On Sunday 08 December 2002 03.27, John Lazzaro wrote: > > David Olofson <[EMAIL PROTECTED]> writes: > > > > Yes - but we're not talking about MIDI here. We *may* require > > that events are never lost, and even that it's not legal to send > > two identical events in line to an event port, unless you really > > mean something else than to set a controller to the same value > > twice. > > Think ahead about how these sorts of requirements will be enforced: > will they be a "law of nature" (code checks to see if an app broke > the law, and takes action, like nature takes action when you try > to change the current flowing through an inductor :-), or will > it be unchecked by code? If its the latter, you can get into > this mode where everyone has extra checking and work-around code, > to handle impolite API users who aren't obeying the requirements.
Well, I wasn't seriously suggesting that we have that kind of silly rules. Still, they would not be totally unreasonable, given that you can never have two event sources manipulate the same control in a useful way; it would just result in the value jumping around. So, who would send the same value twice? If someone frequently tries to set a control to the value it already is set to, that's bad manners. If a plugin actually starts recalculating filter coefficients and stuff as a result of receiving such a control event, that could alse be considered bad manners - BUT, avoiding it would mean an extra conditional. Why have a conditional to avoid doing something relatively harmless, that can only happen as a result of someone else being nasty? That said, if hosts want to filter event streams from poorly written event generators, fine - but IMHO, it's a waste of resources, shouldn't be needed at all, and can only prevents something that's relatively harmless. Anyway, there might be cases where we can use "trigger" controls, where the value is an argument, and the plugin is supposed to actually *do* something as a response, every time, regardless of the value of the argument. If we want those, they should be explicitly marked as special - just like non-RT events. Or just like the few MIDI CCs that filters may not remove. The only difference is that we don't have a fixed set of controls with implicit rules, but use use some hints and flags instead. //David Olofson - Programmer, Composer, Open Source Advocate .- The Return of Audiality! --------------------------------. | Free/Open Source Audio Engine for use in Games or Studio. | | RT and off-line synth. Scripting. Sample accurate timing. | `---------------------------> http://olofson.net/audiality -' .- M A I A -------------------------------------------------. | The Multimedia Application Integration Architecture | `----------------------------> http://www.linuxdj.com/maia -' --- http://olofson.net --- http://www.reologica.se ---
