Allow displaying outlines without any other edges.

As usual, what's displayed is what's exported.

CHANGELOG.md

@@ -8,15 +8,18 @@ New export/import features:
   * Three.js: allow configuring projection for exported model, and initially
     use the current viewport projection.
 
+New rendering features:
+  * The "Show/hide hidden lines" button is now a tri-state button that allows
+    showing all lines (on top of shaded mesh), stippling occluded lines
+    or not drawing them at all.
+  * The "Show/hide outlines" button is now independent from "Show/hide edges".
+
 Other new features:
   * New command for measuring total length of selected entities,
     "Analyze → Measure Perimeter".
   * New link to match the on-screen size of the sketch with its actual size,
     "view → set to full scale".
   * When zooming to fit, constraints are also considered.
-  * The "Show/hide hidden lines" button is now a tri-state button that allows
-    showing all lines (on top of shaded mesh), stippling occluded lines
-    or not drawing them at all.
 
 2.2
 ---

src/export.cpp

@@ -203,10 +203,12 @@ void SolveSpaceUI::ExportViewOrWireframeTo(const std::string &filename, bool exp
         }
     }
 
-    if(SS.GW.showEdges) {
+    if(SS.GW.showEdges || SS.GW.showOutlines) {
         Group *g = SK.GetGroup(SS.GW.activeGroup);
         g->GenerateDisplayItems();
-        g->displayOutlines.ListTaggedInto(&edges, Style::SOLID_EDGE);
+        if(SS.GW.showEdges) {
+            g->displayOutlines.ListTaggedInto(&edges, Style::SOLID_EDGE);
+        }
     }
 
     if(SS.GW.showConstraints) {
@@ -388,7 +390,7 @@ void SolveSpaceUI::ExportLinesAndMesh(SEdgeList *sel, SBezierList *sbl, SMesh *s
 
         // Generate the edges where a curved surface turns from front-facing
         // to back-facing.
-        if(SS.GW.showEdges) {
+        if(SS.GW.showEdges || SS.GW.showOutlines) {
             root->MakeCertainEdgesInto(sel, EdgeKind::TURNING,
                                        /*coplanarIsInter=*/false, NULL, NULL,
                                        GW.showOutlines ? Style::OUTLINE : Style::SOLID_EDGE);

src/graphicswin.cpp

@@ -1076,7 +1076,9 @@ void GraphicsWindow::ToggleBool(bool *v) {
 
     // We might need to regenerate the mesh and edge list, since the edges
     // wouldn't have been generated if they were previously hidden.
-    if(showEdges) (SK.GetGroup(activeGroup))->displayDirty = true;
+    if(showEdges || showOutlines) {
+        SK.GetGroup(activeGroup)->displayDirty = true;
+    }
 
     SS.GenerateAll();
     InvalidateGraphics();

src/groupmesh.cpp

@@ -378,7 +378,7 @@ void Group::GenerateDisplayItems() {
             displayMesh.MakeFromCopyOf(&(pg->displayMesh));
 
             displayOutlines.Clear();
-            if(SS.GW.showEdges) {
+            if(SS.GW.showEdges || SS.GW.showOutlines) {
                 displayOutlines.MakeFromCopyOf(&pg->displayOutlines);
             }
         } else {
@@ -398,7 +398,7 @@ void Group::GenerateDisplayItems() {
 
             displayOutlines.Clear();
 
-            if(SS.GW.showEdges) {
+            if(SS.GW.showEdges || SS.GW.showOutlines) {
                 if(runningMesh.l.n > 0) {
                     // Triangle mesh only; no shell or emphasized edges.
                     runningMesh.MakeOutlinesInto(&displayOutlines, EdgeKind::EMPHASIZED);
@@ -528,17 +528,6 @@ void Group::Draw(Canvas *canvas) {
     DrawMesh(DrawMeshAs::DEFAULT, canvas);
 
     if(SS.GW.showEdges) {
-        if(SS.GW.showOutlines) {
-            Canvas::Stroke strokeOutline = {};
-            strokeOutline.zIndex = 1;
-            strokeOutline.color  = Style::Color(Style::OUTLINE);
-            strokeOutline.width  = Style::Width(Style::OUTLINE);
-            Canvas::hStroke hcsOutline = canvas->GetStroke(strokeOutline);
-
-            canvas->DrawOutlines(displayOutlines, hcsOutline,
-                                 Canvas::DrawOutlinesAs::CONTOUR_ONLY);
-        }
-
         Canvas::Stroke strokeEdge = {};
         strokeEdge.zIndex = 1;
         strokeEdge.color  = Style::Color(Style::SOLID_EDGE);
@@ -562,6 +551,17 @@ void Group::Draw(Canvas *canvas) {
                                  Canvas::DrawOutlinesAs::EMPHASIZED_AND_CONTOUR);
         }
     }
+
+    if(SS.GW.showOutlines) {
+        Canvas::Stroke strokeOutline = {};
+        strokeOutline.zIndex = 1;
+        strokeOutline.color  = Style::Color(Style::OUTLINE);
+        strokeOutline.width  = Style::Width(Style::OUTLINE);
+        Canvas::hStroke hcsOutline = canvas->GetStroke(strokeOutline);
+
+        canvas->DrawOutlines(displayOutlines, hcsOutline,
+                             Canvas::DrawOutlinesAs::CONTOUR_ONLY);
+    }
 }
 
 void Group::DrawPolyError(Canvas *canvas) {