Cairo.Context.PaintWithAlpha C# (CSharp) Метод

        public void PaintWithAlpha(double alpha)
        {
            CheckDisposed ();
            NativeMethods.cairo_paint_with_alpha (handle, alpha);
        }

        private void RenderAnimation(Cairo.Context cr)
        {
            if (stage.Actor == null)
            {
                // We are not in a transition, just render
                RenderStage(cr, current_track, current_image);
                return;
            }

            if (current_track == null)
            {
                // Fade in the whole stage, nothing to fade out
                CairoExtensions.PushGroup(cr);
                RenderStage(cr, incoming_track, incoming_image);
                CairoExtensions.PopGroupToSource(cr);

                cr.PaintWithAlpha(stage.Actor.Percent);
                return;
            }

            // XFade only the cover art
            RenderCoverArt(cr, incoming_image);

            CairoExtensions.PushGroup(cr);
            RenderCoverArt(cr, current_image);
            CairoExtensions.PopGroupToSource(cr);

            cr.PaintWithAlpha(1.0 - stage.Actor.Percent);

            // Fade in/out the text
            bool same_artist_album = incoming_track != null?incoming_track.ArtistAlbumEqual(current_track) : false;

            bool same_track = incoming_track != null?incoming_track.Equals(current_track) : false;

            if (same_artist_album)
            {
                RenderTrackInfo(cr, incoming_track, same_track, true);
            }

            if (stage.Actor.Percent <= 0.5)
            {
                // Fade out old text
                CairoExtensions.PushGroup(cr);
                RenderTrackInfo(cr, current_track, !same_track, !same_artist_album);
                CairoExtensions.PopGroupToSource(cr);

                cr.PaintWithAlpha(1.0 - (stage.Actor.Percent * 2.0));
            }
            else
            {
                // Fade in new text
                CairoExtensions.PushGroup(cr);
                RenderTrackInfo(cr, incoming_track, !same_track, !same_artist_album);
                CairoExtensions.PopGroupToSource(cr);

                cr.PaintWithAlpha((stage.Actor.Percent - 0.5) * 2.0);
            }
        }