Bug report #10605
offset < 0 for simple outline line symbology for polygon creates rounded corners
Status: | Closed | ||
---|---|---|---|
Priority: | High | ||
Assignee: | |||
Category: | Symbology | ||
Affected QGIS version: | master | Regression?: | No |
Operating System: | Easy fix?: | No | |
Pull Request or Patch supplied: | No | Resolution: | |
Crashes QGIS or corrupts data: | No | Copied to github as #: | 19009 |
Description
During the development of upcoming QGIS 2.4, offset for a polygon layer's simple outline line symbology was improved and now relies on a GEOS buffer operation. While it's an overall improvement, it has a create a huge change in rendering:
- Under QGIS 2.2, a negative offset value will keep the offset'ed line's original angles (see QGIS_22-straight_angles.png)
- Under QGIS 2.4, a negative offset value will created rounded angles (see QGIS_24-rounded_angles.png)
While the rounded angle is expected when outputting a buffer, I don't think the user expects that behavior when offsetting a polygon outline. I have mixed feelings as to what should be the appropriate behavior, but after giving it some thoughts, I think the QGIS 2.2 drawing is the right. The 2.2 drawing of polygon's simple outline line with negative offset value also behaves the same as if your offsetting a line layer, which IMO is important.
In addition to the above, any project relying on this styling prior to 2.4 will obviously render very differently too, which should be considered.
Crossing fingers GEOS can do straight angle buffers :)
Associated revisions
Fix #10605 (round corners when using simple line with offset)
History
#1
Updated by Martin Dobias about 10 years ago
- Assignee changed from Alvaro Huarte to Martin Dobias
#2
Updated by Martin Dobias about 10 years ago
- Status changed from Open to Closed
Fixed in changeset ed1d08d435091e2890773b984c64fa96202b9f51.