From alex at zrythm.org Sat May 1 11:50:21 2021 From: alex at zrythm.org (Alexandros Theodotou) Date: Sat, 01 May 2021 18:50:21 +0000 Subject: [LV2] Passing ui:scaleFactor and ui:updateRate as atom messages Message-ID: In the normal case, hosts will pass the scale factor that the host uses to plugin UIs. The scale factor the host uses is likely taken from the physical monitor, so if you drag the host window to another monitor, the host will be able to automatically change its scale factor to match that monitor. GTK supports this for example (GtkWidget has callbacks for scale factor changes and an API to check its current scale factor). So in the case above, when you move the plugin window to another monitor, the host will want to change the plugin window's scale factor to the monitor's scale factor. Unless I'm missing something, the only way to accomplish this with the current API is to re-instantiate the plugin and pass the new options. While it does make sense that the plugin knows this information when it is instantiated, wouldn't these be better suited (or at least also possible to pass) as messages that would be sent while the plugin is active (perhaps with an atom message)? They are simple floats so I'm imagining doing lv2_atom_forge_key() for each URI and then lv2_atom_forge_float() with the new value. Is this valid with the current spec? Related conversation with Gtk devs here: https://todo.sr.ht/~alextee/zrythm-bug/344 -- Alex From falktx at gmail.com Sat May 1 11:53:06 2021 From: falktx at gmail.com (Filipe Coelho) Date: Sat, 1 May 2021 19:53:06 +0100 Subject: [LV2] Passing ui:scaleFactor and ui:updateRate as atom messages In-Reply-To: References: Message-ID: <9c9b528a-88be-2c3f-86ff-2f6d58d17b9a@falktx.com> On 01/05/21 19:50, Alexandros Theodotou wrote: > In the normal case, hosts will pass the scale factor that the host uses > to plugin UIs. The scale factor the host uses is likely taken from the > physical monitor, so if you drag the host window to another monitor, > the host will be able to automatically change its scale factor to match > that monitor. GTK supports this for example (GtkWidget has callbacks > for scale factor changes and an API to check its current scale factor). > > So in the case above, when you move the plugin window to another > monitor, the host will want to change the plugin window's scale factor > to the monitor's scale factor. Unless I'm missing something, the only > way to accomplish this with the current API is to re-instantiate the > plugin and pass the new options. Nope, the UI side can have options interface that host can call to inform of such changes. This is similar to current hosts that inform plugins of (nominal) buffer size changes. Not that there are any hosts that dynamically report scale factor changes anyway. But if you want, you can support this.