At this point, wayfire has been gaining momentum and the pixdecor plugin is becoming more popular. One unsung hero has been lurking however, and that is the filters plugin. The filters plugin allows a glsl shader to be applied from a file on disk to a window, or the entire screen. It comes with a few shaders to do basic things like CRT effect, color inversion and borders. The borders shader is interesting, since it renders a border of color and width on a window surface. However, with pixdecor shadows, the border doesn’t wrap the decoration, it wraps the outermost part of the shadow region. This is not what we want to happen. Meanwhile, in the CSD (client side decorations) case, the shadow area must be computed to know where to render the border. At first, this task seemed nearly impossible. But for the SSD (server side decorations) case of pixdecor, I was able to side band the shadow margin size to the filters plugin using a globally scoped class, shared between the two out-of-tree plugins. This is as if the class were defined once in a common header. Since no such header exists, we just copy and share it. This happens to work very well and allows filters to get the shadow margin size that pixdecor set. For CSD windows, the filter shader can find the shadow margins easily, with a couple of calls using wayfire’s robust plugin API. After all the rest was ironed out, the results are quite awesome. Here is a basic video to showcase the two plugins working simultaneously.

Here is the pixdecor shade effect with filters plugin: