Bug report #6200: Label direction does not take scale-dependent average to determin line orientation - QGIS Application - QGIS Issue Tracking

Bug report #6200

Label direction does not take scale-dependent average to determin line orientation

Added by Robin Lovelace about 12 years ago. Updated over 5 years ago.

Status:	Closed
Priority:	Normal
Assignee:	-
Category:	Labelling
Affected QGIS version:	master	Regression?:	No
Operating System:		Easy fix?:	No
Pull Request or Patch supplied:	No	Resolution:	end of life
Crashes QGIS or corrupts data:	No	Copied to github as #:	15514

Description

This is a simple problem.

The new label interface in QGIS 1.9.0 is excellent and dynamic labelling capabilities impressive.
However, label orientation is not good for wiggly lines like rivers.
When zoomed out, the labels rarely follow the large-scale direction of the river.
Instead, the orientation seems to follow individual (small scale) segments, which leads to labels being 90 degrees rotated from their ideal alignment.

See images and sample river label project (attached).

Perhaps solution could build on this bug fix: https://issues.qgis.org/projects/quantum-gis/repository/revisions/b77d606744ec3721ba15366ff754fcbce0a265d7 .

gis-projects.zip - project file and data illustrating problem (UK) (517 KB) Robin Lovelace, 2012-08-15 03:40 PM

90-degrees-labels.jpeg - incorrect allignment (95.9 KB) Robin Lovelace, 2012-08-15 03:40 PM

compressed-river-labels.jpeg - compressed labels (41.4 KB) Robin Lovelace, 2012-08-15 03:40 PM

History

#1 Updated by Martin Dobias about 12 years ago

Assignee deleted (~~Martin Dobias~~)

This would be most likely fixed with introduction of on-the-fly simplification in the labeling engine. The simplification would also help to resolve #2113.