more obvious method to change way build mode

[sdog]

current state
The player has two methods to build ways by dragging the cursor: (a) the standard behaviour is for Simutrans to chose a path between start- and end-point of the drag automatically; (b) the alternative behaviour, activated by pressing a key (typically control) connects start- and end-point with a straight line, if possible.

why is this not so good?
Mode (a) often has undesirable outcomes, in particular when building nearby tracks. The mode (b) is not obvious to new players. Furthermore, as it is not expected, there is no incentive to look for it actively, unless they stumble over the information it remains unnoticed. Reading on the net about Simutrans experience, I've often noticed that difficulties with building ways is frequently mentioned and Simutrans at times disliked for this. ]A personal note, I hardly ever use method (a), when laying rails, I keep the CTRL-key constantly pressed.]

what could be done?
What immediately comes to my mind is to have a large toggle button in the build menu, that toggles between modes (a) and (b). When CTRL is pressed mode (b) becomes active, visibly depressing the button icon, when CTRL is released it snaps back to mode (a). A tool-tip on the button shows that CTRL is the alternative.

The button is always in the build menu bar. It is inactive (greyed out) when no way-type is selected as tool. When a way-type is selected, the button in the corresponding bar is becoming active. E.g. the rail-tool-bar and the road-tool-bar both have such buttons, both grey. When a rail is selected, it becomes active in the rail bar, while that in the road-tool-bar remains inactive.

[prissi]

There is such a toggle, it is a setting. So you just have to toggle env_t::straight_way_without_control. It is not network safe at the moment, be making it network safe should be possible without big effort. Making it a button is easy too. Making it dependent on the waytype will be more effort, but could be done using the same logic.