OpenGL-Capable Widget 3 GTKGLEXT Library OpenGL-Capable WidgetOpenGL extension to GtkWidget API #include <gtk/gtkgl.h> gboolean gtk_widget_set_gl_capability (GtkWidget *widget, GdkGLConfig *glconfig, GdkGLContext *share_list, gboolean direct, int render_type); gboolean gtk_widget_is_gl_capable (GtkWidget *widget); GdkGLConfig* gtk_widget_get_gl_config (GtkWidget *widget); GdkGLContext* gtk_widget_create_gl_context (GtkWidget *widget, GdkGLContext *share_list, gboolean direct, int render_type); GdkGLContext* gtk_widget_get_gl_context (GtkWidget *widget); GdkGLWindow* gtk_widget_get_gl_window (GtkWidget *widget); #define gtk_widget_get_gl_drawable (widget) GtkGLExt is an extension to GTK which adds OpenGL capabilities to GtkWidget. Its use is quite simple: use gtk_widget_set_gl_capability to add OpenGL support to a widget, it will create a OpenGL drawable (GdkGLDrawable) for the widget, which can be obtained via gtk_widget_get_gl_drawable. OpenGL rendering context (GdkGLContext) can also be obtained via gtk_widget_get_gl_context. With GdkGLDrawable and GdkGLContext, gdk_gl_drawable_gl_begin and gdk_gl_drawable_gl_end can be called, and OpenGL function calls can be made between those two functions. gtk_widget_set_gl_capabilitygboolean gtk_widget_set_gl_capability (GtkWidget *widget, GdkGLConfig *glconfig, GdkGLContext *share_list, gboolean direct, int render_type); Set the OpenGL-capability to the widget. This function prepares the widget for its use with OpenGL. widget : the GtkWidget to be used as the rendering area. glconfig : a GdkGLConfig. share_list : the GdkGLContext with which to share display lists and texture objects. NULL indicates that no sharing is to take place. direct : whether rendering is to be done with a direct connection to the graphics system. render_type : GDK_GL_RGBA_TYPE or GDK_GL_COLOR_INDEX_TYPE (currently not used). Returns : TRUE if it is successful, FALSE otherwise. gtk_widget_is_gl_capablegboolean gtk_widget_is_gl_capable (GtkWidget *widget); Returns whether the widget is OpenGL-capable. widget : a GtkWidget. Returns : TRUE if the widget is OpenGL-capable, FALSE otherwise. gtk_widget_get_gl_configGdkGLConfig* gtk_widget_get_gl_config (GtkWidget *widget); Returns the GdkGLConfig referred by the widget. widget : a GtkWidget. Returns : the GdkGLConfig. gtk_widget_create_gl_contextGdkGLContext* gtk_widget_create_gl_context (GtkWidget *widget, GdkGLContext *share_list, gboolean direct, int render_type); Creates a new GdkGLContext with the appropriate GdkGLDrawable for this widget. The GL context must be freed when you're finished with it. See also gtk_widget_get_gl_context(). widget : a GtkWidget. share_list : the GdkGLContext with which to share display lists and texture objects. NULL indicates that no sharing is to take place. direct : whether rendering is to be done with a direct connection to the graphics system. render_type : GDK_GL_RGBA_TYPE or GDK_GL_COLOR_INDEX_TYPE (currently not used). Returns : the new GdkGLContext. gtk_widget_get_gl_contextGdkGLContext* gtk_widget_get_gl_context (GtkWidget *widget); Returns the GdkGLContext with the appropriate GdkGLDrawable for this widget. Unlike the GL context returned by gtk_widget_create_gl_context(), this context is owned by the widget. GdkGLContext is needed for the function gdk_gl_drawable_begin, or for sharing display lists (see gtk_widget_set_gl_capability()). widget : a GtkWidget. Returns : the GdkGLContext. gtk_widget_get_gl_windowGdkGLWindow* gtk_widget_get_gl_window (GtkWidget *widget); Returns the GdkGLWindow owned by the widget. widget : a GtkWidget. Returns : the GdkGLWindow. gtk_widget_get_gl_drawable#define gtk_widget_get_gl_drawable(widget) Returns the GdkGLDrawable owned by the widget. In fact, this is macro that casts the result of gtk_widget_get_gl_window to GdkGLDrawable. widget : a GtkWidget. Returns :the GdkGLDrawable.