Opened 8 years ago

Last modified 3 months ago

#767 new defect/bug

streets are drawn from to many segments

Reported by: zoff99 Owned by: KaZeR
Priority: minor Milestone: version 0.6.0
Component: core Version: git master
Severity: complex Keywords: graphics, performance, street, rendering, maps
Cc:

Description

in navit streets are drawn with too many lines, and those lines are also rounded. it way too much. no phone can handle that load. thats (i think) the reason for poor graphics performance of navit

look at the screenshot (color enhanced to see the lines better) at the pink road. there are lots of segments, i gues 80% of them are unneeded.

Attachments (1)

too_much_lines_crazy2.PNG (38.3 KB) - added by zoff99 8 years ago.
look at the pink street

Download all attachments as: .zip

Change History (6)

Changed 8 years ago by zoff99

look at the pink street

comment:1 Changed 8 years ago by xor2003

I want to agree with you. I'm not sure maybe the additional draw algorithm optimisation is possible. But I think main reason of slow drawing on real maps (for example OSM Paris) is result of big number of lines and polygons. I have used profiling tool. The main time takers are transform(), graphics_draw_polygon_clipped(), graphics_draw_polyline_as_polygon(). I'm not very into drawing algorithm.

1) But I think maptool must symplify polylines and polygons (for example with 1-2 meters precision). 2) Is it easy to find the map items which are in current window are? Maybe there is need to improve binfile map format for such posibility?

3) How can I understand the drawing alghorithm?

comment:2 Changed 6 years ago by usul

  • Keywords performance street rendering maps added
  • Milestone set to version 0.5.1
  • Priority changed from major to minor
  • Summary changed from streets are drawn with too many lines to streets are drawn from to many segments

Can you please share your benchmarking results? I would be interested to see how rendering performs on embedded devices, too.

As performance is always critical on mobile devices (speed and power saving), I schedule this to the next hotfix

comment:3 Changed 6 years ago by usul

  • Severity set to complex

comment:4 Changed 20 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.

comment:5 Changed 3 months ago by http://wiki.navit-project.org/index.php/user:jkoan

  • Milestone changed from version 0.5.2 to version 0.6.0

Ticket retargeted after milestone closed

Note: See TracTickets for help on using tickets.