Add preliminary opengl widget

transparent.py

@@ -6,6 +6,7 @@ import gi
 gi.require_version("Gtk", "3.0")
 from gi.repository import Gtk  # noqa
 import cairo  # noqa
+from OpenGL.GL import glClearColor, glClear, glFlush, GL_COLOR_BUFFER_BIT
 
 
 class TestWin(Gtk.Window):
@@ -15,10 +16,18 @@ class TestWin(Gtk.Window):
         Gtk.Window.__init__(self, type=self.WINDOW_POPUP)
 
         self._default_monitor = 0
-        self.make_fullscreen()
-        self.label = Gtk.Label(label="Hallo! :)")
-        self.label.show()
-        self.add(self.label)
+        self.set_window_geometry()
+
+        self.layout = Gtk.Box()
+        self.layout.show()
+        self.add(self.layout)
+
+        self.gl = Gtk.GLArea()
+        self.gl.connect("render", self.gl_render)
+        self.gl.connect("realize", self.gl_realize)
+        # self.gl.connect('create-context', self.gl_context)
+        self.gl.show()
+        self.layout.pack_end(self.gl, True, True, 0)
 
         self.make_rgba()
         self.set_app_paintable(True)
@@ -38,7 +47,7 @@ class TestWin(Gtk.Window):
         else:
             self.set_visual(self.visual)
 
-    def make_fullscreen(self):
+    def set_window_geometry(self):
         geo = self.get_screen_size(self._default_monitor)
         scale = (1.05, 6)
         x, y, w, h = (
@@ -57,7 +66,7 @@ class TestWin(Gtk.Window):
     def on_draw(self, widget, cr):
         # make everything transparent
         cr.set_source_rgba(1.0, 1.0, 1.0, 0.1)
-        cr.set_operator(cairo.OPERATOR_SOURCE)
+        # cr.set_operator(cairo.OPERATOR_SOURCE)
         cr.paint()
         cr.set_operator(cairo.OPERATOR_OVER)
 
@@ -72,6 +81,23 @@ class TestWin(Gtk.Window):
     def make_untouchable(self):
         self.input_shape_combine_region(cairo.Region(cairo.RectangleInt(0, 0, 0, 0)))
 
+    def gl_realize(self, gl_area):
+        error = gl_area.get_error()
+        if error != None:
+            print(f"ERROR: No OpenGL ({error})")
+
+    def gl_context(self, gl_area):
+        c = gl_area.get_context()
+        print(c, "context")
+        return c
+
+    def gl_render(self, area, context):
+        glClearColor(1.0, 0.5, 0.5, 1.0)
+        glClear(GL_COLOR_BUFFER_BIT)
+        glFlush()
+        print("rendering... done")
+        return True
+
     def run(self):
         Gtk.main()
         return 0