Reimplement drawing of the mesh wireframe.

OpenGL 2 and newer do not have the glPolygonMode(..., GL_LINES) API,
so produce the wireframe on our side. It's somewhat slow, and draws
every line three times, but it is cached when the OpenGL 2 renderer
is used, and this should do for a debugging feature.

src/export.cpp

@@ -149,8 +149,7 @@ public:
     void DrawPolygon(const SPolygon &p, hFill hcf) override {
         ssassert(false, "Not implemented");
     }
-    void DrawMesh(const SMesh &m, hFill hcfFront, hFill hcfBack = {},
+    void DrawMesh(const SMesh &m, hFill hcfFront, hFill hcfBack = {}) override {
-                          hStroke hcsTriangles = {}) override {
         ssassert(false, "Not implemented");
     }
     void DrawFaces(const SMesh &m, const std::vector<uint32_t> &faces, hFill hcf) override {

src/groupmesh.cpp

@@ -478,20 +478,27 @@ void Group::DrawMesh(DrawMeshAs how, Canvas *canvas) {
                 hcfBack = canvas->GetFill(fillBack);
             }
 
+            // Draw the shaded solid into the depth buffer for hidden line removal,
+            // and if we're actually going to display it, to the color buffer too.
+            canvas->DrawMesh(displayMesh, hcfFront, hcfBack);
+
             // Draw mesh edges, for debugging.
-            Canvas::hStroke hcsTriangle = {};
             if(SS.GW.showMesh) {
                 Canvas::Stroke strokeTriangle = {};
                 strokeTriangle.zIndex = 1;
                 strokeTriangle.color  = RgbaColor::FromFloat(0.0f, 1.0f, 0.0f);
                 strokeTriangle.width  = 1;
-                strokeTriangle.unit = Canvas::Unit::PX;
+                strokeTriangle.unit   = Canvas::Unit::PX;
-                hcsTriangle = canvas->GetStroke(strokeTriangle);
+                Canvas::hStroke hcsTriangle = canvas->GetStroke(strokeTriangle);
+                SEdgeList edges = {};
+                for(const STriangle &t : displayMesh.l) {
+                    edges.AddEdge(t.a, t.b);
+                    edges.AddEdge(t.b, t.c);
+                    edges.AddEdge(t.c, t.a);
+                }
+                canvas->DrawEdges(edges, hcsTriangle);
+                edges.Clear();
             }
-
-            // Draw the shaded solid into the depth buffer for hidden line removal,
-            // and if we're actually going to display it, to the color buffer too.
-            canvas->DrawMesh(displayMesh, hcfFront, hcfBack, hcsTriangle);
             break;
         }
 

src/render/render.cpp

@@ -405,7 +405,7 @@ void ObjectPicker::DrawPolygon(const SPolygon &p, hFill hcf) {
     ssassert(false, "Not implemented");
 }
 
-void ObjectPicker::DrawMesh(const SMesh &m, hFill hcfFront, hFill hcfBack, hStroke hcsTriangles) {
+void ObjectPicker::DrawMesh(const SMesh &m, hFill hcfFront, hFill hcfBack) {
     ssassert(false, "Not implemented");
 }
 

src/render/render.h

@@ -154,8 +154,7 @@ public:
                           hFill hcf) = 0;
     virtual void DrawPoint(const Vector &o, hStroke hcs) = 0;
     virtual void DrawPolygon(const SPolygon &p, hFill hcf) = 0;
-    virtual void DrawMesh(const SMesh &m, hFill hcfFront, hFill hcfBack = {},
+    virtual void DrawMesh(const SMesh &m, hFill hcfFront, hFill hcfBack = {}) = 0;
-                          hStroke hcsTriangles = {}) = 0;
     virtual void DrawFaces(const SMesh &m, const std::vector<uint32_t> &faces, hFill hcf) = 0;
 
     virtual void DrawPixmap(std::shared_ptr<const Pixmap> pm,
@@ -221,7 +220,7 @@ public:
                   hFill hcf) override;
     void DrawPoint(const Vector &o, hStroke hcs) override;
     void DrawPolygon(const SPolygon &p, hFill hcf) override;
-    void DrawMesh(const SMesh &m, hFill hcfFront, hFill hcfBack, hStroke hcsTriangles) override;
+    void DrawMesh(const SMesh &m, hFill hcfFront, hFill hcfBack) override;
     void DrawFaces(const SMesh &m, const std::vector<uint32_t> &faces, hFill hcf) override;
 
     void DrawPixmap(std::shared_ptr<const Pixmap> pm,
@@ -269,7 +268,7 @@ public:
                   hFill hcf) override;
     void DrawPoint(const Vector &o, hStroke hcs) override;
     void DrawPolygon(const SPolygon &p, hFill hcf) override;
-    void DrawMesh(const SMesh &m, hFill hcfFront, hFill hcfBack, hStroke hcsTriangles) override;
+    void DrawMesh(const SMesh &m, hFill hcfFront, hFill hcfBack) override;
     void DrawFaces(const SMesh &m, const std::vector<uint32_t> &faces, hFill hcf) override;
 
     void DrawPixmap(std::shared_ptr<const Pixmap> pm,

src/render/render2d.cpp

@@ -122,12 +122,12 @@ void SurfaceRenderer::DrawPoint(const Vector &o, Canvas::hStroke hcs) {
 void SurfaceRenderer::DrawPolygon(const SPolygon &p, hFill hcf) {
     SMesh m = {};
     p.TriangulateInto(&m);
-    DrawMesh(m, hcf, {}, {});
+    DrawMesh(m, hcf, {});
     m.Clear();
 }
 
 void SurfaceRenderer::DrawMesh(const SMesh &m,
-                               hFill hcfFront, hFill hcfBack, hStroke hcsTriangles) {
+                               hFill hcfFront, hFill hcfBack) {
     Fill *fill = fills.FindById(hcfFront);
     ssassert(fill->layer == Layer::NORMAL ||
              fill->layer == Layer::DEPTH_ONLY, "Unexpected mesh layer");
@@ -160,17 +160,6 @@ void SurfaceRenderer::DrawMesh(const SMesh &m,
         }
         mesh.AddTriangle(&tr);
     }
-
-    if(hcsTriangles.v != 0) {
-        for(const STriangle &tr : m.l) {
-            edges[hcsTriangles].AddEdge(ProjectPoint3RH(camera, tr.a),
-                                        ProjectPoint3RH(camera, tr.b));
-            edges[hcsTriangles].AddEdge(ProjectPoint3RH(camera, tr.b),
-                                        ProjectPoint3RH(camera, tr.c));
-            edges[hcsTriangles].AddEdge(ProjectPoint3RH(camera, tr.c),
-                                        ProjectPoint3RH(camera, tr.a));
-        }
-    }
 }
 
 void SurfaceRenderer::DrawFaces(const SMesh &m, const std::vector<uint32_t> &faces, hFill hcf) {

src/render/rendergl1.cpp

@@ -198,7 +198,7 @@ public:
                   hFill hcf) override;
     void DrawPoint(const Vector &o, hStroke hcs) override;
     void DrawPolygon(const SPolygon &p, hFill hcf) override;
-    void DrawMesh(const SMesh &m, hFill hcfFront, hFill hcfBack, hStroke hcsTriangles) override;
+    void DrawMesh(const SMesh &m, hFill hcfFront, hFill hcfBack) override;
     void DrawFaces(const SMesh &m, const std::vector<uint32_t> &faces, hFill hcf) override;
     void DrawPixmap(std::shared_ptr<const Pixmap> pm,
                     const Vector &o, const Vector &u, const Vector &v,
@@ -597,8 +597,7 @@ void OpenGl1Renderer::DrawPolygon(const SPolygon &p, hFill hcf) {
     gluDeleteTess(gt);
 }
 
-void OpenGl1Renderer::DrawMesh(const SMesh &m,
+void OpenGl1Renderer::DrawMesh(const SMesh &m, hFill hcfFront, hFill hcfBack) {
-                               hFill hcfFront, hFill hcfBack, hStroke hcsTriangles) {
     UnSelectPrimitive();
 
     Fill *frontFill = SelectFill(hcfFront);
@@ -646,24 +645,6 @@ void OpenGl1Renderer::DrawMesh(const SMesh &m,
     }
     glEnd();
     glDisable(GL_LIGHTING);
-
-    if(hcsTriangles.v != 0) {
-        Stroke *triangleStroke = SelectStroke(hcsTriangles);
-        ssassert(triangleStroke->width == 1 &&
-                 triangleStroke->stipplePattern == StipplePattern::CONTINUOUS &&
-                 triangleStroke->stippleScale == 0.0,
-                 "Triangle stroke must match predefined OpenGL parameters");
-
-        glPolygonMode(GL_FRONT_AND_BACK, GL_LINE);
-        glBegin(GL_TRIANGLES);
-        for(const STriangle &tr : m.l) {
-            ssglVertex3v(tr.a);
-            ssglVertex3v(tr.b);
-            ssglVertex3v(tr.c);
-        }
-        glEnd();
-        glPolygonMode(GL_FRONT_AND_BACK, GL_FILL);
-    }
 }
 
 void OpenGl1Renderer::DrawFaces(const SMesh &m, const std::vector<uint32_t> &faces, hFill hcf) {