def apply_glsl_effect(actor):
actor.clear_effects()
effect = Clutter.ShaderEffect()
effect.shader_type = 1
effect.set_shader_source(open('gloom.glsl').read())
effect.set_uniform_value('width', actor.get_width())
effect.set_uniform_value('height', actor.get_height())
actor.add_effect(effect)
return effect
