Add Widget::drawLayer().

include/app/CableWidget.hpp

@@ -46,6 +46,7 @@ struct CableWidget : widget::Widget {
 	void fromJson(json_t* rootJ);
 	void step() override;
 	void draw(const DrawArgs& args) override;
+	void drawLayer(const DrawArgs& args, int layer) override;
 	engine::Cable* releaseCable();
 };
 

include/widget/Widget.hpp

@@ -126,8 +126,6 @@ struct Widget : WeakBase {
 		/** Local box representing the visible viewport. */
 		math::Rect clipBox;
 		NVGLUframebuffer* fb = NULL;
-		/** Custom widgets may draw children multiple times, passing a different layer number each time. */
-		int layer = 0;
 	};
 
 	/** Draws the widget to the NanoVG context */
@@ -135,8 +133,16 @@ struct Widget : WeakBase {
 	/** Override draw(const DrawArgs &args) instead */
 	DEPRECATED virtual void draw(NVGcontext* vg) {}
 
+	/** Draw additional layers.
+
+	Custom widgets may draw its children multiple times on different layers, passing an arbitrary layer number each time.
+	Layer 0 calls children's draw().
+	When overriding, always wrap draw commands in `if (layer == ...) {}` to avoid drawing on all layers.
+	*/
+	virtual void drawLayer(const DrawArgs& args, int layer);
+
 	/** Draws a particular child. */
-	void drawChild(Widget* child, const DrawArgs& args);
+	void drawChild(Widget* child, const DrawArgs& args, int layer = 0);
 
 	// Events
 

src/app/CableWidget.cpp

@@ -131,11 +131,13 @@ CableWidget::CableWidget() {
 	addChild(outputPlug);
 }
 
+
 CableWidget::~CableWidget() {
 	setCable(NULL);
 	delete internal;
 }
 
+
 void CableWidget::setNextCableColor() {
 	if (!settings::cableColors.empty()) {
 		int id = APP->scene->rack->nextCableColorId++;
@@ -144,10 +146,12 @@ void CableWidget::setNextCableColor() {
 	}
 }
 
+
 bool CableWidget::isComplete() {
 	return outputPort && inputPort;
 }
 
+
 void CableWidget::updateCable() {
 	if (cable) {
 		APP->engine->removeCable(cable);
@@ -164,6 +168,7 @@ void CableWidget::updateCable() {
 	}
 }
 
+
 void CableWidget::setCable(engine::Cable* cable) {
 	if (this->cable) {
 		APP->engine->removeCable(this->cable);
@@ -188,10 +193,12 @@ void CableWidget::setCable(engine::Cable* cable) {
 	}
 }
 
+
 engine::Cable* CableWidget::getCable() {
 	return cable;
 }
 
+
 math::Vec CableWidget::getInputPos() {
 	if (inputPort) {
 		return inputPort->getRelativeOffset(inputPort->box.zeroPos().getCenter(), APP->scene->rack);
@@ -204,6 +211,7 @@ math::Vec CableWidget::getInputPos() {
 	}
 }
 
+
 math::Vec CableWidget::getOutputPos() {
 	if (outputPort) {
 		return outputPort->getRelativeOffset(outputPort->box.zeroPos().getCenter(), APP->scene->rack);
@@ -216,11 +224,13 @@ math::Vec CableWidget::getOutputPos() {
 	}
 }
 
+
 void CableWidget::mergeJson(json_t* rootJ) {
 	std::string s = color::toHexString(color);
 	json_object_set_new(rootJ, "color", json_string(s.c_str()));
 }
 
+
 void CableWidget::fromJson(json_t* rootJ) {
 	json_t* colorJ = json_object_get(rootJ, "color");
 	if (colorJ) {
@@ -230,6 +240,7 @@ void CableWidget::fromJson(json_t* rootJ) {
 	}
 }
 
+
 static math::Vec getSlumpPos(math::Vec pos1, math::Vec pos2) {
 	float dist = pos1.minus(pos2).norm();
 	math::Vec avg = pos1.plus(pos2).div(2);
@@ -238,6 +249,7 @@ static math::Vec getSlumpPos(math::Vec pos1, math::Vec pos2) {
 	return avg;
 }
 
+
 void CableWidget::step() {
 	math::Vec outputPos = getOutputPos();
 	math::Vec inputPos = getInputPos();
@@ -262,13 +274,13 @@ void CableWidget::step() {
 	Widget::step();
 }
 
+
 void CableWidget::draw(const DrawArgs& args) {
-	if (args.layer == 0) {
-		// Draw PlugWidgets
-		Widget::draw(args);
-		return;
-	}
+	Widget::draw(args);
+}
 
+
+void CableWidget::drawLayer(const DrawArgs& args, int layer) {
 	float opacity = settings::cableOpacity;
 	bool thick = false;
 
@@ -312,7 +324,7 @@ void CableWidget::draw(const DrawArgs& args) {
 	// Avoids glitches when cable is bent
 	nvgLineJoin(args.vg, NVG_ROUND);
 
-	if (args.layer == 1) {
+	if (layer == 1) {
 		// Draw cable shadow
 		math::Vec shadowSlump = slump.plus(math::Vec(0, 30));
 		nvgBeginPath(args.vg);
@@ -323,7 +335,7 @@ void CableWidget::draw(const DrawArgs& args) {
 		nvgStrokeWidth(args.vg, thickness - 1.0);
 		nvgStroke(args.vg);
 	}
-	else if (args.layer == 2) {
+	else if (layer == 2) {
 		// Draw cable outline
 		nvgBeginPath(args.vg);
 		nvgMoveTo(args.vg, VEC_ARGS(outputPos));
@@ -340,6 +352,7 @@ void CableWidget::draw(const DrawArgs& args) {
 	}
 }
 
+
 engine::Cable* CableWidget::releaseCable() {
 	engine::Cable* cable = this->cable;
 	this->cable = NULL;

src/app/RackWidget.cpp

@@ -62,14 +62,10 @@ struct CableContainer : widget::TransparentWidget {
 		Widget::draw(args);
 
 		// Draw cable shadows
-		DrawArgs args1 = args;
-		args1.layer = 1;
-		Widget::draw(args1);
+		Widget::drawLayer(args, 1);
 
 		// Draw cables
-		DrawArgs args2 = args;
-		args2.layer = 2;
-		Widget::draw(args2);
+		Widget::drawLayer(args, 2);
 	}
 };
 

src/widget/Widget.cpp

@@ -273,7 +273,22 @@ void Widget::draw(const DrawArgs& args) {
 }
 
 
-void Widget::drawChild(Widget* child, const DrawArgs& args) {
+void Widget::drawLayer(const DrawArgs& args, int layer) {
+	// Iterate children
+	for (Widget* child : children) {
+		// Don't draw if invisible
+		if (!child->isVisible())
+			continue;
+		// Don't draw if child is outside clip box
+		if (!args.clipBox.intersects(child->box))
+			continue;
+
+		drawChild(child, args, layer);
+	}
+}
+
+
+void Widget::drawChild(Widget* child, const DrawArgs& args, int layer) {
 	DrawArgs childArgs = args;
 	// Intersect child clip box with self
 	childArgs.clipBox = childArgs.clipBox.intersect(child->box);
@@ -283,13 +298,17 @@ void Widget::drawChild(Widget* child, const DrawArgs& args) {
 	nvgSave(args.vg);
 	nvgTranslate(args.vg, child->box.pos.x, child->box.pos.y);
 
-	child->draw(childArgs);
-
+	if (layer == 0) {
+		child->draw(childArgs);
 #pragma GCC diagnostic push
 #pragma GCC diagnostic ignored "-Wdeprecated-declarations"
-	// Call deprecated draw function, which does nothing by default
-	child->draw(args.vg);
+		// Call deprecated draw function, which does nothing by default
+		child->draw(args.vg);
 #pragma GCC diagnostic pop
+	}
+	else {
+		child->drawLayer(childArgs, layer);
+	}
 
 	nvgRestore(args.vg);
 }