[EPIC] UI design of Lane connector tool for new features.

[kianzarrin]

• Lane Connection tool does not give UI feedback when lane is connected. #1485
• Lane connector: Separate road vs. tracked connections #354
• Monorail node circles are projected on the road under #654
• set dead ends for lanes using lane connector #1213
• lane connector is buggy for bidirectional lanes #784
• bi-directional lane connection UI #1214
• Improve Lane Connection Arrow Heads #1500
• [Astetics] Improve Add/remove lane connection icon #1498
• Future lane connector pimping #670

The UI design for issues above can influence/conflict one another. So I created this issues to discuss solutions.

summary:
1- Hotkeys (#1479 (comment) will be adopted for hotkeys/modifiers. thought we might need a new one for creating dead ends.)
2- how should lane connections differentiate between
- making new connection VS removing older connection (#1485)
- unidirectional VS bidirectional
- dead ends (#1213) : use :X: icon
3- how should we differentiate between car/track/mixed lanes:
- for tracked vehicles we can use 🔺 🔻 🔶 to indicate the direction of the lane (it tells us if the lane is bidirectional, it does not tell us if the lane connection is bidirectional).
- for car lanes we can just use 🟠 because they are always uni-directional anyways.
- for mixed lane we can put 🔺 over 🟠 to create a pointy circle

Problems:

Bidirectional lane connections:

• If we use arrow heads ↔️ to show the direction of the lanes there is two problems:
  • if a lane lane multiple connections then the arrow heads can overlap each other.
  • also the arrow heads can overlap with the lane end icons 🔺 🔻 🔶
  • if we use ❌ for set dead ends for lanes using lane connector #1213 then it can overlap with the lane end symbols above
• @aubergine10 suggested to use dashed line for bi-directional:
  • if we use dashed line then it might conflict with when we want to remove lane connection if we decide to use dashed line for that too.
  • Also using solid line for uni-directional and dashed line for bi-directional does not seem logical. bidirectional has more connections why should we make it dashed? if anything it should be thickened.

[kianzarrin]

How about this modifier key configuration?

• click: both car/tram/..., bidirectional if possible
• Control+click: unidirectional
• Alt+key: cars only
• shift+click: tram only

[kianzarrin]

shift usually means multiple things are selected so maybe we can do it like this:

• no modifier:
  • always unidirectional lane connection
  • car lane-connections for car-only or mixed(car+tram) lanes
  • track lane-connections for tram/metro/monorail/train lanes
• alt: tracked vehicle only - solves Lane connector: Separate road vs. tracked connections #354 and Monorail node circles are projected on the road under #654.
• shift: bidirectional on bidirectional lanes | both car tram on mixed lanes
  • bidirectional lane connection on bidirectional lanes
  • both car/tram on mixed lanes

this also helps to reduce number of modifier keys we use and the shift modifier key makes more sense now.

The downside with this is that I think by default we should make bi-directional lane connections on bi-directional lanes so that more novice users will not get confused.

[kianzarrin]

@aubergine10 what do you think we should do with modifier key assignments?

[originalfoo]

The downside with this is that I think by default we should make bi-directional lane connections on bi-directional lanes so that more novice users will not get confused.

Users - both new and existing - will need to learn new stuff whichever way it works. As long as the UI (tracked via #1214) makes it clear what's going on, there shouldn't be too much of a problem.

IMO having one-directional by default makes more sense than bidirectional; we're routing from lane A to lane B, and additionaly the vast majority of lanes are one-way.

The visualisation should clearly indicate:

• Default lane routings in cases where user hasn't specified custom lane routing (feint/thin dotted white lines?)
• Which lanes are bidirectional (could we overlay a double-ended arrow ↔ on the lane?)
• The direction of a lane connector (pointed triangle at ends? only show where applicable to declutter UI?)

[originalfoo]

As for modifier keys, this approach is best IMO: #1479 (comment)