *moduleBox = new ModuleBox;

src/app/RackWidget.cpp

@@ -104,7 +104,7 @@ void RackWidget::step() {
 	// Adjust size and position of rails
 	Widget *rail = rails->children.front();
 	math::Rect bound = getViewport(math::Rect(math::Vec(), box.size));
-	if (!rails->box.contains(bound)) {
+	if (!rails->box.isContaining(bound)) {
 		math::Vec cellMargin = math::Vec(20, 1);
 		rails->box.pos = bound.pos.div(RACK_GRID_SIZE).floor().minus(cellMargin).mult(RACK_GRID_SIZE);
 		rails->box.size = bound.size.plus(cellMargin.mult(RACK_GRID_SIZE).mult(2));
@@ -369,7 +369,7 @@ bool RackWidget::requestModuleBox(ModuleWidget *m, math::Rect requestedBox) {
 		// Don't intersect with self
 		if (m == m2)
 			continue;
-		if (requestedBox.intersects(m2->box)) {
+		if (requestedBox.isIntersecting(m2->box)) {
 			return false;
 		}
 	}

src/ui/Menu.cpp

@@ -54,7 +54,7 @@ void Menu::draw(const DrawContext &ctx) {
 }
 
 void Menu::onHoverScroll(const event::HoverScroll &e) {
-	if (parent && !parent->box.contains(box))
+	if (parent && !parent->box.isContaining(box))
 		box.pos.y += e.scrollDelta.y;
 }
 

src/widgets/Widget.cpp

@@ -94,25 +94,31 @@ void Widget::step() {
 }
 
 void Widget::draw(const DrawContext &ctx) {
+	// Iterate children
 	for (Widget *child : children) {
 		// Don't draw if invisible
 		if (!child->visible)
 			continue;
-		// Don't draw if child is outside bounding box
-		if (!box.zeroPos().intersects(child->box))
+		// Don't draw if child is outside clip box
+		if (!ctx.clipBox.isIntersecting(child->box))
 			continue;
 
+		DrawContext childCtx = ctx;
+		// Intersect child clip box with self
+		childCtx.clipBox = childCtx.clipBox.intersect(child->box);
+		childCtx.clipBox.pos = childCtx.clipBox.pos.minus(child->box.pos);
+
 		nvgSave(ctx.vg);
 		nvgTranslate(ctx.vg, child->box.pos.x, child->box.pos.y);
 
-		DrawContext childCtx = ctx;
-		child->draw(childCtx);
-
 #pragma GCC diagnostic push
 #pragma GCC diagnostic ignored "-Wdeprecated-declarations"
+		// Call deprecated draw function, which does nothing by default
 		child->draw(ctx.vg);
 #pragma GCC diagnostic pop
 
+		child->draw(childCtx);
+
 		// Draw red hitboxes
 		// if (app()->event->hoveredWidget == child) {
 		// 	nvgBeginPath(ctx.vg);

src/widgets/ZoomWidget.cpp

@@ -29,9 +29,12 @@ void ZoomWidget::setZoom(float zoom) {
 }
 
 void ZoomWidget::draw(const DrawContext &ctx) {
+	DrawContext zoomCtx = ctx;
+	zoomCtx.clipBox.pos = zoomCtx.clipBox.pos.div(zoom);
+	zoomCtx.clipBox.size = zoomCtx.clipBox.size.div(zoom);
 	// No need to save the state because that is done in the parent
 	nvgScale(ctx.vg, zoom, zoom);
-	Widget::draw(ctx);
+	Widget::draw(zoomCtx);
 }