Map EditorVarious improvements to the terrain detection process which is now stable.
You can keep on drawing pieces of terrain whilst the app works out exactly which area your previous pieces cover.
I've added a visual indication to show this is still going on. It appears top right in the toolbar and you get an icon per terrain being processed. Most recent left to right.
I drew a river and then a road for this:

Small pieces of terrain process very quickly.
What's called the "bounding box" is used to decide where to look. This is the rectangle a piece of terrain fits in. A building is therefore a teeny tiny bounding box and almost instant. A road stretching from one corner to the opposite diagonal corner has the whole map as it's bounding box and is the slowest.
I should think few people will often want to draw roads like a giant X on a map but if you do then it's going to take a while to process and you should do them first.
When I did the screen shot above, this is what I did with a road and river. Both took 30 seconds to process.
Your experience will vary so this is ballpark indication only. The time it'll take to run will depend on machine, processor other processes running etc. This is running alongside my development environment and in debug mode. Visual studio is memory and processor hungry itself and the final deliverable compile optimised code will run faster.
In the vast majority of "normal" use I expect all this means usually no wait at all.
The actual game map save to disk is a couple of seconds on my machine.
This has an SSD and your experience may be a little slower but the game map save is not a particularly large file by the standards of today.
If you look closely at the above picture you will see there's a bit of an odd anomaly like a circle on the end of the road.
These are noticeable initially on any "line" type of terrain. They disappear a while after you draw one and i've deliberately took a screen shot before that happened.
I use one geometry type initially for speed optimisation.
I then later replace it with a nicer looking but more process intensive one which is (again) created on a background thread.