[Rwp] Plug-in hot spots

[James Teh]

Hi plug-in hot spot creators (HSC, AutoHotkey, whatever),

As I've watched discussion about creation of hot spots for plug-ins and 
associated problems, I've been starting to wonder about why they aren't 
done in a way which makes them more reliable across different 
configurations. I don't have much experience in this area, so there may 
well be a good reason and I'm just not seeing it. So, I'd appreciate 
some thoughts on the below.

In the following discussion, let's assume we're dealing with simple hot 
spots; i.e. spots which don't change such as the program browser button 
in Dimension Pro, the load button in SFZ, etc. I realise there are many 
cases where this isn't the case, but that's beyond the scope of what I'm 
getting at here.

As I understand it, there are two main problems that cause basic hot 
spots to be unreliable:

1. Different screen resolutions/DPI settings. If hot spots are created 
for one screen configuration, they sometimes don't work on other 
configurations.
I notice that even though some hot spots use relative coordinates, 
they're still absolute as far as the window is concerned. That is, they 
don't account for the window being a different size, only the window 
being in a different starting position. So, why not use width and height 
fractions? So, if the coordinate is half way across the width of the 
window, you would store 0.5 instead of an absolute value like 200. This 
way, if the window shrinks to half size, you can still calculate the 
correct coordinates. In practice, some windows probably don't resize 
everything in direct proportion, but I would have thought this would be 
more rare than not.

2. Different applications. Hot spots created for Sonar don't work in 
REAPER and vice versa. Even in REAPER, hot spots created for bridged 
don't work in non-bridged.
 From what I've seen, even hot spots that are relative are calculated 
relative to the top level window. The problem is that the top level 
window is part of the host (e.g. REAPER), not the plug-in. That means 
it's going to be different for every host. So, why not calculate the 
coordinates relative to the window for the plug-in itself? The plug-in 
should render exactly the same way no matter where it's hosted. 
Therefore, if coordinates are all relative to the plug-in window, they 
will work the same regardless of the host used.

On a related note, I'd be interested to know whether it'd be worth 
implementing some kind of basic hot spot support into OSARA. The 
question is what kind of complexity is needed for the majority of 
plug-ins. I know HSC has support for searching for colours, etc., but I 
never quite grasped how this was applied in practice.

I'd appreciate any thoughts.

Jamie

-- 
James Teh
Executive Director, NV Access Limited
Ph +61 7 3149 3306
www.nvaccess.org
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SIP: jamie at nvaccess.org