Added optional showing of mesh edges.

Author: dov

src/fragment-edge.glsl

@@ -0,0 +1,18 @@
+#version 410
+
+smooth in vec4 vertexColor;
+smooth in vec3 vBC;
+out vec4 outputColor;
+
+float edgeFactor(){
+    vec3 d = fwidth(vBC);
+    vec3 a3 = smoothstep(vec3(0.0), d*1.0, vBC);
+    return min(min(a3.x, a3.y), a3.z);
+}
+
+void main()
+{
+  gl_FragColor = vec4(mix(vec3(0.0,0.5,0.0),
+                          vertexColor.xyz,
+                          edgeFactor()), 1.0);
+}

src/mesh-viewer.cc

@@ -134,47 +134,64 @@ void MeshViewer::init_shaders ()
   /* load the vertex shader */
   Glib::RefPtr<const Glib::Bytes> vertex_source = Gio::Resource::lookup_data_global("/shaders/vertex.glsl");
   Glib::RefPtr<const Glib::Bytes> fragment_source = Gio::Resource::lookup_data_global("/shaders/fragment.glsl");
+  Glib::RefPtr<const Glib::Bytes> fragment_edge_source = Gio::Resource::lookup_data_global("/shaders/fragment-edge.glsl");
 
   guint vertex = create_shader(GL_VERTEX_SHADER, vertex_source);
+  guint vertex_edge = create_shader(GL_VERTEX_SHADER, vertex_source);
   guint fragment = create_shader(GL_FRAGMENT_SHADER, fragment_source);
+  guint fragment_edge = create_shader(GL_FRAGMENT_SHADER, fragment_edge_source);
   m_program = glCreateProgram ();
   glAttachShader (m_program, vertex);
   glAttachShader (m_program, fragment);
   glLinkProgram (m_program);
 
+  // A different program for showing edges
+  m_program_edge = glCreateProgram();
+  glAttachShader (m_program_edge, vertex_edge);
+  glAttachShader (m_program_edge, fragment_edge);
+  glLinkProgram (m_program_edge);
+
   m_position_index = 0;
   m_color_index = 1;
   m_normal_index = 2;
   m_bary_index = 3;
 
-  glBindAttribLocation(m_program, m_position_index, "position");
-  glBindAttribLocation(m_program, m_color_index, "color");
-  glBindAttribLocation(m_program, m_normal_index, "normal");
-  glBindAttribLocation(m_program, m_bary_index, "bary");
-
-  int status = 0;
-  glGetProgramiv (m_program, GL_LINK_STATUS, &status);
-  if (status == GL_FALSE)
+  for (auto p : {m_program, m_program_edge})
     {
-      int log_len = 0;
-      glGetProgramiv (m_program, GL_INFO_LOG_LENGTH, &log_len);
-
-      string error_string;
-      error_string.resize(log_len+1);
-      glGetProgramInfoLog (m_program, log_len, NULL, &error_string[0]);
-
-      glDeleteProgram (m_program);
-      throw runtime_error(
-        format(
-          "Linking failure in program: {}",
-          error_string));
+      glBindAttribLocation(p, m_position_index, "position");
+      glBindAttribLocation(p, m_color_index, "color");
+      glBindAttribLocation(p, m_normal_index, "normal");
+      glBindAttribLocation(p, m_bary_index, "bary");
+
+      int status = 0;
+      glGetProgramiv (p, GL_LINK_STATUS, &status);
+      if (status == GL_FALSE)
+        {
+          int log_len = 0;
+          glGetProgramiv (p, GL_INFO_LOG_LENGTH, &log_len);
+    
+          string error_string;
+          error_string.resize(log_len+1);
+          glGetProgramInfoLog (p, log_len, NULL, &error_string[0]);
+    
+          glDeleteProgram (p);
+          throw runtime_error(
+            format(
+              "Linking failure in program: {}",
+              error_string));
+        }
     }
 
   /* the individual shaders can be detached and destroyed */
   glDetachShader (m_program, vertex);
   glDetachShader (m_program, fragment);
+  glDetachShader (m_program_edge, vertex_edge);
+  glDetachShader (m_program_edge, fragment_edge);
+
   glDeleteShader (vertex);
+  glDeleteShader (vertex_edge);
   glDeleteShader (fragment);
+  glDeleteShader (fragment_edge);
 }
 
 void MeshViewer::init_buffers (guint *vao_out)
@@ -341,19 +358,24 @@ void MeshViewer::build_projection_matrix()
 // Draw the mesh (or meshes)
 void MeshViewer::draw_mesh()
 {
+  guint program;
+  if (m_show_edge)
+    program = m_program_edge;
+  else
+    program = m_program;
+  glUseProgram(program);
+
   setup_world(m_size_scale*m_view_scale, 
               m_view_quat, m_pivot);
 
-  glUseProgram(m_program);
-
   // get the uniform locations
-  m_proj_loc = glGetUniformLocation (m_program, "projMatrix");
-  m_mv_loc = glGetUniformLocation (m_program, "mvMatrix");
-  m_normal_matrix_loc = glGetUniformLocation (m_program, "normalMatrix");
-  guint shininess_loc=glGetUniformLocation (m_program, "shininess");
-  guint specular_loc=glGetUniformLocation (m_program, "specular");
-  guint diffuse_loc=glGetUniformLocation (m_program, "diffuse");
-  guint ambient_loc=glGetUniformLocation (m_program, "ambient");
+  m_proj_loc = glGetUniformLocation (program, "projMatrix");
+  m_mv_loc = glGetUniformLocation (program, "mvMatrix");
+  m_normal_matrix_loc = glGetUniformLocation (program, "normalMatrix");
+  guint shininess_loc=glGetUniformLocation (program, "shininess");
+  guint specular_loc=glGetUniformLocation (program, "specular");
+  guint diffuse_loc=glGetUniformLocation (program, "diffuse");
+  guint ambient_loc=glGetUniformLocation (program, "ambient");
 
   // Fixed light properties - Should be configurable
   glUniform1f(shininess_loc, 10.0);
@@ -642,3 +664,9 @@ void MeshViewer::view_port_to_world(glm::vec3 view_port_coord,
 
   world_coord = glm::vec3(v.x/v.w,v.y/v.w,v.z/v.w);
 }
+
+void MeshViewer::set_show_edge(bool show_edge)
+{
+  m_show_edge = show_edge;
+  queue_render();
+}

src/mesh-viewer.h

@@ -34,6 +34,9 @@ class MeshViewer : public Gtk::GLArea
   // Reset the view to the original view
   void reset_view();
 
+  // Whether to use the edge shader or the non-edge shader
+  void set_show_edge(bool show_edge);
+
   private:
 
   // signals
@@ -75,6 +78,7 @@ class MeshViewer : public Gtk::GLArea
   guint m_vao {0};
   guint m_buffer {0};
   guint m_program {0};
+  guint m_program_edge {0};
 
   // Describe the vertex attribute layout
   guint m_position_index {0};
@@ -95,6 +99,9 @@ class MeshViewer : public Gtk::GLArea
   guint m_diffuse;
   guint m_ambient;
 
+  // which shader to use
+  bool m_show_edge = false;
+
   // world description
   glm::mat4 m_proj_matrix;
   glm::mat4 m_world;

src/pomelo.cc

@@ -66,6 +66,11 @@ Pomelo::Pomelo(shared_ptr<PomeloSettings> pomelo_settings)
   m_refActionGroup->add_action("view_skeleton",
     sigc::mem_fun(*this, &Pomelo::on_action_view_skeleton) );
 
+  bool init_show_edge = m_pomelo_settings->get_int_default("show_edge",0);
+  m_mesh_viewer.set_show_edge(init_show_edge);
+  m_ref_show_edge_toggle = m_refActionGroup->add_action_bool("show_edge",
+    sigc::mem_fun(*this, &Pomelo::on_action_show_edge), init_show_edge );
+
   m_refActionGroup->add_action("settings",
     sigc::mem_fun(*this, &Pomelo::on_action_view_settings) );
 
@@ -76,47 +81,51 @@ Pomelo::Pomelo(shared_ptr<PomeloSettings> pomelo_settings)
     "<interface>"
     "  <menu id='menubar'>"
     "    <submenu>"
-    "      <attribute name='label' translatable='yes'>_File</attribute>"
+    "      <attribute name='label'>_File</attribute>"
     "      <section>"
     "        <item>"
-    "          <attribute name='label' translatable='yes'>_Export STL</attribute>"
+    "          <attribute name='label'>_Export STL</attribute>"
     "          <attribute name='action'>pomelo.export_stl</attribute>"
     "          <attribute name='accel'>&lt;Primary&gt;s</attribute>"
     "        </item>"
     "        <item>"
-    "          <attribute name='label' translatable='yes'>_Load SVG</attribute>"
+    "          <attribute name='label'>_Load SVG</attribute>"
     "          <attribute name='action'>pomelo.load_svg</attribute>"
     "          <attribute name='accel'>&lt;Primary&gt;s</attribute>"
     "        </item>"
     "        <item>"
-    "          <attribute name='label' translatable='yes'>_Quit</attribute>"
+    "          <attribute name='label'>_Quit</attribute>"
     "          <attribute name='action'>pomelo.quit</attribute>"
     "          <attribute name='accel'>&lt;Primary&gt;q</attribute>"
     "        </item>"
     "      </section>"
     "    </submenu>"
     "    <submenu>"
-    "      <attribute name='label' translatable='yes'>_View</attribute>"
+    "      <attribute name='label'>_View</attribute>"
     "      <item>"
-    "        <attribute name='label' translatable='yes'>_Reset 3D View</attribute>"
+    "        <attribute name='label'>_Reset 3D View</attribute>"
     "        <attribute name='action'>pomelo.reset_3d_view</attribute>"
     "      </item>"
+    "      <item>"
+    "        <attribute name='label'>Show mesh edges</attribute>"
+    "        <attribute name='action'>pomelo.show_edge</attribute>"
+    "      </item>"
     "    </submenu>"
     "    <submenu>"
-    "      <attribute name='label' translatable='yes'>_Tools</attribute>"
+    "      <attribute name='label'>_Tools</attribute>"
     "      <item>"
-    "        <attribute name='label' translatable='yes'>_View Skeleton</attribute>"
+    "        <attribute name='label'>_View Skeleton</attribute>"
     "        <attribute name='action'>pomelo.view_skeleton</attribute>"
     "      </item>"
     "      <item>"
-    "        <attribute name='label' translatable='yes'>Settings</attribute>"
+    "        <attribute name='label'>Settings</attribute>"
     "        <attribute name='action'>pomelo.settings</attribute>"
     "      </item>"
     "    </submenu>"
     "    <submenu>"
-    "      <attribute name='label' translatable='yes'>_Help</attribute>"
+    "      <attribute name='label'>_Help</attribute>"
     "      <item>"
-    "        <attribute name='label' translatable='yes'>_About</attribute>"
+    "        <attribute name='label'>_About</attribute>"
     "        <attribute name='action'>pomelo.about</attribute>"
     "      </item>"
     "    </submenu>"
@@ -289,6 +298,22 @@ void Pomelo::on_action_view_skeleton()
   m_skeleton_viewer->show();
 }
 
+void Pomelo::on_action_show_edge()
+{
+  bool active = false;
+  m_ref_show_edge_toggle->get_state(active);
+
+  //The toggle action's state does not change automatically:
+  active = !active;
+  m_ref_show_edge_toggle->change_state(active);
+
+  // Store the new state
+  m_pomelo_settings->set_int("show_edge", int(active));
+  m_pomelo_settings->save();
+
+  m_mesh_viewer.set_show_edge(active);
+}
+
 void Pomelo::on_action_reset_3d_view()
 {
   m_mesh_viewer.reset_view();

src/pomelo.h

@@ -60,6 +60,7 @@ class Pomelo : public Gtk::Window
   void on_action_file_export_stl();
   void on_action_help_about();
   void on_action_view_skeleton();
+  void on_action_show_edge();
   void on_action_reset_3d_view();
   void on_action_view_settings();
   void on_action_load_svg();
@@ -100,6 +101,7 @@ class Pomelo : public Gtk::Window
   std::unique_ptr<std::thread> m_worker_skeleton_thread;
   WorkerAction m_worker_action;  // What is our worker doing
   std::shared_ptr<PomeloSettings> m_pomelo_settings;
+  Glib::RefPtr<Gio::SimpleAction> m_ref_show_edge_toggle;
 };
 
 #endif /* HELLO-WORLD */

src/resources.xml

@@ -4,6 +4,7 @@
   </gresource>
   <gresource prefix="/shaders">
     <file>fragment.glsl</file>
+    <file>fragment-edge.glsl</file>
     <file>vertex.glsl</file>
   </gresource>
   <gresource prefix="/about">

src/smooth-sharp-angles.cc

@@ -83,7 +83,7 @@ static double calc_angle(const Point_2& p,
   Vector_2 v(q,p);
   Vector_2 w(q,r);
   double angle = acos(v*w/(CGAL::sqrt(v.squared_length())*CGAL::sqrt(w.squared_length())));
-  print("angle = {} deg\n", angle*180/MY_PI);
+  //  print("angle = {} deg\n", angle*180/MY_PI);
   return angle;
 }