From 0839a7c041b4bd4c76df41927dac15e1501796fb Mon Sep 17 00:00:00 2001
From: Andrew Belt <andrewpbelt@gmail.com>
Date: Thu, 7 Oct 2021 22:26:49 -0400
Subject: [PATCH] Draw ModuleWidget shadow with drawLayer() instead of a custom
 drawShadow() method.

---
 include/app/ModuleWidget.hpp |  2 +-
 include/widget/Widget.hpp    |  6 +++++-
 src/app/CableWidget.cpp      |  2 ++
 src/app/ModuleWidget.cpp     | 27 ++++++++++++++++-----------
 src/app/RackWidget.cpp       | 15 +++++----------
 5 files changed, 29 insertions(+), 23 deletions(-)

diff --git a/include/app/ModuleWidget.hpp b/include/app/ModuleWidget.hpp
index 5e50c43a..f3879cba 100644
--- a/include/app/ModuleWidget.hpp
+++ b/include/app/ModuleWidget.hpp
@@ -62,7 +62,7 @@ struct ModuleWidget : widget::OpaqueWidget {
 	std::vector<PortWidget*> getOutputs();
 
 	void draw(const DrawArgs& args) override;
-	void drawShadow(const DrawArgs& args);
+	void drawLayer(const DrawArgs& args, int layer) override;
 
 	/** Override to add context menu entries to your subclass.
 	It is recommended to add a blank `ui::MenuSeparator` first for spacing.
diff --git a/include/widget/Widget.hpp b/include/widget/Widget.hpp
index 36d14198..d2795829 100644
--- a/include/widget/Widget.hpp
+++ b/include/widget/Widget.hpp
@@ -128,7 +128,10 @@ struct Widget : WeakBase {
 		NVGLUframebuffer* fb = NULL;
 	};
 
-	/** Draws the widget to the NanoVG context */
+	/** Draws the widget to the NanoVG context.
+
+	When overriding, call the superclass draw() to recurse to children.
+	*/
 	virtual void draw(const DrawArgs& args);
 	/** Override draw(const DrawArgs &args) instead */
 	DEPRECATED virtual void draw(NVGcontext* vg) {}
@@ -138,6 +141,7 @@ struct Widget : WeakBase {
 	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.
+	When overriding, call the superclass drawLayer() to recurse to children.
 	*/
 	virtual void drawLayer(const DrawArgs& args, int layer);
 
diff --git a/src/app/CableWidget.cpp b/src/app/CableWidget.cpp
index a0913d86..8de89140 100644
--- a/src/app/CableWidget.cpp
+++ b/src/app/CableWidget.cpp
@@ -350,6 +350,8 @@ void CableWidget::drawLayer(const DrawArgs& args, int layer) {
 		nvgStrokeWidth(args.vg, thickness - 1.0);
 		nvgStroke(args.vg);
 	}
+
+	Widget::drawLayer(args, layer);
 }
 
 
diff --git a/src/app/ModuleWidget.cpp b/src/app/ModuleWidget.cpp
index 1e3aa25d..791acf00 100644
--- a/src/app/ModuleWidget.cpp
+++ b/src/app/ModuleWidget.cpp
@@ -284,17 +284,22 @@ void ModuleWidget::draw(const DrawArgs& args) {
 	nvgResetScissor(args.vg);
 }
 
-void ModuleWidget::drawShadow(const DrawArgs& args) {
-	nvgBeginPath(args.vg);
-	float r = 20; // Blur radius
-	float c = 20; // Corner radius
-	math::Rect shadowBox = box.zeroPos().grow(math::Vec(10, -30));
-	math::Rect shadowOutsideBox = shadowBox.grow(math::Vec(r, r));
-	nvgRect(args.vg, RECT_ARGS(shadowOutsideBox));
-	NVGcolor shadowColor = nvgRGBAf(0, 0, 0, 0.2);
-	NVGcolor transparentColor = nvgRGBAf(0, 0, 0, 0);
-	nvgFillPaint(args.vg, nvgBoxGradient(args.vg, RECT_ARGS(shadowBox), c, r, shadowColor, transparentColor));
-	nvgFill(args.vg);
+void ModuleWidget::drawLayer(const DrawArgs& args, int layer) {
+	if (layer == -1) {
+		nvgBeginPath(args.vg);
+		float r = 20; // Blur radius
+		float c = 20; // Corner radius
+		math::Rect shadowBox = box.zeroPos().grow(math::Vec(10, -30));
+		math::Rect shadowOutsideBox = shadowBox.grow(math::Vec(r, r));
+		nvgRect(args.vg, RECT_ARGS(shadowOutsideBox));
+		NVGcolor shadowColor = nvgRGBAf(0, 0, 0, 0.2);
+		NVGcolor transparentColor = nvgRGBAf(0, 0, 0, 0);
+		nvgFillPaint(args.vg, nvgBoxGradient(args.vg, RECT_ARGS(shadowBox), c, r, shadowColor, transparentColor));
+		nvgFill(args.vg);
+	}
+	else {
+		Widget::drawLayer(args, layer);
+	}
 }
 
 void ModuleWidget::onHover(const HoverEvent& e) {
diff --git a/src/app/RackWidget.cpp b/src/app/RackWidget.cpp
index 626a7860..8334a3f6 100644
--- a/src/app/RackWidget.cpp
+++ b/src/app/RackWidget.cpp
@@ -40,18 +40,13 @@ static ModuleWidget* moduleWidgetFromJson(json_t* moduleJ) {
 
 struct ModuleContainer : widget::Widget {
 	void draw(const DrawArgs& args) override {
-		// Draw shadows behind each ModuleWidget first, so the shadow doesn't overlap the front of other ModuleWidgets.
-		for (widget::Widget* child : children) {
-			ModuleWidget* w = dynamic_cast<ModuleWidget*>(child);
-			assert(w);
-
-			nvgSave(args.vg);
-			nvgTranslate(args.vg, child->box.pos.x, child->box.pos.y);
-			w->drawShadow(args);
-			nvgRestore(args.vg);
-		}
+		// Draw ModuleWidget shadows
+		Widget::drawLayer(args, -1);
 
 		Widget::draw(args);
+
+		// Draw lights and light halos
+		Widget::drawLayer(args, 1);
 	}
 };