Opened 6 years ago

Last modified 9 months ago

#1083 new defect/bug

Dashed lines render as solid lines under certain conditions

Reported by: mvglasow (2) Owned by: cp15
Priority: major Milestone: version 0.5.2
Component: graphics/gtk_drawing Version: git master
Severity: complex Keywords: map, road, rendering, dashes, dots
Cc: http://wiki.navit-project.org/index.php/user:usul

Description

In a number of layouts I find declarations such as:

<itemgra item_types="footway" order="13-14">
  <polyline color="#ffffff" width="4" dash="4,8"/>
  <polyline color="#ff0000" width="2" dash="4,8"/>
</itemgra>

which leads me to believe that the way is supposed to be rendered as a dashed line on the map; however, Navit currently renders it as a solid line.

Is Navit supposed to support dashed lines?

Change History (9)

comment:1 Changed 6 years ago by tryagain

Hi!

Rendering of dashed lines might depends on the graphics driver used.

For me, it works fine with <graphics type="gtk_drawing_area"/> on linux.

Some of other drivers may have this feature unimplemented.

tryagain.

Last edited 6 years ago by tryagain (previous) (diff)

comment:2 Changed 6 years ago by mvglasow (2)

  • Summary changed from Dashed lines render as solid lines to Dashed lines render as solid lines on Android (and possibly other platforms)

I haven't tried any recent build of Navit on Linux so far, but on Android (using whatever the default graphics driver is for that platform) it doesn't work as of r5219.

I've updated the summary line accordingly; we might want to collect some feedback to find out which platforms/graphics drivers are affected and which ones work.

For a start:

PlatformGraphics driverBuildStatus
Android? (default)r5219Doesn't work
Linuxgtk_drawing_area?Works

comment:3 Changed 5 years ago by usul

I can confirm this bug on Linux(gtk graphics) and WinCE (win32). On low zoom levels (high details), there were no dashes but solid lines.

I checked in detail when the bug occurs:

<itemgra item_types="footway" order="10-12">
  	<polyline color="#ff0000" width="1" dash="3,3"/> <!--ok -->
  </itemgra>

This one is bad, so line with >1 is bad

<itemgra item_types="footway" order="10-12">
	<polyline color="#ff0000" width="2" dash="3,3"/>
</itemgra>

I have n idea about the internals, but guess that should be a pretty small issue?

comment:4 Changed 5 years ago by mvglasow (2)

  • Summary changed from Dashed lines render as solid lines on Android (and possibly other platforms) to Dashed lines render as solid lines under certain conditions

Updated the subject line, as apparently this isn't necessarily a platform-specific issue...

comment:5 Changed 5 years ago by usul

  • Cc http://wiki.navit-project.org/index.php/user:usul added
  • Owner changed from KaZeR to cp15
  • Priority changed from minor to major

comment:6 Changed 5 years ago by usul

  • Milestone set to version 0.5.1

I got feedback on this issue by cp15:

So the problem is that for the 2.5D mode, this dashes has to be converted to polys to get displayed correctly. He will think about a workaround

  • disabling dashes completely
  • disabling dashes for 2.5D
  • disabling 2.5D and switch to full OpenGL support

As this is a fundamental bug that provokes that users think our map is broken, I scheduled it for the upcomming 0.5.1 hotfix.

comment:7 Changed 5 years ago by mvglasow (2)

It is not a pure 2.5D issue, however. I am getting solid lines instead of dashed ones in 2D, OS is Android. I didn't try 2.5D.

@usul: did you test in 2D mode, and did it work for you?

comment:8 Changed 5 years ago by usul

  • Component changed from core to graphics/gtk_drawing
  • Keywords map road rendering dashes dots added
  • Severity set to complex

Maybe this is a misunderstanding: The bug itself is in 2D mode of course. But fixing it can break the 2.5D mode that is what cp15 pointed out.

comment:9 Changed 9 months ago by http://wiki.navit-project.org/index.php/user:jkoan

  • Milestone changed from version 0.5.1 to version 0.5.2

This ticket was pushed back in order to bring 0.5.1 out soon.

Note: See TracTickets for help on using tickets.