Add error message if window doesn't open, refactor SVGPanel

ext/osdialog

@@ -1 +1 @@
-Subproject commit e66caf0f9d3266a79c513dcc73b57b6b3eb38120
+Subproject commit 952d72f925ea5e9086067d47a9d31516878fcaac

include/app.hpp

@@ -121,12 +121,8 @@ struct Panel : TransparentWidget {
 	void draw(NVGcontext *vg);
 };
 
-struct PanelBorder : TransparentWidget {
-	void draw(NVGcontext *vg);
-};
-
 struct SVGPanel : FramebufferWidget {
-	void addBackground(std::shared_ptr<SVG> svg);
+	void setBackground(std::shared_ptr<SVG> svg);
 };
 
 ////////////////////

src/app/PanelBorder.cpp

@@ -1,20 +0,0 @@
-#include "app.hpp"
-
-
-namespace rack {
-
-void PanelBorder::draw(NVGcontext *vg) {
-	nvgBeginPath(vg);
-	nvgRect(vg, 0.0, 0.0, box.size.x, box.size.y);
-
-	NVGcolor borderColor = nvgRGB(0xac, 0xac, 0xac);
-
-	// Border
-	nvgBeginPath(vg);
-	nvgRect(vg, 0.5, 0.5, box.size.x - 1, box.size.y - 1);
-	nvgStrokeColor(vg, borderColor);
-	nvgStrokeWidth(vg, 1.0);
-	nvgStroke(vg);
-}
-
-} // namespace rack

src/app/SVGPanel.cpp

@@ -4,14 +4,30 @@
 namespace rack {
 
 
-void SVGPanel::addBackground(std::shared_ptr<SVG> svg) {
+struct PanelBorder : TransparentWidget {
+	void draw(NVGcontext *vg) {
+		nvgBeginPath(vg);
+		nvgRect(vg, 0.0, 0.0, box.size.x, box.size.y);
+
+		NVGcolor borderColor = nvgRGBAf(0.5, 0.5, 0.5, 0.5);
+
+		nvgBeginPath(vg);
+		nvgRect(vg, 0.5, 0.5, box.size.x - 1.0, box.size.y - 1.0);
+		nvgStrokeColor(vg, borderColor);
+		nvgStrokeWidth(vg, 1.0);
+		nvgStroke(vg);
+	}
+};
+
+
+void SVGPanel::setBackground(std::shared_ptr<SVG> svg) {
 	SVGWidget *sw = new SVGWidget();
 	sw->wrap();
 	sw->svg = svg;
 	addChild(sw);
 
 	PanelBorder *pb = new PanelBorder();
-	sw->box.size = box.size;
+	pb->box.size = box.size;
 	addChild(pb);
 }
 

src/gui.cpp

@@ -3,6 +3,7 @@
 #include "gui.hpp"
 #include "app.hpp"
 #include "settings.hpp"
+#include "../ext/osdialog/osdialog.h"
 
 #define NANOVG_GL2_IMPLEMENTATION
 // #define NANOVG_GL3_IMPLEMENTATION
@@ -216,7 +217,11 @@ void guiInit() {
 	glfwWindowHint(GLFW_MAXIMIZED, GLFW_TRUE);
 	std::string title = gApplicationName + " " + gApplicationVersion;
 	gWindow = glfwCreateWindow(1000, 750, title.c_str(), NULL, NULL);
-	assert(gWindow);
+	if (!gWindow) {
+		osdialog_message(OSDIALOG_ERROR, OSDIALOG_OK, "Cannot open window with OpenGL 2.0 renderer. Does your graphics card support OpenGL 2.0? If so, are the latest drivers installed?");
+		exit(1);
+	}
+
 	glfwMakeContextCurrent(gWindow);
 
 	glfwSwapInterval(1);

src/widgets/FramebufferWidget.cpp

@@ -42,6 +42,7 @@ void FramebufferWidget::step() {
 		Vec fbSize = internal->box.size.mult(gPixelRatio * oversample);
 		// assert(fbSize.isFinite());
 
+		// Delete old one first to free up GPU memory
 		internal->setFramebuffer(NULL);
 		NVGLUframebuffer *fb = nvgluCreateFramebuffer(gVg, fbSize.x, fbSize.y, NVG_IMAGE_REPEATX | NVG_IMAGE_REPEATY);
 		if (!fb)