Mantis - gv
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ID: Category: Severity: Reproducibility: Date Submitted: Last Update:
4368 regular use tweak always 2010-03-23 13:30 2011-01-20 11:04
Reporter: wcohrs Platform:  
Assigned To: james OS:  
Priority: normal OS Version:  
Status: closed Product Version:  
Product Build: Resolution: no change required  
Projection: none      
ETA: none Fixed in Version:  
Summary: 0004368: gv very slow
Description: gv is very slow SPARC and x86 on a Server with Quad-Core AMD Opteron(tm) Processor 8380 2500MHz needs gv several minutes but gs needs only few seconds.
the same picture on a Linux Server with gv needs also only few seconds.
Steps To Reproduce:
Additional Information:
Relationships
Attached Files: gz file icon test.ps.gz [^] (162,809 bytes) 2010-03-23 13:30
Issue History
Date Modified Username Field Change
2010-03-23 13:30 wcohrs New Issue
2010-03-23 13:30 wcohrs File Added: test.ps.gz
2010-03-23 15:16 james Status new => assigned
2010-03-23 15:16 james Assigned To => james
2010-03-23 15:46 james Note Added: 0007730
2011-01-04 10:29 james Note Added: 0008661
2011-01-04 10:29 james Status assigned => resolved
2011-01-04 10:29 james Resolution open => no change required
2011-01-20 11:04 james Status resolved => closed

Notes
(0007730)
james   
2010-03-23 15:46   
The anti-alias device used in gv is what is making gv slower. Turn off anti aliasing and see the difference. Simulate the effect directly with Ghostscript:

gs -sDEVICE=x11alpha test.ps


Try alternate aliasing:

gs -dGraphicsAlphaBits=1 -dTextAlphaBits=1 test.ps
gs -dGraphicsAlphaBits=2 -dTextAlphaBits=2 test.ps
gs -dGraphicsAlphaBits=4 -dTextAlphaBits=4 test.ps


You can set the gs parameters in gv.

The underlying problem is the Postscript itself, it just slow. It's plotting dots by drawing zero length lines with the linecap set to round. Try the dot or as procedure, gylph or similarly cached bit map, user path or form. Even then, it's plotting the dots over each other, I expect the whole thing can be improved but decide if you want to spend time writing a better prologue, time writing better output, or spend time waiting for the Postscript interpreter.
(0008661)
james   
2011-01-04 10:29   
Closing as the underlying slowness is the with the GS parameter which is settable in GV.