New design for reset symbols in diagrams

[a-sr]

Fixes use of unicode symbols in state variables and revises reset trigger figure.
Closes #1219

Result:

for

reactor R (param:int(0)){
    state s:int(0)
    reset state rs:int(0)
    reaction(reset) {==}
}

[lhstrh]

This looks very cool! One concern I have is that the reset arrow might be hard to spot on the state. Would it make sense to wrap the reset arrow all the way around the bullet rather than have it dangle off the side?

[a-sr]

I also thought about this but my feeling is that this would make the "bullet point" too large, resulting in a very inconsistent appearance with others.
Furthermore, I did not want to draw too much attention to it because, same as state variables and parameters in general, its relevance on the diagram level is rather limited because we do not show reactions bodies where this would have an effect.

[lhstrh]

The aspect ratio between the thickness of the arrow and the size of the dot is not quite as I meant, but here is a mock up of what it could look like:

I'm basically suggesting that the outer circle around the filled dot can be replaced by an arrow. That way, it would take up about as much space as an ordinary state icon.

[a-sr]

Ah, now I get it. Yes, this is a good a idea. I will redesign it accordingly.

[a-sr]

Adjusted appearance. Now it looks like this:

[edwardalee]

Maybe lose the dot in the middle of the reset bullet? This might make it look cleaner and distinguish it better (and also match the event icon better).

[a-sr]

Ok. Without the dot in the middle, it now looks like this:

[lhstrh]

Hm, I'm unsure about this one. I agree that the new version relates more obviously to the reset trigger, but it looks less like a state variable, too, which might be confusing. My idea was for the bullet to represent the notion of "state variable" and the ring around it to indicate whether it gets reset (broken, with arrow) or not (solid).

[a-sr]

I agree with @lhstrh, in the previous version the similarities between the sate variables were stronger, which also was my initial intention, to make the reset "only" a minor modification.
I can revert the last change, if we want to go with the previous design.

[edwardalee]

Yes, I see this point... let's revert.

[a-sr]

Ok, I reverted the commit. We are back to the previous appearance.

[lhstrh]

Nice!