Rework bitmap system to load from archived PNGs

Bitmaps are now identified by an enum class instead of by pointers.
Bitmap loading and caching is now handled by a class in common, and
we no longer compile most bitmaps into the binary, so there is no
longer a bitmaps static library.

Instead, bitmaps are archived to a .tar.gz file which is installed
in ${KICAD_DATA}/resources/images.tar.gz

The source PNGs are checked in to Git as the original CPP files were,
so that people can build without the required dependencies to convert
SVGs to PNGs.

Initial support is also added for dark theme icons, although this
is not yet exposed in the GUI.

Stubs are present for multi-resolution image resources, but this is
not fully-baked yet and could use some refinement.

eeschema/sim/sim_plot_frame.cpp

@@ -136,7 +136,7 @@ SIM_PLOT_FRAME::SIM_PLOT_FRAME( KIWAY* aKiway, wxWindow* aParent )
 
     // Give an icon
     wxIcon icon;
-    icon.CopyFromBitmap( KiBitmap( simulator_xpm ) );
+    icon.CopyFromBitmap( KiBitmap( BITMAPS::simulator ) );
     SetIcon( icon );
 
     // Get the previous size and position of windows:
@@ -182,15 +182,15 @@ SIM_PLOT_FRAME::SIM_PLOT_FRAME( KIWAY* aKiway, wxWindow* aParent )
 
     // Toolbar buttons
     m_toolSimulate = m_toolBar->AddTool( ID_SIM_RUN, _( "Run/Stop Simulation" ),
-            KiBitmap( sim_run_xpm ), _( "Run Simulation" ), wxITEM_NORMAL );
+            KiBitmap( BITMAPS::sim_run ), _( "Run Simulation" ), wxITEM_NORMAL );
     m_toolAddSignals = m_toolBar->AddTool( ID_SIM_ADD_SIGNALS, _( "Add Signals" ),
-            KiBitmap( sim_add_signal_xpm ), _( "Add signals to plot" ), wxITEM_NORMAL );
+            KiBitmap( BITMAPS::sim_add_signal ), _( "Add signals to plot" ), wxITEM_NORMAL );
     m_toolProbe = m_toolBar->AddTool( ID_SIM_PROBE,  _( "Probe" ),
-            KiBitmap( sim_probe_xpm ), _( "Probe signals on the schematic" ), wxITEM_NORMAL );
+            KiBitmap( BITMAPS::sim_probe ), _( "Probe signals on the schematic" ), wxITEM_NORMAL );
     m_toolTune = m_toolBar->AddTool( ID_SIM_TUNE, _( "Tune" ),
-            KiBitmap( sim_tune_xpm ), _( "Tune component values" ), wxITEM_NORMAL );
+            KiBitmap( BITMAPS::sim_tune ), _( "Tune component values" ), wxITEM_NORMAL );
     m_toolSettings = m_toolBar->AddTool( wxID_ANY, _( "Sim Parameters" ),
-            KiBitmap( config_xpm ), _( "Simulation parameters and settings" ), wxITEM_NORMAL );
+            KiBitmap( BITMAPS::config ), _( "Simulation parameters and settings" ), wxITEM_NORMAL );
 
     Connect( m_toolSimulate->GetId(), wxEVT_COMMAND_TOOL_CLICKED,
              wxCommandEventHandler( SIM_PLOT_FRAME::onSimulate ), NULL, this );
@@ -293,7 +293,7 @@ WINDOW_SETTINGS* SIM_PLOT_FRAME::GetWindowSettings( APP_SETTINGS_BASE* aCfg )
 struct BM_MENU_INIT_ITEM
 {
     int m_MenuId;
-    BITMAP_DEF m_Bitmap;
+    BITMAPS m_Bitmap;
 };
 
 
@@ -303,31 +303,31 @@ void SIM_PLOT_FRAME::setIconsForMenuItems()
     BM_MENU_INIT_ITEM bm_list[]
     {
         // File menu:
-        { wxID_NEW, simulator_xpm },
-        { wxID_OPEN, directory_open_xpm },
-        { wxID_SAVE, save_xpm},
-        { ID_SAVE_AS_IMAGE, export_xpm},
-        { ID_SAVE_AS_CSV, export_xpm},
-        { wxID_CLOSE, exit_xpm},
+        { wxID_NEW, BITMAPS::simulator },
+        { wxID_OPEN, BITMAPS::directory_open },
+        { wxID_SAVE, BITMAPS::save },
+        { ID_SAVE_AS_IMAGE, BITMAPS::export_file },
+        { ID_SAVE_AS_CSV, BITMAPS::export_file },
+        { wxID_CLOSE, BITMAPS::exit },
 
         // simulator menu:
-        { ID_MENU_RUN_SIM, sim_run_xpm},
-        { ID_MENU_ADD_SIGNAL, sim_add_signal_xpm},
-        { ID_MENU_PROBE_SIGNALS, sim_probe_xpm},
-        { ID_MENU_TUNE_SIGNALS, sim_tune_xpm},
-        { ID_MENU_SHOW_NETLIST, netlist_xpm},
-        { ID_MENU_SET_SIMUL, config_xpm},
+        { ID_MENU_RUN_SIM, BITMAPS::sim_run },
+        { ID_MENU_ADD_SIGNAL, BITMAPS::sim_add_signal },
+        { ID_MENU_PROBE_SIGNALS, BITMAPS::sim_probe },
+        { ID_MENU_TUNE_SIGNALS, BITMAPS::sim_tune },
+        { ID_MENU_SHOW_NETLIST, BITMAPS::netlist },
+        { ID_MENU_SET_SIMUL, BITMAPS::config },
 
         // View menu
-        { wxID_ZOOM_IN, zoom_in_xpm},
-        { wxID_ZOOM_OUT, zoom_out_xpm},
-        { wxID_ZOOM_FIT, zoom_fit_in_page_xpm},
-        { ID_MENU_SHOW_GRID, grid_xpm},
-        { ID_MENU_SHOW_LEGEND, text_xpm},
-        { ID_MENU_DOTTED, add_dashed_line_xpm},
-        { ID_MENU_WHITE_BG, swap_layer_xpm},
+        { wxID_ZOOM_IN, BITMAPS::zoom_in },
+        { wxID_ZOOM_OUT, BITMAPS::zoom_out },
+        { wxID_ZOOM_FIT, BITMAPS::zoom_fit_in_page },
+        { ID_MENU_SHOW_GRID, BITMAPS::grid },
+        { ID_MENU_SHOW_LEGEND, BITMAPS::text },
+        { ID_MENU_DOTTED, BITMAPS::add_dashed_line },
+        { ID_MENU_WHITE_BG, BITMAPS::swap_layer },
 
-        { 0, nullptr }  // Sentinel
+        { 0, BITMAPS::INVALID_BITMAP }  // Sentinel
     };
 
     // wxMenuItems are already created and attached to the m_mainMenu wxMenuBar.
@@ -341,7 +341,7 @@ void SIM_PLOT_FRAME::setIconsForMenuItems()
     {
         wxMenuItem* item = m_mainMenu->FindItem( bm_list[ii].m_MenuId );
 
-        if( !item || !bm_list[ii].m_Bitmap)
+        if( !item || ( bm_list[ii].m_Bitmap == BITMAPS::INVALID_BITMAP ) )
             continue;
 
         wxMenu* menu = item->GetMenu();
@@ -1446,14 +1446,14 @@ void SIM_PLOT_FRAME::onCursorUpdate( wxCommandEvent& event )
 
 void SIM_PLOT_FRAME::onSimStarted( wxCommandEvent& aEvent )
 {
-    m_toolBar->SetToolNormalBitmap( ID_SIM_RUN, KiBitmap( sim_stop_xpm ) );
+    m_toolBar->SetToolNormalBitmap( ID_SIM_RUN, KiBitmap( BITMAPS::sim_stop ) );
     SetCursor( wxCURSOR_ARROWWAIT );
 }
 
 
 void SIM_PLOT_FRAME::onSimFinished( wxCommandEvent& aEvent )
 {
-    m_toolBar->SetToolNormalBitmap( ID_SIM_RUN, KiBitmap( sim_run_xpm ) );
+    m_toolBar->SetToolNormalBitmap( ID_SIM_RUN, KiBitmap( BITMAPS::sim_run ) );
     SetCursor( wxCURSOR_ARROW );
 
     SIM_TYPE simType = m_exporter->GetSimType();
@@ -1561,14 +1561,14 @@ SIM_PLOT_FRAME::SIGNAL_CONTEXT_MENU::SIGNAL_CONTEXT_MENU( const wxString& aSigna
 
     AddMenuItem( this, HIDE_SIGNAL, _( "Hide Signal" ),
                  _( "Erase the signal from plot screen" ),
-                 KiBitmap( trash_xpm ) );
+                 KiBitmap( BITMAPS::trash ) );
 
     TRACE* trace = plot->GetTrace( m_signal );
 
     if( trace->HasCursor() )
-        AddMenuItem( this, HIDE_CURSOR, _( "Hide Cursor" ), KiBitmap( pcb_target_xpm ) );
+        AddMenuItem( this, HIDE_CURSOR, _( "Hide Cursor" ), KiBitmap( BITMAPS::pcb_target ) );
     else
-        AddMenuItem( this, SHOW_CURSOR, _( "Show Cursor" ), KiBitmap( pcb_target_xpm ) );
+        AddMenuItem( this, SHOW_CURSOR, _( "Show Cursor" ), KiBitmap( BITMAPS::pcb_target ) );
 
     Connect( wxEVT_COMMAND_MENU_SELECTED, wxMenuEventHandler( SIGNAL_CONTEXT_MENU::onMenuEvent ), NULL, this );
 }