[gtk] Allow Gtk3 usage

CMakeLists.txt

@@ -58,6 +58,7 @@ option(ENABLE_TESTS   "Enable unit tests? (Default: off)" OFF)
 option(ENABLE_DATA    "Install data from content submodule? (Default: on)" ON)
 option(ENABLE_GLES    "Build for OpenGL ES 2.0 instead of OpenGL 2.1 (Default: off)" OFF)
 option(USE_GTKGLEXT   "Use libgtkglext1 for GTK2 frontend (Default: on)" ON)
+option(USE_GTK3       "Use Gtk3 in GTK2 frontend (Default: off)" OFF)
 
 if(ENABLE_GLES)
   add_definitions(-DGL_ES)
@@ -65,6 +66,11 @@ if(ENABLE_GLES)
   set(USE_GTKGLEXT OFF)
 endif()
 
+if(USE_GTK3)
+  # Disable USE_GTKGLEXT if using Gtk+3
+  set(USE_GTKGLEXT OFF)
+endif()
+
 if(NOT CMAKE_BUILD_TYPE)
   set(CMAKE_BUILD_TYPE "Release" CACHE STRING "Build type." FORCE)
 endif()

INSTALL.md

@@ -339,6 +339,8 @@ List of supported parameters (passed as `-DPARAMETER=VALUE`):
 | ENABLE_DATA          | bool | OFF     | Use CelestiaContent submodule for data
 | ENABLE_GLES          | bool | OFF     | Use OpenGL ES 2.0 in rendering code
 | NATIVE_OSX_APP       | bool | OFF     | Support native OSX data paths
+| USE_GTKGLEXT         | bool | ON      | Use libgtkglext1 in GTK2 frontend
+| USE_GTK3             | bool | OFF     | Use Gtk3 instead of Gtk2 in GTK2 frontend
 
 Notes:
  \* /usr/local on Unix-like systems, c:\Program Files or c:\Program Files (x86)
@@ -356,6 +358,11 @@ On Windows systems two additonal options are supported:
   64-bit Celestia. To build 32-bit Celestia it should be omitted.
 - `CMAKE_TOOLCHAIN_FILE` - location of vcpkg.cmake if vcpkg is used.
 
+Please note that not all options are compatible:
+- `USE_GTKGLEXT` is not compatible with `ENABLE_GLES` and `USE_GTK3` and will
+  be disabled if any of this is set.
+- `ENABLE_GLES` is not compatible with `ENABLE_GLUT` and with `ENABLE_QT` if
+  your `glut` or Qt5 installation don't support OpenGL ES.
 
 Executable files
 ----------------

src/celestia/gtk/CMakeLists.txt

@@ -42,7 +42,11 @@ if (NOT USE_GTKGLEXT)
   set(GTK_HEADERS ${GTK_HEADERS} gtkegl.h)
 endif()
 
-pkg_check_modules(GTK2 gtk+-2.0 REQUIRED)
+if (USE_GTK3)
+  pkg_check_modules(GTK gtk+-3.0 REQUIRED)
+else()
+  pkg_check_modules(GTK gtk+-2.0 REQUIRED)
+endif()
 pkg_check_modules(CAIRO cairo)
 
 if (ENABLE_GLES)
@@ -59,8 +63,8 @@ add_executable(celestia-gtk ${GTK_SOURCES})
 add_dependencies(celestia-gtk celestia)
 cotire(celestia-gtk)
 
-target_include_directories(celestia-gtk PRIVATE ${GTK2_INCLUDE_DIRS})
-target_link_libraries(celestia-gtk celestia ${GTK2_LIBRARIES})
+target_include_directories(celestia-gtk PRIVATE ${GTK_INCLUDE_DIRS})
+target_link_libraries(celestia-gtk celestia ${GTK_LIBRARIES})
 
 if (CAIRO_FOUND)
   target_include_directories(celestia-gtk PRIVATE ${CAIRO_INCLUDE_DIRS})

src/celestia/gtk/glwidget.cpp

@@ -28,7 +28,11 @@
 /* Declarations: Callbacks */
 static gint glarea_idle(AppData* app);
 static gint glarea_configure(GtkWidget* widget, GdkEventConfigure*, AppData* app);
+#if GTK_MAJOR_VERSION == 2
 static gint glarea_expose(GtkWidget* widget, GdkEventExpose* event, AppData* app);
+#else
+static gint glarea_draw(GtkWidget*, cairo_t*, AppData* app);
+#endif
 static gint glarea_motion_notify(GtkWidget*, GdkEventMotion* event, AppData* app);
 static gint glarea_mouse_scroll(GtkWidget*, GdkEventScroll* event, AppData* app);
 static gint glarea_button_press(GtkWidget*, GdkEventButton* event, AppData* app);
@@ -44,8 +48,13 @@ static bool handleSpecialKey(int key, int state, bool down, AppData* app);
 /* ENTRY: Initialize/Bind all glArea Callbacks */
 void initGLCallbacks(AppData* app)
 {
+#if GTK_MAJOR_VERSION == 2
     g_signal_connect(G_OBJECT(app->glArea), "expose_event",
                      G_CALLBACK(glarea_expose), app);
+#else
+    g_signal_connect(G_OBJECT(app->glArea), "draw",
+                     G_CALLBACK(glarea_draw), app);
+#endif
     g_signal_connect(G_OBJECT(app->glArea), "configure_event",
                      G_CALLBACK(glarea_configure), app);
     g_signal_connect(G_OBJECT(app->glArea), "button_press_event",
@@ -102,6 +111,7 @@ static gint glarea_configure(GtkWidget* widget, GdkEventConfigure*, AppData* app
 }
 
 
+#if GTK_MAJOR_VERSION == 2
 /* CALLBACK: GL Function for event "expose_event" */
 static gint glarea_expose(GtkWidget*, GdkEventExpose* event, AppData* app)
 {
@@ -112,6 +122,13 @@ static gint glarea_expose(GtkWidget*, GdkEventExpose* event, AppData* app)
     /* Redraw -- draw checks are made in function */
     return glDrawFrame(app);
 }
+#else
+/* CALLBACK: GL Function for event "draw" */
+static gint glarea_draw(GtkWidget*, cairo_t*, AppData* app)
+{
+    return glDrawFrame(app);
+}
+#endif
 
 
 /* CALLBACK: GL Function for event "motion_notify_event" */

src/celestia/gtk/splash.cpp

@@ -23,7 +23,9 @@
 using namespace std;
 
 /* Declarations */
+#if GTK_MAJOR_VERSION == 2
 static gboolean splashExpose(GtkWidget* win, GdkEventExpose *event, SplashData* ss);
+#endif
 
 
 /* OBJECT: Overrides ProgressNotifier to receive feedback from core */
@@ -58,7 +60,7 @@ SplashData* splashStart(AppData* app, gboolean showSplash)
     gtk_window_set_position(GTK_WINDOW(ss->splash), GTK_WIN_POS_CENTER);
     gtk_widget_set_app_paintable(ss->splash, TRUE);
 
-    #ifdef CAIRO
+    #if defined(CAIRO) && GTK_MAJOR_VERSION == 2
     /* Colormap Magic */
     GdkScreen* screen = gtk_widget_get_screen(ss->splash);
     GdkColormap* colormap = gdk_screen_get_rgba_colormap(screen);
@@ -93,9 +95,11 @@ SplashData* splashStart(AppData* app, gboolean showSplash)
     gtk_fixed_put(GTK_FIXED(gf), ss->label, 40, allocation.height / 2 - 40);
     gtk_widget_show(ss->label);
 
+#if GTK_MAJOR_VERSION == 2
     g_signal_connect (ss->splash, "expose_event",
                       G_CALLBACK (splashExpose),
                       ss);
+#endif
 
     while (gtk_events_pending()) gtk_main_iteration();
 
@@ -133,7 +137,7 @@ void splashSetText(SplashData* ss, const char* text)
     while (gtk_events_pending()) gtk_main_iteration();
 }
 
-
+#if GTK_MAJOR_VERSION == 2
 /* CALLBACK: Called when the splash screen is exposed */
 static gboolean splashExpose(GtkWidget* win, GdkEventExpose *event, SplashData* ss)
 {
@@ -190,3 +194,4 @@ static gboolean splashExpose(GtkWidget* win, GdkEventExpose *event, SplashData*
 
     return FALSE;
 }
+#endif