DO NOT MERGE Example: thick semitransparent crossing polyline in example VectorLayerActivity

[eddiemuc]

Example: thick semitransparent crossing polyline in example VectorLayerActivity

This PR is NOT intended for merge! It gives an example for a problem we're facing in c:geo.

PR adds a polyline in the region of Hamburg/Germany to the android example VectorLayerActivity with following properties:

• it has angles and crosses itself
• it has a very wide strokewidth
• it has a semi-transparent stroke color

This produces a polyline with "too solid" look on regions with sharp edges. Also, the polyline is very big even in the overview.

Question is: what are we doing wrong, and how do we have to adapt settings (maybe style?) to get rid of the overlaps?

Screenshot overview (the big blue dot is the polyine in hamburg):

Screenshot zoomed closer to polyline:

Screenshot very close to polyline:

[devemux86]

@eddiemuc thanks for the example. There are 2 issues:

• Spikes appearing at small zooms (any color)
• Lines overlap (transparent color)

Both seem like OpenGL implementation issues.
There is no quick answer, we should probably check LineBucket for improvements.

[eddiemuc]

I took a quick look into LineBucket. My oh my, that's some code you don't want to mess with.... Nothing to touch lightly.

@devemux86 Should I open an issue for this topic somewhere?

[devemux86]

@eddiemuc please create an issue so we can check it.

Indeed it is more complicated code with OpenGL calls. 🙂

[devemux86]

Closing as we examine the case in #1082.