Opened 12 years ago

Closed 12 years ago

#4143 closed defect (fixed)

MapServer polygon simplifier discards too many points

Reported by: dr Owned by: tbonfort
Priority: high Milestone: 6.2 release
Component: MapServer C Library Version: svn-trunk (development)
Severity: major Keywords:
Cc:

Description

Change History (6)

comment:1 by tbonfort, 12 years ago

Is your postgis source polygon or polyline data ?

try adding

PROCESSING "APPROXIMATION_SCALE=FULL"

to your layer definition

comment:2 by dr, 12 years ago

Source data is polygonal.

Thanks, with this directive my map looks better! But I can't find any information about this in documentation.

comment:3 by tbonfort, 12 years ago

Component: WMS ServerMapServer C Library
Status: newassigned
Summary: MapServer rendering at the lowest zoom levelsMapServer polygon simplifier discards too many points

The feature is currently undocumented, you are correct. the relevant code is in mapdraw.c (reading of the processing key) and mapprimitive.c (transformation from geo to pixel)

There's a bug in the simplifying code that needs to be fixed, renaming this ticket. The simplifier should keep at least 4 points of the original polygon instead of the 3 as it does actually, as 3 points results in a degenerate polygon (i.e. point[0],point[1],point[0] is a line segment, not a polygon)

comment:4 by tbonfort, 12 years ago

Milestone: 6.2 release
Priority: normalhigh
Severity: normalmajor

comment:5 by tbonfort, 12 years ago

fixed in r13058 .

comment:6 by tbonfort, 12 years ago

Resolution: fixed
Status: assignedclosed
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