+#include <gtk/gtk.h>
+
+/***************************
+ * GtkGlExt implementation *
+ ***************************/
+#if defined(USE_GTKGLEXT)
+#include <gtk/gtkgl.h>
+void gtk_gl_enable(GtkWidget *widget)
+{
+ GdkGLConfig *glconfig = gdk_gl_config_new_by_mode(
+ GDK_GL_MODE_RGBA | GDK_GL_MODE_DEPTH |
+ GDK_GL_MODE_ALPHA | GDK_GL_MODE_DOUBLE);
+ gtk_widget_set_gl_capability(widget,
+ glconfig, NULL, TRUE, GDK_GL_RGBA_TYPE);
+}
+
+void gtk_gl_begin(GtkWidget *widget)
+{
+ GdkGLContext *glcontext = gtk_widget_get_gl_context(widget);
+ GdkGLDrawable *gldrawable = gtk_widget_get_gl_drawable(widget);
+ gdk_gl_drawable_gl_begin(gldrawable, glcontext);
+}
+
+void gtk_gl_end(GtkWidget *widget)
+{
+ GdkGLDrawable *gldrawable = gtk_widget_get_gl_drawable(widget);
+ gdk_gl_drawable_swap_buffers(gldrawable);
+ gdk_gl_drawable_gl_end(gldrawable);
+}
+
+void gtk_gl_disable(GtkWidget *widget)
+{
+}
+
+
+/**********************
+ * X11 implementation *
+ **********************/
+#elif defined(USE_GLX)
+#include <GL/glx.h>
+#include <gdk/gdkx.h>
+void gtk_gl_enable(GtkWidget *widget)
+{
+ g_debug("GtkGl: enable");
+ GdkScreen *screen = gdk_screen_get_default();
+ Display *xdisplay = GDK_SCREEN_XDISPLAY(screen);
+ gint nscreen = GDK_SCREEN_XNUMBER(screen);
+
+ /* Create context */
+ int attribs[] = {GLX_RGBA,
+ GLX_RED_SIZE, 1,
+ GLX_GREEN_SIZE, 1,
+ GLX_BLUE_SIZE, 1,
+ GLX_ALPHA_SIZE, 1,
+ GLX_DOUBLEBUFFER,
+ GLX_DEPTH_SIZE, 1,
+ None};
+ XVisualInfo *xvinfo = glXChooseVisual(xdisplay, nscreen, attribs);
+ GLXContext context = glXCreateContext(xdisplay, xvinfo, NULL, False);
+ g_object_set_data(G_OBJECT(widget), "glcontext", context);
+
+ /* Fix up colormap */
+ GdkVisual *visual = gdk_x11_screen_lookup_visual(screen, xvinfo->visualid);
+ GdkColormap *cmap = gdk_colormap_new(visual, FALSE);
+ gtk_widget_set_colormap(widget, cmap);
+
+ /* Disable GTK double buffering */
+ gtk_widget_set_double_buffered(widget, FALSE);
+}
+
+void gtk_gl_begin(GtkWidget *widget)
+{
+ g_debug("GtkGl: begin");
+ Display *xdisplay = GDK_SCREEN_XDISPLAY(gtk_widget_get_screen(widget));
+ Window xwindow = GDK_WINDOW_XID(gtk_widget_get_window(widget));
+ GLXContext context = g_object_get_data(G_OBJECT(widget), "glcontext");
+ glXMakeCurrent(xdisplay, xwindow, context);
+}
+
+void gtk_gl_end(GtkWidget *widget)
+{
+ g_debug("GtkGl: end");
+ Display *xdisplay = GDK_SCREEN_XDISPLAY(gtk_widget_get_screen(widget));
+ Window xwindow = GDK_WINDOW_XID(gtk_widget_get_window(widget));
+ glXSwapBuffers(xdisplay, xwindow);
+}
+
+void gtk_gl_disable(GtkWidget *widget)
+{
+ g_debug("GtkGl: disable");
+ Display *xdisplay = GDK_SCREEN_XDISPLAY(gtk_widget_get_screen(widget));
+ GLXContext context = g_object_get_data(G_OBJECT(widget), "glcontext");
+ glXDestroyContext(xdisplay, context);
+}
+
+
+/************************
+ * Win32 implementation *
+ ************************/
+#elif defined(USE_WGL)
+#include <windows.h>
+#include <gdk/gdkwin32.h>
+static void on_realize(GtkWidget *widget, gpointer _)
+{
+ g_debug("GtkGl: on_realize");
+ gdk_window_ensure_native(gtk_widget_get_window(widget));
+ gtk_widget_set_double_buffered(widget, FALSE);
+
+ HWND hwnd = GDK_WINDOW_HWND(gtk_widget_get_window(widget));
+ HDC hDC = GetDC(hwnd);
+
+ PIXELFORMATDESCRIPTOR pfd = {
+ .nSize = sizeof(pfd),
+ .nVersion = 1,
+ .dwFlags = PFD_DRAW_TO_WINDOW
+ | PFD_SUPPORT_OPENGL
+ | PFD_DOUBLEBUFFER,
+ //.dwFlags = PFD_SUPPORT_OPENGL
+ // | PFD_DRAW_TO_WINDOW,
+ .iPixelType = PFD_TYPE_RGBA,
+ .cColorBits = 24,
+ .cAlphaBits = 8,
+ .cDepthBits = 32,
+ .iLayerType = PFD_MAIN_PLANE,
+ };
+ int pf = ChoosePixelFormat(hDC, &pfd);
+ if (pf == 0)
+ g_error("GtkGl: ChoosePixelFormat failed");
+ if (!SetPixelFormat(hDC, pf, &pfd))
+ g_error("GtkGl: SetPixelFormat failed");
+ HGLRC hRC = wglCreateContext(hDC);
+ if (hRC == NULL)
+ g_error("GtkGl: wglCreateContext failed");
+ g_object_set_data(G_OBJECT(widget), "glcontext", hRC);
+}
+
+void gtk_gl_enable(GtkWidget *widget)
+{
+ g_debug("GtkGl: enable");
+ g_signal_connect(widget, "realize", G_CALLBACK(on_realize), NULL);
+}
+
+void gtk_gl_begin(GtkWidget *widget)
+{
+ g_debug("GtkGl: begin");
+ HWND hwnd = GDK_WINDOW_HWND(gtk_widget_get_window(widget));
+ HDC hDC = GetDC(hwnd);
+ HGLRC hRC = g_object_get_data(G_OBJECT(widget), "glcontext");
+ if (!wglMakeCurrent(hDC, hRC))
+ g_error("GtkGl: wglMakeCurrent failed");
+}
+
+void gtk_gl_end(GtkWidget *widget)
+{
+ g_debug("GtkGl: end");
+ HWND hwnd = GDK_WINDOW_HWND(gtk_widget_get_window(widget));
+ HDC hDC = GetDC(hwnd);
+ if (!SwapBuffers(hDC))
+ g_error("GtkGl: SwapBuffers failed");
+}
+
+void gtk_gl_disable(GtkWidget *widget)
+{
+ g_debug("GtkGl: disable");
+ HGLRC hRC = g_object_get_data(G_OBJECT(widget), "glcontext");
+ wglDeleteContext(hRC);
+}
+
+
+
+/**************************
+ * Mac OSX implementation *
+ **************************/
+#elif defined(USE_CGL)
+void gtk_gl_enable(GtkWidget *widget) { }
+void gtk_gl_begin(GtkWidget *widget) { }
+void gtk_gl_end(GtkWidget *widget) { }
+void gtk_gl_disable(GtkWidget *widget) { }
+
+
+/****************************
+ * Undefined implementation *
+ ****************************/
+#else
+#warning "Unimplemented GtkGl"
+void gtk_gl_enable(GtkWidget *widget) { }
+void gtk_gl_begin(GtkWidget *widget) { }
+void gtk_gl_end(GtkWidget *widget) { }
+void gtk_gl_disable(GtkWidget *widget) { }
+#endif