GTK不规则窗体

GdkBitmap *window_shape_bitmap = gdk_pixmap_new(NULL, m_ROI.width + 2, m_ROI.height + 2, 1);
GdkGC *gc = gdk_gc_new(window_shape_bitmap);
GdkColormap *colorMap = gdk_colormap_get_system();
GdkColor black, white;
gdk_color_black(colorMap, &black);
gdk_color_white(colorMap, &white);
gdk_gc_set_foreground(gc, &white);
gdk_gc_set_background(gc, &black);
gdk_draw_rectangle(window_shape_bitmap, gc, true, 0, 0, m_ROI.width + 2, m_ROI.height + 2);
gtk_widget_shape_combine_mask((GtkWidget*)m_RootWindow->gobj(), window_shape_bitmap, m_ROI.x - 1, m_ROI.y - 1);